Precision Pecking Order: Slug Brands

[Trent A]

So here is my assumption in where the level of precision falls in trying to create a pecking order amongst all the various brands of slugs:

Altaros
Griffin
Air Velocity Sport (AVS)
FX/Rocky Mountain Reloading (RMR)
Haendler & Natermann (H&N) (Varies... assume using their best line: Heavy Slug)
Neilson Specialty Ammo (NSA)
ZAN

There were a few I didn't rank due to having no knowledge about their performance... and correct me if I am wrong, but I am assuming if I haven't read any posts about the following brands, they likely are not good and/or not intended as 'precision' slugs(?):

JSB
Daystate
Patriot
Wildman
Seneca

SO... what order would you put them in, regarding precision only (not cost, etc)?

Any other precision centered brands out there that I'm missing? Any small batch mom & pop outfits I missed that deserve a spot on the list?

Bonus points if you want to share how much you typically pay for each slug for various brands and/or have any tips on how to get them cheaper comparatively to the greater online storefronts, such as who sells in bulk and what they charge in various quantities for big purchases, etc.

Thanks in advance for your opinions and any info you're willing to share!!!


*Disclaimer: My list is based purely off of reading what others experiences have been/word of mouth. I am new to PCP and have only ever previously used pellets in my years of shooting springers.

 

[Trent A]

@Nu-Aira & @Sound Tribe

I know each of you had mentioned another brand of precision slugs to me that I hadn't heard of elseware, but couldn't rack my brain well enough to come up with what they were called/what their brand names were. Mind reminding me so I can add them to the list? Also, where do you think those brands would fall in order of precision amongst the list above?


@Hard2hurt223

I know you spoke very highly as to the Altaros, and that it sounded like you basically live to review things and help others with your knowledge, so was hoping to have you weigh in on the matter.


Thanks in advance to all 3 of you!

 

[allinssd]

Stop racking your brain it literally doesn't matter. Stop letting the marketing get to you, which is what all these companies are trying to do.

No slug or pellet is better than another.

It's what you tune your weapon for.

 

[Trent A]

Stop racking your brain it literally doesn't matter. Stop letting the marketing get to you, which is what all these companies are trying to do.

No slug or pellet is better than another.

It's what you tune your weapon for.

While I do think there is a lot of truth to the last sentence you wrote, to the rest, I agree marketing is a big factor in how people look at a brand, but, don't you think there is something to be said for detail, consistency, quality control, and the results in general that people are getting out in the real world that have no stake in a company when posting how good or bad a particular slug performed for them? And I don't mean joe blow that doesn't know what he is doing (aka myself currently, lol) but talking about people that REALLY know their gun, PCP as a whole, and how to wring the potential out of their projectiles?

In addition to all of those factors, one that seems pretty solid to me that I would think is arguable against your claims would be: how do you explain BC if they are all the same? That seems like a pretty solid factor in the predictability of a slugs potential performance. I don't know, maybe I'm off base and don't understand what I'm talking about, as I am new to everything PCP, but from what I know coming from the world of PB, the above is what seems 'right' in my mind currently (referring to what I have said above in this post; not necessarily in the initial thread post which is very subject to change as I learn more), but, I plan on reading and learning from the replies I get here to help improve upon the little I do know thus far about all things PCP

 

[Sound Tribe]

@Nu-Aira & @Sound Tribe

I know each of you had mentioned another brand of precision slugs to me that I hadn't heard of elseware, but couldn't rack my brain well enough to come up with what they were called/what their brand names were. Mind reminding me so I can add them to the list? Also, where do you think those brands would fall in order of precision amongst the list above?


@Hard2hurt223

I know you spoke very highly as to the Altaros, and that it sounded like you basically live to review things and help others with your knowledge, so was hoping to have you weigh in on the matter.


Thanks in advance to all 3 of you!

Varmint Knockers all the way. By far my favorite slug with some of the largest hollow points you'll find and amazing expansion.


Altaros are very good as well, they are very different though as they are made by being turned on a lathe instead of swaged or cast.
BUT if you order direct from them (based in the Czech Republic) it took me about 2 weeks to get them and the shipping cost was higher than normal. Sometimes stores in the US have them for sale but they run out quick.


Varmint Knockers are made here in the U.S. as a 1 man operation by Dale, one of the nicest and most knowledgeable guys you'll ever talk to in the Airgun community... he ships out very fast and has a fair price. Right now they're only for sale on Ebay or via direct contact with him but I think soon there might be a new method of purchasing/payments.

When I want slugs for basic plinking but still very good quality and accuracy I go with NSA, another US brand and very well priced as well.

 

[mtnGhost]

If by "precision" you mean in the product sense with consistent geometry and weight of the projectiles, obviously swaged are going to be more consistent presuming the dies aren't worn to sh*t.

Then there's a factor of the ammo retaining their shape once it leaves the die and gets delivered to the customer. Some ammo makers are pretty rough when they handle their ammo, dumping them into bins and packaging them. I don't like the idea of shipping big fat bags of soft lead ammo (like Corbin's lead) that are loose in the bags during shipping in the summer time. Some of the noses / meplats / bases get damaged and / or deformed in transit. It's just another variable that affects product "precision".

If you meant precision shooting in terms of down range performance, that just comes down to the barrel (specs and bore tolerances) and rifle used to shoot the ammo. A given projectile will shoot most precise and fly stable with the correct twist rate for its geometry.

There are often ballistic "sweet spots" with velocity ranges that shoot verifiably more precise than other ranges (especially higher BC ammo in high transonic) that make them group just a tad bit tighter more consistently, and it has nothing to do with barrel harmonics. However, there's a lot of BS out there where people somehow get the idea that their slugs are going to shoot MOA or better in high transonic when they shoot 1.5-2MOA subsonic. That just isn't the case. There are some edge cases where a projectile will stabilize better with a certain barrel twist rate when shot supersonic vs. subsonic (e.g. from slower twist bores with longer nose projectiles when they need a faster twist sub/transonic), but that doesn't usually apply in most circumstances.

In reality, the most important tolerance for shooting slugs is the bore diameter. You "generally" want to shoot for 0.003" smaller than the projectile diameter and to be within <=0.0002-0.0003" of that. The smallest bore ID should be at the muzzle end. Pellet barrels are often choked to hit that tolerance before the projectile leaves the barrel, but you typically find them in barrels with large groove diameters that make it impossible for a slug to obturate when using slugs that are of the appropriate diameter for the bore diameter. Choked bores can definitely work with slugs, but the tolerances are extremely important and they are less forgiving with ammo having larger section densities (I personally despise the run of the mill slugs with long shanks and flat bases).

On top of chamber throating / reaming airgun barrels for slugs, there's an underappreciated amount of work and technique involved with lapping and polishing the bore to hit what is effectively the ideal +/- 0.00015" tolerance for a given projectile. It gets even more meticulous with choked bores when setting them up for anything but short stubby slugs.

Then there's the issue of airgun barrel quality. It's very common to see airgun barrels and blanks that have warps and various bore imperfections. Quality control just isn't usually on par with firearm barrels due to their typical market value. I also think FX is responsible for making the airgun barrel standards as such that the typical value of barrels are 5-10x cheaper than firearm barrels, so most airgunners balk at spending 1-3x the cost of their barrel for gunsmithing machine time (and traditional gunsmiths either know nothing about airguns or don't care enough to hit internal bore tolerances). For a number of years, the only tolerance that FX cared about was the chokes, but anyone with a good set of micrometers can see the randomness from liner to liner lol. I mean FFS, they ran their liner twist machine with the gear REVERSED and made Lord knows how many left hand twist liners accidentally . I also have good reason to believed that the reason their twist rates are never consistent is because of their lack of mass production QC in not setting up the machines correctly between production runs for the various calibers / types of liners.

That's my $0.02.

 

[delooper]

I'd like to say something uncontroversial. Altaros slugs are the prettiest.

 

[Vetmx]

What mtnGhost said is more than just his 2 cents, it’s on the money. There is no pecking order for slugs if your barrel is crap. You use what works best. All of my slug guns have quality self machined barrels on them except for one that uses a regular FX liner. And all of them still use a different slug from a different manufacturer from your pecking order. You use what works based on its dimensions. Not necessarily who makes it.

 

[JungleShooter]

If by "precision" you mean in the product sense with consistent geometry and weight of the projectiles, obviously swaged are going to be more consistent presuming the dies aren't worn to sh*t.

Then there's a factor of the ammo retaining their shape once it leaves the die and gets delivered to the customer. Some ammo makers are pretty rough when they handle their ammo, dumping them into bins and packaging them. I don't like the idea of shipping big fat bags of soft lead ammo (like Corbin's lead) that are loose in the bags during shipping in the summer time. Some of the noses / meplats / bases get damaged and / or deformed in transit. It's just another variable that affects product "precision".

If you meant precision shooting in terms of down range performance, that just comes down to the barrel (specs and bore tolerances) and rifle used to shoot the ammo. A given projectile will shoot most precise and fly stable with the correct twist rate for its geometry.

There are often ballistic "sweet spots" with velocity ranges that shoot verifiably more precise than other ranges (especially higher BC ammo in high transonic) that make them group just a tad bit tighter more consistently, and it has nothing to do with barrel harmonics. However, there's a lot of BS out there where people somehow get the idea that their slugs are going to shoot MOA or better in high transonic when they shoot 1.5-2MOA subsonic. That just isn't the case. There are some edge cases where a projectile will stabilize better with a certain barrel twist rate when shot supersonic vs. subsonic (e.g. from slower twist bores with longer nose projectiles when they need a faster twist sub/transonic), but that doesn't usually apply in most circumstances.

In reality, the most important tolerance for shooting slugs is the bore diameter. You "generally" want to shoot for 0.003" smaller than the projectile diameter and to be within <=0.0002-0.0003" of that. The smallest bore ID should be at the muzzle end. Pellet barrels are often choked to hit that tolerance before the projectile leaves the barrel, but you typically find them in barrels with large groove diameters that make it impossible for a slug to obturate when using slugs that are of the appropriate diameter for the bore diameter. Choked bores can definitely work with slugs, but the tolerances are extremely important and they are less forgiving with ammo having larger section densities (I personally despise the run of the mill slugs with long shanks and flat bases).

On top of chamber throating / reaming airgun barrels for slugs, there's an underappreciated amount of work and technique involved with lapping and polishing the bore to hit what is effectively the ideal +/- 0.00015" tolerance for a given projectile. It gets even more meticulous with choked bores when setting them up for anything but short stubby slugs.

Then there's the issue of airgun barrel quality. It's very common to see airgun barrels and blanks that have warps and various bore imperfections. Quality control just isn't usually on par with firearm barrels due to their typical market value. I also think FX is responsible for making the airgun barrel standards as such that the typical value of barrels are 5-10x cheaper than firearm barrels, so most airgunners balk at spending 1-3x the cost of their barrel for gunsmithing machine time (and traditional gunsmiths either know nothing about airguns or don't care enough to hit internal bore tolerances). For a number of years, the only tolerance that FX cared about was the chokes, but anyone with a good set of micrometers can see the randomness from liner to liner lol. I mean FFS, they ran their liner twist machine with the gear REVERSED and made Lord knows how many left hand twist liners accidentally . I also have good reason to believed that the reason their twist rates are never consistent is because of their lack of mass production QC in not setting up the machines correctly between production runs for the various calibers / types of liners.

That's my $0.02.

$0.02 — 2 cents?!?

That was a whole LOT more than that!!

Thank your for your very informative write-up!

Matthias


Oh, while I was typing, Frank already said this!

 

[Hard2hurt223]

@Nu-Aira & @Sound Tribe

I know each of you had mentioned another brand of precision slugs to me that I hadn't heard of elseware, but couldn't rack my brain well enough to come up with what they were called/what their brand names were. Mind reminding me so I can add them to the list? Also, where do you think those brands would fall in order of precision amongst the list above?


@Hard2hurt223

I know you spoke very highly as to the Altaros, and that it sounded like you basically live to review things and help others with your knowledge, so was hoping to have you weigh in on the matter.


Thanks in advance to all 3 of you!

I have experience with altaros, h&n heavies, and nsa and I would rate them in that order I have shot other slugs but not enough to give an honest opinion.

 

[Trent A]

Varmint Knockers all the way. By far my favorite slug with some of the largest hollow points you'll find and amazing expansion.


Altaros are very good as well, they are very different though as they are made by being turned on a lathe instead of swaged or cast.
BUT if you order direct from them (based in the Czech Republic) it took me about 2 weeks to get them and the shipping cost was higher than normal. Sometimes stores in the US have them for sale but they run out quick.


Varmint Knockers are made here in the U.S. as a 1 man operation by Dale, one of the nicest and most knowledgeable guys you'll ever talk to in the Airgun community... he ships out very fast and has a fair price. Right now they're only for sale on Ebay or via direct contact with him but I think soon there might be a new method of purchasing/payments.

When I want slugs for basic plinking but still very good quality and accuracy I go with NSA, another US brand and very well priced as well.

Thank you for all of that great information! I couldn't remember their name but sure did remember you left me definitely wanting to try them out the way you described them! I'll be looking over on eBay for them shortly!

I feel like I read that NSA is either a one man, or family, operation as well(?). I also read that though it isn't advertised, if you call them, they DO sell in bulk as well. Interested to find out what a minimum bulk purchase might be in quantity and what kind of discounted rate they might offer on various quantities vs buying in their typical sized offering on their website.

Where do you think I should stick the Varment Knockers in on the list in terms of precision? Thinking either above or below Griffin, maybe? Do you have any experience with the Griffin slugs to make a comparison?

Thanks!

 

[Trent A]

If by "precision" you mean in the product sense with consistent geometry and weight of the projectiles, obviously swaged are going to be more consistent presuming the dies aren't worn to sh*t.

Then there's a factor of the ammo retaining their shape once it leaves the die and gets delivered to the customer. Some ammo makers are pretty rough when they handle their ammo, dumping them into bins and packaging them. I don't like the idea of shipping big fat bags of soft lead ammo (like Corbin's lead) that are loose in the bags during shipping in the summer time. Some of the noses / meplats / bases get damaged and / or deformed in transit. It's just another variable that affects product "precision".

If you meant precision shooting in terms of down range performance, that just comes down to the barrel (specs and bore tolerances) and rifle used to shoot the ammo. A given projectile will shoot most precise and fly stable with the correct twist rate for its geometry.

There are often ballistic "sweet spots" with velocity ranges that shoot verifiably more precise than other ranges (especially higher BC ammo in high transonic) that make them group just a tad bit tighter more consistently, and it has nothing to do with barrel harmonics. However, there's a lot of BS out there where people somehow get the idea that their slugs are going to shoot MOA or better in high transonic when they shoot 1.5-2MOA subsonic. That just isn't the case. There are some edge cases where a projectile will stabilize better with a certain barrel twist rate when shot supersonic vs. subsonic (e.g. from slower twist bores with longer nose projectiles when they need a faster twist sub/transonic), but that doesn't usually apply in most circumstances.

In reality, the most important tolerance for shooting slugs is the bore diameter. You "generally" want to shoot for 0.003" smaller than the projectile diameter and to be within <=0.0002-0.0003" of that. The smallest bore ID should be at the muzzle end. Pellet barrels are often choked to hit that tolerance before the projectile leaves the barrel, but you typically find them in barrels with large groove diameters that make it impossible for a slug to obturate when using slugs that are of the appropriate diameter for the bore diameter. Choked bores can definitely work with slugs, but the tolerances are extremely important and they are less forgiving with ammo having larger section densities (I personally despise the run of the mill slugs with long shanks and flat bases).

On top of chamber throating / reaming airgun barrels for slugs, there's an underappreciated amount of work and technique involved with lapping and polishing the bore to hit what is effectively the ideal +/- 0.00015" tolerance for a given projectile. It gets even more meticulous with choked bores when setting them up for anything but short stubby slugs.

Then there's the issue of airgun barrel quality. It's very common to see airgun barrels and blanks that have warps and various bore imperfections. Quality control just isn't usually on par with firearm barrels due to their typical market value. I also think FX is responsible for making the airgun barrel standards as such that the typical value of barrels are 5-10x cheaper than firearm barrels, so most airgunners balk at spending 1-3x the cost of their barrel for gunsmithing machine time (and traditional gunsmiths either know nothing about airguns or don't care enough to hit internal bore tolerances). For a number of years, the only tolerance that FX cared about was the chokes, but anyone with a good set of micrometers can see the randomness from liner to liner lol. I mean FFS, they ran their liner twist machine with the gear REVERSED and made Lord knows how many left hand twist liners accidentally . I also have good reason to believed that the reason their twist rates are never consistent is because of their lack of mass production QC in not setting up the machines correctly between production runs for the various calibers / types of liners.

That's my $0.02.

O dang, now that you say that, I definitely should have clarified as I can see how it would be interpreted in that way, and no, I intended precision to be judges in the sense of repeatable results of tight groups at the range. I have gotten used to using the term precision over that of saying accurate/accuracy, because, well... it's more precises, lol. Didn't think about the fact that precision could apply just as readily in the manner you described as well. So to clarity, I mean it in your latter assessment vs the initial.

 

[Trent A]

In reality, the most important tolerance for shooting slugs is the bore diameter. You "generally" want to shoot for 0.003" smaller than the projectile diameter and to be within <=0.0002-0.0003" of that. The smallest bore ID should be at the muzzle end. Pellet barrels are often choked to hit that tolerance before the projectile leaves the barrel, but you typically find them in barrels with large groove diameters that make it impossible for a slug to obturate when using slugs that are of the appropriate diameter for the bore diameter. Choked bores can definitely work with slugs, but the tolerances are extremely important and they are less forgiving with ammo having larger section densities (I personally despise the run of the mill slugs with long shanks and flat bases).

On top of chamber throating / reaming airgun barrels for slugs, there's an underappreciated amount of work and technique involved with lapping and polishing the bore to hit what is effectively the ideal +/- 0.00015" tolerance for a given projectile. It gets even more meticulous with choked bores when setting them up for anything but short stubby slugs.

Thank you for such specific information! From reading things I did gather the sense that you wanted to be just a bit smaller with the projectile compared to the bore diameter, but to exactly what degree, I had no idea.

You said the smallest diameter is down at the muzzle end?... I read about the importance of 'slugging' a barrel to determine it's diameter, but, in the tutorial that I was pointed to, they only put the slug in a couple inches down the barrel from the breech side. If the tightest area of the barrel is on the muzzle end, wouldn't this method yield a result that is actually wider than what your narrowest point is in diameter of the barrel? Or, maybe, is the variance from the two points going to be negligible?

I have heard 'choked' and 'unchoked' several times... what exactly does that mean? What's the difference? Unchoked is the better for slugs, and choked are better for pellets, is that correct?

Thanks!

 

[Trent A]

Then there's the issue of airgun barrel quality. It's very common to see airgun barrels and blanks that have warps and various bore imperfections. Quality control just isn't usually on par with firearm barrels due to their typical market value. I also think FX is responsible for making the airgun barrel standards as such that the typical value of barrels are 5-10x cheaper than firearm barrels, so most airgunners balk at spending 1-3x the cost of their barrel for gunsmithing machine time (and traditional gunsmiths either know nothing about airguns or don't care enough to hit internal bore tolerances). For a number of years, the only tolerance that FX cared about was the chokes, but anyone with a good set of micrometers can see the randomness from liner to liner lol. I mean FFS, they ran their liner twist machine with the gear REVERSED and made Lord knows how many left hand twist liners accidentally . I also have good reason to believed that the reason their twist rates are never consistent is because of their lack of mass production QC in not setting up the machines correctly between production runs for the various calibers / types of liners.

Moving from PB to PCP, I was blown away by how cheap the liners were. I couldn't believe that I could change out an entire caliber swap on an impact for, what, like $150 for a liner and the other parts needed to do so?! I'm used to looking at several hundred dollars just to obtain the barrel blank, and then spending hundreds more to have it spun up. If memory serves me correct, even with a substantial discount through a membership I have, even a not so custom Proof barrel that is premade by their in house services still will set me back $700-$800 pre tax and shipping. Haven't looked it up in a while so could be off on that number but do believe it is correct. I'm surprised that there isn't a aftermarket company making precision liners to use vs the current brand offerings. Or, maybe there is and I just haven't learned/heard about any of them yet? I know I would be willing to pay several hundred dollars for a precision liner if it held a much greater potential for precision down range and consistency in the product. I'd kill to be able to have a liner/barrel spun up that could be used on an impact by the likes of my favorite shop, DI Precision (I'm almost exclusively a 22 LR shooter for PB, though do have 223's and 308's that never get used anymore).

 

[Trent A]

I'd like to say something uncontroversial. Altaros slugs are the prettiest.

I'd 100% agree with that assessment, on multiple levels:

-Pretty expensive
-Pretty dam precises (machining and down range)
-And yes, they are just plain 'pretty' to look at as well, lol

 

[Trent A]

What mtnGhost said is more than just his 2 cents, it’s on the money. There is no pecking order for slugs if your barrel is crap. You use what works best. All of my slug guns have quality self machined barrels on them except for one that uses a regular FX liner. And all of them still use a different slug from a different manufacturer from your pecking order. You use what works based on its dimensions. Not necessarily who makes it.

So really, matching the barrel with it's most compatible slug based on that particular barrels characteristics, is much more important than just picking up what might be considered the 'best' slug on the market, correct?

That being said, I would think that there is still an order of most likely to least likely to work slug lines, is there not? I mean, lets assume all the brands are putting out slugs that are the same weights and the same diameter offerings, then, would the brands producing slugs with the tighter tolerances not be more likely to produce a winner for a greater number of barrels compared to the more inferiorly made slugs?

Thanks!

 

[Sound Tribe]

Griffin Slugs are great from what I hear, but have not personally had much experience with them myself. I've talked to the guy and he seems like someone great to deal with. However this was a long time ago and he didn't have the tooling to make the diameter slug I was after at the time, while Varmint Knockers did.

But like everyone else is saying the gun, the barrel, and the tune comes first for sure.

 

[mtnGhost]

Thank you for such specific information! From reading things I did gather the sense that you wanted to be just a bit smaller with the projectile compared to the bore diameter, but to exactly what degree, I had no idea.

You said the smallest diameter is down at the muzzle end?... I read about the importance of 'slugging' a barrel to determine it's diameter, but, in the tutorial that I was pointed to, they only put the slug in a couple inches down the barrel from the breech side. If the tightest area of the barrel is on the muzzle end, wouldn't this method yield a result that is actually wider than what your narrowest point is in diameter of the barrel? Or, maybe, is the variance from the two points going to be negligible?

That procedure doesn't usually apply to measuring chokes. The typical use case for casting bores is firearm chambers to get references / measurements for headspace, thorat / throat wear and then a general bore/groove measurement. You don't really see too many chokes in rifled firearm barrels though beyond some rimfires.

I have heard 'choked' and 'unchoked' several times... what exactly does that mean? What's the difference? Unchoked is the better for slugs, and choked are better for pellets, is that correct?

Consider the ideal bore diameter is about 0.003" smaller than the projectile OD. That OD for slugs is the OD of the largest section of the projectile, which is typically the shank. For pellets, it's the head diameter which is the most dense section. Pellets are like a shuttlecock and the skirts also expand to groove diameter to oburate (seal) to groove diameter.

The chokes are just concentric sections of at the last ~0.7-1.25" of the barrel that gradually reduce the bore diameter down to where it should be for the caliber. The choke geometry is somewhat comparable to a chamber throat (or what many call the lead in), but they're usually steeper than the standard throat angles (0.5-3 degrees).

The heads of pellets are generally less dense than slugs. The bore and groove diameters are usually relatively large (around 0.002' smaller than the caliber), so the chokes provide the projectile with that extra ~0.001-0.0015" of tighter bore that are needed for precision shooting. Chokeless barrels can be just as good with pellets, depending on the pellet and other factors. Pellets doesn't have as much mass / density as slugs, so choked barrels are usually much more forgiving in getting them to shoot with consistent precision. Whereas slugs with greater section density aren't going to be as consistent with a standard choked pellet bore.

In .22 cal, it's been my experience that slugs up to 30gn are very compatible with standard choked pellet barrels. When you try and shoot some of these run of the mill flat base 40gn slugs with long cylindrical shanks from pellet barrels having more "aggressive" chokes that are a true >=0.003" tighter than the slug diameter - they either shoot like sh*t or throw lots of flyers.

 

[Ballisticboy]

Even in external ballistics, the word "precision" has different meanings. What is called precision in the US is called dispersion in the UK, and precision is used to denote the combination of accuracy and dispersion. This is why there have been attempts to define terms in international ballistic meetings.

However, in terms of group size, there is much more to consider rather than just the slug itself. For instance, the gun itself needs to match the slug design. The best design slug in the world may not behave well from a barrel with the wrong twist rate, or a gun which has a short barrel with a high muzzle pressure.

The combination of gun, slug and shooter is a system, which all needs to work together for the best results. There is no one component of the system which can be considered the "best".

 

[Trent A]

That procedure doesn't usually apply to measuring chokes. The typical use case for casting bores is firearm chambers to get references / measurements for headspace, thorat / throat wear and then a general bore/groove measurement. You don't really see too many chokes in rifled firearm barrels though beyond some rimfires.



Consider the ideal bore diameter is about 0.003" smaller than the projectile OD. That OD for slugs is the OD of the largest section of the projectile, which is typically the shank. For pellets, it's the head diameter which is the most dense section. Pellets are like a shuttlecock and the skirts also expand to groove diameter to oburate (seal) to groove diameter.

The chokes are just concentric sections of at the last ~0.7-1.25" of the barrel that gradually reduce the bore diameter down to where it should be for the caliber. The choke geometry is somewhat comparable to a chamber throat (or what many call the lead in), but they're usually steeper than the standard throat angles (0.5-3 degrees).

The heads of pellets are generally less dense than slugs. The bore and groove diameters are usually relatively large (around 0.002' smaller than the caliber), so the chokes provide the projectile with that extra ~0.001-0.0015" of tighter bore that are needed for precision shooting. Chokeless barrels can be just as good with pellets, depending on the pellet and other factors. Pellets doesn't have as much mass / density as slugs, so choked barrels are usually much more forgiving in getting them to shoot with consistent precision. Whereas slugs with greater section density aren't going to be as consistent with a standard choked pellet bore.

In .22 cal, it's been my experience that slugs up to 30gn are very compatible with standard choked pellet barrels. When you try and shoot some of these run of the mill flat base 40gn slugs with long cylindrical shanks from pellet barrels having more "aggressive" chokes that are a true >=0.003" tighter than the slug diameter - they either shoot like sh*t or throw lots of flyers.

Extremely helpful information for a newcomer like myself, thank you!!