Most slugs are a waste of money because you did not slug your barrel

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Roachcreek

Roachcreek

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Mar 18, 2017
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Orego\'n, United States
Switching from hollow base diablo projectiles to slugs is seldom a plug and plat senecio.

I was making u-tube video’s 7 years ago hitting 12 oz cola cans at 500-550 and 615 yards with a Haley 257, so I have been doing this for a while.

What I learned is that if you do not match your barrels groove diameter with a slug that is .0005 to .001 over barrel groove diameter, and determine if your twist rate will stabilize the slug weight, you wasting time and money, it is as simple as that. 


Groove diameter is the recess in the barrel that is caused by forming the rifling, either cut or swaged, it is the raised section on your fired slug caused by obturation of the lead forced into the those rifling cuts or recesses.

Never, ever will a undersized slug perform at their best. With powder burners yes, they have the power to cause the base of the bullet to to travel faster than the nose of the bullet upon ignition which causes the bullet to ‘bump up’ to fill the groove diameter, airguns do not posses that kind of power.

As a result most slugs gather dust on the air gunners bench due to poor accuracy, or end up in the classified section.

Slugging your barrel to determine groove diameter is accomplished by driving a slug from the muzzle of a uncooked barrel, then driving that slug out the chamber, them measuring it with an ACCURATE caliper or better yet with a mike. Choked barrels are more difficult to slug, because you have to drive the slug from the chamber end, halfway down the barrel, then reversing direction and drive it back out the chamber, this avoids the choke and gives you the barrels groove diameter. To measure the choke, you drive it from the chamber and out the muzzle to determine the chokes groove diameter. Choked barrels are more difficult to get accurate results with slugs, some do make it work, I don’t bother to try.

As mentioned above, accuracy of the Caliper is of foremost importance. I ordered my first airgun mold from LBT 8 years ago, lacking a accurate caliper, I slugged the barrel, then wrapped the slug in cotton, boxed it and sent it to Veral to avoid any errors in measurement.

I have been preaching this for years, but like the song “Hello darkness my old friend” it seems it has mostly fallen on ‘ears that do not hear.’

To size your slugs you cast, I have found the NOE sizing system for airguns to be the best. I used to order custom Lee dies, but the cost, wait time, combined by inconsistency of the size I wanted was better served by the many off the shelf airgun sizing dies that NOE offers.



Regards,



Roachcreek

Properly matched sized slugs drying after moly coating

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The barrel still needs to be slugged, and mated to a slug that is .0005 to .001 over groove diameter for best results.

Ever wonder why some air gunners want specific skirt sizes for their pellets?

whether they put a dish on the base or not, and some of them do seem shoot better, again, airguns do not posses the power to bump a slug up. You also need to realize that swag9ng dies are very expensive, they put the point shape and hollowpoints on a bullet, the ram however is relatively cheap compared to the swaging die, so it is very cost effective to put a rounded head on your ram that pushes the bullet into the die and forms that cup.



I purchased a set of swaging dies to make 22 lr empties into bullet jackets and the swaging dies to make .224 bullets in 1981 from Dave Corbin. I won the first Oregon Practical Rifle Championship with those bullets, it was called OPSA, Oregon Practical Shooting Association and was a forerunner of IPSC. I used the Corbin bullets for commercial hunting as they were very fragile and would blow up inside coyotes and not exit, saving me sowing time.

If you are able to buy a off the shelf slug without doing all this, that shoots well, stop what your doing immediately and buy a lottery ticket.

Hoot, one of my myriad of ex wives was a a cat lady and she was like that gal with the curl in the middle of her forehead, she was horrid.

Roachcreek

Many of these coyotes were killed by me using Corbin swaged bullets in a Ruger #3 in 223.

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As I write this, I am moly coating bullets for my Seneca 25 carbine, the carbine has a groove diameter of .2515, these bullets are from a Arsenal mold that was requested by me to drop @ .252, it is the Arsenal 257-283 that they custom cut to drop at .252, which is exactly .0005 over the groove diameter of the Seneca 25 barrel. It drops them just a hair over .252, enough that it will not drop through the NOE .252 sizing die I size them with.



Roachcreek



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Thank you, this is a timely post for me because I’m starting to tinker with slugs. I have about as much need for slugs as I do another hole in my head but it’s fun to learn new things.



Just a quick comment about the significance of head size…going by what you say regarding slugs and my experience with pellets, pellet head size doesn’t seem nearly as sensitive. As long as the head is not so small as to allow it to tip in the bore, it has an opportunity to be accurate. I was just commenting in another thread about how on multiple occasions I’ve found disparate head sizes being equally accurate, like JSB 18.1gr at 5.52mm and 5.48mm matching each other with frequent sub-MoA groups at 43 yards from my B51. Granted, they do have a different POI but produce virtually identical groups. Oh, and it’s not a choked barrel that makes it possible. The larger pellets had distinct engraving and the smaller ones had only burnish marks.



Harry (yrrah) has also written on this topic but unfortunately I can’t get the archived post to come up on the new host. I’ll try hunting for it later but it was a .177 he was demonstrating and I think he had to size the heads down to 4.45mm (.1752”) or so before accuracy degraded. He concluded the heads need only “ride the rails” meaning skating along the tops of the lands.



Logically, this behavior makes sense. A pellet has sort of a division of labor thing going for it. The head is responsible for keeping it pointed axial to the bore and the skirt is responsible for the seal. Whereas with a slug, the whole thing is the head so it has to serve both purposes.
 
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Funny thing about me and pellets, as long as they group I am okay with them. And like most here I have shot more than a few.

I weight sort my bullets to + or - .1/10th if a grain, the bullets in the last picture are 57.9 to 58.1 anything else is remelt with the exception of 57.7 to 57.8 which lately I have decided to send to Seneca shooters to try, the bullets in the first picture posted here are for Sumatra’s owners and me if I ever buy one.

However I do not sell bullets, I just love to cast and have been at it with proper equipment for 48 years. Before that at 15 years of age, I optimistically poured lead down a old Crosman 101 barrel to try to cast bullets for my Ted Williams 150. I had a Airedale that kept chasing bobcats and treeing feral house cats on the ranch I grew up on and thought if I could get that barrel to yield bullets for the TW 150, I could penetrate their skulls, it was a dismal failure that a Ruger Standard auto cured.

My best experience with bullet casting was not winning the 1000 yard buffalo SASS shoot in 1999, it was shooting a spike elk 600 yards from my front door with a bullet I cast with a Lee pot powered by my solar panels.

Anyway I hope this helps you readers get a proper start shooting cast airgun bullets and thanks for reading my drivel.

If you want to see that 615 yard shot on a cola can, google Roachcreek 615 yard Haley airgun shot on 12oz cola can. It is pretty grainy, my wife used a Handy cam to video it, but you can still see the can burst.

Regards,

Roachcreek


 
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Every day is a school day, and all info is welcome, so thank you.

Are any slugs bought over the counter likely to be within the .0005 to .001 tolerance range out of the tin?.

and if so

H&N , JSB, are offering slugs in .217, .218, .001 steps, this then leads this newbie to think it should not be hard to work out which size "slug" to buy, 

and if not

are we all being sold a lie.

sorry if this make no sense.
 
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A lot of good info for cast bullets!

However Most of the airgun slugs on the market are swaged from pure soft lead which makes sizing less critical as you make it seem....granted sizing does help in some barrel's and I'm in no way dismissing your information! 

But I've been playing with these slugs for better than a year now and as long as the slug isn't way oversized there soft enough to get sized upon firing. And the new FX hybrids with there hollow core make that job even easier and is why they perform so well in a lot of different barrel's 

Tight choke barrel's will never be good slug shooters but slightly choked and unchoked barrel's do very well with what's on the market for hunting...and that is exactly what slugs are for HUNTING! Not to practical for the back yard paper puncher or plinker.

And as a hunter I'm not trying to shoot 615 yards with an airgun...but at moderate airgun ranges I've had awesome results especially with my two CZ barreled guns in .22 and .25 cal.

James from Michigan 
 
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James,



And the key is slightly over sized, but never under sized.

I have been casting some slugs to experiment for a friend in his Gauntlent, which slugged at .247, we tried the 254-51 and the 252-283 sized to .249 which is my smallest sizer, not great results and very hard chambering. They were cast from 100-1 alloy. Another problem may be a too slow twist.

What did work best was Bobs boatrail bought from Rick Morrill, cast from a NOE Mold sized to .249 from the original diameter of .252, those driving bands are thin and he could chamber then with just a bit more resistance compared to a 34 grain JSB.

Problem we ran into, was the very short lead, one of the above mentioned bullets has no lube rings and were nearly impossible to chamber.

I prefer a slug that casts to the groove diameter plus .0005 to .001, I suspect the Arsenal mood 252-283 will shoot well as cast in my Seneca carbine.

Sizing too much can be detrimental. The best bullet I had for my for Sharps black powder rifles, a Shilo 74 # 1 Sporting rifle and an engraved Sharps Borshardt model 1878, both in 45-100, was a Tapered Hoche mold that I shot as cast, after pan lubing them in my homemade version of SPG Lube.

Most AG swaged commercial bullets seem to be .249 which is to small for most airguns, a better approach is a swaged or cast .254, I forget who offers that bullet, and a NOE sizing kit that will size to that .0005 to .001 criteria.

This is the sizing set up I use. a Lee portable press with NOE sizing body and NOE dies emptying into a Lee die container, which is JB welded at the NOE die exit barrel and two holes drilled at the Lee containers joint for cotter pins. It keeps the parts together while I size. I use it upside down for better leverage and size while watching TV.



1579965378_4911427765e2c5bc20a02a1.59818316_236E8E2B-F08A-40C3-BC86-53FA94078257.jpeg






 
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And the key is slightly over sized, but never under sized.

I have been casting some slugs to experiment for a friend in his Gauntlent, which slugged at .247, we tried the 254-51 and the 252-283 sized to .249 which is my smallest sizer, not great results and very hard chambering. They were cast from 100-1 alloy. Another problem may be a too slow twist.

What did work best was Bobs boatrail bought from Rick Morrill, cast from a NOE Mold sized to .249 from the original diameter of .252, those driving bands are thin and he could chamber then with just a bit more resistance compared to a 34 grain JSB.

Problem we ran into, was the very short lead, one of the above mentioned bullets has no lube rings and were nearly impossible to chamber.

I prefer a slug that casts to the groove diameter plus .0005 to .001, I suspect the Arsenal mood 252-283 will shoot well as cast in my Seneca carbine.

Sizing too much can be detrimental. The best bullet I had for my for Sharps black powder rifles, a Shilo 74 # 1 Sporting rifle and an engraved Sharps Borshardt model 1878, both in 45-100, was a Tapered Hoche mold that I shot as cast, after pan lubing them in my homemade version of SPG Lube.

Most AG swaged commercial bullets seem to be .249 which is to small for most airguns, a better approach is a swaged or cast .254, I forget who offers that bullet, and a NOE sizing kit that will size to that .0005 to .001 criteria.

This is the sizing set up I use. a Lee portable press with NOE sizing body and NOE dies emptying into a Lee die container, which is JB welded at the NOE die exit barrel and two holes drilled at the Lee containers joint for cotter pins. It keeps the parts together while I size. I use it upside down for better leverage and size while watching TV.
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Great detailed info. from experience. 

That's what I've found to be the case. Slugs I bought 4 years ago weren't all the same diameter or weight. The reason I chose to make my own. 

I've found some slug designs in .25 cal. don't swag to full diameter if swagged too fast. I swag slow and consistent. 

I have a .2495 slug that "groups" about 6" at 100 yards. Exact same everything slug at .2500" (only .0005" larger) and MOA or better just as you are pointing out. 


 
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