Finishing A New Barrel Blank ?

[nervoustrig]

Well the groove dimension is indeed large but a lot of unchoked barrels I’ve gauged have a larger land dimension.

I consider chokeless barrels to be for slugs and choked barrels to be for pellets.

Some recently developed airgun barrels are designed with slugs in mind but that is not the presumed default, and most definitely not the historically dominant position for unchoked barrels. LW’s designs are one such example, a perennially proven design for shooting pellets. So with all due respect, it is a bit like asking why their pellet barrels aren’t designed for slugs. 

 

[heavy-impact]

We'll see, if slugs fail pellets will still fit.

 

[nervoustrig]

There are some success stories out there. It’s just that the odds are stacked in the other direction. A lot of variables go into the mixing bowl but one of them is usually a slug that is within a thou or fraction of a thou of the groove diameter. Push a .217 slug into the breech of a 12-groove LW barrel and shine a flashlight behind it, then look into the muzzle at all the light spilling around the sides.

 

[heavy-impact]

It's a 6 groove poly barrel but we'll see how it turns out.

 

[corny]

I know quite a few guys with hm1000x shooting slugs in .22 cal. 

that’s the standard barrel raw uses. LW poly, no choke 

 

[Seeker]

Standard LW 12-groove barrels cannot really work with slugs very well. The difference between lands and grooves diameters is too big. Even if the slug enters the choke the grooves do not touch the projectile. If one makes the slug which can be touched by the grooves then it would look like shuriken once it leaves the barrel.

 

[boscoebrea]

love all this informative stuff...seems like you need to know what you are really after.Also, use other "builders" experiences to help cut some of the guesswork out.

 

[Seeker]

It seems that LW works on the slug barrels:

https://youtu.be/6l68OlvUWBE?t=48

0:48

 

[heavy-impact]

Standard LW 12-groove barrels cannot really work with slugs very well. The difference between lands and grooves diameters is too big. Even if the slug enters the choke the grooves do not touch the projectile. If one makes the slug which can be touched by the grooves then it would look like shuriken once it leaves the barrel.

It's a 6 groove poly barrel but we'll see how it turns out. If it does not shoot slugs well I will use pellets. This is an experiment in my hobby with the goal being to shoot 17.5gn NSA slugs well because they are always easy to get, the price is less than pellets and the overall quality is better than pellets. Having over 24 inches to work with (615mm) I can always refit the barrel to a different gun. I call this a cheap education combined with entertainment all for $131 usd.

 

[heavy-impact]

I can't help thinking a .218 pellet should perfectly fill a barrel with a .215 bore and .221 grooves.

The .003 of lead displaced by the bore should take up .003 in the grooves. Your thoughts ?

 

[heavy-impact]

So with all due respect, it is a bit like asking why their pellet barrels aren’t designed for slugs.

With all due respect they're not listed as pellet barrels, they're listed as airgun barrels.

One would have to assume they were marketed specifically for pellets.

Kidding aside I respect your opinion and I'm grateful for the knowledge you share with me.

 

[nervoustrig]

One would have to assume...

Haha, yes it is rather presumptuous of me to think they were developed with the idea of shooting pellets. Sometimes I'll go ahead and step out on that limb

I can't help thinking a .218 pellet should perfectly fill a barrel with a .215 bore and .221 grooves.

The .003 of lead displaced by the bore should take up .003 in the grooves. Your thoughts ?

A little better than a thought...a picture! I don't have a .22 polygon lying around but did put my hands on a conventionally rifled LW. Mic'd a slug at precisely 0.2180 and pressed it into the breech. Weak flashlight behind it, camera at the muzzle. Futzed around with the manual exposure settings like a completely inept buffoon. Tried a dozen different settings until I got a picture that doesn't look like it was taken with a potato.

 

[heavy-impact]

Did the same amount of light come through when you pushed it further down the barrel ?

I'll have my blank tomorrow.

 

[nervoustrig]

Yes, I just checked with one about 2" from the muzzle and the amount of light spilling around looks the same.

 

[Seeker]

I have the same experience as nervoustrig.

JSB has KO slugs Mk2 which have a skirt-like base. That may be a solution.

The only slug which worked well in a standard LW 12-groove barrel was FX Hybrid .22 despite the fact there was no contact between the grooves and the slug itself. However, regular slug really needs to touch the grooves.

 

[heavy-impact]

I just tried the same with my Vulcan 3 barrel and had lots of light around the 66gn NSA slug the full length of the barrel and about half as much light with a 50gn JSB pellet. I may rebarrel it as well.

 

[Seeker]

Pellets are different because a burst of HPA makes their skirts touch the grooves and seal. However, solid slugs cannot adapt like that and what you see while pushing them down the bore is pretty much what happens during the shot cycle.

 

[thomasair]

If you have the tools to properly machine a barrel, then you have the tools to make your own slug dies. 

There is no need to hope that someday someone will make a barrel to shoot slugs properly….Rimfire barrels already have it all figured out. Huben had it right when they were using Rimfire barrels….but there was very little selection of slugs to fit them.

Im not convinced that it’s better to have a large selection of slugs that don’t work than it is to have only one or two offerings that don’t work. 

Get a good Rimfire barrel and figure out how to make a slug for it. That’s going to be the fastest road to any real success….although it probably doesn’t seem like it right now.

Just my opinion.

Mike 

 

[heavy-impact]

You would think that manufacturers could see the demand as well as the rest of us and make better products. Rather than relying on a blast of high pressure air to seal a pellet in the bore why not make the barrels to actually fit industry standard dimensions so the widest range of ammunition will shoot well?

 

[nervoustrig]

I share your sentiment and the aspiration for one barrel to rule them all. Seems only logical that if someone were to design it and make it, shooting sport aficionados would beat a path to their door to buy it. My guess is the reason we don’t have such a barrel is not explained by a lack of motivation, and most definitely not by an obliviousness that said barrel would be a best seller.