Benefits of polygonal rifling. Caster? Dolomite? Anyone else?

[Clod Stomper]

So, I'm getting closer and closer to ordering a barrel for my 7.62x40 WT project. I'm down to two choices. This barrel has traditional rifling, and this one has polygonal rifling.

I have never had a polygonally rifled rifle barrel, only true handguns (yes, this will technically be a pistol, but still...). I understand the benefits and drawbacks of both polygonal rifling and traditional rifling.

At some point, I MAY want to shoot cast bullets through it. Of course, that would rule out the polygonal barrel. Otherwise, it would be my only choice.

So here's my question. In your experience, are the benefits of poly rifling great enough to exclude the possibility of shooting cast bullets? By far, my primary shooting will be with jacketed bullets. I just don't cast very much any more.

Of course, if there is only a slight benefit, I may forego the poly and get the regular rifling. If the benefit is great enough, I will forget shooting cast and get the poly.

Thanks,

Will

[Dolomite_supafly]

I cast and shoot my own bullets so for that reason I would say polygon rifling is out. And even though you don't plan on casting it does make shooting much cheaper. It shouldn't be a problem casting and loading for under .15 a shot.

They say that barrel life as well as velocity are increased with polygon rifling. I have never owned one so I do not know. For me the extra 100-200 fps isn't worth it because you can make that up with proper handloading techniques. And as far as barrel life are you really expecting to shoot it enough to wear out a barrel. And if that 100-200 fps is making you cast to the limits of case pressures then you need to go to a larger caliber.

I know we taked about it but I honestly can't understand why the x40 over the BLK when there is plenty of support for the BLK. The ballisticas are identical except on the edge. If you plan on shooting subsonics mostly then they are equal.

Dolomite

[Guest kingarmory]

Polygonal rifling is a lot more resistant to wear (no grooves to wear out) and a lot easier to clean (no grooves to clean out).

[Smith]

Polygonal rifling is a lot more resistant to wear (no grooves to wear out) and a lot easier to clean (no grooves to clean out).

Unless you use lead bullets. Then it's the exact opposite

[Caster]

You say you MAY want to.....what you NEED to do is know for a fact. Then make a decision.

Sorry, that's not much of an answer. For what it's worth, despite my obvious loathing of the things, I carry a poly barrel every day.

[mikegideon]

I may cast bullets one day. For now, it's no glove, no love. I have a hard time getting around to all the reloading tasks I've created for myself. I like the idea of polygonal rifling.

[Clod Stomper]

I cast and shoot my own bullets so for that reason I would say polygon rifling is out. And even though you don't plan on casting it does make shooting much cheaper. It shouldn't be a problem casting and loading for under .15 a shot.

They say that barrel life as well as velocity are increased with polygon rifling. I have never owned one so I do not know. For me the extra 100-200 fps isn't worth it because you can make that up with proper handloading techniques. And as far as barrel life are you really expecting to shoot it enough to wear out a barrel. And if that 100-200 fps is making you cast to the limits of case pressures then you need to go to a larger caliber.

I know we taked about it but I honestly can't understand why the x40 over the BLK when there is plenty of support for the BLK. The ballisticas are identical except on the edge. If you plan on shooting subsonics mostly then they are equal.

Dolomite

I know it's super cheap to cast. I used to do it regularly. Now when I cast, I'm thinking about the time and care I put into each bullet each time I pull the trigger. Not to get too deep here, but it seems nowadays I value my time more than dollars (and no, I don't put a dollar value on my time. That's not possible in my view) . I doubt I'll do a whole lot of casting in the near future (that could always change). I guess I just answered my question...

I think you've helped me decide on the barrel, though not in the way you may think. You are correct that I will probably never shoot out any barrel. I can't afford that much ammo, even handloading. But what I AM looking for is a hard-hitting round, at short range, from a short barrel. That extra 100 fps from the poly barrel and the extra 100-200 fps from the 7.62x40 over the .300 BLK is what I'm looking for. Combined with the fact that I most likely will not be casting for it, and I will be shooting primarily supersonics, and a polygonal is supposed to be easier to clean....

That said, I very well may download it to .300 BLK for practice to reduce wear and tear. Why not go with the .300, then? Yes, it has more industry support. But chances are I will never buy a factory round. As as long as I have a barrel and dies, there is no difference to me as far as making ammunition. And with the x40, I don't have to cut as much off the 5.56 cases. I have never bought a factory round for my Grendel. Most of my cases were formed from 7.62x39. I bought a few factory cases that were included with a used barrel.

Some of my friends have bucketfuls of .300 Whisper brass from their jobs. If I were in their shoes, there wouldn't even be a question. I'd be .300 all the way.

Not to say I wouldn't like to have one. If I find a good deal on a .300 BLK barrel (after I'm done with this project), I'll almost certainly snatch it up and start a whole new project. Perhaps I'll shoot cast through that one.

Caster, you are correct. I am reasonably certain that I won't be casting so I'll probably go with the poly. I also thought it would probably be easier to clean, but I'm glad to hear that from someone else. That's another point for the polygonal.

Thanks very much to everyone. I truly do value everyone's opinion.

Will

[TNWNGR]

I cast and also purchase hard cast or swaged bullets as well simply because I'm not out for high velocity but rather lower cost and less wear and tear on theg gun and me. I don't reload for my Glock's but do for most everything else and if given the choice would pass on the polygon barrel. My reason's may not appply to your perspective on this and in the end you are the deciding factor.

[Jonnin]

I shoot lead in my makarov, but they are hard cast lead designed to work with the poly barrel. So you *can* cast for at least some calibers (certainly pistols!) if you know how to change the hardness and control that in your casting. Seems like a lot of trouble --- as I said, I buy mine that way and let someone else do all the work.

Really, poly guns were designed for jacketed bullets, and any use of lead is going to take some care on your part and is probably not worth it.