Neck turning & ARs
- Thread starter 232593
- Start date
I allways saw it as a waste for an AR since they generally by design arent particularly gentle on brass and more prone to loosing brass with them.
So never bothered, on my bolt guns sure even though many see that as a waste as well but i have the tooling so why not use them.
So never bothered, on my bolt guns sure even though many see that as a waste as well but i have the tooling so why not use them.
That is one of the things I was wondering about. If one turns the necks and then anneals the brass and then uses the appropriate neck bushing it can lead to a reduced ES. But I wonder if removing material from the necks puts the brass at risk with an AR platform.
I don't even do it on my bolt gun ammo.
Turning necks makes sense if you have a tight neck chamber.
If you don't (can't imagine why any ar-15 would), I see no reason to turn necks.
I'm skeptical it would help ES much if at all. What kind of ES are you trying to achieve? I don't even bother turning necks on my bolt gun ammo (none of my chambers are tight neck), but ES is sub 20.
If you don't (can't imagine why any ar-15 would), I see no reason to turn necks.
I'm skeptical it would help ES much if at all. What kind of ES are you trying to achieve? I don't even bother turning necks on my bolt gun ammo (none of my chambers are tight neck), but ES is sub 20.
If its thinner its lighter and more susceptible to increased damage but sizing brings it back i guess.
If i had a AR built just for the best possible precision maybe but still dont think it would matter much if using high quality or weight sorted brass. I have some LC98 i think it is ,that once sorted is as good as anything else ive bought with less cost incurred.
The brass i turn for a couple of my bolt guns isnt really neccesary since they are not chambered with a tight neck and i turn just for a 85-90% clean up.
It gives me something to tinker with and i dont have to worry about loosing them at matches just target shooting.
Don't think neck turning is going to help much outside of a tight neck chamber.
I can speak for an AR10 in 308 - I neck turned a bunch of brass loaded 1/2 of it for my bolt gun , great lower did down to mostly single digits , thought mmm I wonder if that’ll perform in the AR … long story short the AR beats brass up, I had a neck separate and cause a bunch of grief , never did it again . Btw it was only 1x fired lapua brass full length sized - ymmv just not worth it to me
Actually you want the bullet in the freebore to align the bullet on the bore, that is why the case neck is loose in the chamber.
Ohh
I thought a bit otherwise.
As on some podcast (cortina?) the F class guns had to had their brass turned as otherwise it would not fit in safely. So with that logic, they want maximum support and tight specs around case and bullet as possible.
I would say that you are correct about it when it comes to ARs, I rather have bit too much than not enough.
All in all, when you have a loose chamber, I would guess tightening your brass is not what you want to do.
I think they also want it thinner to make the case grip the bullet with less force. Which we semiauto users do not want.
It won't improve things. It's arguable that it makes much of an accuracy difference in bolt guns (aside from tight neck chambers where it's required). I turn necks on my F-Class guns, and even at 1k on a calm day it's not like there's a meaningful difference on target.
I've done it on an AR10 platform .260 and saw zero improvement across a Lilja and Proof barrel. In aggregate, guns just put up higher ES/SDs.
I've done it on an AR10 platform .260 and saw zero improvement across a Lilja and Proof barrel. In aggregate, guns just put up higher ES/SDs.
Benchrest and F class guys use special chambers with tight necks to make the brass last longer, less expansion from the factory size. Turning the necks apx 80% will provide a clean release of the bullet.
This book goes into great depth about loading for extreme accuracy- Amazon product ASIN 1931220123
I am going to go out from the rest of the pack on this one, and this is just from my experience...it really depends on what brass you're using. If you're running Lapua, I wouldn't worry about it.
If you measure the neck wall's thickness around the entire neck, depending upon the manufacturer, you can see that you'll have one side that could be up to .003" thicker than the opposing side. The way it was explained to me by someone who has forgotten more about precision rifle shooting and reloading than I'll ever know is that this is about consistent neck tension, the grip that the neck has on the projectile.
If you have one side of a neck that is thicker, that side will require more force/pressure than the other side to "let go" of the bullet. The unequal force makes the bullet's entry into the bore non-concentric. Following this unequal pressure curve out of the muzzle, it is my experience that you will also see the results in your ES's and SD's.
Essentially, there is a reason why we all use bushing dies, right? Why would you bother trying to establish neck tension when it can be inconsistent, round to round?
If you measure the neck wall's thickness around the entire neck, depending upon the manufacturer, you can see that you'll have one side that could be up to .003" thicker than the opposing side. The way it was explained to me by someone who has forgotten more about precision rifle shooting and reloading than I'll ever know is that this is about consistent neck tension, the grip that the neck has on the projectile.
If you have one side of a neck that is thicker, that side will require more force/pressure than the other side to "let go" of the bullet. The unequal force makes the bullet's entry into the bore non-concentric. Following this unequal pressure curve out of the muzzle, it is my experience that you will also see the results in your ES's and SD's.
Essentially, there is a reason why we all use bushing dies, right? Why would you bother trying to establish neck tension when it can be inconsistent, round to round?
I have turned the necks on some of the brass for my JP LRP-07. I was running a lot of Winchester branded .243 brass, and that definitely needed uniforming around the necks. It did not lead to any brass issues, I never had any necks split, etc...if that is what you're wondering?
You gotta remember, you are taking the brass down to whatever the thinnest portion of the neck is. So if you're thinnest portion is .013, and another portion is .015, you're gonna just shave .002 off to get that .015 down to the .013.
If you're running brass that is known to not have uniformity with regards to the neck wall's thickness, I would definitely encourage you to go ahead and spend the time to make them concentric. Because I'm a lazy fucker, and have since had my JP re-barreled, I will only be running Lapua brass. As I stated before, I don't worry about this issue with Lapua brass.
I do have a metric shit ton of Hornady 6.5CM brass. I've never checked their brass, namely because it is soft as shit and the primer pockets don't last but maybe 2 reloads. In this instance, I wouldn't waste my time even if they are not consistent.
