Keeping it simple with reloading

[Alex Wheeler]

If I had to pick one area of load development least understood its neck tension. Most guys just pick a number like .002" and go with it. Thats a big mistake.
Neck tension is the grip the neck has on the bullet. We actually have no way to measure this. The interference fit is what we are describing when we talk neck tension. So if I say .002" of neck tension what I mean is the neck will be expanded .002" when I seat a bullet. What this does not take into acount is the hardness of the brass. A soft neck will not have the same grip on the bullet as a hard neck even if they have the same "neck tension". So when you anneal you are reducing the grip the neck has on the bullet. In my experience you cant just increase the interference fit to get it back. You can get some of the grip back but not all of it.
Seating force is mainly a measurement of friction during seating. The internal surface of the neck has a far greater effect on seating force than the interference fit does, so again your not measuring neck tension directly. Ultimately this is not a problem since the only thing we should be using to measure this is the target.
First of all, if your not doing it you need to be testing neck tension just like you do powder charge and seating depth. If your not your leaving a lot on the table. And no, you cant tune around any neck tension you want. If its wrong, you will never get the most out of the gun, sometimes it will flat out not shoot. Im sure theres been many barrels blamed for accuracy because the guy was on the wrong bushing. When you start doing the testing you will understand how annealing has a huge effect here. So in the instances that the load likes a light grip, annealing will not hurt you most likely. If the combo requires more grip, annealing will harm your accuracy. Its part of the tune. The tune is far more critical than raw consistency. You cant cheat the tune with consistency.
So far as extending brass life that should not be a problem in the first place for most. If your using quality brass and not over working it you wont have that problem. Even in saami spec chambers. Now there are many poorly designed chambers and cartridges that good brass is not available for. In that case yes it will help. I recommend a bushing style die without an expander (no the expander wont push inconsistency to the outside). For example, in that little 6BRA case we are using a .260 bushing in a .268 neck. So the brass is worked .008 every time. Never annealed, and I know of guys with 50+ on cases. Honestly cant remember ever splitting a neck in my life other than the bargain brass I got cheap for my .223 service rifle.

 

[Ol' Red]

Alex, I normally don't anneal unless it's my 30 Herrett cases. That's due to trimming and pushing the shoulder back into new territory. Does a crimp help keep neck tension consistent?

 

[nealm66]

Microphone…drop

 

[nealm66]

So do you play with the neck tension in the last part of development? I've noticed a huge difference in neck tension just from ammunition sitting a while. Or at least that's my perception when I'm pulling bullet. I've heard of letting the brass rest after sizing before seating. I've seen accuracy fall when I don't anneal after about 3 firings in weatherby ammunition is the reason I started annealing. Maybe I should have played with the original neck tension? I just use non bushing dies for weatherby cartridges. I'm not even sure if they make a bushing dies for weatherby cartridges and was always under the impression that cartridges with lots of freebore should have good neck tension to prevent secondary ignition and the annealing (amp) doesn't seem to lessen the grip at least with the setting it uses. Very interesting, I would have never guessed your opinion on the matter

 

[Baker Alvin]

Tagging in

 

[E4aker]

If I had to pick one area of load development least understood its neck tension. Most guys just pick a number like .002" and go with it. Thats a big mistake.
Neck tension is the grip the neck has on the bullet. We actually have no way to measure this. The interference fit is what we are describing when we talk neck tension. So if I say .002" of neck tension what I mean is the neck will be expanded .002" when I seat a bullet. What this does not take into acount is the hardness of the brass. A soft neck will not have the same grip on the bullet as a hard neck even if they have the same "neck tension". So when you anneal you are reducing the grip the neck has on the bullet. In my experience you cant just increase the interference fit to get it back. You can get some of the grip back but not all of it.
Seating force is mainly a measurement of friction during seating. The internal surface of the neck has a far greater effect on seating force than the interference fit does, so again your not measuring neck tension directly. Ultimately this is not a problem since the only thing we should be using to measure this is the target.
First of all, if your not doing it you need to be testing neck tension just like you do powder charge and seating depth. If your not your leaving a lot on the table. And no, you cant tune around any neck tension you want. If its wrong, you will never get the most out of the gun, sometimes it will flat out not shoot. Im sure theres been many barrels blamed for accuracy because the guy was on the wrong bushing. When you start doing the testing you will understand how annealing has a huge effect here. So in the instances that the load likes a light grip, annealing will not hurt you most likely. If the combo requires more grip, annealing will harm your accuracy. Its part of the tune. The tune is far more critical than raw consistency. You cant cheat the tune with consistency.
So far as extending brass life that should not be a problem in the first place for most. If your using quality brass and not over working it you wont have that problem. Even in saami spec chambers. Now there are many poorly designed chambers and cartridges that good brass is not available for. In that case yes it will help. I recommend a bushing style die without an expander (no the expander wont push inconsistency to the outside). For example, in that little 6BRA case we are using a .260 bushing in a .268 neck. So the brass is worked .008 every time. Never annealed, and I know of guys with 50+ on cases. Honestly cant remember ever splitting a neck in my life other than the bargain brass I got cheap for my .223 service rifle.

I use an expander for some rifles that are prone to getting the necks dinged up when then case is ejected. Sometimes using a bushing only won't completely iron out a dented neck.

Benchrest is a lot more controlled environment then most other disciplines. The NRL/prs guy's brass can take a beating.

Like you I've tested annealed vs non annealed and most of the time the results are not very different. Most of the time non annealed will edge it out though.

I imagine because I use a bushing first to neck down and then expand back up afterwards that I'm regaining some hardness by working the brass two times after annealing.

I will say that bigger cases that require a lot of squeeze to resize (ex: 300 nmi 40deg and 338 lmi 40deg). Do seem to get more consistent shoulder bumps with annealing.

I have an amp, but if I had to flame anneal I 100% wouldn't do it.

 

[Alex Wheeler]

I use an expander for some rifles that are prone to getting the necks dinged up when then case is ejected. Sometimes using a bushing only won't completely iron out a dented neck.

Benchrest is a lot more controlled environment then most other disciplines. The NRL/prs guy's brass can take a beating.

Like you I've tested annealed vs non annealed and most of the time the results are not very different. Most of the time non annealed will edge it out though.

I imagine because I use a bushing first to neck down and then expand back up afterwards that I'm regaining some hardness by working the brass two times after annealing.

I will say that bigger cases that require a lot of squeeze to resize (ex: 300 nmi 40deg and 338 lmi 40deg). Do seem to get more consistent shoulder bumps with annealing.

I have an amp, but if I had to flame anneal I 100% wouldn't do it.

I guess if your shooting on a hard surface like concrete you have no choice. But if its the action dinging the necks it needs to be tuned. In BR the guys run those bolts as fast as they can be run and it doesnt hurt the necks.

The 338 Lapua imp likes really light neck tension, the 300 NMI also gets along well with light, just not quite as light as the 338. But both are happy with .002 or less. So you probably wont see much difference annealed vs not. In some cases its night and day.

The one nice thing about a flame annealer is you can aim the flame at the shoulder to get the shoulder bump consistency without annealing the necks much. I used to do that quite often. But theres other ways to get really good bumps. That said, if we were to make a decision on bench tests, we'd all anneal because it does give better bumps and more consistent seating force.

 

[Alex Wheeler]

Alex, I normally don't anneal unless it's my 30 Herrett cases. That's due to trimming and pushing the shoulder back into new territory. Does a crimp help keep neck tension consistent?

When you crimp a bullet without a cannelure you are hurting the bullet. When you squeeze that neck and jacket down into the lead core the jacket and neck will spring back some. The lead core will not. You just compromised that bond. Core are swaged into the jacket, expanding the jacket to ensure an interference fit. Just dont do it.

 

[E4aker]

I guess the amp annealers will plague the classified ads like the labradars now! Lol

 

[Huntnful]

I guess the amp annealers will plague the classified ads like the labradars now! Lol

Hahaha I like the consistent shoulder bump between firings. I know when I don't anneal I have to adjust my die deeper because of the extra spring back and it seems like it increases progressively with more firings without annealing. I don't shoot well enough notice the drawbacks in regards to neck tension though.

 

[Alex Wheeler]

Doubt it. I have been telling guys to test this stuff for years, nothing new. I shot 2 classes in 1kBR side by side with the same gun for a full season agg. Only difference was annealed vs non. That was 2014. And I have tested in many times since in almost every rifle I have had including the wildcats I have designed like the 300 nmi and 338 lmi. Its a lot easier to read and repeat stuff your read on a forum. Not just on this subject but many. If you have been around the forums a while, you see a lot of stuff that gets repeated, almost copy and paste from the original poster... Ultimately, everyone can do as they please.

 

[crashlanding]

Alex, the common method for determining a neck bushing size has been loaded round neck diameter - .002 equals neck bushing size. In your experience, have you seen a number that shows up more often that provides the optimum squeeze versus the - .002?

 

[Alex Wheeler]

Heres a good example of a neck tension test at 1k. This is a 257 Kulzer, my version of a 25x47. We already know it doesnt like .0024" of neck tension from other test so this test went from .002 and down. As you can see theres about a .0005 window it likes. This is typical and this shows how critical the correct neck tension is. This is not annealed. But since this combo likes the lighter side it probably would work ok. But its not gonna shoot smaller than that.

 

[Korhil78]

What step in the load work up process are you testing neck tension? Is this after you have found a powder charge and seating depth?