What's a sensible frequency of annealing .308 cases?

[Campbell]

Please will you advise re the above-mentioned title.

The load is 47.6 grains of RS52 behind a 155 grain bullet and the cases are Lapua Palma

 

[R.Morehouse]

What ever you decide be consistent. Some shooters let the brass tell them when by how they behave when sizing. I shoot a few different calibers and anneal using the AMP every time...........Happy Shooting

Regards
Rick

 

[Joe Wade]

I shoot F-tr using Lapua Palma brass and anneal every time.
Just becomes another step in my brass prep.

 

[watercam]

I am a sling shooter with Lapua Palma brass. I anneal every 5th firing and am coming up to my 20th firing on my brass with no end in sight. Primer pockets tight and no cracked necks.

 

[Dusty Stevens]

Consistency is key right? If you anneal every 2nd firing, every 5th firing, whatever- that’s not consistent. Every firing do the exact same thing and you’ll see those results on target

 

[rijndael]

I anneal every time.

I have 100 cases in my batch, but I often have 25'ish unfired and get used on the next range session. If I annealed every other firing, I'd have to keep those 25 brass separated so they can be annealed (caught up), while the rest can be resized. I don't want to setup the annealer for 25 pieces, or the hassle of trying to keep those 25 rounds separated after firing.

I'm sure this is the wrong approach and someone will tell me why, but it works for me.

 

[Bart B.]

Consistency is key right? If you anneal every 2nd firing, every 5th firing, whatever- that’s not consistent. Every firing do the exact same thing and you’ll see those results on target

What ballistics will change across cases reloaded 2 dozen times and never annealed?

4 dozen times?

Both are consistent.

 

[jepp2]

Please will you advise re the above-mentioned title.

What I would find more important to decide:

- what is the neck diameter of your sizing die (or bushing used)
- what is your chamber neck diameter

These two values give me an idea of how much you are working the case neck each firing/sizing cycle. The more work, the less cycles between annealing.

 

[riflewoman]

Well Brian Litz has data to prove all this hubbub about annealing doesn’t affect accuracy.

“The Modern Advancements series of books can best be described as a journal of his research and development activities. They explore common questions such as the effect of barrel twist at longer ranges, how muzzle velocity affects hit percentages, laser range finders, etc. Volume II explores handloading techniques and what the shooter can do to produce higher quality ammunition. The key objective is to approach the subject matter in a “Myth Busters” science driven approach. They take commonly held beliefs, explore the science behind them and share the results of their testing. One of their more scintillating findings involves annealing and their discovery that it does not have a noticeable impact on accuracy. We can just see the forums lighting up on that topic!”

Above is quoted from http://www.65guys.com/applied-ballistics-seminar/

And there are metallurgical reasons NOT to anneal every firing.

 

[Mozella]

What ballistics will change across cases reloaded 2 dozen times and never annealed?

4 dozen times?

Both are consistent.

No, that is definitely not consistent.

During every reloading cycle the brass becomes harder by a process known as "work hardening". The neck expands when you fire it, it contracts when you size it, and (assuming you do this third step) it gets expanded again when you insert the final sizing mandrel just prior to charging the case with powder. Each of these steps makes the brass harder. That increases the spring back and it will continue to do so. That means a certain size neck bushing, for example, will produce a different neck ID depending on if the brass is on its first cycle or the forth-dozen cycle. That will change the bullet grip. Of course, eventually it will get so hard that neck splits will put a stop to the reloading process, at least for most folks.

Annealing returns the brass to a softer state. No matter where in the reloading process you anneal, your brass will have consistent hardness which translates into consistent sizing results and, in theory at least, make for consistent bullet release when the round is fired. Bullet grip is considered important by many precision shooters.

I anneal each and every cycle but I have an auto-feed DIY "Skip Design" annealer which is a pleasure to use. It is very precise as well.

Having said all that, I'm reminded of the test Bryan Litz performed. He shot quite a few rounds in several different calibers and tried to measure the accuracy degradation associated with not annealing every time. I think he tested annealing every time, annealing every five times, and every ten times if I remember correctly. Something like that anyway. Bottom line: If there is a difference, Mr. Litz was unable to detect it. Personally, I believe that annealing is like a lot of stuff most of us do, like deburring flash holes, uniforming primer pockets, and so-on. The effect is almost surely positive but actually measuring the improvement of any one step is impossible when our testing procedure involves a human shooting at a far distant target through an uncontrolled atmosphere. It should be noted that Mr. Litz didn't claim that annealing each time doesn't work. He was simply unable to detect the improvement, if any.

 

[riflewoman]

What I would find more important to decide:

- what is the neck diameter of your sizing die (or bushing used)
- what is your chamber neck diameter

These two values give me an idea of how much you are working the case neck each firing/sizing cycle. The more work, the less cycles between annealing.

You also have to add in the expander and the bullet seating, though the latter may not add much. I added it all up for a 223 and got about 13% cold work per firing cycle. From what I can gather from technical literature, brass needs about 40% cold work to get the “critical” temperature down to 800-900 deg F. So that would be about 3-5 firings.

Unsurprisingly, the older articles from the likes of Julian Hatcher, Townsend Whelen, P.O. Ackley and others tended to agree. They also said that a good way to anneal the case mouth was to use the case in water and torch “to a dull red in a darkened room” ( which gives a temp of about 950F) then tip it over. These old guys knew what they were doing, what worked and what didn’t. They didn’t explain the why because the average guy didn’t care. Now we get all fancy and there is scant evidence presented that the fancy is truly better.

 

[jepp2]

They also said that a good way to anneal the case mouth was to use the case in water and torch “to a dull red in a darkened room” ( which gives a temp of about 950F) then tip it over.

An excellent post!

I started annealing that way. Worked, but I didn't like the fact I was only apply heat to one side of the case neck. Also I felt starting to see dull red was too hot.

Regarding your 223 calculation. For the fun of it, I ran a case life test of LC brass fired in various AR15's. I picked 5 firings as the point I would anneal. None of the brass failed due to neck cracks from work hardening. I got up to 35 firings on some of the brass. More than I would have expected. And none had stretching that could lead to incipient case head separation. I was moving the shoulder about 0.004-5" each sizing. After around 10 firings, I never cut any material when trimming.

 

[CharlieNC]

Well Brian Litz has data to prove all this hubbub about annealing doesn’t affect accuracy.

“The Modern Advancements series of books can best be described as a journal of his research and development activities. They explore common questions such as the effect of barrel twist at longer ranges, how muzzle velocity affects hit percentages, laser range finders, etc. Volume II explores handloading techniques and what the shooter can do to produce higher quality ammunition. The key objective is to approach the subject matter in a “Myth Busters” science driven approach. They take commonly held beliefs, explore the science behind them and share the results of their testing. One of their more scintillating findings involves annealing and their discovery that it does not have a noticeable impact on accuracy. We can just see the forums lighting up on that topic!”

Above is quoted from http://www.65guys.com/applied-ballistics-seminar/

And there are metallurgical reasons NOT to anneal every firing.

I also have data that proves annealing affects neck tension and seating depth uniformity; I only started annealing to fix those problems. Annealing is one of those variables that fits in the "depends upon" category where there is not a concrete answer.

 

[swadiver]

I shoot F-tr using Lapua Palma brass and anneal every time.
Just becomes another step in my brass prep.

+1

 

[LHSmith]

Well Brian Litz has data to prove all this hubbub about annealing doesn’t affect accuracy.

“The Modern Advancements series of books can best be described as a journal of his research and development activities. They explore common questions such as the effect of barrel twist at longer ranges, how muzzle velocity affects hit percentages, laser range finders, etc. Volume II explores handloading techniques and what the shooter can do to produce higher quality ammunition. The key objective is to approach the subject matter in a “Myth Busters” science driven approach. They take commonly held beliefs, explore the science behind them and share the results of their testing. One of their more scintillating findings involves annealing and their discovery that it does not have a noticeable impact on accuracy. We can just see the forums lighting up on that topic!”

Above is quoted from http://www.65guys.com/applied-ballistics-seminar/

And there are metallurgical reasons NOT to anneal every firing.

Did Litz used a full blown BR comp. rifle off a concrete bench with a field of windflags?
One has to preface what discipline they are basing their experience on to validate their answers to these threads.

 

[riflewoman]

You’d have to read his report. But there are many short range benchresters who don’t anneal at all. Litz, so far as I can tell, is more concerned about long range accuracy.

 

[Bart B.]

My test reloading the same case about 4 dozen times had about 30 fps spread in velocity averaging about 2700 fps. Full length sized Federal 308 Win case in a full length RCBS die with neck honed out to .335". 42 grains of IMR4895 over a Fed 210 primer with a Sierra 165 gr. spitzer boattail.

Velocities stayed consistent in that spread.

 

[LHSmith]

My test reloading the same case about 4 dozen times had about 30 fps spread in velocity averaging about 2700 fps. Full length sized Federal 308 Win case in a full length RCBS die with neck honed out to .335". 42 grains of IMR4895 over a Fed 210 primer with a Sierra 165 gr. spitzer boattail.

Velocities stayed consistent in that spread.

I know of no rifle competition where rewards are based on the least ES or SD. Results on paper TRUMP ballistic data.

 

[Bart B.]

I know of no rifle competition where rewards are based on the least ES or SD. Results on paper TRUMP ballistic data.

The metallic sighted rifle put all shots in about 5/8ths inch at 100 yards.

Another like test with 56 rounds from a machine rested rifle went in 3/8ths inch at 100 yards with Sierra 168 HPMK bullets.

 

[LHSmith]

The metallic sighted rifle put all shots in about 5/8ths inch at 100 yards.

Another like test with 56 rounds from a machine rested rifle went in 3/8ths inch at 100 yards with Sierra 168 HPMK bullets.

And the results using annealed brass for comparison?
In score BR the 30 BR dominates. Most anneal their brass periodically if not every firing. To be at all competitive in registered matches one has to have a rifle that agg's below 0.200" for 25 shots for record. Most load in the upper end (high chamber pressure) because that is predominately where the best accuracy lies. Ease of chambering and extraction is extremely important in order to get rounds fired in a chosen condition (no bag upset). Properly annealing cases is a necessity.
I would imagine fighting with the bolt is a huge deterrent to shooting well in any discipline. Annealing provides insurance that sticky cases are unlikely to happen.