Need for case annealing

F

fishbone

Guest
My first lot of brass (new to BR) has the bullets seating with various effort; not consistent.
I found the neck walls varied in thickness (.0002" to .0003" on a case; .0005" between cases), which may account for this. I have new brass on order to which I'll turn the necks myself. I'm not happy with the supplied "turned" first lot.
Anyway, the non-uniform seating resistance got me into looking at annealing.
I hear very little about annealing from BR people, and wonder about serious competitors thoughts/actions on annealing.
 
fishbone said:
My first lot of brass (new to BR) has the bullets seating with various effort; not consistent.
I found the neck walls varied in thickness (.0002" to .0003" on a case; .0005" between cases), which may account for this. I have new brass on order to which I'll turn the necks myself. I'm not happy with the supplied "turned" first lot.
Anyway, the non-uniform seating resistance got me into looking at annealing.
I hear very little about annealing from BR people, and wonder about serious competitors thoughts/actions on annealing.
Click to expand...

There is a real possibility you need to anneal..what is the caliber/case that you are having problems with?...I can tell you from first hand experience that I made some 30BR cases from "new" Lapua blue box brass and had problems getting it into and out of the chamber ( after 2 firings) until I annealed it...solved the problem instantly...
 
If you do a search on annealing you should find quite a few threads.
It has been discussed and rediscussed with people on both sides of the fence.
There are several good machines that have gotten good reviews.
You can also see videos of them on youtube.

There are also several other manual methods used.
I tried it year before last, not sure of the results.
 
How well were the case mouths chamfered? That can give a certain variability of drag that's not related to anneal state.
 
The cartridge is 6ppc with 5 firings, including fire forming.
I suspect the neck wall variation is the cause of varying seating force.
I'll look closer for good chamfering, which I think is ok.
All this has lead to my exposure on annealing, hence the questions.
Tony Boyer talks about (in his book) of prepping brass in the off season. He expects 20 firings over the season, with no mention of annealing.
Other shooters have posted annealing every load, every other load, every 5 loads, and so on.
Then there is the clamping pliers test of squeezing the neck 0.005" and measuring for spring back to dictate when to anneal.
 
Fish, we need a little more information if you can provide.
How much are you sizing the necks? .001, .002, .003, .004 etc.
Also are you brushing the interior of the neck during case prep?
Centerfire
 
Annealing is so unnecessary. Turn up some cases to fit and when they get "irregular" seating force turn your neck bushing over. When the become irregular again, drop to the next bushing. When that match is over make new cases. Frankly, I've never been able to tell the difference on the target shooting cases with irregular seating force in the first place. Said differently, when you get tis "problem" fixed, your aggs will not improve.

It is my preference that my bullets don't slip in the case but I don't have any evidence to support that preference. I've won a few matches with my bullets all but falling out. Probably as many as I've won with "perfect" necks.
 
It makes you wonder when the powder explodes and causes 50 bazillion PSI in your chamber exactly how much does small seating force variation really matter.
Some great shooters use 3 or 4 thou. of tension and many others use almost none and then there are guys that use just enough to hold things together and let the rifling force the bullet back in the case when closing the bolt thinking that will give repeatable seating depth. Hmmmmm.

Then you have to wonder if neck tension matters more if your jumping since when your jamming the bullet is already at the place where it will start moving. Is that why most PPC type benchrest shooters overwhelmingly prefer to jam?
 
twentytwoguy said:
It makes you wonder when the powder explodes and causes 50 bazillion PSI in your chamber exactly how much does small seating force variation really matter.
Some great shooters use 3 or 4 thou. of tension and many others use almost none and then there are guys that use just enough to hold things together and let the rifling force the bullet back in the case when closing the bolt thinking that will give repeatable seating depth. Hmmmmm.

Then you have to wonder if neck tension matters more if your jumping since when your jamming the bullet is already at the place where it will start moving. Is that why most PPC type benchrest shooters overwhelmingly prefer to jam?
Click to expand...

Some time back, somebody, I think it was Henry Childs, created a computer simulation of a rifle firing. I made a statement that I thought (guessed) that the case neck was well out of the way before the bullet moved. The computer supported the statement. Not saying that the computer made my statement correct but it did agree. Given that "great" shooters have differing opinions regarding neck tension, logic would indicate that it doesn't seem to matter.

Y'all correct me on the developer of that computer simulation if I'm wrong.
 
Wilbur said:
Some time back, somebody, I think it was Henry Childs, created a computer simulation of a rifle firing. I made a statement that I thought (guessed) that the case neck was well out of the way before the bullet moved. The computer supported the statement. Not saying that the computer made my statement correct but it did agree. Given that "great" shooters have differing opinions regarding neck tension, logic would indicate that it doesn't seem to matter.

Y'all correct me on the developer of that computer simulation if I'm wrong.
Click to expand...

But Wilbur, some shooters like Jackie Schmidt, use cases for one two gun agg and give them away, making new cases for the next match. Annealing certainly isn't in his universe. How many other serious and successful shooters do the same thing? --greg
 
I don't think the specific amount of neck tension is the "key" (example .002 vs .004) - but having consistent neck tension IS important. (example case 1 has .003 and case 2 has .003, etc) This is one area where annealing comes into play. Annealing also has other benefits if done correctly; consistent shoulder bump and spring back after firing for example.

Are there otherways to keep these things conistent other than annealing = yes.

If you think neck tension is not important take and switch neck bushings, during a match, on the "top shooters" in your area. Let us know how it goes.
Stanley
 
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Wilbur said:
Some time back, somebody, I think it was Henry Childs, created a computer simulation of a rifle firing. I made a statement that I thought (guessed) that the case neck was well out of the way before the bullet moved. The computer supported the statement. Not saying that the computer made my statement correct but it did agree. Given that "great" shooters have differing opinions regarding neck tension, logic would indicate that it doesn't seem to matter.

Y'all correct me on the developer of that computer simulation if I'm wrong.
Click to expand...

Wilbur,
I don't know about computer simulations, but I did some fairly simple calculations for a 0.308 with 0.010" neck thickness. For dead soft brass (yield stress of 10 ksi) sized with a 0.326 bushing, it takes 649 psi of chamber pressure to expand the neck, but 1282 psi to overcome friction between the bullet and the neck (with no expansion of the neck by the chamber pressure, friction coefficient of 0.76). Because the expansion pressure is less than the friction pressure, the neck will be blown out before the bullet starts sliding.

For work hardened brass (yield stress of 33 ksi), the numbers are 2143 psi for neck expansion and 4230 psi to slide the bullet in the neck. The neck still expands before the bullet slides, which agrees with you and Henry.

Cheers,
Keith
 
Keith,
When a bullet is loaded into the lands you will have a much higher pressure in the case before the bullet moves, and that will expand the case more. What I say is, "which came first the chicken or the egg".
john
Mims, Fl.
 
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