How many reloads on a case? 338 LAP

[Lowpull]

I am only getting 3 reloads per case. I dont think my loads are excessive but would like some feed back. Maybe some ideas to increase brass life. ( besides just dropping the powder charge)


Rifle 338 lap AI
Sierra 300 gr
Lapua case
94 grains Retumbo
Fed 215 match
Bumping the should only and doing redding comp neck die.

I am getting case head separations. no other case failures and no additional signs of over pressure.

I recently started doing ultrasonic cleaning with citranox. (spelling) i am wondering if i need to neutralize the acid.

I would like to know how many reloads people are getting and any suggestions please. Thanks for the help

Lowpull

 

[turbo54]

Re: How many reloads on a case? 338 LAP

TRG42
300SMK
90.5 Retumbo
2665fps

So far I've fired my brass 8 times, neck sizing ONLY. Primer pockets are tight like a bank vault.

Casehead separations are almost ALWAYS caused by repeated firings with too much headspace.

The firing pin pushes the cartridge forward against the chamber's shoulder, the pressure rise causes the case to bite into the chamber, and then the ass-end of the case (at the web) stretches/grows until the Casehead contacts the boltface.

If you don't have tools to measure cartridges from Casehead to the datum ring on the shoulder (headspace), you need them.

If you do, you need to investigate your sizing procedure, because you are almost certainly oversizing/overbumping your shoulder.

 

[ChrisGarrett]

Re: How many reloads on a case? 338 LAP

I'm on twelve cycles with one batch of twenty Lapua brand cases. Ten on another twenty, eight on a batch of Norma, with one neck split after only two cycles.

I pretty much only neck size and I expect a few more cycles out of them.

Put another way, I have about a thousand rounds on my TRG-42 since early '06 and I'm on the same 80/20 (Lapua/Norma) cases I started out with, back then.

It can last pretty long.

Chris

 

[MitchAlsup]

Re: How many reloads on a case? 338 LAP

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">Casehead separations are almost ALWAYS caused by repeated firings with too much headspace.</div></div>

Agreed, OP should dial out his body sizer until it sizes the body less than 0.0015

 

[BK7saum]

Re: How many reloads on a case? 338 LAP

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MitchAlsup</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">Casehead separations are almost ALWAYS caused by repeated firings with too much headspace.</div></div>

Agreed, OP should dial out his body sizer until it sizes the body less than 0.0015</div></div>

+1 You need to adjust the sizing die so that you are sizing about 0.0015" from the fired measurement. If you don't have tools to measure headspace, check your fired cases to find one that has some resistance to closing the bolt when placed back into the chamber. Back off your sizing die approximately one turn. Wipe down the case and try it in the chamber. It may be more difficult to chamber. If the die squeezed down the sides ofthe case, it makes the case longer.

Lube the case, turn the die in about 1/16 turn, and size again. Wipe down and try in chamber.

Repeat the 1/16 turn and sizing until the bolt closes without much resistance. Don't forget to lightly lube each time before sizing. You might get away with not lubing a time or two due to residual lube in the die.

This will get you close to optimum resizing of the case. Currently I thing you are oversizing which is causing the cases to stretch at each firing, giving the case head separations you are seeing.

In lieu of headspace measurement tools, you might try a .45 acp case placed over the case mouth to get you a shoulder to base measurement. Try this on an unfired case, then on one of your sized cases. The difference in the measurement is how far your shoulders are bumped. (you need to remove the fired primer from the .45 acp case. Ridges or cratering of the primer will affect the accuracy of your measurements.)

You can use this measurement with the 1/16 turn sizing to determine where you will get the 0.0015 - 0.002" setback of the shoulder.

Good Luck.

Brad

 

[Lowpull]

Re: How many reloads on a case? 338 LAP

You guys rock! i am little new to rifle reloading and doing my best to get a good process. The last couple times i bumped the shoulder back more than .002 on quite a few cases.(mainly due to not wanting to reset the dies, ie lazy and not understanding the importance.) I thought nothing of it till you all answered my post. I bet you any thing you are 100 percent correct.

Thank you for the great explanations too i totally get it.

Thanks again.