Body die playing tricks on me. WTF.

[RotARy15]

I'm prepping brass for my buddies LR308. We already loaded up some ammo and shot it with great results. We bumped the shoulder back .003 on that batch. NOTE: We are body sizing and then neck sizing since we already have those dies for my bolt gun.

I went to body size this time and none of the cases were bumped. They maintained the same headspace they left the gun with. I'm thinking, "WTF, I've had trouble with this die doing this before."

So I decided to just screw it and I spent time sanding the base of the body die so I could get it further into my press. I only sanded .005 off the die.

I screw it back into my press and size a few cases. I measure the cases and adjust the die until I got the right headspace. I finish sizing all the 50 rounds and throw them in the tumbler to clean the lube off.

When I get the brass back to the bench and measure them, most of them are .001 shorter than my target but a few are .005 shorter than my goal making them .008-.009 shorter than the chamber. WTF?!?!

Is .009 an unsafe gap? This is all FC brass 2x fired going onto its 3rd firing.

 

[YAOG]

Re: Body die playing tricks on me. WTF.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RotARy15</div><div class="ubbcode-body">I'm prepping brass for my buddies LR308. We already loaded up some ammo and shot it with great results. We bumped the shoulder back .003 on that batch. NOTE: We are body sizing and then neck sizing since we already have those dies for my bolt gun.

I went to body size this time and none of the cases were bumped. They maintained the same headspace they left the gun with. I'm thinking, "WTF, I've had trouble with this die doing this before."

So I decided to just screw it and I spent time sanding the base of the body die so I could get it further into my press. I only sanded .005 off the die.

I screw it back into my press and size a few cases. I measure the cases and adjust the die until I got the right headspace. I finish sizing all the 50 rounds and throw them in the tumbler to clean the lube off.

When I get the brass back to the bench and measure them, most of them are .001 shorter than my target but a few are .005 shorter than my goal making them .008-.009 shorter than the chamber. WTF?!?!

Is .009 an unsafe gap? This is all FC brass 2x fired going onto its 3rd firing. </div></div>
Is there a reason you are not sizing the necks first follwed by the body die?

What tools are you using to measure the datum line?

 

[turbo54]

Re: Body die playing tricks on me. WTF.

They're safe if this is their first time getting bumped so far.

Improper/inconsistent sizing lubrication can cause this. That's where I'd start the investigation.

 

[former naval person]

Re: Body die playing tricks on me. WTF.

Use the gun as a gauge to bump the cases. Back the die off until when the case is sized it is hard to chamber the case. Screw it in a 1/16th of a turn at a time until the case chambers with a 'ittsy bittsy teenny tiny" bit of touch when you chamber it. Try it with a new fired case...may have to screw it in 1/16th turn more. Set the die there. Forget the damn fool aftermarket case gauge. It probably does NOT match your chamber. JMHO

 

[turbo54]

Re: Body die playing tricks on me. WTF.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: former naval person</div><div class="ubbcode-body">Use the gun as a gauge to bump the cases. Back the die off until when the case is sized it is hard to chamber the case. Screw it in a 1/16th of a turn at a time until the case chambers with a 'ittsy bittsy teenny tiny" bit of touch when you chamber it. Try it with a new fired case...may have to screw it in 1/16th turn more. Set the die there. Forget the damn fool aftermarket case gauge. It probably does NOT match your chamber. JMHO </div></div>

I might add to be gentle with your BCG when test chambering sized brass. DON'T let the BCG slam home into battery. It's really easy to get one stuck in the chamber of an AR rifle.

 

[RotARy15]

Re: Body die playing tricks on me. WTF.

I'm using a Hornady Headspace comparator. And this is a gas gun.

I can't "feel" it chamber. As far as testing the case in the chamber, I tried chambering the brass that had the same headspace as the chamber and the bolt wouldn't close. If I dropped the bolt onto the brass from the bolt stop, the gun itself would bump the shoulder back .002.

Now that I think about it the over lubing may be an issue as far as consistency goes.

 

[Fuzzball]

Re: Body die playing tricks on me. WTF.

I recently moved and most of my liberary is still stored so I can't look up the headspace tolerance of a .308. But, most bottle neck cartridges are 9 thou or close to it so you're within 'standard' headspace tolerance. That's safe for ONE firing and you'll surely get some case stretching; try to get those shoulders closer to the fired length next time!

Good luck!

 

[RotARy15]

Re: Body die playing tricks on me. WTF.

Will do.

This is FC brass going on its 3rd firing, I doubt the primer pockets will last much longer much less the rest of the case.

For all I know, this may be the last firing on this brass.

 

[Deadshot2]

Re: Body die playing tricks on me. WTF.

You may have run into some "spring back" issues when trying to "bump" the shoulders. With my bolt action .308 I've had this problem from time to time. I've finally taken to annealing after every firing on the brass I get this picky on when prepping.

As for being too short, you may (or may not) have some misfire issues if the combined tolerances are stacked, headspace, primer seating depth, etc. If the combination yields a situation where the primer is too far from the firing pin you'll get light strikes and no fire. It's not a good idea to rely on the extractor for "headspacing".

 

[MALLARD]

Re: Body die playing tricks on me. WTF.

man , you really should have took .005 off your shellholder and not the body die , but its to late for that.

 

[JByrd]

Re: Body die playing tricks on me. WTF.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MALLARD</div><div class="ubbcode-body">man , you really should have took .005 off your shellholder and not the body die , but its to late for that. </div></div>


I havent examined the whole thread line by line, but he may be runnin forster press so shell holder would be a no go. Ive had to take a lil off redding dies with mine to get them to bump my headspace.

If its 3x fired your prob getting a combination of lack of annealing and inconsistent lube as mentioned previously.

 

[Suasponte]

Re: Body die playing tricks on me. WTF.

Slow your press stroke down. Run the brass into the die and hold it for at least a four second count to allow the brass to normalize at the dimension your trying to size it to. If you fast stroke it in and out, you more than likely will see your brass length grow from what you had measured prior to sizing.

I made a video a while back showing how quick stroking your sizing die actually lengthens your headspace. So, when you think your doing one thing your actually getting the reverse results.

Slow your press stroke and see if that helps.

Terry

 

[scatterbrains]

Re: Body die playing tricks on me. WTF.

Ill add one more thing in 223 and 44mag i have had the worst inconsistencies and brass problems with FC. i use it for work up loading and thats it. Winchester and remington have been the best so far FC seems very soft.

Ill soon be sorting all the fc out since its been so problematic.

Just something ive noticed.

 

[Fuzzball]

Re: Body die playing tricks on me. WTF.

I've never understood why some folk suggest modifying a shell holder to correct for a die problem! ??

 

[scatterbrains]

Re: Body die playing tricks on me. WTF.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fuzzball</div><div class="ubbcode-body">I've never understood why some folk suggest modifying a shell holder to correct for a die problem! ?? </div></div>

Prob because shell holders are waay cheaper if you screw it up

 

[RotARy15]

Re: Body die playing tricks on me. WTF.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NJHKAR</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fuzzball</div><div class="ubbcode-body">I've never understood why some folk suggest modifying a shell holder to correct for a die problem! ?? </div></div>

Prob because shell holders are waay cheaper if you screw it up </div></div>

Forgot to mention. This is on a Hornady LnL AP press. Body die is much cheaper than the shellplate.

I've got 99 pieces of Winchester .308 brass from my bolt gun that has been 4x fired that I'm about to bump for the first time. I'll see if I can get better results this time around. I'll be using a different Redding Body Die than was used on my friends gas gun.

BTW: Is there any difference when body sizing before neck sizing or vice versa?