Having an issue holding groups using fired brass

[Shooter_308]

Hey all, been a while since i've posted here but i've come to a stand-still with my handloading and i knew this is the place to go. To make a long story short, i found the pet load for my current rig (Remington 700 AAC-SD in a B&C Light Tactical stock) a few months back. I was loading brand new Lapua brass as the following:

Lapua Brass (FL sized)
42gr Varget
Fed 210m Primer
Hornady AMAX 178gr
Set to 2.800" COAL

My first groups after finding this load were consistent .5moa at 100 yards, more than fine in my book. After sticking with this, i cleaned/neck sized all my brass and reloaded. I noticed after reloading the first time i had 4-5 fliers opening my groups to about 1.5" here and there. I figured maybe my shooting was off that day, wind etc and didn't care too much.

My biggest problem was last thursday at the the range. This brass is on it's 3rd reload by then. Same recipe, same COAL, but not my groups were opened to 1.5" occasionally a really wicked flier here and there. Sometimes i'd be lucky and pull a nice 1" group, but average was 1.5-2"....

My question is could it be because i'm neck sizing instead of full sizing? Or maybe i need to anneal the necks? Is my brass volume changed after it's been fired? I've never used once, twice or three times fired brass before (all from one rifle obviously). Any ideas as to what my deal could be???

 

[NoFail]

Re: Having an issue holding groups using fired brass

Probably best to work up a load with 1x fired. You may have to start from scratch in his case.

 

[gimpy]

Re: Having an issue holding groups using fired brass

I'd give annealing a shot.

 

[culater]

Re: Having an issue holding groups using fired brass

Do you buy powder in 1lb or 8lb?

 

[Jayman_10X]

Re: Having an issue holding groups using fired brass

You should not have to anneal after only 1 firing. So there is something else at play here. Treat this as a process of elimination more than anything else. A few things to consider:

1. Are you drawing out of the same powder lot? Varget is known to vary from lot to lot.

2. What are the temperatures between the 1st and 2nd firings? Varget is supposed to be temp stable. But this may contribute (though I don't think so).

3. You mention the 2nd firing had wind. How much? If you had 15 mph+ winds that may be a cause.

4. What are you using for neck sizing? My intuition tells me this is the primary issue. I only use Redding, but Forester would also be acceptable. You have to be careful neck sizing because you can actually make ammunition less accurate than full length resizing. Why? The neck tension will be different than when you FL size (most likely). Also, some neck sizing dies (not Redding or Forester) size brass the wrong way which ends up bending the neck and actually creating non-concentric brass. The only way to know for sure is to use a concentricity gauge (Sinclair, Hornady, etc. make them). If you do not have a gauge, don't invest in one just yet - FL size the brass first, then test at range. If they group 0.5 MOA again, you know your neck sizing dies and/or method is wrong. OR you have to adjust tension (too much tension may actually cause non-concentric bullet seating, on account of the bullet over stressing the case mouth upon entry, something to definitely consider).

Keep us posted - thanks, Jason

 

[jkonzal]

Re: Having an issue holding groups using fired brass

I think NoFail has the right idea. You probably need to re-work you pet load after the first firing. Once your case is fire-formed to your chamber, the case capacity changes.

 

[YAOG]

Re: Having an issue holding groups using fired brass

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Shooter_308</div><div class="ubbcode-body">Hey all, been a while since i've posted here but i've come to a stand-still with my handloading and i knew this is the place to go. To make a long story short, i found the pet load for my current rig (Remington 700 AAC-SD in a B&C Light Tactical stock) a few months back. I was loading brand new Lapua brass as the following:

Lapua Brass (FL sized)
42gr Varget
Fed 210m Primer
Hornady AMAX 178gr
Set to 2.800" COAL

My first groups after finding this load were consistent .5moa at 100 yards, more than fine in my book. After sticking with this, i cleaned/neck sized all my brass and reloaded. I noticed after reloading the first time i had 4-5 fliers opening my groups to about 1.5" here and there. I figured maybe my shooting was off that day, wind etc and didn't care too much.

My biggest problem was last thursday at the the range. This brass is on it's 3rd reload by then. Same recipe, same COAL, but not my groups were opened to 1.5" occasionally a really wicked flier here and there. Sometimes i'd be lucky and pull a nice 1" group, but average was 1.5-2"....

My question is could it be because i'm neck sizing instead of full sizing? Or maybe i need to anneal the necks? Is my brass volume changed after it's been fired? I've never used once, twice or three times fired brass before (all from one rifle obviously). Any ideas as to what my deal could be??? </div></div>

If you want to load ammunition that works the same every time you may find that full length sizing every time you reload resolves some of your inconsistency issues. By sizing the neck and case body you also normalizing the shoulder height and case volume. The last thing you can do is anneal the case necks to normalize neck tension.

What dies are you using? Are you using an expander ball? This could also be a part of the problem as expander balls even the floating type tend to cause concentricity problems.

If you have not read his articles go to <span style="font-style: italic"><span style="font-weight: bold">The Rifleman's Jour</span>nal</span> and read very carefully. Take your time to understand what his reloading articles reveal. You may be very surprised to learn that some of what is taken as SOP for many reloaders may actually causing problems.

HTH!

 

[M14 Shooter]

Re: Having an issue holding groups using fired brass

I would check my scope mount and rings and make sure they are tight.If you have not cleaned your barrel for a while it may be an issue.If you clean barrel I would fire 5-6 fowler rounds before testing.
Also check to see if action bolts are torqued to the proper tension.

Regards,Mike

 

[insight3b]

Re: Having an issue holding groups using fired brass

Most likely a different lot of powder

 

[Deadshot2]

Re: Having an issue holding groups using fired brass

Just out of curiosity, does it feel like it takes the same amount of effort to seat each bullet when reloading the fired brass? In the firing and resizing process, brass moves, often into the neck/shoulder junction and neck tension can be quite erratic.

Are you neck turning your cases even if just to make their thickness more uniform (as opposed to trying to fit a custom chamber).

With my .308 I fire all new brass once, neck size, then turn necks so that they're uniform in thickness at least through 3/4 of their circumference. I also use a Mandrel type expander so that all ID's are the same, giving me the most uniform neck tension. I also go further and while seating bullets segregate those rounds that seem to require more effort than the others. By keeping them separate like this I don't have any wide swings of neck tension/bullet release effort in ammo groups. Granted, this last step relies a lot on "feel" but it seems to work with some nice small groups and great accuracy at distance.

 

[NoFail]

Re: Having an issue holding groups using fired brass

DeadShot, what die with mandrel expander do you use?

I think you're right about neck tension, too. And I can sometimes feel a big difference when seating, as you describe. I don't have a neck turner or this mandrel expander of yours.

 

[jlow]

Re: Having an issue holding groups using fired brass

There are lots of possibilities some of which are mentioned here. However, if you have some from the original lot reloaded with new brass and they work fine next to the once fired, then read on.

One of the problem with 1x brass is it has gone through your chamber and expanded. The reason this is a problem is when you get new brass, and especially Lapua, they are nice and straight with little runout because they came straight from the factory and so they shoot straight.

However, not all brass are created equal and if you have brass that has unequal wall thickness (true for all makes and yes includes Lapua), when it is fired, the brass will take on a banana shape since the side of the case that is thicker will expand more and so the end result is a piece of bras that is banana in shape. You cannot see this as the runout is slight but it will be obvious if you use a concentricity gauge on it. If the case is bent, then the bullet when you seat it will be pointing to the side and of course if you fire a bent cartridge, the bullet will enter the barrel slightly cockeyed and you can image what that will do to stability and POI.

The learning here for you is to always check the brass after you fire it both for case neck thickness variation and concentricity. You got to cull out those bad boys or you will get what you are seeing.

BTW, you cannot fix the really bad brass as FLR or neck size or neck turn (this only fix the neck but….) for that matter cannot fix this.