Why do my primers keep backing out?


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lopezni
December 17, 2009, 08:16 PM
I am loading for the .222 rem using H335 and BLC(2) powder, CCI primers, and all my primers tend to back out of the case when fired. It does not matter how light or heavy a load I use, look at BLC(2) it definitely does not produce a high pressure cartridge for the .222. I have made sure the chamber is dry and there are no other signs of high pressure.

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ants
December 17, 2009, 08:32 PM
The case head expands slightly with every firing, and expands a lot when heavy loads are fired. Eventually the primer pocket stretches too big to hold the primer.

It is also possible that your pockets were made oversize. Doesn't happen often, but it happens.

What's the brand of brass? How many times have you fired each one?

lopezni
December 17, 2009, 09:15 PM
its Remington brass and its brand new.

Walkalong
December 17, 2009, 09:18 PM
Normally it is caused from too low pressure loads.

If you loaded hot enough to expand primer pockets and they are just backing out from being loose, I think you would know that.

What are your loads?

Sport45
December 17, 2009, 09:41 PM
Could also be the rifle has headspace issues or the brass is sized too short from the neck to the base.

How much do the primers protrude above the case head after firing? Is there any radial extrusion of primer cup metal?

lopezni
December 17, 2009, 11:09 PM
I am thinking it could be a headspace issue, it is an old Savage and from the looks of the barrel nut, someone removed it for some reason. It also looks like they put the recoil lug in a vice when they did it. They also started to inlet the stock for bedding, then never finished. The rifle groups well, there is also some cratering in the primer. It does this with every load from the suggested starting load up, I have not tried a max load with H335, with BLC(2) the max load is less than 40,000 C.U.P. so I'm not worried about that. Factory Remington ammo no problem, it has a much shorter OAL than recommended by the reloading manuals I own. 2.085" vs 2.125" should I shorten my OAL with a lighter load to see if it makes a difference? Oh and the primers are backing out about .0075"

The Bushmaster
December 17, 2009, 11:27 PM
If they are backing out a small amount then the length of the case from the shoulder to the head is too short. Move the shoulder forward by adjusting the die out a turn or two until the primer stops backing out.

rfwobbly
December 17, 2009, 11:40 PM
Just my 2 cents...

I keep a Universal Decapper die in a nearby press. While reloading, if I suspect a loose primer pocket during primer seating, I remove the case and gently push it up into the UD. If the primer is fitted loose, then one hand can easily push it back out.

I'm wondering why you suspect your primers are backing out. What in particular are you seeing? I ask because all primers come out during firing, but an instant later the case gets blown back and the bolt face re-seats the primer. So maybe the primer movement is normal, and what is abnormal is that the case is not moving.

lopezni
December 17, 2009, 11:44 PM
Well I can see they are backing out. I'm gonna try to adjust the die, thanks.

SomeSmuck
December 18, 2009, 12:26 AM
I get the same results with Remington brass for the 444, so I'd be very interested in seeing what you find to be the issue. As the 444 has no shoulder and the gun is brand spanking new, I would think it not to be a sizing or headspace issue in my case, but I guess you never know... My gun's a handi-rifle, and I'm using Win LR primers... Good luck and please post any findings on your end!

Husker_Fan
December 18, 2009, 10:57 AM
Did you size the new brass before loading it?

rcmodel
December 18, 2009, 01:22 PM
Factory Remington ammo no problem,Well, that right there tells you it is one of two things.

1. Not enough pressure to stretch the case & re-seat the primer.

Or:
2.
Excess headspace due to pushing the shoulder back to far with the sizing die.

With that said, the Savage 340 has a very stretchy action due to the two-piece bolt and single locking lug.
They can do weird stuff to brass & primers under the best of conditions.

rc

dagger dog
December 18, 2009, 01:36 PM
A low pressure sign :the case neck is smokey, as stated previously, not enough pressure to "seal" the case in the chamber, usually causes the primer to remain at its full rearward position and the case necks will be black with smoke. Try neck sizing a few cases and use your regular loading, shoot these and see if the condition goes away, if it does then you know the full sizing die is screwed in to far,if the condition persists with neck sized cases then your rifle is the problem.

ranger335v
December 18, 2009, 02:48 PM
"If they are backing out a small amount then the length of the case from the shoulder to the head is too short. Move the shoulder forward by adjusting the die out a turn or two until the primer stops backing out."

Bushy is righty. And increase the charges, they're too light.

lopezni
December 18, 2009, 10:11 PM
yeah the case neck does tend to be smokey, yes I did size the new brass before I loaded it. What is weird is the bolt when the firing pin is coked, is very tight. When the bolt is un-cocked there is some back and forth play with the bolt. I assume when it is fired the bolt must move around some. Gonna get an RCBS precision mic, see where everything needs no be set, and up the charge using neck sized ammo that is from my factory rem used cases.

Walkalong
December 19, 2009, 10:37 AM
yeah the case neck does tend to be smokey, yes I did size the new brass before I loaded itAlmost surely low pressure, but perhaps over sized as well. A case gauge (http://www.midwayusa.com/viewProduct/?productNumber=456614) is good insurance here.

What is weird is the bolt when the firing pin is coked, is very tight. When the bolt is un-cocked there is some back and forth play with the bolt.Normal.

With that said, the Savage 340 has a very stretchy action due to the two-piece bolt and single locking lug.
They can do weird stuff to brass & primers under the best of conditions.
A good reason to size the case to match his rifle, and not just screw the die all the way down.

counterclockwise
December 19, 2009, 01:07 PM
Since your as-fired assembly has the primer cup protruding .0075 above the rim face, then the chamber is at least .008 longer than your shoulder to rim dimension. So, those as-fired cases are not fire formed to chamber size. Don't let that confuse you when resetting the die in the frame to make longer cases. Use your comm'l as-fired cases that do not have the protruding primer cup, to determine the chamber dimensions, with your RCBS Precision Mic., not your primer-backed-out cases. To reduce the shoulder bump-back by .008, you would need to come back out of the frame with approx. 0.1 turns on the die (assuming 7/8-14 TPI threads).

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