loose primers

[stuka762]

I have some .308 IMI cases that I reloaded 4times with CCI #34 primers,on the 5th reloading which would be the last I used some Winchester large rifle primers I had left.Upon seating the bullets I found one of the primers had fallen out of the case(the primers seated easily maybe too much so)I noticed another primer was high after bullet seating ( icheck all cartridges and this one had been correct when I installed the primer)I have used #34 primers for up to 8 loadings when I was low on brass and have never had this problem before are Winchesters smaller ? any ideas will be appreciated.

[bfoster]

stuka762... You don't give particulars on the load or the rifle so it is tough to say what is happening, but the most frequent cause for the condition you describe is pressure beyond what the rifle/cartridge combination was designed to handle. The load may be too hot.

A headspace problem could be responsible for this.

One other possiblility is soft cases. This is an extremely uncommon condition, and as it is dangerous word of such an problem generally spreads through the shooting community very quickly.

I have ring gauged a statistically signifigant sample from each case of primers I have purchased during the past thirty years. I have found less than 5 primers which were below specified minimum diameter. I'm not about to say that you can't have received an entire lot of primers which are too small, but it is my opinion that the likliehood of this is very small.

Bob

[Big Bunny]

Excellent answer -my guess is excess pressure ...especially if the old brand do not fit snugly either!

[stuka762]

The load was 39.5 gr. of 4895 pulldown I have gone thru 12lbs of this powder with no problem the bullet was .173 gr.special ball seated to 2.800 again nothing I havn"t done before with CCI34 primers,in fact this was an exact reload that works for me(with the exception of the primers)The rifle was a m14.I know reading primers is not an exact science but they did not show signs of excess pressure ????

[bfoster]

stuka762... "Tipping" the powder can isn't the only way in which excess pressure can be produced. On the face of it the load you quote should be safe in most rifles, so look at your rifle and your ammunition for the answer.

A few ideas:

Closely look at the barrel, preferably with a borescope, for signs of heat checking and/or jacket fouling- any signifigant faults just ahead of the chamber can lead to very high pressure.

Check the neck diameter of the loaded cartridges against a chamber cast. If there is not 0.0015 to 0.0020" clearance minimum this may be the cause of the poor case life you are seeing. Critically check the cases for burrs at the case mouth.

Check headspace.

Check the diameter of a signifigant sample from your current lot of bullets. It is remotely possible that 0.311, 0.318, or 0.323" diameter bullets have become mixed into the lot you are using.

If all of the above prove OK, have a a machine shop with a ROckwell Testing machine part off the body of 10 cases just ahead of the web (keep 'em cool!), and then face the remainder of the case until it just "cleans up." I'd consider an average reading of greater than Rockwell 86 F with no case softer than 84 F to be acceptable.

Bob

[Bill in NM]

It's funny that I find this here this morning...I was going to ask virtually the same question about my .243 Win.

Rifle is an Armalite AR-10.
Primers that have problems are Win WLR's purchased within the last 3 months.
Loads are varied from mild to max with various powders as I'm locate the most accurate load.
Brass is of varied brands, lots and ages.
Press is a Dillon RL550b.

One thing I tried is CCI LR Mag primers. These fit much better and had no problems.
The CCI primers took approx twice the amount of force to seat (which felt normal) than the WLR's, which felt like they seated WAY too easy.
Using a digital caliper that goes to .000x, I did find that the CCI Mag Primers are approx. .0003 larger in diameter than the WLR's (if I remember my numbers right, I measured them last night). Whether this is because they are mag primers, or because they are CCI, or just what, I can't say, as these are the only 2 LR primers I have. This really annoys me, because I have approx 2000 WLR's, and only 100 CCI's.
I plan on picking up some CCI LR (standard) primers and seeing how they work out.
Will post info when I have it.
Bill

[Bill in NM]

I picked one box of 100ea of CCI 200, CCI 250 , Federal Gold Match, and a brand new box of WLR primers, and did some testing this morning.
Results:
All primers other than WLR's felt fine going in, no looseness.
Opened brand new box of WLR's. Tried one, went in way too easy. Would appear that the WLR's are a bit smaller.

And to think, I've been throwing brass away because I figured that the primer pockets were loose. ARRRGGGG!!!!

Bill