Primer issue

[BigDaddie]

Hi all,

I have recently had a problem with Fed 210 LR primers in my 308 F-Class rifle. Here's the component list: Lapua 308win cases,blueprinted), Fed 210 primers, AR2208,Varget)45.5gns under the 155SMK.

These primers have suddenly become hard to seat....I mean real hard! I usually use a Lee Hand Auto prime tool but have had to use the press since this problem arose. The pockets have been uniformed with the Sinclair tool which I spin thru again to clear the primer residue each reload. Ive noticed that the primers are quite flattened on extraction. The rifle is still shooting good groups and to my usual elevations across the range. I do not believe there is a headspace problem...Ive never had one before. Nothing has changed on the rifle.

I have never had this problem before with this batch of primers or this brass. It just started happening. I tried seating them in virgin Lapua cases,blueprinted the same) and there is no problem.

The brass is neck sized with a Redding S-type bushing die and then body sized every 4th firing with the Redding body die. As I said, I have never had a problem in the past with this method in this rifle for 2 lots of brass.

Looking at the pockets, I cant see any shelf or step in the pocket wall that is causing the primer to false seat and the depths are the all the same...indexed off the sinclair
uniformer. I have no idea why this is happening. Could anyone shed some light on the problem? I'm not sure if I should junk the cases now.

Cheers,

BD

 

[Lane]

Have you checked to see if you have a sloppy fit with your shell-holder in case fit and alignment? I would also suggest you could check the alignment of the priming punch. Perhaps the primers are getting canted in first contact with the mouth of the primer pocket when seating starts. The Shell-holder slot and case rim may have a sloppy fit and be creating a alignment issue with the particular batch of brass. If the primer cup is off center with the mouth of the primer pocket it could be causing the primer to cant and deformed when seated, flatten, compress the top of the primer cup) and enlarge the diameter of the primer. Federal 210 primers cup diameters I measured have run very close to .2120" + or- about .003" variance. Primer height average .116" Winchester LR have run close to .2114" with a average height of .115". Hard to measure correctly, however you may want to check primer diameter with your primer pocket uniformer diameter to get some idea of the diameter of your uniformed primer pockets and alignment issues along with primer seating depth in your particular cases. None of this could be your problem, however I thought it may help you find a solution. Wish you the best Lane

 

[BoydAllen]

Once, after replacing the decapping stem on a die, I adjusted the stem too far down and was bumping the insides of my case heads at the top of the ram stroke. This made it impossible to fully seat primers due to the bulge created in the floor of the primer pocket. Luckily this only involved a few cases, which I threw away.

 

[BigDaddie]

I don think it has anything to do with the priming tool or shellholder as it works fine with new brass.

I hadn't thought about bottoming out on the head when depriming. I use an RCBS universal deprimer in an old Lee press. I'll have to check where it is set.

 

[Travelor]

Put a micrometer or dial caliper on the primers and compare the diameter size to some "older" primers. My 210M's are mic'ing .2095" or 5.33mm.

Could be some large primers are getting out with the wartime productions.

Please let us know what diameters you find.


George

 

[BigDaddie]

Well I checked a heap of them,15) randomly throught the box of 1000. All of them came in at 5.35mm in diameter. No variance noted.I dont have any of the old batch left so I cannot do a comparative.

I checked the decapper and it was bottoming out on the 308win head so I reckon that may be the cause. Its correctly adjusted now.