.50 Beowulf Range Report Not encouraging.

Ok I got my New .50 Beowulf Upper the other day. Loaded about 75 rounds of ammo. Brand New Starline cases from Alexander Arms. WW Large Pistol Primers, 38 Grs of Lil Gun under the Rainer 275Gr JHP. Nice load, accurate. Couldn't chrono as I was at work supposed to be Qualing! I had about 10 round where the primer just had a slight dent from the firing pin. One didn't have any mark at all. Took the bolt out checked the firing pin retainer and the pin itself. All seem fine. Pin protrusion might not be enough will check it against my other AR's. Maybe a headspace problem I don't know. I will measure the cases after I pull the bullets. Not encouraging. Any Ideas Alexander Arms? I'm sure if you would test fire what you build this wouldn’t happen, even test fire with just primed cases would uncover this instead of wasting expensive rounds. I have been reloading for almost 30 years and I reload and cast for everything I shoot, from the .25 ACP to the .50 Beo........After reinstalling the bolt, half of the duds went off the second time. I still have 5 that won’t go bang...... Group was shot at 75 yds.

My cases fall somewhere between these, most are on closer to the Minimum case length. I replace the firing pin with a known good one and replaced the firing pin key. Cases that have a light strike still won’t go off. I pulled the pullets so all I have is a primed case. Longdayjake, I will replace the hammer spring and get back to you, here are a sample of my case lengths........Cases that fired are next to the calipers.......Most fall around 1.643 to 1.647.

One-Time Member,
I have been reloading for over 27 years, <deleted insult -- Sam>, If it's my reloading, I would have found it by now and all would have been duds......It's a headspace thing or case length problem, I have no control over either.........

Maximum Case Length 1.655 inches
Minimum Case Length 1.644 inches

Swapped out the lowers with my RR Varmint 20" Match lower. Ok I didn’t want to take a lower apart, the .50 has a brand new parts kit in it and it worked on the M-4 in .223. Still no bang on duds. One more check. Punched out lightly dented primers, they are still good. Reseated new primers…………watched the seating depth. These cases Have deep primer pockets. Beo uses large pistol primers. Ok I feel the lightest bit of pressure as the primers bottoms out, stopped here. Tried the primed round, BANG! Gotta watch the primer seating depth on these closely with mimimal length cases…..

<Deleted insults--Sam>

There is a depth gauge on the end of the caliper but it might be hard to get a good thickness reading on a primer with the anvil. The lot of cases I got are from this April, last week. They seem to run on the minimal length side and looking at the loaded rounds I still have from the other day, I culled one, pulled it and test fired it with a primer only.........Yep just what I thought, too deep. They are almost indistinguishable from the others, maybe just a slight flattening around the edges of the primer but I know what to watch out for now.......They are just a tad below flush. You almost cant feel it.

Found this here by Googling Large Pistol Primer sizes:

According to SAAMI, the depths for small pistol, small rifle, and large pistol primer pockets are .118" to .122", while large rifle primer pocket depths are .128" to .132". Small pistol and small rifle primers have the same diameter (.175") while large rifle and large pistol primers are also the same (.210").

Also, Speer recommends primers be seated .003" to .005" below flush.

http://www.thehighroad.org/archive/index.php/t-369751.html

I think it is a combination of minimal length cases as you see how short mine are and deep primer pockets. I think I got it licked; will know next time at the range.. Or I gotta lots of bullet pullin' to do! It's not the crimp, Lee Dies from Alexander Arms are a 4 Die set and come with a factory taper crimp. I used to use CCI primers all the time but they had issues with Dillon presses so I switched to Winchester..... I use Winchester for all my reloading. My Crimps look like factory and I load for 9 MM, .25 ACP, .380, 9 Largo, and .45 ACP, I got the crimping thingy down. If this doesn’t fix it; it goes back. I don't know how to mess with the headspace nor should I have too.

Most of my cases fall around 1.643 to 1.647. At least the ones I have fired and some of the new ones still not reloaded. Nothing is close to the 1.655.