Difference in primer pocket shape..!!!!

[LVLAaron]

To make the primer pocket stronger. I shot a alpha case 50 times in a row with an average velocity of 3020 shooting 105gr in my 6BRA. That’s a fairly stiff load. After the 50 firering the primer pocket was still good to go.

Bart

Same w/ .308 for me. 50 firings and a "go" primer gauge still doesn't fit. They're definitely tight.

 

[rsbhunter]

Just to be clear, I don't have a problem with the quality of Alpha brass, I honestly think it's great brass, and I will continue to use it. I did measure to bottom of pocket, with a caliper ,and both brands, along the wall of pocket measure ..121-.122 consistently. Now I know that is not "precision, but my money goes to bullets and powder, not depth mic's. All I was curious about was if the " step" was keeping the primer from bottoming out? That Alpha brass has shot great for me, I can average 1/4" @ 100 consistently.Alot of new loading accuracy procedures come up, and I like to get a consensus of the guy's opinions here BECAUSE of the experience and intelligence that you guy's have. I will read and reread the responses here, and thank you for taking your time to reply...rsbhunter

 

[dgeesaman]

I don't put a lot of trust in that primer chart, especially that 4th decimal place. The chart has been around for years. Different lots I'm sure can vary. Over the years as equipment wears so does the various dimensions.

Frank

I have a decent variety of primers on hand and a primo digital micrometer, I should do some comparative measurements.

David

 

[dgeesaman]

Just to be clear, I don't have a problem with the quality of Alpha brass, I honestly think it's great brass, and I will continue to use it. I did measure to bottom of pocket, with a caliper ,and both brands, along the wall of pocket measure ..121-.122 consistently. Now I know that is not "precision, but my money goes to bullets and powder, not depth mic's. All I was curious about was if the " step" was keeping the primer from bottoming out? That Alpha brass has shot great for me, I can average 1/4" @ 100 consistently.Alot of new loading accuracy procedures come up, and I like to get a consensus of the guy's opinions here BECAUSE of the experience and intelligence that you guy's have. I will read and reread the responses here, and thank you for taking your time to reply...rsbhunter

If it makes you feel any better, .001 resolution is accurate enough to investigate primer pocket seating force. Loosened primer pockets, for example, stretch a few thou by the time they’re seating more easily.

 

[Ned Ludd]

In my hands, the Alpha .308 Win SRP primer pockets behave as though there is a slight bevel or "step", to use Bart's terminology, that is very near the bottom corner of the pocket. I definitely feel it near the end of the primer seating stroke. It feels as though the the primer cup is being constricted slightly just above the mouth when it bottoms out in the pocket.

One could certainly uniform Alpha primer pockets with a uniforming tool. I tried it with one piece after fire-forming, just to see if it would work. The amount of effort it required and the toll it took on my fingers convinced me that there was no way I was going to uniform another 799 pieces for the two rifles in which I am using it. Although I appreciate what Bart and LVLAaron are stating about the apparent longevity of the Alpha brass (50 firings from any brand of brass is crazy good), I am not a big fan of the bevel in the pocket because it precludes the use of the uniforming tool to get the corners of the primer pocket free of any remaining primer residue after cleaning. However, my Alpha brass is only its second firing. I may well change that opinion at some point during during the next 48 firings.

 

[rsbhunter]

I do clean my pockets with an RCBS "brush" , and it does what I need...I won't uniform primer pockets for the fact I don't have a srp tool, and I honestly don't know if my level of shooting would show any difference. Secondly, I have a bad problem with having a steak appetite on a hamburger wallet!!! Promethius scales, amp annealers, and amp press's are not in my future.....but, I have more fun and less expectations the older I get.....maybe wisdom does come with age.....I truly appreciate the time and experience you all share , Thank you...rsbhunter