Primer testing with Palma brass

[ronas]

Primer testing

I want to compare accuracy of load using Wolf sr primer against CCI 450 sr Magnum primer.

Suggestions welcome.

My plan so far includes 50 pieces of Lapua Palma brass all weighting within 2 grs. of each other. All bullets were weighed and I’m using batch of 175 SMKs that all actually weigh 175 gr.

All are loaded with 45 grs. of Varget. Only difference is the primer.

My plan is to shoot rifle with 10 rounds of other 175s to dirty up the barrel a bit. Then shoot five rounds with Wolf primers, wait 3 mins. then shoot five rounds with CCI primers and so on until I have shot the entire 50 rounds then see what it looks like. It no wind I’ll shoot at 200 yards if 10 or more mph then shoot at 100 yards.

 

[MALLARD]

Re: Primer testing with Palma brass

personally , i wouldnt bother.

i did some testing on primers awhile back , i tested CCI BR2, CCI large rifle , Win MAG , and Fed Mag Match.

shooting groups the BR2 produced 1/2in groups at 200y , the federal mag also produced the same results. My ES/SD between all the primers was relativly the same. So nothing really stood out.

but i also have a pressure trace machine which measures the internal ballisitics of my gun. The federal magnum match beat out all the other primers , hands down. Without the pressure trace machine i would have not been able to come to a solid conclusion about which primer i should use , since the BR2's produced the same velocities and group sizes as the Fed mag match, i could have easily settled on the br2's.

i used the n560 during that test , its a slow burning powder , so logically the mags seem like the better choice. You are using varget , im not sure people use mag primers for that.

so , part of me says dont waste your time on your test since its probable your results won't be easy to intrepret. Part of me thinks you might get some compelling results so maybe you should. Shit even if you do the test and you get results similar to mine , that kind of suggests that any primer will do the job.

 

[xs hedspace]

Re: Primer testing with Palma brass

I found that BR2 was the best for my 308 and varget, with 155 gr SMK moly coated. Against old Fed GM, and Win LR, anyway.

 

[clmayfield]

Re: Primer testing with Palma brass

This is for Lapua Palma, which is small primer brass. You know, I actually noticed a difference switching to CCI BR4 from Federal 205M. I hate it because BR4's are so expensive and I am sitting on a bunch of 205M, but I had some on hand that I was using during load development. I switched back on a lark and groups seemed to tighten up. Could be all in my head.

The other advantage to BR4's is that the cups are harder and slightly larger than 205M's, which gets me a few extra firings in loose primer pockets.

Interestingly, one of the reasons cited for development of the Palma brass is that there are fewer quality difference between manufacturers of small primers.

I would test it... but be sure to shoot on the same day alternating groups and shoot enough groups that the results aren't random. A 5X5 of each load should be good.

 

[Clark]

Re: Primer testing with Palma brass

The 6mmBR case is like a 308 Lapua Palma case. They are 1889 Mauser case heads build with a small rifle Boxer primer pocket.


This guy set a world record with CCI450 primers.
They use those, because they can take the highest pressure [primer pierce is the weakest link, not lose primer pocket as in most rimless cases].
That case head is so strong, the 308 can run 80 kpsi.

http://www.6mmbr.com/gunweek051.html

 

[Trevor]

Re: Primer testing with Palma brass

Now isn't that funny Carter must be a lot thing i ran the BR4 and the 205m and the more consistant primer for me was the 205m. i ran mine over the chrony and noted an immediate spike in the br4's speed with a high of 25fps compared to the 205's went back to the federals and the velocity dropped down to previous speeds.
the end result was the BR4 must have had a hotter higher pressure spike which increased the speed. it also gave me larger ES SD both had an SD under 10 but the BR4 had an Sd of 7 while the 205m were 4.

 

[clmayfield]

Re: Primer testing with Palma brass

I have no doubt it is a lot thing. And I have a lot of 205m, no pun intended. My brand switch could be from a bad lot, but I don't feel like buying any more 205m to find out...

 

[DHDeal]

Re: Primer testing with Palma brass

I didn't exactly do a primer test, but I did find my rifle "liked" 450's better than 205, 205M, and Wolf SRM. It is 42.5 H4895, 175 SMK, 450, 2.815", Lapua Palma, .336" bushing. Never tried BR4's.

This is through a Gradous/Surgeon, McM A5, Krieger, Jewell, Nightforce rifle shot from 100 yards to 600 yards.

FWIW, $.02, etc, etc.