primer differences and their effects on accuracy (Read 428 times)

ren

primer differences and their effects on accuracy
« on: September 01, 2019, 11:31:44 AM »
I was reading about a WOA barrel that didn't shoot well on supposedly "known" good loads.
Here are some perspectives on primer diffs.

https://web.archive.org/web/20110823001518/http://riflemansjournal.blogspot.com/2009/06/primers-small-rifle-primer-study.html

https://www.6mmbr.com/primerpix.html

macsak

Re: primer differences and their effects on accuracy
« Reply #1 on: September 01, 2019, 05:10:31 PM »

ren

macsak

Jmoto808

Re: primer differences and their effects on accuracy
« Reply #4 on: September 02, 2019, 01:08:22 AM »
I dont know about the differences in brands or "match" primers but have had improvements in SD when switching to small rifle primer brass when available, ie 260 or 6 5 creed. Also drastic increases in primer pocket life as well with smaller primers.

Bushido

Re: primer differences and their effects on accuracy
« Reply #5 on: September 02, 2019, 09:38:45 PM »
I have found primers to make a difference but it is small IME, especially with the higher quality primers. Powder charge, seating depth, neck tension, etc  makes more of a difference. I am looking for ES over a string of 10 at least, better if 20. SDs don't mean anything to me, an 8 is unacceptable in my book.

Like Jmoto808 mentioned, I've heard many 6mm and 6.5 shooters swear by SRP and brass over large.   

ren

Re: primer differences and their effects on accuracy
« Reply #6 on: September 03, 2019, 05:30:50 PM »
I know a lot of highpower shooters swear by Rem 7.5. I have a whole bunch since I don't shoot anymore. I did come across some instances when groups would open up.

Heavies

Re: primer differences and their effects on accuracy
« Reply #7 on: September 03, 2019, 08:33:52 PM »
With large rifle primers in .308, I've researched, and found by experience, "softer" primers have much better SD numbers.  By "softer" I mean the ignition or fire from the primers, not the cup hardness.  Wolf and S&B primers where the best.  Federal match primers are said to be real good, but I don't like the cup softness, nor the "touchiness" of these primers, especially when used for semi autos, like those with floating firing pins.

Also found an improvement with small primer .308 Lapua Palma brass, however, I needed to ream the flash hole larger (normal size) and use CCI 450 small magnum primers to ensure reliable ignition of the powder.  The single digit SDs where similar to slightly better than that of the large primer wolf/S&B loads, but the better pressure handling and case longevity of the small primer brass made the decision to use .308 Palma brass for my target loads an easy one.

Heavies

Re: primer differences and their effects on accuracy
« Reply #8 on: September 03, 2019, 08:42:08 PM »
Learned a lot from German Salazar.  He was an awesome prone shooter and did a ton of useful and logical experimentation of accurate riflery.  Wish he still was active.

I size my brass in the same method he used.  I never used my runout gauge since.  ah but not like I've been doing much target rifle shooting lately.  Time is scarce.   

ren

Re: primer differences and their effects on accuracy
« Reply #9 on: September 03, 2019, 09:45:30 PM »
Learned a lot from German Salazar.  He was an awesome prone shooter and did a ton of useful and logical experimentation of accurate riflery.  Wish he still was active.

I size my brass in the same method he used.  I never used my runout gauge since.  ah but not like I've been doing much target rifle shooting lately.  Time is scarce.

I hear ya :thumbsup: Life is short...

Bushido

Re: primer differences and their effects on accuracy
« Reply #10 on: September 04, 2019, 09:22:10 PM »
I hear you and agree. With the "mouse gun" group, the only way to keep up with the 308s pushing the variety of 200s is velocity. With velocity comes pressure especially doing the 90s. The "softer" primers simply can not handle the pressures on the upper scale. CCI has had some issues with their BR4s and 450 as of late. Seems their newer lots may have had a slightly thicker cut or "harder" cup than previous lots. This has lead to many FTFs in some actions and many competitors have gone away from them. I've had good results recently from 205Ms but haven't had much data from distance as the new regulations have hindered me. I get good ES numbers with them so I'm pretty confident they will do well. I've been looking into other venues to shoot/practice.