Home Forums Hunting & Shooting Ask The Gunwriters Small vs. Large Rifle primers 6.5 Creedmoor

Small primer / primer pockets handle higher pressure a bit better.

MZ5,

Yeah, I've grown a little weary of standard deviations calculated from 5-shot strings!

What am I to do? I been bite by the Creedmoor bug and like many fine details in the shooting world I often rely on what I consider to be reliable information that is gained as a result of others expertise and hard work.

I try to sort through the "wheat and chaff" of the info that is publicized for the shooting world. I will never shoot enough to know if small or large or hotter primers or a certain brass will be worth the expense for my type of shooting.

I bought a Diamondback AR10 in 6.5 Creedmoor and have a SWFA 3-15x42 mm scope with the Mil Dot Master book coming and purchased 200 rounds of Hornady ammo and will get 200 more rounds after the scope gets here.
This will be my spear into shooting past 500 yards and learning the mil dot system.

After that I will get the 6.5 Creed dies for my Dillon 550B and use up what ever old powder and primers I have laying around that works in the rifle/caliber. I have a stock pile of H4350 and more coming as I use it in a couple of 30-06 rifles and plan on getting a good bolt gun with a detachable magazine some day in 6.5 Creed. Eventually I will settle on an accurate enough load, these will be my "range/bench" guns and personal defense if needed guns, as I am an old Alaskan and prefer the 30-06 or my .338 for hunting moose, caribou and bears. Yes, I am aware the Creed will kill them, I just want to kill them deader.

In the mean time I will gleam info from smarter and more experienced shooters then me. So to all of you hard working, dedicated and smart shooters, I give you a big THANK YOU !

I have gone to ten shot strings over the chronograph.

living and hunting in northern Minnesota with my rifles staying in a cold truck or in a cold pole shed and up here we have dang cold weather lots of below zero weather . I have had much better results always with large rifle primers and to be honest Federal seems to make a better cold weather primer too. I have even left my AR-10/243 built by Norene Firearms out on my shooting bench for 2 days, it stayed below 20 below on both nights, third day tested rifle with 3 shots at 300 yards, the group was at 1 1/2 inches- 1st shot was 1 1/2 from the other 2 shots, those were about a 1 inch with one inside the 3 shot group, this off a bench with bench bags and there was no wind that day.

Not withstanding the potentially improved accuracy argument, I was under the impression that Lapua went with a SR pocket to facilitate the higher end loads that seem to be desired by so many Creed shooters. With such limited case capacity, using higher pressure loads really limits case life in cases not designed to handle the pressure as well.

Alpha brass anyone? Where I live I can buy Hornady brass at $63 per 50 or Alpha at $125 per 100. Seems like a no brainer to me.

shoots4fun,

30-40 chronographed rounds is more like it for calculating standard deviation.

If I recall correctly, Ken Oehler once posted here that SD from 10-shot strings is much like using 3-shot groups to determine a load's accuracy.

Ive read numerous accounts of hang fires in the Creedmoor with SR primers. There is a Bergara Facebook page with many post about pierced SR primers in the Creedmoor due to Bergaras firing pin hole size in the bolt. Using Hornady and Starline large primer brass has given me zero issues and good case life with great SD numbers seems like small primer brass is more trouble than its worth.

And my luck is I always have just one in ten that makes the other nine look bad.


I have one buddy who uses his Labradar at the bench and chronographs every round he fires (LR BR shooter).

It’s amazing stuff. Definitely a no-brainer.

I'll just that Lapua has made 308 Palma brass which is small primer pocketed for years for various reasons and people like it if you're having hangfire issues with a Creedmoor and other stuff you're doing the wrong s*** flat ass simple some of y'all need to really get educated

I keep a log-book for each session and tally-up multiple shot strings over time. Depending on how many range sessions you get to, over a few months you can have a few dozen shots cataloged.
That gives you, I believe, a very valid look at your rifle's accuracy, load consistency and a measure of your skills at the bench at home and on the range.

the 6.5x47L case has the small primer. I don't shoot in sub-zero temps and I suspect that more than 99% of us don't shoot in sub-zero temps where the difference in accuracy between the two will matter.

I have found two loads with my 6x47L where the ES is less than 5 for as many shots as I have taken. I use Russian primers. I have no idea how "hot" they are. I suspect that IF I ever decide to hunt Musk ox or polar bear with my 6x47L I will use CC 450s.

The small primer pockets do indeed hold up much better than the large ones do to pressure. When brass costs $1 a pop or more, you want it to last. My powder charges in the 6x47L are generally 38-40 grains- over the Tubb threshold. I don't have any way of comparing since nobody makes this brass but Lapua.

All the Creed stuff I have tried has shot wonderful and has been LR Hornady brass.

I saw that piece by Pearce. Also, there's an article on the 6CM in the 2018 Hodgdon Annual by Layne Simpson, for which he used reformed 6.5 brass with both primer sizes in an RPR and an American Predator. Hard to see any advantage either way from his data, as he got impressive results with both. My main takeaway from article is that Superformance looks like a good place to start for the 6 powder-wise.

My notion is that I would be foolish to let the my choice for hunting loads be dictated by what target shooters prefer, risking poor ignition, as long as I get good accuracy with LRs. They should do what works best for them, of course.

A small rifle primer pocket would limit the number of angels who could dance in the pocket when primerless.

Let us know how that Diamondback shoots, I've been curious about it, and the price is decent on them.

Dennis, it's not the accuracy part that worries me in sub-zero temps. It's the thing going BOOM when commanded that concerns me.

Not necessarily. What is the Lebesgue measure of an angel's footprint in R2?

Layne ALWAYS gets impressive results
While I use more Hodgdon powder than any other brand, I do not get the results others do with Superformance or H100V powders. Also, after quite some time behind the 6 Creedmoor stoked with H4350, I have found my best performance from Alliant RL16. The accuracy node was wider than a LA freeway and I get more velocity (with less pressure) from the same 42 grain charge behind 105 Hybrids.
I know that has nothing to do with this discussion of SRP v. LRP but just trying to say don't lock in on the Superformance bandwagon without trying other powders. I seem to remember during the peak H4350 shortage that Hornady was said to be using H100V in 6.5 Creedmoor loads and the results were much less favorable.