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6.5 Creed - Should I Get Large or Small Primer Brass

jds holler

jds holler

Gold $$ Contributor
It's time to quit screwing around and get som GOOD brass. I'm gonna get a hundred Lapua for now. Both primer sizes are available. I kinda like the idea of small primer, but -- I'd rather someone with experience with this cartridge tell me why I should or shouldn't.
jd
 
I’ll vote for small primer. I use starline srp brass cci450’s and H4350 in my 6.5 creed with great results and I know a few others who are also successful with similar combinations.

I like the idea of more case head support with srp vs lrp and in theory keeping the primer pockets tighter for longer … but admittedly haven't shot high pressure loads or enough reloads to see primer pockets loosen up or work better on one or the other. I’ve also never seen ignition issues with srp when shooting down to 20 degrees.
 
If you can find the info ( should be on here using a search but I’m uncertain if it was a post) German Salazar did extremely extensive research on primer size. Even had photos!
 
I had issues with small primer loads with 2 6mm creedmoors, particularly in cold weather (35 to 40 deg. F). Lots of hang fires, and several that just plain failed to ignite. The SRP brass seemed to work OK for 308 cases with Varget, but not the 6 Creed and H4350 or RL16. So when I finally had a 6.5 creedmoor built, I went 100% LRP Lapua for the brass and have been very pleased with it.
 
I shot both, and couldn't tell where one was better than the other in my rifle. I think you should split them as not too long ago one of those and I can't remember which was get to get. I got 200 of each, it's a little hard keeping up with the two, but it would be worth it if one of the two gets hard to come by.
 
jds holler said:
It's time to quit screwing around and get som GOOD brass. I'm gonna get a hundred Lapua for now. Both primer sizes are available. I kinda like the idea of small primer, but -- I'd rather someone with experience with this cartridge tell me why I should or shouldn't.
jd
Click to expand...
You can get very good performance with the SRP cases, AND. . . SRP primers are more readily available in the current market than LRP's. ;)
 
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I have both in Lapua. If you open up the flash hole they will shoot more like each other. With Imr 4350 I had to use 1 grain more powder to match the velocity of the LRP brass if I did not enlarge the flash hole. Maybe a different powder would not be affected. It makes sense that the primer pocket will be stronger with the SRP. But I have not shot enough of them to see a difference in longevity.
 
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Around here, large primers are still hard to find. CCI 450,s are very gettable. I've got a pretty good selection of powders all through the range of Creedmoor possibles. -- a buttload of ancient H380 which has been great, and an uncracked 8 lbs of IMR 4320. Got newer stuff also, but would be happy to hit a winner with some of the old free stuff.

I guess I was wondering if any particular powders present an ignition problem for the small primers, and Spacegunr mentioned some.

As I think about it, I've got 50 odd Federal sp brass that I got from someone on one of the forums. Maybe I should try some of it for burners and such and see how they act. The brass I've been using "for real" has been a box of new Hornady that came with this rifle. It's all got two shots on it now. jd
 
I use small primer Lapua brass in the 6.5 Creedmoor I run in F Class. The primer pockets have held up through a lot of firings and the load shoots less than 1/2 MOA. I just prepped 500 rounds of it yesterday. Ran it through a small base full length sizing die but not all the way to cam over. Then a regular full length sizing die to bump the shoulder followed by pushing over a Wilson mandrel. Re-verified my loads today. Ready to start loading all that brass.
 
In 6.5 creedmoor i have 200 lrp but have not opened them up yet. Wanna use up all the hornady brass before i try them. But in my 308 years ago i tried both. This was just on target i noticed that with the srp my poi was low right compared to the lrp. Had exactly same powder charge, bullet weight and seating depth. I never chronograph speeds between the 2. The group sizes were identical between them. Gun was sighted in for the lrp so when i shot the srp was easy to see the change. Now with the way primers have been last 4 years id might opt for srp and stockpile the crap out of the ones you wanna use. I mainly shoot all my rifles last few years that only take srp since they were easier to find.
 
jds holler said:
I kinda like the idea of small primer, but -- I'd rather someone with experience with this cartridge tell me why I should or shouldn't.
jd
Click to expand...
@Laurie (on this forum) did a good review some time back - here's the link to Part 3.

www.targetshooter.co.uk

Small Rifle Primer Performance Pt 3 by Laurie Holland

In parts 1 and 2, I’ve got as far as listing the primers that are generally available in the UK and summarising their characteristics - in particular, cup thickness/strength. I’ve questioned the significance and role of the so-called ‘magnum’ type and worked up a 308 Win ‘Palma brass’ load to be...
www.targetshooter.co.uk
 
As Steve Donlon pointed out earlier, there's another factor at play with the Lapua SRP cases. The flash hole is smaller than a "standard" SRP flash hole, which undoubtedly affects ignition to some degree.

I found that my ES and SD numbers go up in cold weather with the Lapua brass, but that's normally not competition season for me anyway. I'm told that opening up the flash hole to a normal size will eliminate that issue, but I've not done that.
I wanted to keep the small flash hole intact for the warm weather season.

There's undoubtedly a reason Lapua uses the combination of SRP and a smaller flash hole in their 6.5 cases.
The small primer pocket withstands high pressure better, being more supported by the thicker head that results from using that design. That part's easy to see.

Why they chose to use a smaller flash hole is probably about ignition consistency under normal shooting conditions, and they have more resources than I do to determine that. I'm not going to second guess them.

95% of my 6.5 CM brass is Lapua SRP, just because it's what was available locally when I started loading for that rifle several years ago. Some of the original cases have 25 firings on them now, and are still going strong.

I started annealing every 4th firing, then switched to annealing at every firing. That's definitely a factor in long brass life, the cases that didn't get annealed regularly early on failed at about 8-10 firings due to cracks in the neck area.
 
jds holler said:
It's time to quit screwing around and get som GOOD brass. I'm gonna get a hundred Lapua for now. Both primer sizes are available. I kinda like the idea of small primer, but -- I'd rather someone with experience with this cartridge tell me why I should or shouldn't.
jd
Click to expand...

In addition to the small primer tests I did in SRP 308 Win mentioned by @Martin52 in post #12, here's an overview I did for people wondering about general pros & cons of SRP vs LRP brass:

https://www.targetshooter.co.uk/?p=4072
 
Laurie said:
In addition to the small primer tests I did in SRP 308 Win mentioned by @Martin52 in post #12, here's an overview I did for people wondering about general pros & cons of SRP vs LRP brass:

https://www.targetshooter.co.uk/?p=4072
Click to expand...
Thank you Laurie, for this extremely thorough article on the subject. It pretty much answers any questions I had -- and I've still got a decision to make.

I think I'm going to do some reloading with the sp Federal brass that I haven't tried yet. We'll see how it compares with some of the same loads I've been using on the large primed Hornady. I've already got lots of choreograph data to compare with. jd
 
Here's my strikes. the four at the bottom look like leakers, but they were marked with a sharpie for warmers. jd

IMG_1717.jpeg
 
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