6.5 Creedmoor loads different primer pocket sizes

rooster22

rooster22

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I just started to trim my factory federal brass that was shot threw my 6.5 creedmoor. Non typical and fusion.
I have two different primer pocket holes.
I checked my other boxes of 11 and only one has large primer in it.
So I will reload with small primers, sell the the large primer hole brass I guess.
I'm going to try CCI 450 with w76o, since the 760 works excellent in my other calibers.
Are the CCI450 mag primers the best bet for W760 or does anyone else use a different primer for W760 for 6.5 creedmoor.
 
Not sure about that combination but I use CCI450 primers exclusively in my 6mm CM small primer brass and federal 210 in the brass that has large primer pockets, however I use IMR 4350. CCI 450's are very consistent
 
waldo54 said:
Not sure about that combination but I use CCI450 primers exclusively in my 6mm CM small primer brass and federal 210 in the brass that has large primer pockets, however I use IMR 4350. CCI 450's are very consistent
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I was surprised the federal brass had 2 sizes of primer pockets for 6.5 creedmoor. I use CCI 250 mag primer for my other rounds with win 760. I thought I was going to use the same primer and powder for the 6.5cm
 
jamesharrison said:
I use the exact same loads in my SRP & LRP Starline brass; same with Hornady LRP brass. Remington 7 1/2 & 9 1/2 respectively.

I do the same with my .308 Winchester loads, small & large rifle brass.

I do not, however, use W760 powder. I use RL15 or Varget in both cartridges.
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So when you reload 308 are you mixing small and large primers, and using the same powder, and getting the same results?
 
QUOTE>>>>>when loading 308, are you mixing small and large primers, and using the same powder, and getting the same results?<<<<<ENDQUOTE

Sort of.

In order to do a "somewhat" scientific test, I used Starline SRP & Starline LRP brass [as well as Hornady, Norma & Lapua LRP brass] in .308 WCF.

Net case capacity of the brass was Starline LRP - 54.4 grs. H20, Starline SRP - 53.7 grs. [a 1.3% difference between the 2 Starline types], Hornady LRP - 56.9 grs., Norma 56.6 grs., Lapua LRP - 54.4 grs. The gross mass of the 2 Starline cases were 2.6 grs. apart. Interestingly, the average case weights were higher in the LRP brass!

I used R-P 7 1/2 primers in the SRP brass & R-P 9 1/2 in the LRP brass.

Powders used were Reloader 15 & Varget [44.0 grs. in both instances] in both SRP & LRP brass. My initial testing also included S.W. Tactical, WC735, W748, X2924, WC852 & H4895, but the accuracy from those powders was worse, sometimes much worse than the 2 powder initially mentioned which I subsequently re-tested in depth.

Bullets used were Hornady 165 gr. SP-IL, seated with a Hornady seating die to achieve a C.O.A.L. of 2.800". The rounds were not crimped. I saw no need to test using target bullets as the rifle is designed for hunting, not target shooting.

Groups were segregated as to primers & re-tested on subsequent days. The barrel was allowed to cool down between groups [When I go to the range, I typically bring 5 or 6 rifles, ~200 rounds of ammunition & stay the day. Because I go during the week, I am typically the only one there.]

It was late last fall when I completed the testing, so I did not do a chronograph test, as I prefer to first work up an accuracy load & only then chronograph the loads in order to make a trajectory card.

Rifle used was a Whitworth Classic in .308 Winchester, with Warne bases, Leupold 1" Low QRW rings & a Swarovski Z3 3-9x36 scope. It is equipped with a Timney trigger & a PO had had the rifle glass bedded. I subsequently re-barrelled a Savage action with a 30" ss FTR barrel & also put together my version of a Savage "Euro Classic", but have not yet tested those. That's the plan once the darn white stuff has melted.
 
Appreciate your input, I have 40 large primer pocket brass trimmed and sized as well as the small primer pockets, I will load both the small and large primer and see what I get at the end. I will duplicate the powder charge for both tests. And compare accuracy. I load for hunting once I find an accurate load I will mass produce for hunting, practice and sighting in b4 hunting.
 
That was an issue with .45 ACP pistol brass already years ago, that you had to be careful to sort small-primer from large-primer, and now it's an issue with 6.5 Creedmoor as well. Most other calibres are consistently one primer size or other.

Having both sizes around helps navigate around primer availability issues affecting one size more than the other.

Loading for accuracy, you want to pick one headstamp and primer size and make very consistent handloads; the rest of the brass could go to plinking ammo.

There are claims Lapua small-primer brass with the tiny flash hole gives more consistent ignition, although large primers can be more reliable in extreme cold, so I have the large-primer brass set aside for winter shooting.
 
Here is a test I did a couple years ago it may shed some light on the matter

I have brass with both SRP and LRP for my 6mm creedmoor so I loaded up some identical loads with 40.5gr IMR4350 and 105gr Barnes match burners, for the small primers I used CCI 450 SRMP and for the large primers I used Fed 210 then headed off to the range to test them. The SR brass was Lapua and the LR brass was Hornady.
The rifle is an Insite arms build spec's below, the scope is a bushnell elite tactical XRS - 4.5 - 30 x 50mm FFP Mil the gun complete weighs in at 19.2 lbs.
Mack Bros Evo Stainless Action
Krieger 1/7.5 MTU 26"
Bix'n Andy Tac Sport Pro
MDT XRS Chassis BLACK
10/12rnd AICS Mag
Heathen Brake 4 Port G2
Cerakote Graphite Black
3/8moa Guarantee with Target

I shot 2 groups of 5 shots each with both it's a small sample size I know but figured if there is a big difference it would show up.

CCI 450 - average velocity 3011 ES 34.7 SD 12.6 average of both groups .512"

FED 210 - average velocity 3011 ES 26.5 SD 10.15 average of both groups .521"

Strangely enough both were identical average velocity, the LRP had a better ES and SD but the groups were just a tad larger by .009" which could be the shooter
smile.gif


The best group was with the FED 210 @ .387 but also the worst group @ .655"

There is clearly no winner as both shot really well and stay around that magical .500" that I am looking for.

I have more loaded but really didn't have time to shoot any more groups as I was also doing some load development for my 6.5 PRC with 143gr ELDX and my 7 PRC with 175gr ELDX so I had a lot of shooting to do.

Anyway it's fun to play and I love burning gun powder.
__________________
 
rooster22 said:
I'm happy with anything under MOA. I think I will develope a SR first I will duplicate my best round/group with LR and see what it does. Thanks you have been very helpful. Do you compete, or shoot for personal gratification?
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No I don't compete I just like to shoot and develope accurate loads to ring steel way out there, all my test groups are at 100 yards, I have had the little 6 CM out to 1100 yards and my 6.5 PRC and 7mm PRC out to 1400 yards. The 6 CM is the only custon build that I have, both my PRC's are Christensen Arms Mesa long range guns.
 
rooster22 said:
I just started to trim my factory federal brass that was shot threw my 6.5 creedmoor. Non typical and fusion.
I have two different primer pocket holes.
I checked my other boxes of 11 and only one has large primer in it.
So I will reload with small primers, sell the the large primer hole brass I guess.
I'm going to try CCI 450 with w76o, since the 760 works excellent in my other calibers.
Are the CCI450 mag primers the best bet for W760 or does anyone else use a different primer for W760 for 6.5 creedmoor.
Click to expand...
CCI 450 primers will be your Best Bet with W760 ball powder . JMO
 
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