6.5 CM primer size

[fly223]

Hey folks, I started building a 6.5 CM in semi-auto and was wondering is there any difference using small and large primer brass to reload? Also what powders work best for 130gr SMK Game changers?
Thanks in advance folks.


Joe

[Ted_Feasel]

Hey folks, I started building a 6.5 CM in semi-auto and was wondering is there any difference using small and large primer brass to reload? Also what powders work best for 130gr SMK Game changers?
Thanks in advance folks.


JoeThe pretty much "standard" for creedmoor is large primer and H4350 powder. Now in all that, i switched my 308 to starline match brass with small primer and w748 and have had perfect results and its said the small primer pockets will last longer since the have more brass surrounding them. I would imagine the same could be true for creedmoor but not sure what powder would be good for small primers in creedmoor

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[Texas10]

I used RL17 for my 130 gr. Berger VLD's and got close to 3000 fps with good but not fantastic groups. I'm shooting bench only so they'd do well for half a minute of deer, quarter minute of pig loads. I tried both primer sizes and found little difference.

[wbm]

I tried both primer sizes and found little difference.

Same here.

[Ted_Feasel]

I have read that the small primers are more conducive to slower cooler burning powders which kinda seems logical. That is what made me give the starline match brass a try, i switched from varget to w748 for my 28" shilen and found a 10 shot 1 hole load. So far the pockets are holding extremely well.. lapua has nothing on startline or IMI match imo. I pay half as much for twice as many cases and can easily come up with a 100 that have virtually no deviation. I have 10 starline match I have set aside to reload while at the range and so far I have 10 reloads on them annealing 3 times. Lapua can keep their over priced garbage

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[fly223]

Fantastic, thank you folks.

[Shooter0302]

Lots of "stuff" out there on Lg. vs Sm. rifle primers,
OP, IMHO, the SRP brass is on the pricey side to be running through an AR, but to each his own.

https://www.google.com/search?client=firefox-b-1-d&q=small+rifle+primers+vs+large+rifle+primers

[Ted_Feasel]

Lots of "stuff" out there on Lg. vs Sm. rifle primers,
OP, IMHO, the SRP brass is on the pricey side to be running through an AR, but to each his own.

https://www.google.com/search?client=firefox-b-1-d&q=small+rifle+primers+vs+large+rifle+primersI dont use small primer on my AR10s , just my 308 & 6.5 CM bolt guns

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[CFJunkie]

I tried large rifle primers with my first 6.5mm CM - Savage 12 LRP - and then switched to Lapua brass with small rifle primers when I found that the primer pockets on Norma large rifle primer brass was wearing out more quickly than I had experienced with other calibers.
I have been shooting Lapua small rifle primer brass ever since with that rifle and with my other two 6.5mm CMs - 10T-SR and 12 FV.

Accuracy was slightly better with the Lapua brass so I never had the desire to change back.

As for powder results with 130 Game Changers

I have used H4350 and IMR4451 with my 12 FV with the following results for 5-round groups:
H3450 - 10 groups - average 0.365 - best load 0.328 @ 2726 fps.
IMR4451 - 22 groups - average 0.345 - best load 0.321 @ 2702 fps.

Overall average for the 12 FV with all powders and bullets is 0.340 for 480 groups.

With the 12 LRP I only used IMR4451 powder:
IMR45451 - 14 groups - average 0.379 - best load 0.362 @ 2711 fps.

I hope this helps.

[Ted_Feasel]

I tried large rifle primers with my first 6.5mm CM - Savage 12 LRP - and then switched to Lapua brass with small rifle primers when I found that the primer pockets on Norma large rifle primer brass was wearing out more quickly than I had experienced with other calibers.
I have been shooting Lapua small rifle primer brass ever since with that rifle and with my other two 6.5mm CMs - 10T-SR and 12 FV.

Accuracy was slightly better with the Lapua brass so I never had the desire to change back.

As for powder results with 130 Game Changers

I have used H4350 and IMR4451 with my 12 FV with the following results for 5-round groups:
H3450 - 10 groups - average 0.365 - best load 0.328 @ 2726 fps.
IMR4451 - 22 groups - average 0.345 - best load 0.321 @ 2702 fps.

Overall average for the 12 FV with all powders and bullets is 0.340 for 480 groups.

With the 12 LRP I only used IMR4451 powder:
IMR45451 - 14 groups - average 0.379 - best load 0.362 @ 2711 fps.

I hope this helps.I have switch my 308 and 6.5 creedmoor bolt actions to small primer brass. It definitely is a plus in multiple ways.. now I pretty much use #41 primers across all my small primer rounds like my 5.56, 6.5 grendel ARs, 6.5 cm and 308 bolt guns. Still use large primer in AR10s 6.5 cm and 308. On the ar10 308 went to exclusively IMI match brass.. has the toughness of lake city , very very consistent weight, extremely tight pockets

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[Stumpkiller]

Shooting Magazine had an article on this and it was really inconclusive. As I recall one rifle was consistently better (accuracy and S.D.) with the small primers and another with the large - so it, like so many reloading things, is a matter of what YOUR rifle prefers.

[Ted_Feasel]

Shooting Magazine had an article on this and it was really inconclusive. As I recall one rifle was consistently better (accuracy and S.D.) with the small primers and another with the large - so it, like so many reloading things, is a matter of what YOUR rifle prefers.It really comes down to what you dev around it

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[Robinhood]

Savage PTA and Bighorn TL3 with identical AGW 6.5 CM barrels. Both in chassis with cheap front rest for one and a sinclair bipod on the other with a rear bag. Different loads particular to each rfle.
Lapua SRP brass, CCI SR BR primers and H4350.
.75 5 shot groups at 400 < .2 moa.
Each load was trippled checked to be within .02 grains.

[Larrykwebb]

If your punching paper try h4831 sc, it maybe a slower burning powder than h4350 but I found it to be very good .. I used 140 grain barnes match burnes with 43.0 grains of 4831 sc and shot .260 group . The velocity on 2500 to 2700 fps.
The 6.5 loves a fuller case of powder...imo

[Ted_Feasel]

Savage PTA and Bighorn TL3 with identical AGW 6.5 CM barrels. Both in chassis with cheap front rest for one and a sinclair bipod on the other with a rear bag. Different loads particular to each rfle.
Lapua SRP brass, CCI SR BR primers and H4350.
.75 5 shot groups at 400 < .2 moa.
Each load was trippled checked to be within .02 grains.You like your Bighorn?? Been thinking about getting one.

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[Robinhood]

Like is an understatement. I did have to time the trigger. I used a Diamond Special, It had a slight notch on the close so and had to take some off the cocking piece to smooth it out. They will help you get it right if your trigger action combo needs it.

[charlie b]

Savage PTA and Bighorn TL3 with identical AGW 6.5 CM barrels. Both in chassis with cheap front rest for one and a sinclair bipod on the other with a rear bag. Different loads particular to each rfle.
Lapua SRP brass, CCI SR BR primers and H4350.
.75 5 shot groups at 400 < .2 moa.
Each load was trippled checked to be within .02 grains.

What scale do you use to weigh down to .02gn? Last one I used that sensitive was in a lab and had a hood to keep air currents away.

[Robinhood]

What scale do you use to weigh down to .02gn? Last one I used that sensitive was in a lab and had a hood to keep air currents away.

A&D FX-120i

It can be done with a tuned and mounted beam scale or a Gempro if you have that much patience. keeping the latter scales calibrated and consistent is the tough part.

No fans and no florescent lights. Led's and a closed small room.

[Stumpkiller]

Schmoikies! I just went down cellar and slapped my Ohaus/RCBS 5.10.

[Ted_Feasel]

A&D FX-120i

It can be done with a tuned and mounted beam scale or a Gempro if you have that much patience. keeping the latter scales calibrated and consistent is the tough part.

No fans and no florescent lights. Led's and a closed small room.I have a set that's accurate to .05 , ive been able to verify against some scales my wife uses at Lilly that are accurate to .01, they are for measuring pharmaceutical ingredients

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