204 Ruger

sharp shooter

sharp shooter

CGN frequent flyer
Rating - 100%
83   0   0
Location
Essex county (Ontario)
Hi all,

I am playing around with load development for my 204 Ruger (CZ 527 Varmint). So far my best groups are .5" with 40gr V-max and 27.5 grains of H4895 lit by a CCI BR4 primer.

My question:
I see lots of loads with Rem 7-1/2 or CCI 450 primers. I have read that these are small rifle magnum primers. Is it safe to go from a BR4 to a 7-1/2 nearing max powder charges?

My velocities were anywhere from 3690 to 3800 fps with the BR4.

Thanks,
Steve
 
sharp shooter said:
Hi all, I am playing around with load development for my 204 Ruger (CZ 527 Varmint). So far my best groups are .5" with 40gr V-max and 27.5 grains of H4895 lit by a CCI BR4 primer. My question: I see lots of loads with Rem 7-1/2 or CCI 450 primers. I have read that these are small rifle magnum primers. Is it safe to go from a BR4 to a 7-1/2 nearing max powder charges? My velocities were anywhere from 3690 to 3800 fps with the BR4. Thanks, Steve
Click to expand...

The three primers you mention (CCI BR4, CCI 450, and Rem 7 1/2) all have relatively thick cups. The CCI 450 being my personal favourite. These are the kinds of primers you want when testing warm loads with your 204. Avoid using the thinner cup primers like CCI 400, Federal 200, etc.
 
sharp shooter said:
Yes but will switching from a small rifle benchrest to small rifle magnum be safe using the same powder charge?
Click to expand...

If you're not seeing any pressure signs with your current loads, I wouldn't worry terribly about switching to magnum primers. The safest course of action is always to start low and work your way up, of course, but you're in the better position to see what your reloads are producing now.
 
Thanks guys. Anybody shooting a 527 Varmint? What are your OAL's with the mag? I have tons of free bore so that my rounds fit in the mag, I may try seating out to the lands and single feeding to see what that does for accuracy.
 
Last edited:
sharp shooter said:
Thanks guys. Anybody shooting a 527 Varmint? What are your COL's with the mag? I have tons of free bore so that my rounds fit in the mag, I may try seating out to the lands and single feeding to see what that does for accuracy.
Click to expand...

I shoot a 527 American. OAL is 2.310 with a 38 gr Wildcat (a custom bullet) load I have been using.
 
I got a ruger m77 Hawkeye predator. Max col with the 39gr sbks is 2.320. Unfortunately my internal mag only allows me to seat out to 2.300
 
Last edited:
sharp shooter said:
Hi all,

I am playing around with load development for my 204 Ruger (CZ 527 Varmint). So far my best groups are .5" with 40gr V-max and 27.5 grains of H4895 lit by a CCI BR4 primer.

My question:
I see lots of loads with Rem 7-1/2 or CCI 450 primers. I have read that these are small rifle magnum primers. Is it safe to go from a BR4 to a 7-1/2 nearing max powder charges?

My velocities were anywhere from 3690 to 3800 fps with the BR4.

Thanks,
Steve
Click to expand...

I wouldn't call the Remington 7-1/2 primer a magnum primer. It is more powerful than the 6-1/2 primer, but the 6-1/2 primer is especially mild.
 
The big thing with Remington 7 1/2 primers is the thick, tough cup. They find favor with those loading the snot out things.

My load is a 205M, 27.5 grains of Benchmark and a 32 grain Berger Varmint match. Kills coyotes dead, the odd one a lot deader than needed.
 
You must log in or register to reply here.
Back
Top Bottom