300 PRC

[markl323]

Cci200s gave me better SDs then 210M or mag primers.

Most my SDs are in the 6 to 10 range.

Also single SDs as cool as they are doesn’t necessarily mean smaller groups.

thanks for that suggestion. I tried the CCI 200's, 210M's and 215M's with Retumbo (76.4gr) and the CCI's were the best and easy to find too! I shot 3x 5 shot groups for each type of primers. and SDs for the CCI 200's were 13, 12, 3. significantly better than the other two primers.

how do some people get their SDs down to 4-6? my steps are as followed:

anneal
full length size (with neck bushing - but no shoulder bump possible yet since brass have only fired once)
ultrasonic clean brass
dry brass
trim brass with 21st Century case trimmer
chamfer, deburr case mouth
apply imperial dry lube case mouth then mandrel (0.002" tension) twice
seat primers with 21st Century primer seater (0.002" crush - as in below flush?)
dispense powder with the A&D FX-120i scale
apply Imperial Dry Wax on bullets (Berger 220 LRHT)
seat bullets with 21st Century inline bullet seater and K&M pressure gauge. then use the ones that have unusually higher seating pressure for sighters.

I also shot when it was 100F. not sure if that caused high SDs?

 

[markl323]

I tested the CCI 200s with N565 and got a better SDs on average. Again I did 3x 5-shot groups. SD for each were 8.8, 9.3 and 5.1.

I also tried the CCI 250s with this powder as well and they are not as good, at least for this gun.

 

[Williamtell]

What’s your first thought on this factory ammo chambered and then ejected?

A little late replying, but have you used a borescope? Have you checked for carbon ring/deposits?

 

[robozebra]

Anyone have experience with a 210 Cayuga in 300 PRC? I’ve shot the 7mm (151 and 170) in my SAUM and have had great results. Considering 210 in my new 300 PRC. 24” Bartlein CFW LH gain twist 1:9 to 1:8.

 

[SEPAboltrifle]

Are you considering the 210 grain Cayuga strictly for hunting application?
If the intended applicaiton is long range target then you might consider PVA .30 caliber 212 grain Seneca solid projectile. PVA advises 1:8 twist rate required to stablize the Seneca 212 grain projectile.

 

[robozebra]

I was planning on using the 300 PRC for hunting. Specifically an elk hun in Colorado at end of Oct.