PTG 300 WSM II VS a 300 WSM Can anyone tell me the difference in pressure?

[ddavis510]

Hi folks,
I'm sourcing parts for an F Open rifle. I think the 300 WSM is the ticket. So there I am cruising the PTG site and there it is....'Great Groups No Pressure' 300 WSM II. Has anyone used this? Is there any quantitative data on how much less pressure?

I'd like to use the 215 or 230 berger's and I'm hoping to see 2800 FPS. Is that reasonable in a 30 inch 5r(ish) barrel?

Thanks for the insight,
Dan

 

[wboggs]

Ask Steve Blair for his advice on the .300WSM and heavy Bergers

 

[dragman]

Steve is the authority on them.

My info for what it's worth:
I like the .338 neck just personal preference there
.235 of freebore
and with a handful of powders and a 30" pipe 2800 isn't hard at all too hit they can be run all the way up too 3000 but it is killer on the brass.

 

[Steve Blair]

Without knowing the specs on Dave Kiff's ".300 WSM II" reamer, I can't comment. You might call PT&G and talk to Dave. He'll tell you what the difference is. [br]
As for velocity: I run 34" barrels and have no problem hitting ~2865 fps with H4831 SC. Higher velocities are possible with IMR 7828 SSC but it's more recoil than I can manage. Using my values in QL, and cutting barrel length back to 30", it predicts 2800 fps with 230's. Obviously, 215's can do better. I would stick with 230's if you can obtain reliable tracking. As reference: I had a slow barrel that tuned at ~2805 fps and won the CA State LR and 29 Palms LR Regional. So, 2800 will work well and still provide more than a 1/4 MOA over a typical 7mm 180 load. If you are using a brake, consider both H4831 SC and IMR 7828 SSC. Both performed very well for me.