300 Win Mag 20" barrel / short barrel

[Willie16wild]

I have a 300 win mag defiance action with proof barrel 1:10 twist and I have been reloading for it a little bit. It has 20" barrel.

I am using
185gr berger bullet's
69.00 grs powder - IMR-4350

I am getting around 2860fps
Sometimes my SDs are great and sometimes they suck but 1/2 moa to 3/4 moa groups.

But anyway do you think 2860fps sounds right? Do you think it's too fast for a 20" barrel?

 

[Boatninja]

Interested, I've been thinking about same type build.

 

[Maurygold]

My 19” 300 win mag shoots under 7-8 sd. I’m around 2700

 

[Willie16wild]

My 19” 300 win mag shoots under 7-8 sd. I’m around 2700

View attachment 8556796

I was actually thinking my SD are so crazy because my pressure is too high plus fps. I can shoot 5 in a row and the SD is perfect then I come back shoot it again the SD gets a lot bigger. 2860fps seem fast for me for that short of barrel. I should of listened to myself when i was doing the load development. I will do more testing eventually next year in the spring when it's warmer out.

I wanted to do the same thing you did. I shortened up the barrel so my suppressor doesn't stick out so far.

 

[supercorndogs]

I shoot 200eld 3000fps out of a 26". That's woukd be around 2850 if I cut it to 20. I see lots of people shooting 208-210 at 3k. In general I don't think loading past sammi pressure limits would cause high standard deviation.