338 edge 34" barrel 300 smk or berger

timeless61 · #1 09-03-2010, 05:34 PM

I have a question, regarding velocities. my rifle has a 34" barrel 338 edge, last year shooting 300 smk's I was around 2950 fps, no pressure signs, but probably getting close. What should my velocity be with a 34" barrel? I am doing load development with the 300 bergers this weekend. and was curious what the 34" barrel should gain over the 26-28" lengths

jmden · #2 09-03-2010, 06:08 PM

Quote:

Originally Posted by timeless61

I have a question, regarding velocities. my rifle has a 34" barrel 338 edge, last year shooting 300 smk's I was around 2950 fps, no pressure signs, but probably getting close. What should my velocity be with a 34" barrel? I am doing load development with the 300 bergers this weekend. and was curious what the 34" barrel should gain over the 26-28" lengths

Just a word of caution if you don't know, but there's been issues with folks shooting the hybrid that fast. It seems that much over typical 30" EDGE MV's and it's believed to be developing 'nose slump' due to the long ogive. There's a few posts about it here. Folks that are staying under a certain MV (about 2825 or so?...guys?) are typically seeing great accuracy. Good luck.

timeless61 · #3 09-03-2010, 06:14 PM

I talked to Brian, and he said if I am under 3000, I should not have a problem, but they will also take them back if I do have a problem. Thanks for the heads up

as for the original question, whats a 338 edge with 300 grain and 28 or 30" barrel shooting at max? i know most people don't run theirs to max, so what is the average velocity then? thanks

Broz · #4 09-03-2010, 06:37 PM

What twist is your barrel? If you are going that fast and you are tighter than a 1 in 10 twist you are getting in the area that accuracy with the Bergers may not work out well.

If you are seeing pressure and want to optimise the 34" tube I would look into a slower burn rate powder. Maybe 50 BMG?? or Retumbo ?? But everytime I get to max with retumbo the primer pockets are toast.

As for the primer fit question. You should feel the resistance of the primer going in. If you feel the primer is loose enough that it could slip back out any or might leak I would discard that case.

Blowing primers is not anything you want to do, you could be injured, and for sure hot gases on the bolt face of your rifle will not do it any good either.

Jeff

timeless61 · #5 09-03-2010, 06:40 PM

I have h50bmg and retumbo from a 300 rum, any load data for the 338 edge? it is a 1-10" twist

Broz · #6 09-03-2010, 06:48 PM

Quote:

Originally Posted by timeless61

I have h50bmg and retumbo from a 300 rum, any load data for the 338 edge? it is a 1-10" twist

I would just test with those two powders keeping in mind that if accuracy goes to heck you may have just crossed the line.

Jeff

jmden · #7 09-03-2010, 07:57 PM

Quote:

Originally Posted by timeless61

I talked to Brian, and he said if I am under 3000, I should not have a problem, but they will also take them back if I do have a problem. Thanks for the heads up

as for the original question, whats a 338 edge with 300 grain and 28 or 30" barrel shooting at max? i know most people don't run theirs to max, so what is the average velocity then? thanks

Under 3K? Well, he should know. I thought guys had been having issues at much lower than that. Maybe with faster twists...?

On the H50BMG I doubt you'll be able to pack enough in there to get anywhere near the velocities you may want--maybe 2800. I messed around with up to 107.5g H50BMG not too long ago in my 338 AX (Lap Imp--'bout 123g water capacity) and I wasn't even hitting 2800 with that and crunching pretty bad when seating. Every gun is different. Let us know what happens. I'd guess you'd have much better success with US869 as you can pack alot of that stuff in a case, but in my 300RUM with 240's, I found it too temp sensitive for my taste. However, in the EDGE it may be a different story. Hodgdon still ads it as pretty temp insensitive, but that may be only for the 50BMG case...I don't know.