some fast H4350! I've got a Beanland 6.5x47 Lapua that Jon built for me several years ago and I've mostly shot the Berger 130 VLD bullets through it using Varget. Recently I decided to see how the Berger 140 Hybrid bullets shoot. I have Varget and H4350 powders and 37.0 grains H4350 seems to be the max I can use with the 140; 37.2 grains will blow a primer! Varget...probably 36.8 grains is tops! Zeroed at 100 yards my zero at 900 which I just finished shooting the elevation is 29.75 MOA! Kinda hard to figure it's shooting just a tat over 2500 fps!! Accurate however. Fired these 8 shots this afternoon.
It must be.....
- Thread starter M14AMU
- Start date
germanlongbow
Scott M Bainbridge
I'm shooting 36.8 grains in my x47 with Varget and 130 Bergers. Three months ago with temp in 30's was running 2850 fps, last weekend in 60 degree weather hard bolt and extractor marks, chrono up to 3040 fps. Nothing changed, same lot Varget CCI 450 and second loading on lapua brass. No explaination?
Maybe you blew a primer because the P-pocket is loose ???
It doesn't make sense why you can't get to 40 gr H-4350.
Quickload estimates 37 gr H-4350 generates almost 48,000 psi and 2,560 fps. The velocity you reported from the elevation dialed is in line with the QL velocity estimate. So something doesn't add up.
It doesn't make sense why you can't get to 40 gr H-4350.
Quickload estimates 37 gr H-4350 generates almost 48,000 psi and 2,560 fps. The velocity you reported from the elevation dialed is in line with the QL velocity estimate. So something doesn't add up.
FeMan
Gold $$ Contributor
With various powder lots and barrels, my max has been between 39.8 and 41.2 with 140s in my 6.5x47s. If it were burn rate, your H4350 would be up there with Varget.
To me, the low velocity indicates it really isn't chamber pressure. If it were high enough to blow a primer, the MV should be a lot higher. I agree, something doesn't add up here.
Could it be a bad batch of primers; soft cup? I might try a different brand/lot and see if the issue remains.
To me, the low velocity indicates it really isn't chamber pressure. If it were high enough to blow a primer, the MV should be a lot higher. I agree, something doesn't add up here.
Could it be a bad batch of primers; soft cup? I might try a different brand/lot and see if the issue remains.
It’s typical behaviour of a large clearance between firing pin and associated hole. 140 grain series and fast powder and pow - blown primer.
With lighter bullets and the same powder you probably have a lower rate of change in pressure.
A good place to start is to measure the pin and clearance. Not guaranteed that this is the issue - but something that can be checked and eliminated.
With lighter bullets and the same powder you probably have a lower rate of change in pressure.
A good place to start is to measure the pin and clearance. Not guaranteed that this is the issue - but something that can be checked and eliminated.
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