Am I having a pressure problem.

[WildBillG]

My brother had a 338 Edge built. So I loaded him a few rounds to try it out. The load was 92.0 grains of IMR 7828 in neck expanded ADG 300 RUM brass and a 215 Fed primer. The first 2 rounds were fine no pressure signs at al. The 3rd shot flattened the primer so bad you can hardly tell it from the brass and the primer was pierced. The case came out really easy. but the extractor was pushed out. I forgot to mention I was using a225 hornady sst. The rifle is a Sako AV with a 30 inch Jury barrel. The 4th shot was just like the 3rd and we called it quits.. This load was out of the Nosler manual for the 338 Rum and is 1 grain under max. I figured it was a safe load as the Edge is a bigger case. Any body have any ideas of whatwent wrong.

 

[waveslayer]

Yes... you always start low and work up if it's an unknown load / Rifle. Looks like you need to reduce your powder charges.

Next... I'd check your reloading technique if you are SURE 100% same loads no different lot of powder, etc.

Start low and work up, like a proper OCW method.

 

[budlight]

I only was a 338 lapua person. I had trouble with 7828 in my 30-378 popping primers and cracked necks. I never used it again. You really need to be using Retumbo or even better like Mag Pro or Ramshot magnum. I actually went to US 869.

distance to the lands is a big thing also

 

[manitou]

New or used brass? Was the shoulder set back?
Custom barrel may have a tight/short chamber? (or improperly cut)... but really wouldn't explain the discrepancy between shots1-2 and 3-4.

Were the brass necks black with carbon/suet after firing?

It is weird that the first two shot fine and things went "Western" on the next two.

Was the brass from pulled loads? (could have had previous powder compacted into primers).

I am just tossing a few ideas your way... grasping for straws.

 

[waveslayer]

7828 I had issues in my Warbird, went H1000 or Retumbo and pressure dropped big time. Plus a tad more temp stable I hear

 

[manitou]

Waveslayer has good points. I assume you used the same powder lot and had no mixed powder.
Were all powder charges weighed?
What scale was used? I have accidentally knocked the tiny increment weight on my bar scale before, increasing the charge a few tenths. I did notice it before bullet seating... luckily. Would have proved frustrating at the range.

 

[RidgeTop]

Too much powder in the last two.

 

[Lefty7mmstw]

yup... powder orientation varying in the case... 90% or better fill in a bigger chambering like a rum or I won't shoot it.
I am running h50bmg in my short throated 7rum as it was one of only a few powders I could get decent case fill with, have a mild load (I'd rather not tear this rifle up), and shoots accurately enough... My other choices were rl50 and wc872, but rl50 wasn't terribly accurate, and I'm not really a fan of cold weather and mild loads with ball powder.

 

[Willys]

Get some H1000, RL33, Retumbo, or N570. 92 gr H1000 golden - start low!
Fyi recent RL33 I got is 4% slower than prev lot - thats 4 grains in an edge!

 

[DUSTY NOGGIN]

picking power with possibility of full case capacity

size brass to feel a crush fit when closing bolt , removing ejector plunger , soot the front and the back to see how much contact

i think you over sized those brass slightly , the plunger held forward into the shoulder datum cone , enough to slam back into the bolt ,

 

[WildBillG]

The brass was brand new never fired. All of the powder charges were the same measured on a RCBS beam scale. I measured the brass both the normal looking fired and the high pressure looking brass. Both were right at book specs for 300 RUM brass but had expanded from virgin brass. I thought firing 338 Edge compared to RUM would be like an AI version. From what I have read when firing AI case you start at max load of standard case.

 

[Gater]

I take a small flashlight to check each case for powder and any obvious difference in amount.

 

[Bob Wright]

I wouldn't go anywhere near max until I would have worked up a ladder test looking for pressure.
Unless you have Edge load data it's a gamble going with 1 under max. If you're seeing no pressure then over pressure, go find reliable data.
Double check the trim length of brass.
Do a 10 shot ladder looking for pressure.
Do you know what the chamber neck diameter is? Compare that to loaded brass neck diameter. You'll want .003-.004 diameter clearance.

 

[436]

Double-check your scales... I am assuming you scaled each powder shot. The other may be the difference in case volume .300 Rem 110.2 gr H2O and the .338 Edge 122.5 gr H2O again I'm assuming you were forming brass with the first load, so perhaps a combination of both so to speak. just my 0.2
Cheers