Need your help. Been doing some ladder testing with my 7 mm RM and found a load that had a low vertical dispersion at 1,000 yards. The load showed no pressure signs and was developed in temps above 90. I shot the same load yesterday in 70 degree weather and my brass, primer, bolt showed major pressure signs. I've changed nothing... Here is some basic information:
Load is 72.5 gr of Retumbo (I know it's hot but was working before)
168 grain bergers
Fed 215 GM primers
Brass is on 4th shooting
I've only bumped shoulders and bushing sized the necks (which are turned)
I've only shot about 200 rounds through the barrel with proper break-in
I clean thoroughly after 20 plus rounds
Why did this load work before and now seems way too hot? The speed jumped so much I was over my target a couple of feet. I'm fairly meticulous with my load development so I am sure I didn't change anything from before.
Does anyone know what would cause this to happen?
Load is 72.5 gr of Retumbo (I know it's hot but was working before)
168 grain bergers
Fed 215 GM primers
Brass is on 4th shooting
I've only bumped shoulders and bushing sized the necks (which are turned)
I've only shot about 200 rounds through the barrel with proper break-in
I clean thoroughly after 20 plus rounds
Why did this load work before and now seems way too hot? The speed jumped so much I was over my target a couple of feet. I'm fairly meticulous with my load development so I am sure I didn't change anything from before.
Does anyone know what would cause this to happen?