300 RUM and retumbo

[justgoharder]

I've worked up a very accurate load with my rum using 200gn accubonds and 95gn of retumbo. I started with a low charge and worked my way up. the groups really started coming out tighter and tighter as i went up in charge load. i settled on 95 gn and since then I've fired about 35 rounds with the 95gn charge using fed 215m primers. I haven't noticed anything odd; no stiff bolt, loose primers etc...however yesterday i took the rifle out to shoot it over the chrony a few times. i fired 6 rounds at 8215ft altitude, 29.20 pressure. 38' f. the es of the 6 shots was 23ft/s and the average was 3265! doesn't this seem a bit high for a 26" barrel??? the load isn't compressed but is probably pretty close. maybe my chrony is just way off?

 

[MontanaRifleman]

It might be your chrony. I worked up a load with 200 AB's and 96 gr of Retumbo and have seen velocities ranging from 3250 to 3300 plus, (no excessive pressure signs) 26" barrel. I think some of the reading are off. I have a Pact Alpha and it seems to give different reading depending on angle of sun, clouds, shade, etc.

8200' is a pretty high rifle range....

Mark