300 ultra case damage

[300ultramag]

I am wondering if anyone would know what happened.I fired
a round with 86 grains of Retumbo,200 Accubond,Fed215m primer COL at 3.595" Fired like any other round except that
when i removed the case there was a 1/16 dia hole just below the shoulder.I have never used this powder before and I did not fire anymore until i find out what happened. The brass i used was shot maybe 3 times prev. with different loads. Suggestions??

 

[bailey1474]

My guess would be a bad case. Just chunk it and go on. I'm shooting 85 gr Retumbo under a 240 SMK so I don't think your over pressure.

 

[Eaglet]

Agree with Bill Bailey, I'm using 92 grains of Retumbo with Berger 210 gr. bullet. MV = 3025 ft/s.

 

[Guest]

I also agree with Bill as I'm using 85grs of Retumbo with the 240 SMK too, 2855 fps out of a 29" Lilja.
Wayne aka WAMBO

 

[bailey1474]

[ QUOTE ]
I also agree with Bill as I'm using 85grs of Retumbo with the 240 SMK too, 2855 fps out of a 29" Lilja.

[/ QUOTE ]

That sounds exactly like my setup!! I believe my bbl is just a smidge shy of 30" though. Getting the same velocity.

 

[arthurj]

That load sounds like its a little on the lighter side. 85 grains under a 240 is a lot different than 86 with a 200 acc. 86 with the 200 should be on the bottom end. My thought is under pressure. I've had a 7rum and a 300 rum, sometimes with light loads they would dent right on the edge of the shoulder. Never had a hole though. The gases pass down the side of the neck before it seals the chamber.

 

[300ultramag]

The reason for the 86 is the loads on the internet i seen started at 89.5 thought i would work up to. I dont have the Reloading manual for that powder. I guess i will try the other rounds and see what happens....

 

[Jon A]

Yeah, you're about 10 grains under max which isn't a good idea with such a slow powder. If you want a reduced load for some reason (less recoil, etc) use a faster powder like H1000. Otherwise add about 5 grains to your load at a minimum and work up from there.

 

[dbhostler]

Had the same problem with my 300 RUM. Problem solved by adding more powder. You could also increase the neck tension, seat the bullet deaper maybe use a hotter primer. But first choice is more powder.
db