Compressing IMR 4831

[tomt]

I am begining to start working up a load for my Browning X-Bolt in 300WSM using the 190 Berger VLD. I am going to start at 61.6gr with IMR 4831 and end at 64.6gr. The longest my magazine will allow me to seat the bullet out is 2.900. This gives me .110 jump to the lands. My make up will vary the loads by .3gr for a total of 11 rounds. At 64.6gr the load is compressed 102.6%. Is there a problem compressing IMR 4831 2.6%?
Thanks Tom

 

[Kevin Thomas]

Tomt,

Assuming the pressures generated by the load itself aren't excessive, the slight compression you're talking about here won't be a problem. Compressed charges with many of the slow burning powders are more common than not, and the 2% you're talking about here, may not even be a true compressed charge, given differences in case capacity, how well the powder settles into the case during charging (use a long drop tube), etc..

 

[tomt]

Thanks Kevin, I have never use a drop tube, but I hear more and more people refering to them. I guess I'm going to have to get one.

 

[backwoods83]

I'm not recommending loads to you but I will say I currently run 65.5grns Hybrid compessed under a 208 amax and 69grns Imr4350 under a 180nbt. The nbt has a 2.94" oal and the 208 has a 2.994" oal. I 63grns of Imr4350 under a 208 with no pressure so if anything 64.6 may be conservative, always work up no matter what, but I think you'll have better luck with 65-66.5grns of Imr 4350, better velocity and probably better accuracy and lower es.

 

[royinidaho]

In a smaller '06 family cartridge I compressed 4831 to the point that the bullet, after seating, was forced out by compression pressure. This condition was the limiting one for me. Kinda dumb but years ago I knew even less than I now know.

Kevin Thomas' statement was spot on.