30BR Whisper

[Skunce]

Have any of you loaded the 30BR with heavy bullets like the 240 SMK at subsonic velocities? If so where did you find loading data? If you worked up your own loads would you share or give some advice on what powder and starting loads.

 

[tiny68]

Hard to believe but you would really have to down load the 240 in the 30BR to be sub-sonic I think. Sierra's load table for the 200 SMK list a minimum velocity of 1800 fps and and maximum of 2300 fps. I guess with the right powder it is easily possible. tiny

 

[jthyttin]

Just do an internet search. Here's link to one discussion:

http://www.quarterbore.net/forums/showthread.php?t=1898

Subsonic loads are work of art. You'd want to start high,supersonic) and work your way to subsonic. Pistol powders work best, but you need to exercise some caution when choosing your start load.

Depending on your barrel length etc., lodging a bullet in barrel is a real threat; do inspect your bore after each shot, plus all the usual advice,barrel fouling has impact on velocity and lodging and so on)!

I might also try to come up with some loads based on the fact that 300 Whisper is smaller capacity than 7.62x39 is smaller capacity than 30 BR. That is, compare Whisper and x39 subsonic loads, and try to guess-timate a load for 30 BR.

 

[Skunce]

I had a thought that maybe the 240 SMK could be seated very deep in the 30BR case to use up some of the extra space. And then yes use pistol powder to get high enough load density. I don't know if very deep seating like that would be safe, but the factories have done similar loadings like the 284 win. I also understand that SSK makes a round that may be a subsonic 30BR called the 302 Whisper. Also in the 30BR guide on this web site there is a brief mention of subsonic loads, but no loading data.

 

[mechanix54]

Skunce, you might want to try Hornady's reload data. They don't list 30BR but they do list .308WIN,and .223REM w/55gr) subsonic loads for 168gr using Titegroup & Clays and on their web site they tell you how to make reduced,youth) loads using H4895. Hope this helps.