Subsonic 30-06

if the cast bullets have a blunt round nose instead of spitzer they may have a better chance of stabilizing than a spitzer of the same weight because the round nose bullet will be shorter

twist and stability are more about length than weight, heavier bullets are generally longer, but density and shape play a factor in the weight length relationship.

try out this calculator
http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

temperature also plays a role, what works in your back yard this summer may not in the winter.

While they weren't sub-sonic, I had reasonable accuracy with a 1:10 twist and 169-grain gas-check lead bullets. Probably 1,800 ft/sec, though.

I have used 220gr bullets in a 1-10 in a .308 win...10-11gr trailboss did the job for me

247 grs will be on the limit for 1:10 twist so when you take them down to subsonic speed they will struggle at any distance. Certainly worth trying though. A 30:1 alloy 311284 would seem a treat probably weigh in at 225? Are you thinking pest or noise control? Either way a decent .22 air rifle would likely do easier, no?

how far of a shot is in your back yard. Out to 50 yards about anything stays fairly stable. At least good enough to plink with cast bullets.

Do you have Unique powder in your collection?

I made a pretty accurate .308 subsonic load with Lee C309-200-R bullets with 6.5g Red Dot. Trail Boss would be very nice also. Start with about 7-8 grains with your bullets and work down until your bullets chrony below 1000 fps.

See the group in the lower left:

I worked up a subsonic 30-06 load. Using 2.8 grains of Trail Boss, drilled flash holes. I used 115 grain cast bullet that I bought at Midway USA. Velocity was 500 fps and was very quiet without a suppressor.

My dad used 7.5gr Unique behind 31141 but I think it clocks slightly supersonic from a 24"barrel.

I could hit 15" steel at 100 yards with a double-ought buck and five grains weight of pistol powder. (Disremember; like Unique or 231.)

Noise control makes it easier. Any old .310 lead bullet or the plated 110 gr 30 cal bullets over 6-8 grs Trail Boss. If you really want cheap and quiet push 32 cal round ball through a .310" Lee sizer coat with liquid alox and seat in the. 30-06 case over 8 - 10 grs of shotgun powder topped by cornmeal to the bullet base. Perfect gallery load. Although... That cornmeal blowing through your suppressor may not be ideal.....

For a period of time I shot our local High Power matches with a Swiss K-31 chambered in 7.5x55 (Virtually identical case capacity to the '06). Since it was a reduced course and all firing was at 100 yds., I chose to load subsonic. I did so using a home cast 155 gr. FP bullet initially loaded over around 8.0 grs. of Red Dot, then finally 6.7 grs. of Bullseye. The load was very, very accurate and I ultimately attained an Expert classification using this load:







The top two targets were fired prone using a sling, the bottom one off a bench.
The load was very quiet and ran around 1050 fps.

35W

More data with different powders:

http://www.gmdr.com/lever/3006s170_dat.htm

From this page:

http://www.gmdr.com/lever/lowveldata.htm