Subsonic 270 loads help
Subsonic 270 loads help
I am not new to reloading or shooting, but I have never tried subsonic hand loading. I would like to try some 270 win subsonic loads. Is there anyone who can help me get started or turn me in the right direction? Can I just use Mag primers, bore out the flash hole, and Quick Load w/ Trail Boss to get in the neighborhood and adjust the charge from there?
jmason,
Why don't you start out with "unmodified" brass and normal loading of the bullets. I shoot subsonic 308 and 338 and just use unmodified brass, regular large rifle primer and bullets loaded normally. I get excellent performance. in both.
I think all those abnormal procedures you mentioned have no value whatsoever. If you want to make it more difficult, when you start the loads, throw a pinch of salt over your left shoulder and prepare the loads standing on one leg.
Try Trailboss powder. Don't bore out the brass, don't use magnum primers, don't coat your bullets with bacon grease, don't load your bullet backwards. Load as normal and it will work fine.
After you do it normally and see that they work fine, then use 5 brass to experiment with all the oddball things you mentioned. With those 5 drill out the primer holes and use magnum primers. I think you'll find that magnum primers work, but give the same result as large rifle primers. The drilled out brass works the same as non drilled-our brass. Using bacon grease or moly on bullets for subsonic actually will cause your ES and SD to increase.
What matters most for subsonic is consistent neck tension and precise measurement of powder. For accuracy, the jump distance to lands.
Why don't you start out with "unmodified" brass and normal loading of the bullets. I shoot subsonic 308 and 338 and just use unmodified brass, regular large rifle primer and bullets loaded normally. I get excellent performance. in both.
I think all those abnormal procedures you mentioned have no value whatsoever. If you want to make it more difficult, when you start the loads, throw a pinch of salt over your left shoulder and prepare the loads standing on one leg.
Try Trailboss powder. Don't bore out the brass, don't use magnum primers, don't coat your bullets with bacon grease, don't load your bullet backwards. Load as normal and it will work fine.
After you do it normally and see that they work fine, then use 5 brass to experiment with all the oddball things you mentioned. With those 5 drill out the primer holes and use magnum primers. I think you'll find that magnum primers work, but give the same result as large rifle primers. The drilled out brass works the same as non drilled-our brass. Using bacon grease or moly on bullets for subsonic actually will cause your ES and SD to increase.
What matters most for subsonic is consistent neck tension and precise measurement of powder. For accuracy, the jump distance to lands.
Last edited by johndoe3 on Thu Oct 22, 2009 1:57 pm, edited 1 time in total.
Will do. All that stuff with the brass was just stuff I saw pop up when searching the net. I though it was pretty odd. I just got my suppressor put on and thought I'd give it a go. My standard hand loads don't require ear protection but I though it might be fun to try some subsonic and lose the sonic crack.
From: Reduced Load Round-up, Handloader's Digest, 9th Ed.
130-gr jacketed - 12.0 - Unique - 1500 fps
From: Complete Guide to Handloading
95-gr HP -0.220" seating depth - 15.0 gr - 2400 - 1575 fps
95-gr WTCW - 0.220" - 14.0 - Unique - 1875
100-gr - 0.275" - 12.0 - SR80 - 1150 fps
100-gr - 0.275" - 16.2 - SR80 - 1550 fps (Speer #11 shows 16.0 - SR4759 - 1548 fps)
111-gr lead - 0.336" - 11.5 - SR80 - 1400 fps
111-gr lead - 0.336" - 14.0 - SR80 - 1625 fps
111-gr lead - 0.336" - 8.0 - Unique - 1402 fps
129-gr - 0.300" - 13.7 - SR80 - 1140 fps
129-gr - 0.300" - 18.0 - SR80 - 1560 fps
130-gr - 0.319" - 17.0 - 2400 - 1500 fps
130-gr - 0.319" - 13.0 - Unique - 1470 fps
130-gr - 0.300" - 20.0 - SR80 - 1675 fps (Speer #11 shows 20.0 - SR4759 - 1651 fps)
138-gr lead gas check - 0.395" - 8.0 - Unique - 1240 fps
150-gr - 0.355" - 17.0 - 2400 - 1420 fps
150-gr - 0.355" - 13.0 - Unique - 1325 fps
I have substituted SR4759 for SR80 data in the 7.62x54mmR and got higher velocities with 147- to 150-gr. bullets; with 170-gr. and heavier bullets, SR4759 velocities were closer to SR80 velocities. A chronograph would be a big help with reduced loads.
From: Pet Loads - .270 Winchester, Handloader, Jan. 1977
90-gr Sierra HP, Federal cases, 210 primer, 3.16" COL
15.0 - 4227 - 1519 fps - 1 3/8" at 100 yds, SR4759 may be substituted
16.0 - 2400 - 1771 fps - 1.5" at 100 yds
22.0 - 4198 - 1827 fps - 1.5" at 100 yds
110-gr Sierra spitzer, Federal case, 210 primer, 3.30" COL
21.0 - 4198 - 1772 fps - under 1 inch at 100 yds, best small game, turkey load
There aren't any true subsonic loads here, but maybe you can extrapolate a good load.
130-gr jacketed - 12.0 - Unique - 1500 fps
From: Complete Guide to Handloading
95-gr HP -0.220" seating depth - 15.0 gr - 2400 - 1575 fps
95-gr WTCW - 0.220" - 14.0 - Unique - 1875
100-gr - 0.275" - 12.0 - SR80 - 1150 fps
100-gr - 0.275" - 16.2 - SR80 - 1550 fps (Speer #11 shows 16.0 - SR4759 - 1548 fps)
111-gr lead - 0.336" - 11.5 - SR80 - 1400 fps
111-gr lead - 0.336" - 14.0 - SR80 - 1625 fps
111-gr lead - 0.336" - 8.0 - Unique - 1402 fps
129-gr - 0.300" - 13.7 - SR80 - 1140 fps
129-gr - 0.300" - 18.0 - SR80 - 1560 fps
130-gr - 0.319" - 17.0 - 2400 - 1500 fps
130-gr - 0.319" - 13.0 - Unique - 1470 fps
130-gr - 0.300" - 20.0 - SR80 - 1675 fps (Speer #11 shows 20.0 - SR4759 - 1651 fps)
138-gr lead gas check - 0.395" - 8.0 - Unique - 1240 fps
150-gr - 0.355" - 17.0 - 2400 - 1420 fps
150-gr - 0.355" - 13.0 - Unique - 1325 fps
I have substituted SR4759 for SR80 data in the 7.62x54mmR and got higher velocities with 147- to 150-gr. bullets; with 170-gr. and heavier bullets, SR4759 velocities were closer to SR80 velocities. A chronograph would be a big help with reduced loads.
From: Pet Loads - .270 Winchester, Handloader, Jan. 1977
90-gr Sierra HP, Federal cases, 210 primer, 3.16" COL
15.0 - 4227 - 1519 fps - 1 3/8" at 100 yds, SR4759 may be substituted
16.0 - 2400 - 1771 fps - 1.5" at 100 yds
22.0 - 4198 - 1827 fps - 1.5" at 100 yds
110-gr Sierra spitzer, Federal case, 210 primer, 3.30" COL
21.0 - 4198 - 1772 fps - under 1 inch at 100 yds, best small game, turkey load
There aren't any true subsonic loads here, but maybe you can extrapolate a good load.
I ended up with 8-9 gr of trail boss and standard rifles primers getting me subsonic. I did use the sierra 90 grainers as heavier bullets would not stabilize. I only have about 60% case fill so I was going to try some Puff-lon to fill them and see what happens. Will be tweaking a bit. Thanks for the help guys!