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Suppressors Sub sonic .308 load
- Thread starter Mader
- Start date
I am interested in this as well. I have a new Kreiger 1-11.25 twist bbl I am gonna finish at 24" My main load will be 175 SMK's at approx 2700FPS. I would like a Subsonic load as well that will stabilize with this twist. A PTG Bisley reamer will be used if that helps with throat dimension. I think I would prefer to use 200-220gr roundnose bullets. I have a YHM Phantom QD Ti can that will be used on this. I am feeling no love with the 300 BlkOut in the AR platform yet.
sub 308 load
I use 8.0gr trailboss with 147 to heavier bullets in 308. I have several twists of 30 caliber that all stabilize the shorter (lighter) bullets. The pointed 200-220 require faster twist, so rely on the 220 rn if you need the heavies. I have hit deer with 147 fmj bt and 220 SMK subsonic. Nervous system shots are mandatory for predictable kills. I have severed a heart from a WT doe with the 220 SMK from a 7 twist 300blk, but that's a crapshoot. 1100# bison drop like nothing with 147 gr subs from an 11 twist 308 when hit in the brain.
If you really want quiet, avoid any semi-auto; the action noise is quite noticeable as compared to a fixed action. And remember how loud the bullet impact is. The only "silent" shot was a miss.
I use 8.0gr trailboss with 147 to heavier bullets in 308. I have several twists of 30 caliber that all stabilize the shorter (lighter) bullets. The pointed 200-220 require faster twist, so rely on the 220 rn if you need the heavies. I have hit deer with 147 fmj bt and 220 SMK subsonic. Nervous system shots are mandatory for predictable kills. I have severed a heart from a WT doe with the 220 SMK from a 7 twist 300blk, but that's a crapshoot. 1100# bison drop like nothing with 147 gr subs from an 11 twist 308 when hit in the brain.
If you really want quiet, avoid any semi-auto; the action noise is quite noticeable as compared to a fixed action. And remember how loud the bullet impact is. The only "silent" shot was a miss.
Its hard finding round nose bullets so i used 168 Hornady bthp and 175 smks with trailboss. The 168gr pills would not stabilize with any powder charge weight. The 175gr pills would leave nice clean holes with any charge weight. My best load was 175gr smk with 10.4 gr of trailboss. I have a Bartlien 11.25 twist barrel at 22in.
175 Berger VLD's 11.1 Trail Boss. Shoots exactly 8MOA lower than my full power load using same bullet.
The 200gr Lapua subsonic bullet over 10gr of Trail Boss. Works well so far, barrel is 16" with 1:8 twist.
Anyone using powders other than trail boss? I know it is the preferred powder but can't find any locally.
Because the case capacity of the .308 Win is way way too large for realistic subsonic use you're pretty much stuck with trailboss. Its a very bulky powder that takes up a lot of space while remaining light. The only other alternative is to use cases machined from solid with a reduced capacity powder chamber. For practical purposes you're much better off going to something like the 300 blackout which allows a wide range of powders and components to be used. It has just about the perfect capacity for launching the heavies at subsonic speeds. It also allows you to use a much more compact and lightweight rifle.
Frank
Check out Lehigh's ME projos. 194 grains, awesome expansion at subsonic velocities. I threw some in a 300 BLK sub load and am very pleased with the results. Working up a 308 load for a longer barrel is up next.
Anyone have suggestions for getting stabilization out of a slower twist? I've got a 24" 1-12" barrel, and can't seem to stabilize anything I tried in it using Trailboss. 175gr SMKs, 200gr Lapua Subsonics, 178gr AMAX, etc. Pushing them up to supersonic and they'd *almost* stabilize, but you could still see a tiny hint of yaw in the slightly-oval holes. My only other route is to go much lower in weight...any suggestions?
i have had great success with hornady 180gr round nose bullets. they stabilize good because more of the bullet is in contact with the lands. i read every thread out there on 308 subs and the horn 180rn was mentioned several times. i shoot it out of a 20" 1/11 barrell with a supressor and it stabilizes fine. of course check before yous slap the suppressor on. i have had great accuracy too. it takes a big hold over but i can ring a 10" plate round after round at 200 yards no problem. easily moa at 50-100 yards. im running around 11gr of trailboss in lapua brass.
10-10.5 gn of trailboss under a hornady 180 roundnose up to the 200 laupa which was made for subsonic is a great starting point. the 200 grain laupa is a great load and ive shot it out to 600 with great results.
A metric shit ton. Last year at the SH Cup they were demo'ing the McMillian Alias in 308 and were running the 200gn Lapua subsonic load. We were shooting a 12" plate at at 600. I was so impressed with the load I stayed in touch with them and they sent me the load details. Ill have to find it.
Like I said, the rifle wasnt mine and was being demo'd at the cup. Its pretty easy to figure out drop via JBM, Shooter, AB , etc. We were holding over in addition to dialing but they were all right there. That 200gn lapua in a sub load was really impressive. I dont get anywhere near those results with the 180gn roundnose but its also a completely different shape bullet and a plow going through the air compared to the 200gn lapua which was designed for sub usage.
I believe the Alias runs a 10t but you may want to check their webpage to make sure.
I shoot a 170 grn 30-30 bullet with 10.5 gr of trailboss out of a Remington 700 police that was cut down to 18inches with a 1-12 twist and a YHM Titanium can.
Im going to try the 180s when i find them. Eventually i will re-barrel it to a 1-10" barrel
Im going to try the 180s when i find them. Eventually i will re-barrel it to a 1-10" barrel
Right now I'm trying 175gr SMK seated to 2.800. LCLR case with flash hole drilled to 9/64". 9.4gr of trailboss, no filler, getting around 1050fps. Accuracy is ok and it's really quiet with my 762sdn6 on my 20" REPR. at 80 yards I'm getting 1.5" groups roughly. That's off my patio furniture on the back deck, not a solid shooting surface.
Try horaday 160 ftx I use it and is very stable in my 1-12 in 308. Shot it out to 600yds the other day, useing trail boss at 1040fps hits the steel hard with a big ring and a BIG SMILE.
I'm using 10.6 gr of Trail Boss. Lapua Brass, 175 grain Berger OTM in a 11.25 twist Krieger 5r. Chrono'd at 1070 fps and produced a 1/10th MOA group. 13.5 minutes low from regular zero.
DTA 22" barrel 1/8 twist
208 AMAX -11.0 Grains Trailboss (1045 FPS)
168 Moly -10.6 Trailboss (1030 FPS)
DTA 16" barrel 1/8 twist
168 BTHP -8.0 Titegroup (1067 FPS)
175 SMK -7.8 Grains Titegroup (1019 FPS)
208 AMAX -11.3 Grains Trailboss (1035 FPS)
AI AE MK3 Covert 16" 1/10 twist - 7.0 Grains Titegroup (1030 FPS)
208 AMAX -11.0 Grains Trailboss (1045 FPS)
168 Moly -10.6 Trailboss (1030 FPS)
DTA 16" barrel 1/8 twist
168 BTHP -8.0 Titegroup (1067 FPS)
175 SMK -7.8 Grains Titegroup (1019 FPS)
208 AMAX -11.3 Grains Trailboss (1035 FPS)
AI AE MK3 Covert 16" 1/10 twist - 7.0 Grains Titegroup (1030 FPS)
Can anyone tell me where I can find Trail Boss? I have searched locally and on line but for the life of me I can't find any. Any help would be greatly appreciated.
I run a TBAC 338BA suppressor on my 24" savage. My load is 208 AMAX in winchestester brass with 12.4gr of trailboss and 215m primers. EVERY single time I shoot it at the range it gets attention. People cant believe what caliber the rifle is because of how quite it is. You can barely hear anything more than the firing pin and a puff of air coming out the front.
I tried producing sub-MOA loads and after alot of load development with different bullets and charges, this is what I settled on. The ammo is about 1.5MOA, which isnt exactly benchrest accuracy but at the realistic ranges this can be shot at its MORE than good enough. It's not realistic to shoot out past 400 yards anyways (because of drop) and at that distance it's still only a 6" spread (hypothetical 1.5moa, haven't tested it that far), which is more than good enough for any kind of realistic situation. The other nice part is at that range, it still has the energy of a 45ACP hit from point blank range!
I tried producing sub-MOA loads and after alot of load development with different bullets and charges, this is what I settled on. The ammo is about 1.5MOA, which isnt exactly benchrest accuracy but at the realistic ranges this can be shot at its MORE than good enough. It's not realistic to shoot out past 400 yards anyways (because of drop) and at that distance it's still only a 6" spread (hypothetical 1.5moa, haven't tested it that far), which is more than good enough for any kind of realistic situation. The other nice part is at that range, it still has the energy of a 45ACP hit from point blank range!
Update: I finally had a chance to really group test this load. Today I shot a 4-round group that you can cover with a dime at 100yds. With a 200yd zero for supers this one was shooting 3.8mils low at 100yds.
I did the "crowd pleaser" at the range today, I only had five rounds of subs with me so the first round was used to see if I could get on paper. Now I need to find a supersonic load for my DTA Covert that can match this.
