• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

Trail Boss - wide insonsistency subsonic .308?

T

tiNdvenTFHwMdqKW

Sergeant
Full Member
Minuteman
Apr 24, 2010
270
367
It's probably me but I just shot 20 test rounds of sub-sonic .308 loaded as follows:

Winchester Brass
175 SMK
Fed 210 Primer
Trail Boss

My groups were good ~.5-1" at 50 yards with no tumblers but the speeds through my Chrony F1 were all over the place:

Grains | Speeds
10.2 | 1059 | 847 | 1035 | 978
10.4 | 744 | 720 | 997 | 670
10.6 | 599 | 697 | 848 | 754
10.8 | 1037 | 1058 | 799 | 694
11.0 | 841 | 847 | 889 | 797

I know my Chrony isn't the best but it usually isn't off that much.

Anyone else see these sort of results with Trail Boss? I was really expecting to see faster speeds at the higher powder loads.

Rifle is a Savage 11 Hog Hunter with 20" barrel.
 
Yes, mine do the same thing. I was using 10.5 gr TB with a rem corlokt 180 gr. Though most are subsonic, every now and then one will break the barrier and sounds like a 22LR HV. TB is good because it's real light compared to volume and does a better job of filling all that empty space in the case. But as far as I can tell, that's the ONLY redeeming factor. Well, maybe it burns cleaner than those other powders when loaded light. I only briefly ventured into the subsonic stuff after I got my suppressor-enough to see I had no practical use for it other than for suppressor demonstrations for my friends. There are probably other powders like Unique or something that may be more consistent, but i have not tried any of them.
 
Do you know anyone who has a Magneto Speed or a Oheler 35? I've chronoed with both using subsonic loads and spreads weren't nearly this wide. You're not going to get better than MOA if your FPS varies by 40%.
 
That's crazy. I have only used it for 45-70 sub loads. With 405 jsp it was always between 1027 and 1033. I was just searching for a 308 sub load with 210smk's with trailboss.
 
Two things to try. One is use magnum primers to ensure you are lighting off the full load. Second is to open up the flash hole, although then your brass can only be used for those subsonic loadings. I would give some magnum primers a try first and see if your consistency improves.

While I've never shot my sub 308 load across a chrono, I havent seen bad groups out of it. Maybe 2" groups at 100. I can consistently hit my 8" plate at 125y too.
 
koz said:
Do you know anyone who has a Magneto Speed or a Oheler 35? I've chronoed with both using subsonic loads and spreads weren't nearly this wide. You're not going to get better than MOA if your FPS varies by 40%.
Click to expand...

Unfortunately, I don't but since my groups were decent even with the wide speed variations, I'm thinking it might be the crappy chrono.
 
rjacobs said:
Two things to try. One is use magnum primers to ensure you are lighting off the full load. Second is to open up the flash hole, although then your brass can only be used for those subsonic loadings. I would give some magnum primers a try first and see if your consistency improves.
Click to expand...

Good idea on the magnum primers - I'll give that a try.
 
Magnum primers and Titegroup will make you a happy camper. I should say as happy as you can be with .308 subsonic.
 
Last edited:
I personally WOULD NOT use TiteGroup for subsonic 308. I know that Hodgdon posts loads for it, but IMO with basically NO case fill you run a risk of having the flame from the primer go over the top of the powder as it sits on its side spread out in the case. I haven't experimented with it because of this concern I have with it. Maybe its an unfounded concern, but its a concern of mine none the less. I personally havent seen any issues with TrailBoss expect its hard to find and im running out.

10.5g of TrailBoss and a 180g RN FB bullet seems to do just fine in my Rem 700 AAC-SD. I put some 220g SMK's down range with 12.5g of TrailBoss and they did ok too, just to dang expensive.
 
Titegroup has worked the best for me in cases that have a lot of left over case capacity after charging. Titegroup burns a lot hotter than other powders which seems to help with insuring all of it gets ignited consistently regardless of powder position in the case.
 
rjacobs said:
I personally WOULD NOT use TiteGroup for subsonic 308. I know that Hodgdon posts loads for it, but IMO with basically NO case fill you run a risk of having the flame from the primer go over the top of the powder as it sits on its side spread out in the case. I haven't experimented with it because of this concern I have with it. Maybe its an unfounded concern, but its a concern of mine none the less. I personally havent seen any issues with TrailBoss expect its hard to find and im running out.

10.5g of TrailBoss and a 180g RN FB bullet seems to do just fine in my Rem 700 AAC-SD. I put some 220g SMK's down range with 12.5g of TrailBoss and they did ok too, just to dang expensive.
Click to expand...

In these days of companies trying to be totally lawsuit-proof, I find it hard to believe that Hodgdon would advertise a powder as safe for sub loads if they had any hint of concern about the safety of that powder. Titegroup has worked better for me than any other powder I have tried - including Trail Boss, Clays, and SR 4759. As usual, YMMV.
 
I'm using Trail Boss w/ subsonic .308 and bullets from 170-240 grains. My velocities are much more consistent than what you're seeing. I put a light crimp using a Lee factory crimp die on them. Seems to level em out. I don't use magnum primers or open up the flash hole. If your groups are consistent I'd take another look at the chrony or try them through another one for a second opinion.
 
Scoop said:
In these days of companies trying to be totally lawsuit-proof, I find it hard to believe that Hodgdon would advertise a powder as safe for sub loads if they had any hint of concern about the safety of that powder. Titegroup has worked better for me than any other powder I have tried - including Trail Boss, Clays, and SR 4759. As usual, YMMV.
Click to expand...

Im not saying it is dangerous, just that IMO it might not be as consistent since you may get inconsistent powder burn due to how the powder will lay in the case.

Like I said, my concern may be unfounded in the real world, but I have seen it brought up as a concern by other people as well.

I have tons of TG so I MAY try it out and see if and how it works for me, but so far I have been having great luck with trailboss.
 
SAB brought up a good point that I had forgotten about. A good crimp is the key to consistency with .308 subs IMHO. I used a fairly stout Lee FCD crimp.
 
You must log in or register to reply here.

Similar threads

R
308 Subsonic - suspiciously low velocity?
Replies
15
Views
1K
Gunfighter14e2
Gunfighter14e2
Top Bottom
Back