Powder choices for subsonic 308?

[Elkins45]

Anybody shooting suppressed 308? I have been using Trail Boss and while it's good at taking up space in the case it's less accurate than I had hoped. I'm concentrating on bullets in the 190-200 grain range and but don't know whether to focus my next attempts on shotgun/pistol powders like Unique or fast rifle powders like 4227 or 4759.

Advice appreciated.

 

[Brad]

I plan to get an NOE mould to try subsonic loads. I will focus on 1680.
I hope Ian chimes in, he did lots of testing with his upper last year

 

[KHornet]

I have the same opinion of Trail Boss as most (other than Cowboy action shooters) seem to have. Have tried it in every thing from Hornet to 45-70, and it shoots FAIRLY well in all of them, with the emphasis being FAIRLY. Makes for decent off hand 25 and 50 yd tin can and clay loads in rifles. A safe powder for beginner loaders as it is impossible (I think) to double charge any recommended load. I shoot 50 yd cast pb's out of 308 with small charges of bullseye/unique/Tight Group etc. I shoot GC loads out of moderate loads for vols from 1500-1800 with 2400 and Reloader 7. Have not had great luck in 3008 with 4227, though a lot of folks have. Have run out of 4759. Good luck.

 

[Elkins45]

Are you sure you aren't thinking 300 blackout? I have that one pretty well dialed in. It's the bigger 308 case I don't have a firm handle on yet.

I would prefer to forgo using fillers if it can be avoided, hence my initial trials with Trail Boss.

 

[Brad]

Oops, my bad. I saw subsonic and instantly thought 300 blk.

For a 308 I would want Red Dot or Bullseye. That is where I would start.
Unique on up will give too much velocity at reasonable pressures.

 

[300BLK]

I would agree with Brad that Unique might be on the slow end of the spectrum for subs in the 308, although I used Herco in the '06 with 200gr plainbase with good results. Anything slower probably won't yield the desired results. Take a look at Ben's plainbase loads for sure!

 

[Brad]

Great idea. Look at what Ben uses. He might not be subsonic but is certainly close.
Shoot him a PM, he is very good about helping and sharing info.

 

[Texas Hillbilly]

Ummm be careful with reduced loads of to much,I have shot a 93gr. Cast bullets with 2.9grs of bullseye,almost the same as my 243 on recoil,pleasant load to shoot,just watch out for sticking bullet in the barrel

 

[Ian]

I haven't started on the .308 subs for lighter than 230-245-grain bullets but it's on the short list, should get a Form 1 stamp for it sometime around the end of this month.

If it's a ten-twist, you should be in the right range of bullet weight and I agree they're a bit light and velocity too low for Unique, but still I'd try it. Red Dot or Promo and Dacron with a Winchester pistol primer might do better, and is what I'm planning to try first. Dacron and suppressors is probably a no-no, but I'm going to find out. I don't have any, but American Select might also be good.

 

[Pistolero]

Brad, for 300 BLK, I had best results with H110, bought some 1680 and find no real
need for it for heavy bullet subsonic, like the 220 SMK and 980 fps loads that I settled
on.

Not sure about H110 in a .308, but see no particular reason why not. Also, why not a
small charge of Unique, perhaps 5-7 gr?

Bill

 

[RBHarter]

Brad, for 300 BLK, I had best results with H110, bought some 1680 and find no real
need for it for heavy bullet subsonic, like the 220 SMK and 980 fps loads that I settled
on.

Not sure about H110 in a .308, but see no particular reason why not. Also, why not a
small charge of Unique, perhaps 5-7 gr?

Bill

It is my understanding that bad things with H110 with airspace and necked cases.

Unique is fine ,while 4.0 gr of my old Hercules stash all but fills the the bullet base in 9mm for a full tilt load (in my gun) it is also quite plesent to plink with at 1600 fps on a 120 gr cast at 8.0 in a 264 WM. I've backed it to 3.5 in a 6.8 Rem bolt gun.

 

[Rick]

It is my understanding that bad things with H110 with airspace and necked cases.

That's my belief also. Reduced loads of H-110 in anything can be bad not to mention poor accuracy. I did try reducing H-110 in an FA 454 figuring it to be strong enough should I run into the reported pressure problems. No signs of pressure problems but the load wouldn't hit a barn if I were standing inside it.

H-110 is great powder used in the correct calibers at or near full pressure loads and preferably with heavy for caliber bullets. H-110 burns very poorly without enough pressure behind to make it burn.

 

[Pistolero]

OK, I was a bit skeptical of H110, although my discussions with Hodgdon folk in the past indicated
LOW pressures not high were the problem when less than book charges would be used, although
that was for straight wall pistol charges.

The expert I talked to did say that unequivocally, pressures were never seen to spike up
to unsafe levels with reduced charges, just erratic and potentially very low pressures some times. My
guess is that the main risk is sticking a bullet in the barrel, although very poor accuracy is
also likely, as Rick has reported.

300 BLK isn't technically a straight wall case, but sure darned close.

 

[freebullet]

I know a feller that worked this powder backward from a start charge. His experience was as Rick describes with the addition of rounds failing to fire at a certain point. He mentioned the weak older primers he'd bought at a yard sale were likely a contributing factor on that issue.

 

[Ben]

In a 308 Win., B'Eye, Unique, Green Dot, Red Dot, American Select, and Tite Group would accomplish what Elkins45 wants.

 

[Texas Hillbilly]

Yes sir,I've got some load data around here somewhere for the 150 gr to 200gr reduced loads,Uncle Bill, wrote a article for HandloadingGuide.back in the late 60's,it's a NRA book by WmCDavisJr.back then we made each shot count,so going after more speed wasn't our thing,recoil was more of a element than it is today,I hunted with a old 45/70 trap door as a kid, that mule had enough kick with out a souped up round,as soon as I could I got a 30-06 and a 30-30,
As you know we didn't have the powder selection then that we do now, remember when three powders covered all handgun loads

 

[Texas Hillbilly]

It is my understanding that bad things with H110 with airspace and necked cases.

Unique is fine ,while 4.0 gr of my old Hercules stash all but fills the the bullet base in 9mm for a full tilt load (in my gun) it is also quite plesent to plink with at 1600 fps on a 120 gr cast at 8.0 in a 264 WM. I've backed it to 3.5 in a 6.8 Rem bolt gun.

Sir if you don't mind me asking which 120gr cast bullet did you use? And what
mold I'm working on a 6.8 now I've not got a mold for yet but it's sweet with a110gr HP
Sorry didn't mean to Hijack your thread.

 

[RBHarter]

Tex,
I'm papering a NOE 260-120 FP in the 264 .
In the 6.8 it is the NOE 279-124 FP.

 

[KHornet]

12 gr of H110 in a Khornet under a 35 gr Hornady is my favorite pdog load. Shoots well to 225, and once stretched it (on the 3rd shot) on a pdog to a lazered 255 yd, but it was a big pdog.

 

[Texas Hillbilly]

Tex,
I'm papering a NOE 260-120 FP in the 264 .
In the 6.8 it is the NOE 279-124 FP.

Thank you,I'm just getting started with the 6.8.