Hi again, got another question for the community. I've got some 150gr soft point that I got from hornady for buying their stuff, rebate program or what ever. I was doing some reading and found 2 subsonic loads for the 150gr bullet. One uses trail boss and another uses tight group. I would assume the TB to be the better powder for this application? Besides the lack of volume that the TG would have what would be the issue with using TG. Not sure why I want to try this little experiment, haven't bought a suppressor yet (YET!). Any one loading subsonic for varmint control?
Subsonic .308 loads
- Thread starter 308Loader
- Start date
Usually, you go subsonic with a heavier bullet, but no reason you can't make it happen with less powder with the lighter one. Trail Boss has very low bulk density, so it fills the case better than TG. I've seen one report of a gun that was explosively disassembled firing about 3 grains of N320 (a fairly quick pistol powder) as in detonation on the Finnish Gunwriters site. So, I avoid all loads, even of quick powders for light loads that are below about 20% fill (the N320 was at about 10% fill in the .308 case it was in).
A 150 gr bullet is too light for subsonic work. You really need to be 180-200 gr range. Barrel twist will play a large factor in determining your ideal weight. My R700 ACC-SD 20" with a 1-10" twist won't stabilize >210 gr at subsonic speeds, so I shoot mainly 180 sierra game king RN's and 190 or 200 smk's . Trail Boss is the go to standard for 308 subsonic work. You want to be at about 1020 fps .
Marco Califo
New member
Why take a cartridge that tops 3000 fps with light bullets and load it down so low? If you want subsonic in 30 cal. there are better cartridges for that 30 cal carbine, 300 BO.
There are subsonic 9mm loads.
Varmint control with 308 is 110 gr Sierra HP with H335 52.5g for 3,358 fps. Not subsonic, but exploded varmints wont care.
There are subsonic 9mm loads.
Varmint control with 308 is 110 gr Sierra HP with H335 52.5g for 3,358 fps. Not subsonic, but exploded varmints wont care.
Last edited:
Marco Califo
New member
22 LR. Target rifle is good for that. And you do not even need a suppressor. Anyway, I am not trying to argue. I just believe in firearms I possess having a realistic purpose. I own 308s for power. I have 223/556 for less power, still long range. 22 LR for less. Sidearms as permitted and required. Select the right tool.
You can drive a Ferrari in reverse. That does not mean it is a worthwhile goal.
If I was to dabble in 308 subsonic it would be with 220 grain bullets, but you can do that with 300 BO.
thanks for all the reply's. this is a "just because I can" type project. The reason for 150 gr bullet is because of the data I found on an IMR sheet, think I got is off the hogdon site, as well as the TG load. I figured tight group would be a bad idea in .308. so far the only 2 powders I found for subsonic 308.
edit:
My bad, the TG load is a 168gr projectile. Still think that one is a bad idea.
edit:
My bad, the TG load is a 168gr projectile. Still think that one is a bad idea.
For what use???
Below the approx. 1100fps sound barrier, I get that, what I don't get is WHY?? (yes, I know about the "crack" when a supersonic bullet passes close enough to a solid object, I just don't get why one needs to avoid that, outside of special military applications)
Maybe its because I'm from a different era, but I fail to see the point in subsonic loads in transonic calibers. Back then, we called them "gallery loads" and often used round balls or cast bullets, and certainly never "wasted" good jacketed bullets on low speed loads.
I don't get how some people are always saying how poor a manstopper ANY handgun is, yet shooting a special low power rifle round (that doesn't even match the .30 Carbine) is the greatest thing since sliced bread....
You certainly can do it, if you want, and every cartridge has a use, but compared to the greater effectiveness in the field of full power loads, or more powerful rounds, I have to wonder why bother??
It is all purpose-driven. Townsend Whelen used to carry more catsneeze loads than full power loads on his extended hunts, figuring to shoot many more rabbits for food than anything else. A person wanting to practice trigger control or follow-through without recoil hiding sight movement, yet still print on paper. Whelen used buckshot for rabbit projectiles, IIRC. Cast bullets are great for this, too. And now that powder coating is commonly available, you can probably even avoid the bother of cleaning out leading.
As stated before it is a "just because I can" kind of thing. so can we get past the why? I have no can, I'm not doing covert wet work, my range only goes out to 200M, don't plan to hunt large body game or even rabbits... just a dude, with stuff, and this is an option for loading. I have been loading for a few years now and have wanted to try this. Why, as you have asked? because. Enough said.
so from what I've seen in the responses to this post so far, the take away might be:
Cast or powder coated bullets work well. Why better than jacketed? Remember these 150's were free after buying some Hornady stuff, cost is no issue at this point.
TB is a better choice. Because of case fill? too fast burn + too little powder = BOOM and or rapid firearm / face disassembly?
What else am I missing?
so from what I've seen in the responses to this post so far, the take away might be:
Cast or powder coated bullets work well. Why better than jacketed? Remember these 150's were free after buying some Hornady stuff, cost is no issue at this point.
TB is a better choice. Because of case fill? too fast burn + too little powder = BOOM and or rapid firearm / face disassembly?
What else am I missing?
Last edited:
Trail Boss, because of case fill and less worry over pressure/powder shifts. Have had good luck with it in 20 in with Lapua 200 grainers. Do not see any reason you could not try it with lighter bullets, especially with a slow twist rifle. Have not tried the smaller charges of very fast powders, and heavier bullets have more energy at same velocities.
A sub sonic suppressed 308 through 20 in barrel is very quiet, with a rainbow trajectory. And it is fun. Am not real worried what internet exspurts care why, or what for. Am getting old and like having fun.
A sub sonic suppressed 308 through 20 in barrel is very quiet, with a rainbow trajectory. And it is fun. Am not real worried what internet exspurts care why, or what for. Am getting old and like having fun.
Why do I load subsonic ? I shoot with a suppressor. When you shoot subsonic 308 using 200 gr bullets at only 1000 fps you see and hear things you will never experience shooting traditional supersonic. When shooting heavy subs suppressed I actually hear the bullet spin vortex as it travels downrange. I see a unique silent bullet splatter as it impacts the steel gong , then I hear the loud steel gong report. It's a unique interactive gratification . That's why I bother. Don't need to explain to the question askers. If you want the answer load subsonic suppressed and try it for yourself.
so mark where the base of the bullet would be when seated, fill to the line and weigh = max. Take that weight and x .7, that is start load? the bullet I'm using has a crimp groove, so I measured the bullet from crimp grove to base. then applied that number from the case mouth down to the shoulder. the sheet I got from IMR - hodgdon says fed 210 (magnum) primers would cci br2 be too weak?
Last edited: