Subsonic loads for .308 Win

Thanks for the reply. The rifle has a supressor, but obviously still has the sonic crack down range. Wanted to try some subsonic ammunition to see for myself, the pros and cons.
 
I think you will find that Blunt Nosed GC lead bullets will work best in the 150-180 grain weights. Cast lead blunt projectiles are as short about as any bullet can be for its weight, and therefore will be easier to stabilize in a standard twist .308 barrel. They are also cheap. Also, you will not need as much powder to get the same velocity with cast lead as they are softer and lead is a natural dry lubricant (which is why it was used in gasoline for so long). I don't remember what twist rate mine was but I think it was a 1-10" or a 1-12" so going heavier than 200 grains may be totally out at subsonic velocity as the bullets will not be moving fast enough to fully stabilize. Flatnosed bullets will kill better than the round nosed variety, but your speed will be so slow I am not sure it will make much difference.

If you don't want to shoot lead, look to round nosed 150-180 grain copper jacketed slugs.

I don't know what you are planning on hunting with them but subsonic bullets typically will not expand as they are moving too slowly so I personally used to limit myself to coyote sized animals (<50-70lbs.)

It is too bad you don't have access to TrailBoss powder, as it is PERFECT for subsonic rifle loads. You don't even need data for it. IMR just states that you leave an air gap etween the bullet and powder and you cannot possibly overcharge it because it is so fluffy. It took about 15 grains to completely fill a .308 shell.

Sorry, I cannot give you data for somchem powders. What I will say though it DO NOT USE Cream of wheat or a similar substance as a filler. Only use dacron or similar stuff that is made for the purpose. Grain based fillers will clump from moisture and turn to cement in the case and when it is fired, it blocks the case neck until it is cleared out of the way, at the very least, it will lead to terrible accuracy, at worst it will spike pressure ridiculously.

Alas, I no longer have a .308 and stopped using subsonics because standard velocity killed things SO much faster. It would still be fun with a suppressor though... I live in NY and owning a suppressor immediately means that you are a serial killer and/or assassin. Because why else would someone want a suppressor other than to murder people? :A Bang Head:
 
May I ask why ? I have used subsonic, and they suck at accuracy.. why not just use suppressor ?

Suppressor's have some effect on supersonic bullets, but much less than most people assume. Even a .22 LR has quite a report with a normal round. About all you hear with a subsonic is the noise of the action itself. Subsonics on game animals have to really be thought through. With a .308, you are essentially firing a moderate velocity .30 cal pistol round. Not much of a thumper. That class round gets used on pigs at night around here. A lot of animals seem to go unrecovered.
 
I have made some subsonic loads for my 708. Very quiet, but unless you use a projectile specifically made for subsonic velocity do not expect any expansion. The Lehigh projectiles are pricy but do expand. Otherwise you are pretty much limited to head and neck shots.
I use trailboss.
 
I'm planning on building something very soon which will be primarily sub sonic to allow me to hunt with one of my dogs who is an excellent hunter but gun shy as hell. I plan on a 375 "Something" with heavy subsonic bullet "lehigh" or similar. but by choosing 375 cal I still have option of using Supersonic loads which have a decent trajectory as well if necessary.
With subsonic bullet weight is everything, no question
 
Thanks for all the replies and the time taken to answer..
 
There is a poster that goes by Seafire on another forum who had come up with Blue Dot loads for a bunch of rifle cartridges; you might ask him. He says he has had good accuracy with them.

I have a 300 Blackout in which I shoot subsonic loads. To shoot subsonic requires a heavy bullet (I go with 220 grainers) and my rifle has a 1:8 twist. Most 308 Winchester rifles have a 1:10 or slower twist which may or may not be fast enough to stabilize a long heavy bullet. If the bullet was too unstable, you could have a baffle strike which would not be good for the suppressor.

Here is some information I picked up somewhere (I don't think from Seafire). I have never tried it so use it AT YOUR OWN RISK:

"A good powder to use is Blue Dot which has a formula for all case sizes. I have used it for cases in varying sizes and it will work for the 375 as well.

Fill a case to the mouth and weigh the powder. 20% is the starting load and 50% is the max load. around 17-18 gn is great in the 303 and x57sized cases (18-1900fps) with 22 gn being brilliant in the 405 Winchester under a 320gn bullet for 16oofps)

Blue Dot is the most versatile powder in my cabinet and have used it very successfully in cases as small as the fireball case and through to and including the 404 Jeffery. This powder is not position sensitive so there is no worry with fillers etc. Standard primer, powder bullet and shoot, (lots of times for little cost)"
 
I use IMR Trailboss for reduced/subsonic loads in larger calibers. Check with the powder manufacturer to see which powder they may have with a burn rate close to TB. Max charge is 70% of the case capacity.

Wish I could be of more assistance.
 
Thanks for the reply. The rifle has a supressor, but obviously still has the sonic crack down range. Wanted to try some subsonic ammunition to see for myself, the pros and cons.
That "crack" is deceptive. Sort of like a ventriloquist act if I would say, you hear the crack because you are right behind the rifle. From the receiving end you have NO idea where that shot came from. They hear it, no doubt, but again it's deceptive as far as th point of origin was.
 
Some years back a friend raised pigs on his rural acreage. the feed attracted rats and he didn't want to use poison and a high powered rifle in the middle of the night would have been a problem with the neighbors. I could have used sub-sound 22s, but I found the surest way to kill some of those big rats was with a 170 gr flatnose cast bullet (actually designed for 30-30) loaded in a target grade 308 Win. I used fast powders such as Bullseye. About 5 grains would chronograph the bullet to about 800 feet per second. The shot a muffled thud, the rat quite dead and not an exploded mess.
 
I have recently been working up subsonic loads for 308 using Trail boss and TiteGroup with 170gr Sieerra flat noses. 30-30 bullets. I have gotten loads with each that come in right about an inch at 100 yards.
 

Forum statistics

Threads
53,617
Messages
1,131,237
Members
92,672
Latest member
LuciaWains
 

 

 

Latest profile posts

Impact shots from the last hunt

Early morning Impala hunt, previous link was wrong video

Headshot on jackal this morning

Mature Eland Bull taken in Tanzania, at 100 yards, with 375 H&H, 300gr, Federal Premium Expanding bullet.

20231012_145809~2.jpg
 
Top