308 subsonic loads?

[Lizard333]

Has anyone worked up a load for a 200 grain boolet that is subsonic? I am seeing that midway wants two fifty a round and that's just nuts. I'm looking at a velocity of 1050 FPS or less. It will be shot out of my m1a, with the gas port closed. Anyone mind sharing a load? Not much data I can find anywhere. Thanks!!

[Doc_Stihl]

Trail boss will do it.
Hodgdon has data on their website.

[stubshaft]

Shot alot of subsonic in my Whisper but never in my 308. The twist was too slow.

[subsonic]

Stabilization can be an issue, especially with pointy spitzers.
10gr of trailboss works behind a 175gr SMK for ~1050fps. But only in warm weather. In cold weather this bullet isn't stable at this speed in my 11.25" twist rifle. YMMV.

Start there and work backwards, making sure all bullets exit. You can stick a long bullet and not know it pretty easily, especially jacketed. Check Hodgdon's data.

Other powders may work, but be wary of velocity swings as a result of powder orientation in the case.

[shotman]

they list a load of 8gr tightgroup and 175gr jacket I tried it with a GC 173 lead and it was good to about 50yds .At 100yds was about 6 in low. dont know a bout sub sonic but was not loud from open rifle .
they list as 1100fps but I dont think the cast was that fast
It did not open bolt enough to eject on any of the 10 I shot

[tonyjones]

From the Lyman Cast Bullet Handbook No. 2 I found the following starting loads for 311334:

700X 8.0 grains 1,142 fps 23,400 CUP
PB 9.0 grains 1,146 fps 23,400 CUP

Their test barrel had a 1:12" twist and a length of 26".

Good luck,

Tony

[chboats]

I have shot some 190gr RCBS 180 FPs with 7-8 gr of unique. They shoot to 3/4" at 50yds but 6-12" at 100. Don't know how fast they are but they don't make much noise.

Carl

[Bulltipper]

I did a lot of research on this as I have a suppressed .308. I use 8 grains of 700x shotgun powder in a large rifle primed case, use dacron or your preferred filler to fill the empty space, I use a 220 grain JRN Sierra bullet, (my twist is 1-10 and will stabilize a 220gr bullet down to 1000FPS according to the research done on the 300 Whisper) and I do not crimp the cartridge I load to 1050 FPS on my Chrony, and with my particular rifle and barrel length the powder charge works, each rifle will need a different powder load to get the speed right for subsonic. When fired with the can on, they are subsonic until about 30 deg F, below which they sound like a .22LR
If you are going to make subsonic loads, I highly recommend researching the term," Ringing the chamber" and understand the uses, pro's and con's of filler. Get a wood dowel to bang out squibs, have fun and be safe.

[Lizard333]

Thanks for the recommendations guys. I at least now have a place to start. Thanks again.

[badgeredd]

Has anyone worked up a load for a 200 grain boolet that is subsonic? I am seeing that midway wants two fifty a round and that's just nuts. I'm looking at a velocity of 1050 FPS or less. It will be shot out of my m1a, with the gas port closed. Anyone mind sharing a load? Not much data I can find anywhere. Thanks!!

First, I haven't tried subsonic loads in the 308, as yet. It's on my to-do list. Second, I have shot a pile of 150 grain cast boolits from a little 30 calibre wildcat in a rifle with a 1:10 twist barrel. By subsonic, I mean at 600-650 fps. :twisted: My experience so far is not only does boolit weigh, but boolit shape also influences my accuracy. So far a modified 311291 that fits the bore diameter as well as the groove diameter has given me the best results. Another thing that I find also seems to affect my accuracy is boolit hardness, A softer alloy obturates better and gives better results for me. YMMV.

Edd

[RU shooter]

My favorite plinker load is one that Mr Larry Gibson recommended to me a few yrs ago for most 30 calibers. take your best fitting/shooting cast bullet on top of 5-6 grs of Bullseye. While I shoot mine in a 03A3 30/06 and not a 308 it should be subsonic none the less. I have great results with a load of 5.9 grs of BE with the lee 155 shot unchecked in my rifle ,10 round groups routinely average 1.75-2" at 100 yds , I have also shot this same load at 200 with 'decent" accuracy but with a bit of vertical stringing.

Tim

[honus]

My plinker load for the 308 is the Ohaus/RCBS 150 grain FN over Red Dot and fiber fill.

[Lizard333]

Do you guys think I should add filler with the bullseye load? I think I'll try that one first.

[badgeredd]

Do you guys think I should add filler with the bullseye load? I think I'll try that one first.

I think you'll get more consistent ignition if you use a tuft of dacron or dryer lint to hold the powder against the primer. I have noticed a more consistent velocity over the chrono with a light filler in a much smaller case, so it therefore follows in my mind it will improve your shot consistency. My opinion though.

Edd

[RU shooter]

So do some dont ,I never did but I never chrono'ed any loads either, try ten rds. on target both ways at 100 yds and see what happens

[daschnoz]

These are estimates from a computer program. Use with caution.

Quickloads Predicts:
- 308WIN
- Lee C309-200-R
- 2.8" OAL
- 5.5gr to 6gr of Unique
- 21" barrel

Velocity is calculated at 957 fps and 1005 fps respectively.

You can start as high as 10gr and work down.

The same numbers can be used with Red Dot or Green Dot as well. Velocities are predicted to be a bit higher than with Unique.

Again, these are estimates from a computer program. Use with caution.

[Ola]

You can start as high as 10gr and work down.

And 5,5 gr is the starting point? So it would not be a disaster to accidentally double charge the case with the starting load? Sounds like a good load for a beginner (assuming one is reading this thread).

[daschnoz]

5.5 - 6.0 is where you end up in sub-sonic territory. When working on sub-sonic stuff, it's a good idea to work down rather than up in case you end up with a bullet that doesn't make it out of the bore.

It's easier to find the point where they start sticking rather than finding the point where they stop sticking.

But yes, if you did double charge (even a double charge of 6.0 gr), you would still be ok.

[rosst]

Lyman 311284 (210grns) 311291, 311291 (170's) are my moulds of choice with .308s at subsonic speed, one in ten twist for the heavy weights

i use 8.0grns of nobels No.2 which is comparable to Unique, use a dacron filler, first driving band engaging rifling - 2inch groups at 100 yards if your doing your part - bullet drop to 100 is ok, after that its plunging fire . . .

noise level without suppressor is similar to .22mag, with a suppressor its close to an air rifle, alot less if theres nothing for the noise to bounce off . . ..

if the bullet is hollow pointed killing power can be improved some

cheers