Subsonic .308 load

[jackmanuk]

im after a subsonic load for my 308 since iv just bought a moderator and might as well try it to its full extent . i only use 2400 to reload atm and im wondering if anyone make a subsonic load with this to save me doing the testing my self

[ironhead7544]

Trailboss and Red Dot are the favorites right now. If you do a search you will find lots of info. Let us know how it works out.

Dont know about 2400. I checked the Lyman #47 manual but the minimum is well over subsonic.

[Outpost75]

These chronograph data are for .30-'06 and chronographed from a Winchester 54 with 24" barrel, will give you a place to start. These charges are very light and would be safe in a .308 Win., but to remain subsonic you will want to reduce powder charges with Bullseye 1/2 grain or so. Be careful going below that unless you have your squibb rod and dead blow mallet handy, as you may stick a bullet in the bore, particularly if you try reduced loads in a rifle length barrel with jacketed below about 1050 fps.

Lee .311-230 Blackout, 7.8 grains Bullseye (no filler, Lee Liquid Alox), Rem. 9-1/2, 1058 fps, 10 Sd, 33 ES n=10 rds. THIS BULLET NOT STABLE SUBSONIC IN 10 INCH TWIST, GROUPS > 3" @ 100 YDS with Tipping!

HM .312-160-5, 6.0 grains Bullseye (no filler, no GC, Lee Liquid Alox), Rem. 9-1/2, 1087 fps, 11 Sd, ES 52, n=20 rds. VERY accurate in 10 inch twist, average under 2" at 100 yards over long series of ten-shot groups.

HM .312-160-5, 5.5 grains Bullseye (no filler, no GC, Lee Liquid Alox), Rem. 9-1/2, 1022 fps, 10 Sd, ES 33, n=10 rds. VERY QUIET, like shooting .22 LR, acceptably accurate for training, but less accurate than the 6 grain load.

LC43 Ball M2 152-grain FMJ pulls, 7.8 grains Bullseye (no filler) Rem. 9-1/2, 1046 fps, 9 Sd, 46 ES, n=10 rds. Quiet and acceptably accurate for training purposes, 2-3" at 100 yards.

If you don't have Bullseye pistol powder, these same charge weights in a .308 case, but substituting Winchester Super Target, aka WST or any common 12-ga. shotshell powder available in UK which is recommended for loading light field or target loads with 32 grams of shot at 350 m/s will give approximately the same results.

[jackmanuk]

thanks for the info , i should of picked up some bullseye when i was at the shop today, I heard that 2400 starts getting abit iffy when you go for light loads, i use 24 grains in my 308 for my normal load, and 17 in my 44 mag rifle , when i was testing in my 44 with a 200 grain bullet i got all the way down to 13 grains and left it there and that felt like a 22 wmr . so maybe i will do some tests and work down from i guess 16 grains in the 308 and see what happens ( since the bullets are jacketed and 165 grain ) and il make sure to take a rod with my to the range .... and a large hammer

[Outpost75]

I have used #2400 in the '06 and .303 British for light cast loads, but it will not go subsonic.

FYI some data for your notebook:

Ernst Appel Wurzburg Mauser Sporter, .30-'06, 24" barrel. Zeiss 4x32mm Diatal-C, Post reticle
#311299, 205-grains WW, as-cast, no GC, Lee Liquid Alox
LC78NM cases neck turned 0.011", Remington 9-1/2 primers, 12.8 grains #2400, NO FILL
1249 fps. Avg., 17 Sd, 68ES, n=50!

Ten 5-shot groups at 100 yds. avg. 1.88", largest 2.3", smallest 1.35"

As above 13.5 #2400
1328 fps, 8 Sd, ES 27 n=10, one 10-shot group 2.8", slight leading, NEEDS GC

Repeat as above with GC, bullets sized .311," Lee Alox-Beeswax in grooves over LLA. - no leading.
Ten 5-shot groups at 100 yds. Avg. 2.18", largest 2.7", smallest 1.5"

This is the same charge I shoot in my .303, but with #314299 sized .314". These charges are below suggested starting loads in Lyman handbook for .308 Win and will certainly be safe, and you will get somewhat higher velocities in the smaller case, my guess about 1400 fps, which will require a GC, but makes for an economical and pleasant load for military rifle target shooting at 200 yards.

[jackmanuk]

thanks outpost , im only gonna be attempting upto 100 yards otherwise it would be more of a paintball than a bullet, im also not to fussed about hte groups , as long as its hits a dinner plate should be ok . iv got some 110 grain fmj do you rekon its better to go for a lighter load and hte lighter bullet to reduce drop or go for a nice heavy say 185 grain and more power and use it like a morter , i guess its the only option with 2400

(only reason i wanna use 2400 is cause its all i got and i have alot of it ... so might as well use it if i can

[RickinTN]

Assuming similar start velocities the heavier bullet will have a flatter trajectory than a lighter bullet. The lighter bullet will shed velocity faster and it will be more like the "mortar" you mention. The heavier bullet will also be more conducive to clean powder burn than the lighter as well because it will create more pressure. I would expect a trajectory similar to a standard velocity 22 lr.
Good Luck,
Rick

[jackmanuk]

o thats good then i spend most my team shooting 22 lr. iv been looking around and it looks like bullseye or even trail boss is gonna be the best option , maybe il switch to maybe bullseye since you use so little per round in 308 or 44 it may be a better option and cheaper than 2400 in the long run

[Outpost75]

thanks outpost , im only gonna be attempting upto 100 yards otherwise it would be more of a paintball than a bullet, im also not to fussed about hte groups , as long as its hits a dinner plate should be ok . iv got some 110 grain fmj do you rekon its better to go for a lighter load and hte lighter bullet to reduce drop or go for a nice heavy say 185 grain and more power and use it like a morter , i guess its the only option with 2400 (only reason i wanna use 2400 is cause its all i got and i have alot of it ... so might as well use it if i can

With a 110-grain jacketed bullet 16 grains of #2400 in the .30-'06 shoots well and gives ballistics similar to a .32-20 rifle, about 1400 fps. You will pick up about 100 fps in the smaller .308 Win. case. I do not recommend reducing further with #2400 and a jacketed bullet. A charge of 20 grains will gives ballistics almost identical to the US Cal. .30 M1 carbine, about 2000 fps in the '06, and will be a safe, but full load in the .308 about 2200 fps.

[jackmanuk]

i made up a couple 12 .... ish grain rounds just to see what happens

[Outpost75]

12 grains in a .308 case will exit the barrel OK, but if you check velocities over a chronograph, they might be a little erratic, though maybe not. I've used 12 grains with cast OK, just not sure how it will react with greater engraving/shot-start force and increased bore drag compared to lubricated lead. If they sound alike and shoot well, then go for it.

[jackmanuk]

il just have to remember to take my chrono with me to the range

[NSP64]

I load 6 gr of 231 under a 195gr plain base cast. I can hit an 8" gong at 186 yrds (15" high @90 yrds).
1025 fps avg. No power slouch either. gong is 1" thick and 8" octagon(25 pounds I guess) and it dances on the chains when hit. lol

[MT Chambers]

For subsonic loads in such a large case, I would go for Trail Boss powder.

[Outpost75]

For subsonic loads in such a large case, I would go for Trail Boss powder.

While Trail Boss will work, Bullseye is less expensive, readily available, meters better and gives excellent ballistic uniformity for reduced loads ever since the US Army used it to load the M1919 Guard cartridge.

I've used Bullseye for loads of this type for over 40 years and never had any issues, as long as you exercise care to avoid double charging.

[DanWalker]

i use 24 grains in my 308 for my normal load, 24 grains of 2400? In a 308? What bullet? I am using 20 grains in my 308 with a 160 grain cast boolit. Didn't know how much hotter was safe with 2400.

[jackmanuk]

i use it with a 168 grain A-max or a 155 matchking .....also with these 110 domed things i found , its my standard charge for my 308 .... 500 plus shots and no trouble so far

[rosst]

82906

2 inch circle, the group was shot at 100 yards the day before i went down south shooting for a week

.308 BRNO with CAN ( barrel forward ) suppressor
Leupold Mk4 TMR


RCBS WW 30-180-FN boolit
7.0grns Nobels No.2 ( similar to Unique ) dacron filler
WLR primer
1025fps

R.

[DanWalker]

i use it with a 168 grain A-max or a 155 matchking .....also with these 110 domed things i found , its my standard charge for my 308 .... 500 plus shots and no trouble so far Any idea on velocity with the 168's and 155's?

[jackmanuk]

i managed to get down the range yesterday and i now know 2 things

1) 12 grains 2400 being a 168 amax down my 26" barrel ..... is not subsonic (nice light load if your a 5 year old and a drop from my standard load of about 3 feet @100 yards but still snap .... might have to try 11 or even 10 but thats such a small amount of 2400 in a large case)

2) after 150 rounds the silencer get F ING HOT ...... went to unscrew it and ......didnt the marriage through the scope was mental .... least it was self drying in the rain


o and i forgot to take the chrony

[supersniper]

using 7.0 of Titegroup with Hornady 178 BTHP match in my 16" 308 - getting 1040fps and had a 5-shot group of 3/4" at 100yd

also use 7.5 with 311284 WW for about 1070fps and it runs sub 2" at 100yd

working on Lee 160 TL and Lyman 314299 now for subsonic loads

[supersniper]

UPDATE:

Lee 160 TL only gets about 1.5" for 5 shots at 100yd but engages rifling making for stiff chambering.

314299 sized to .309 shows great promise as 3 shot groups have been 3/4" at 100yd - need to cast some more for further testing.

[bretNorCal]

Just remember that altitude, temperature and humidity all affect where the speed of sound is. If you do borderline rounds for summer they may be supersonic in winter, etc.