Thread: Subsonic load for 308

Thanks Stug. Am looking at doing some sub loads as want to shoot over my dog. Looks as if i will be spending plenty of time at the range

@jim160 mate im sorry i haven't seen this post, probably best in some respects this is my first 24hrs in months with NO meds....... so hang on with any ramblings....

so, rifle that i used in this project was / is a single shot omark, I had a little removed from the end, threaded and a Gunworks maximus suppressor made up for it. Love Omarks and for the purest, ive saved a fair few over the years and this one was never going to be a target rifle again....i digress, but ive just found some reloading 2B4 old reloading notebooks so.....

the following is only around the subsonic development, my goal was to create a hard hitting accurate quiet round,

Powders that ive tried, 2206H, Alliant 2400, Trailboss, 700x wow a raft of them, found the 2400 lethal with a Carcano 6.5 with lead cast projectiles, the 308, it was trail boss!

Cast projectile weight ranged from 208Gr looks as if i sized to .312 of which with a very classic annoyed handwriting "with much annoyance, ive realised ive not properly written down the previous top load" "the author is a poor recorder of loads, an idiot"..............which makes me laugh, and a little cry as from what i can tell i was making a 224gr projectile sized .310 GC with wool filler, with 9gr trail boss another with 12gr of 2204 i know one was super quiet and more than adequately accurate, how so i made up a box of 50, and am now down to only a couple, owell ill be more attentive!

i also found a load for a 150rn sized to 310, notation = "quiet, very accurate" was with a filler, possibly with flared case 1430,1418,1407,1385, 1399fps

i will keep looking and see what moulds i was using, i know i was even making my own gas checks, my go to guru was / is The Cast Bullet Kid, jeff is truely a legend! in fact i may bug him next now that im able too!

ramblings done!

I’ve seen people drill out the flash hole to guarantee a god burn rate when using trail boss? Is this necessary or just a waste of time?

Originally Posted by G.I_Joel

I’ve seen people drill out the flash hole to guarantee a god burn rate when using trail boss? Is this necessary or just a waste of time?

I was told I didn't need to, so I don't.

Originally Posted by G.I_Joel

I’ve seen people drill out the flash hole to guarantee a god burn rate when using trail boss? Is this necessary or just a waste of time?

I skimmed through the Hodgdon sheet on using Trail Boss for reduced loads in rifles and a later article on the same subject by John Haviland on loaddata.com. Neither mentioned drilling out flash holes so I will not do it. Incidentally John got about 1050 feet per second from both 150 and 165 grain jacketed projectiles in a 16 inch barrel.
Grandpamac.

Originally Posted by G.I_Joel

I’ve seen people drill out the flash hole to guarantee a god burn rate when using trail boss? Is this necessary or just a waste of time?

Any body recommending drilling out flash holes steer clear of him he is an idiot, And knows little about reloading and nothing about cast bullets and loading subsonic loads.
I have a note on my pad to message you, I am back casting again, what was it you need I will fit it in some where I have couple of big orders to do but it is good to take a break
and cast something else.
Cheers
Robert.

Hi Robert, are you casting any heavier projectiles than the 151

Originally Posted by Martin358

Hi Robert, are you casting any heavier projectiles than the 151

I have a 170 grain pointed GC mold and a 200 grain flat point plain based mold the 200 grain is not stable at subsonic velocity in some rifles
the 151 works in all barrel twists at all velocities

This is a 151HP subsonic taken from a pig shot at 20 metres,
All the recovered bullets look like this,
You can email me at 'robs.reload@gmail.com'
I am still busy with orders but can probably do you some 151HP I am casting them this week
Cheers
Robert.

I will flag the 208gr or heavier.
Will stick with the 150gr ones. And then leave it with the 8.5gr trail boss at 1040fps.
Might have to modify slightly with cast projectiles but not by much if any

Greetings All,
Articles appeared in Handloader Magazine in 1987 and 1990 written by Roger Stowers about loading for the 240 Gibbs. The 240 Gibbs was a wildcat from the 1950's developed by Rocky Gibbs. It was basically a 6 mm-06 Max with the shoulder moved forward and increased to 35 degrees. Roger's first article dealt with his struggles with start loads. Roger used 49 grains of IMR 4831 in fire formed cases with Speer 105 grain spitzer projectiles. This should have been a mild load but blew primers, case heads and extractors. Roger found that he could minimize the problems by elevating the muzzle prior to firing, seating the bullet backwards or increasing the jump to the lands. Velocity was 2,800 feet per second, a pedestrian load for the .243. In his second article Roger works up to a max of 57 grains of IMR 4831 with the 105 grain projectile for 3,224 fps with no problems. Roger felt that the excess air space in the case was the problem and eliminated all loads with more than 1/4 inch or more air space between the powder and the base of the bullet. Incidentally Roger had the same problem with IMR 7828 and a little less with H 4831.
So there you have it, pressure excursions with non case filling loads of a slow powder related by someone who was actually there and cleaned up the mess afterward. The factors seem to be: case large for calibre, steep shoulder? and load over 10% less than max.
Should this be a problem in the .308? No. Could we stick a projectile in the bore with a light load of powder? Definitely. .308 Mauser could be right that current powder has been improved to eliminate the problem but we should not take any chances.
Regards Grandpamac.

Sooooo, maybe slightly off recent topics but! I have gotten my hands on some of Roberts 151gr projectiles...and have loaded some into sub loads. Stupid question about to emerge from this... the projectiles are super short and only marginally seated into the neck of the case to get OAL, this is a good thing? That the projectile is only a small amount pressed into the neck?

Originally Posted by G.I_Joel

Sooooo, maybe slightly off recent topics but! I have gotten my hands on some of Roberts 151gr projectiles...and have loaded some into sub loads. Stupid question about to emerge from this... the projectiles are super short and only marginally seated into the neck of the case to get OAL, this is a good thing? That the projectile is only a small amount pressed into the neck?

I seat to the cannelure and lightly crimp the case. Other forum members have said crimping improved accuracy.

Does this look right? I’ve just wound my seating die all the way out and press them in and continue to do so until I achieve the OAL. I mean they stay in there so shouldn’t be an issue? Will add a light crimp when I know that they are seated correctly. I guess I’m just so used to boat tail projectiles seating right in the neck...

Originally Posted by G.I_Joel

Does this look right? I’ve just wound my seating die all the way out and press them in and continue to do so until I achieve the OAL. I mean they stay in there so shouldn’t be an issue? Will add a light crimp when I know that they are seated correctly. I guess I’m just so used to boat tail projectiles seating right in the neck...

Seat to the crimp groove the bullet is designed to be seated so the base is flush with the base of the neck in a .308 give it a light crimp
and you are set

I seat so that the case mouth is at the top groove in your photo.
I don’t load to an OAL with the cast bullets, I don’t even measure them.