Thread: .308 subsonic load development.

Hey chaps I started to have a play with subsonic rounds yesterday.
200gn flat nose lead cast projectiles
Started at 10.5gn of trailboss and worked down to 10.2gn.
Magnum primers.
So at 10.5gn I was still getting 1215fps and at 10.2gn 1120fps. Will have to go lower I'm expecting that it will be 9.9gn-10gn.
I fired 12 rounds and the recoil was bugger all. The best grouping was with the 10.2gn at 50meters. Only issue I noticed was the amount of lead fouling in my barrel.
Here is the group of 10.2gn and a little video to show recoil and sound.
Cheers. https://vimeo.com/197216818


Sent from my iPhone using Tapatalk

You need to load between 8.0 grs and 8.5 grs to get down to 1050fps and don't use magnum primers they are way to hot for Trail Boss,
and get all the copper fouling out of the barrel cast bullets don't like copper even a little bit it will pull lead off the bullet and deposit in the barrel

Originally Posted by shooternz

You need to load between 8.0 grs and 8.5 grs to get down to 1050fps and don't use magnum primers they are way to hot for Trail Boss,
and get all the copper fouling out of the barrel cast bullets don't like copper even a little bit it will pull lead off the bullet and deposit in the barrel

I got my projectiles from a guy in tokoroa rob is his name. That's not you by any chance?:-)


Sent from my iPhone using Tapatalk

Yep that's me, Thanks for trying my bullets let me know if I can help, the 151HP's are the better bullet don't really need the extra 50 grains, customers have shot goats pigs and deer with them
not many recovered bullets usually they are through and through, it may take a few rounds for the barrel to settle down if you keep shooting lead it will polish the barrel like a mirror
and will never wear out with the light loads, you can easily push gas checked bullets to over 2000fps but it is very technical getting there much less drama keeping to 1800-1900 fps or less,
Have fun it's a buzz getting small groups with cast bullets,
Cheers
Robert.

thems good alright

Originally Posted by shooternz

Yep that's me, Thanks for trying my bullets let me know if I can help, the 151HP's are the better bullet don't really need the extra 50 grains, customers have shot goats pigs and deer with them
not many recovered bullets usually they are through and through, it may take a few rounds for the barrel to settle down if you keep shooting lead it will polish the barrel like a mirror
and will never wear out with the light loads, you can easily push gas checked bullets to over 2000fps but it is very technical getting there much less drama keeping to 1800-1900 fps or less,
Have fun it's a buzz getting small groups with cast bullets,
Cheers
Robert.

I have your 150gn hp and I have your 186gn as well. You sent me a couple other samples too. Will get into them in the next couple days.


Sent from my iPhone using Tapatalk

Originally Posted by Micky Duck

Attachment 61308

thems good alright

How fast have you got them going micky duck?


Sent from my iPhone using Tapatalk

somewhere AROUND the speed of sound....4.1 grns trailboss in x39mm case std primer.
I was usung 7 grns but have kept dropping to try to get subsonic without use of chrony...they arent hear the hammer drop hushed but that could be my tired spartan with 10mm exit hole too.... lets just say you dont hear stuff all if you arent the one squeezing trigger.

What's the accuracy like? the 150hp's are really a little under size for the 7.62x39, they were designed for the .308 so it is hard to make them much over .309" I guess at sub sonic speed it's not a problem
upping the velocity could be tricky.

well any bunnies under 50 yards are in trouble..... sounds like I need to go shoot a group to find out LOL
one thing I keep forgeting to mention .... when resizing cases I only ever use the .308 rod/ball/insert the lee dies came with both .308 and .311 and since we use .308 pills thats the one we use.
guess it helps heaps with holding projectile steady and giving it a good start off.
with 125 nosler ballistic tips rifle holds to under 3" at hundred,bought some SST hornady loads but Ive been too tight to shoot them at paper....
photo doesnt show it well but rifling marks are good and deep,with well defined edges so they must be fat enough/barrel tight enough.

with subsonics as in anything you need to ask yourself how far do i want to go . . . if its 50yds then you wont have a problem

if its 100, 200, 300 or further ( which are achievable ) you'll need to put time and money into it . . . that goes double or more for cast

whatever you decide I'm sure you'll have fun, they are addictive . . . good luck

R.

I have achieved what I set out to do
a quiet load that is great for bunnies or my house muttons with more authority than the humble .22lr
I can take possum out of tree while out hunting and not disturb the whole neighbourhood.
and its a load of fun
wallaby at 100 yards would be the futherest I would be interestd in pushing them....again just for grins n giggles.

i shot this 3 inch group this evening at a paced 250yds (forgot my rangefinder ) letting the bullet drift with the wind. Strelok predicted .5mil which was pritty close.
rifle was a .308 using cast 197grn. RCBS bullets at 1070fps

keep in mind at that range if your out by 5yards bullet drop will be + or - 3 or 4 inches

[QUOTE=shooternz;549546]Yep that's me, Thanks for trying my bullets let me know if I can help, the 151HP's are the better bullet don't really need the extra 50 grains, customers have shot goats pigs and deer with them
not many recovered bullets usually they are through and through, it may take a few rounds for the barrel to settle down if you keep shooting lead it will polish the barrel like a mirror
and will never wear out with the light loads, you can easily push gas checked bullets to over 2000fps but it is very technical getting there much less drama keeping to 1800


I just ordered some of these from you Robert. Thanks for the informative replies on TM. Very helpful.

Thanks for the order, I need the cash