Thread: 7.62x39 sub sonic loads

As has been stated, no need or use for TB in this case for heavy subs. Similar to the 300blk, even with more normal powders, there just isn't the case capacity to get such a heavy projectile going supersonic.
Interestingly, well before the .223 progenated the .300blk, the 7.62x39 progenated a subsonic round known as the 9x39. It is likely that while the 300blk is largely inspired by 7.62x39, it also derives some inspiration from the 9x39.
@Ammo Direct NZ also stock a factory 255gr subsonic load, @338Lapua_cam you can pick up a packet just up the road in Whanganui if you order online ahead of time. Might be a good way to gauge the suitability of the 255gr projectile before buying 100 to risk having 90 left over that are no good to you.

When a 151 grn goes through n through I fail to see need for 200 plus lol.

Originally Posted by Micky Duck

When a 151 grn goes through n through I fail to see need for 200 plus lol.

Yeah i agree, and i would love some cast ~100gr pills for subsonic possum medicine. Cause I definitely wouldnt shoot a possum with the 240gr

Also Mickey you know that 'need' has little to do with why we play around with different loads and cartridges

There is plenty of trail boss around... Folks just not parting with it lol.

Originally Posted by Roarless20

Yeah i agree, and i would love some cast ~100gr pills for subsonic possum medicine. Cause I definitely wouldnt shoot a possum with the 240gr

Also Mickey you know that 'need' has little to do with why we play around with different loads and cartridges

Hornady .309 90gn XTP?

Originally Posted by Micky Duck

When a 151 grn goes through n through I fail to see need for 200 plus lol.

Probably the main advantage, and it is relevant in that it is hard to get TB powder right now, is that you don't need to use TB powder to get subsonic speeds. Call it a work around that doesn't compromise on pentrating ooomph.

Originally Posted by longshot

Probably the main advantage, and it is relevant in that it is hard to get TB powder right now, is that you don't need to use TB powder to get subsonic speeds. Call it a work around that doesn't compromise on pentrating ooomph.

Yeah we never really did. What it did do was sort of bring everything up into the light as it were, with a bit more safety than the old ways and no arcane drilling out flash holes or weirdities like that.

Originally Posted by Micky Duck

When a 151 grn goes through n through I fail to see need for 200 plus lol.

Yes, the increase in energy between the two bullets at the same is speed is only 100 or so ft lbs. Subsonics need a different mindset I think. Expansion only really occurs if bone is hit even with the flash expensive jobbies otherwise there's a leaky hole with virtually no tissue damage. Flat nosed bullets seem to perform best. There's no need for streamlined stuff subsonic. 174 gr mk V11 303 fmjs loaded backwards are pretty impressive.

Originally Posted by Marty Henry

Yes, the increase in energy between the two bullets at the same is speed is only 100 or so ft lbs. Subsonics need a different mindset I think. Expansion only really occurs if bone is hit even with the flash expensive jobbies otherwise there's a leaky hole with virtually no tissue damage. Flat nosed bullets seem to perform best. There's no need for streamlined stuff subsonic. 174 gr mk V11 303 fmjs loaded backwards are pretty impressive.

I think that's why Robert's 151gr cast pills seem to perform so well. Bloody great hole in the front end which is virtually flat...

I've seen a few rounds made up with the .303 FMJ pill loaded backwards - for some reason very unreliable performance from them. Some tumbled and went sideways through things, some flew straight - I have no idea what the problem with them was as I've heard a lot of people put forward that they are quite good performers.

Yeah, it's a bit of an interesting question. 255gr will usually go straight through unless you hit something bloody solid - the 170gr Sub-X has a serious amount of penetrating ooomph (I shot one into a block of wood in the wife's garden and it went straight through and I still haven't found the pill after digging down over 40cm so the 255gr is more of the same!

If the lighter pills are going straight through unless they hit something as well, I'm not too sure what the gain is going for an extra 105gr except maybe recoil...

There are some wicked hollow points made for the M1 carbine something like hundy grain. Years since seen them but cavity was 11 mm deep.

a good bit of info here lads, thanks for that. but yes trail boss is not something that can be easily obtained so will be looking at alternatives.

Didn't Keith extoll the virtues of flat point bullets for cutting good wound channels using Pistol calibres and cast bullets? Back in the 30s or when ever? Translates well to rifle subsonics

Pretty definitive contemporary article right here from our very own world famous Naki-ite

https://www.ballisticstudies.com/Kno...allistics.html

The mindset thing is similar to using a bow. Got to hit animal just right,be prepared to shoot again and wait for it to bleed out if chest shot...spending more on Lehigh projectiles seems to give big increase in performance but that price tag...yeah nah not for me lol.

OOOPS here's the photos

PM me if you want any.
cheers,
Phil.