7.62 Tracers in 300 blackout

[pbtohiglo]

Hey guys! I've been reloading 300 blackout for a few months now, and have been using 147gr m80 fmjs. I recently acquired a can of old 7.62 147gr tracer projectiles, and am planning to load them for plinking ammo (yes, I am aware of the possibility of starting fires, not going to be an issue here.)

my question is, these things are REALLY long compared to my other 30 cal projectiles, do I need to consider pressure, and start these below min? or should I be ok to just start with hodgdon minimums and go from there?

thanks in advance!

 

[[email protected]]

The tracers that I have are alot longer than normal FMJ bullets. I would back off a little starting off.

 

[Edarnold]

I would back off a LOT, not only do you have a long bearing surface but you are losing a lot of the powder space in that little case, which is going to raise pressures all by itself.

 

[blarby]

You're gonna need a full rework on that'n.

 

[stubbicatt]

Deleted

 

[Jesse Heywood]

The 300 cartridge fires at a maximum pressure with a minimal case volume, which leaves little room for experimentation. With the greater seating depth required for the tracer, you will probably be far beyond the parameters for the cartridge. If you compare the volume difference of the loaded cases and it is greater than 10%, don't even think about it. At the least you could blow up your gun.

 

[rcmodel]

I think if you can find Barnes TSX solid copper bullet load data for that caliber, you would be safe.

However, I doubt you can get the heat & pressure to reliably light the tracers in it.

rc

 

[pbtohiglo]

Thanks everyone for the input! I used one of my low, doesn't cycle the bolt loads as a starting load and laddered up. the lowest loads performed much like my higher end hunting loads (no pressure signs, but a lot warmer than is comfy out of my pistol), so I'll back down a bit more and try to find the sweet spot. I'll let you know what I learn!

 

[pbtohiglo]

Quick update, loaded a few with 10.5 gr of w296, and was able to eject the case, but wouldn't load the next round or lock back on an empty magazine. I'm betting the sweet spot is close to 12 gr, as 14 gr compressed the powder a bit, which doesn't sit right with me at all...

back to the loading bench...

 

[rg1]

At 14 it may cycle and lock the bolt on the last round of the magazine. I'd work up to 15 to 15.5 grains of 296 and compressing the powder a bit is no issue. Nothing wrong with starting at 12 grains and going up but 12 grains is still a very light load. One to 1 1/2 grains below your M80 147 gr. loads should be close.

 

[Jesse Heywood]

If you have any 4227 you could give it a go. Does best when compressed slightly.