Duplex SKS Plainbase Loads

[HARRYMPOPE]

My buddy Bob went on one of his little tweaks.He decided he wanted to shoot up a large lot of 308241 ideal bullets that were given to him.He worked up a duplex load of 12g of AA2200 and the rest with 14g of unk surplus 50 BMG powder? Shooting at 50 yards with 4X scope full magazines of 10 were mostly 3" and the best went into 2".After 250 or so shots no reliability problems raised their ugly head.Oh yea, they were going 1700 fps.

Nothing ground breaking but i found it entertaining.

[Catshooter]

Very interesting. But oh man Harry, you're gonna get jumped on by the safety Nazi's for this one for sure. :)


Cat

[geargnasher]

Nothing wrong with that, good cheap fun.

Gear

[madsenshooter]

Sometimes that 860 makes good filler! I was able to get 2300fps and reasonable accuracy out of my 6x45 AR using 860 w/a kicker.

[45 2.1]

Half the amount of 2200 would have given better results...................

[HARRYMPOPE]

It took 12 of 2200 to get the slow powder to ignite well.if Unique was used then less worked.

[TheGrimReaper]

Very interesting. But oh man Harry, you're gonna get jumped on by the safety Nazi's for this one for sure. :)


Cat
Yep thought the same thing.

[jonk]

I have played with duplexes a bit, but in the little 7.62 round, I see no reason to. Mainly my efforts have been in SR 4759 with black powder in antique big bore guns (45/70, 11mm, etc) and with a few grains of the same to touch off 20mm powder in 30-06 and the like.

For what you're doing, or what he's doing, just go with 14 gr of 2400 and call it a day.

That said: cool report.

[Andy_P]

It would be interesting to compare results with loads consisting of just AA2200, starting at 12 grs for both MV and accuracy. You state that The WC860 (?) burned, so it surely contributed to the MV, while acting secondarily as a filler.

[303Guy]

I think the idea of a combustible filler is a good one. I suspect that the use of a slow powder - one that's too slow for the cartridge - lit up with a kicker charge would give the best of both worlds with the pressure only really rising after the boolit is launched down the bore. I did something similar with my hornet with the objective of getting more performance out that tiny case, using H4227 and H4350. It did pretty well but then I discovered Lil'Gun which turned the cartridge into a super hornet. Same principle for cast only there is the case filler function thrown in.

I've done something similar in the 303 Brit with cast using a light charge of slow powder (W780) with H4227 for a kicker and also using a filler. The powder burned pretty well and there was no boolit base damage (plain base). Obviously this would not work with a full case of the W780 but a small charge (about half a case full) would not burn properly without the kicker charge even with a filler.