Winchester Autocomp Powder?

[COSteve]

Was at the local indoor shooting range talking to my friend who has a small reloading business inside the building. Anyway, a guy came over looking for some Unique powder and small pistol primers and his hands were full of soot even though he said he'd just washed them off.

We asked if he was shooting black powder and he said, "No, I'm puzzled with this 1 lb of Winchester Autocomp powder I started to use. I load 5.0 grns under a 158grn semi-wadcutter for my .38spl revolver and shooting it is like shooting a black powder pistol."

He opened his range bag and took out a ziplock bag of brass that actually looked like it was loaded with black powder; it had the worst soot buildup on every case I've ever seen. Then he pulled out his revolver and it was down right filthy too. We speculated that he may have loaded a too light load but the load data said 5.3 grns was max for the bullet.

I asked if maybe the cylinders were oversized or something else wrong with his pistol and he said that it shot Unique just fine. Plus, he loaded some Autocomp in 9mm for his son and he had the same cloud of smoke and filthy pistol after just a couple of mags full.

Anyone else seen or heard of this? Suggestions?

[Rimfire McNutjob]

I've never used Auto Comp. It does sound like a light load not reaching proper pressures. I know when I shoot any of the Winchester white box stuff as practice ammo my hands are green afterward.

[GunnyMack]

Just looked at hodgdon site, yup 5.3 is max.
Dunno, haven't used that powder.
Maybe he needs a bit more crimp to build pressure, it's a low pressure generator- like 16k psi at max load.
Be kind of interesting to talk to the engineers at Hodgdon and get some best use info about it.