DI45 acp Rifle

[Bigslug]

Some hypotheses. . .

In my experience, Unique is just too doggone slow a powder for the .45ACP. I've had a lot of incomplete burning and when used with conventional grease-groove lubes on cast bullets, a lot of greasy granules clogging up the works of a 1911.

Bullseye was the official GI powder back in the day, and I've found it to be MUCH cleaner in duty caliber and pocket auto rounds. My thought with regards to a direct impingement gun is that the burn of Bullseye will be complete or at least more complete by the time the bullet gets to the gas port, and this may reduce flame-cutting off the base of the bullet at the intersection of the port.

You might also consider reducing your hardness to about 9-10 BHN. I've been switching to tumble lube mold designs to simplify production, and was getting lead streaks with 45/45/10 lube using alloys in your 12-14 BHN range. Thus far, going softer has helped bore sealing.

Atfsux is also in the right zone with using a correct "lube": What the DI system of the AR actually needs is a combined cleaner/lubricant that keeps fouling inside the bolt carrier dissolved and fluid so that the reciprocating parts can push it out of the way and keep running. I got to witness a good example of this when another agency was renting the bay next to us for their training. They had designated training rifles (5.56) that weren't being deployed in the field, and their "maintenance" practice was to pull the bolt carrier groups out, hose them down with Break Free CLP, and put them back in. A few shots into the gas escape holes in the side of the carrier works wonders. This prevents the "baby diamonds" carbon build up inside the carrier that many can spend hours with specialty scrapers trying to remove. Run the bolt group wet, wet, WET and it pretty much just wipes off with rags and patches. If you're getting lead vapors in addition to carbon, this will at least make it harder for the condensing lead to adhere to anything.

[popper]

Be very careful cleaning lead off the bolt tail - that is the back side of the gas cylinder, and should be a tight tolerance. Rings are the other end.

[Warhead]

As a update on this project, I have acquired a plain base gas check maker, and have made some checks out of some soda cans, and have have had good luck with them seating easily on the boolits already cast and coated, when sized to .452 they are very secure on the base of the bullet. I am hoping to get to get a batch of 100 assembled this coming week for testing, the upper has about 2200 rounds on it currently and has ran great with jacketed bullets, with very little build up on the tail of the bolt, seems like just carbon that wipes off fairly easily.

So far AA#5 has been by far and away the best performing powder with 230gr xtps and 185 haps and 230gr Rmrs.

I do have a lot of Bullseye around, and I will have to give it a go, for 200gr swc out of the comp guns, and bullseye guns, it is a fantastic powder, just haven't tried it in the di gun yet.
My thought processes was the slower powders would provide more volume of gas to run the action, as when I tried Vectan A1 even at the top charge, it was struggling to cycle with a standard carbine buffer, it did cycle with a gutted buffer.

[Baltimoreed]

If jacketed bullets are ok then try gas checked lead bullets. I have Olympic Arms blowback and CMMG rotary bolt guns and other than sooty brass have no issues. All are 45acp and use CNC Enterprises dedicated greasegun mag lowers. I corresponded with Rudy when I was building my first couple pcc’s but never bough his system.