Antique gave you some very straight information. If the bore isn't lapped it isn't target grade.
The bullet is awful short to expect it to be a tack driver, yet if it is used in a large enough diameter to cause a close cartridge neck fit in the chamber, if the bullets are made hard, like 20 bhn +, and if the bore is smooth and straight, which it would be if lapped, it should print much tighter groups than you are getting at FAR higher velocities, if you are using LBT lube. If you want to lap, get the LBT lap kit and a pack of 45 rifle push through slugs. Lap with your own bullets, and check progress with the push through slugs. They will tell you when the barrel is made into a target grade one.
The only 45 rifle I've played with was a Ruger 1 chambered for 458 Win Magnum. I was able to get 3/4 inch groups using I believe a 350 gr WFN bullet launched at 3450 fps. No leading, just consistent accuracy even in AZ 110 deg temps. The WFN does have more bearing than the LFN, if that's what you have, and the extra bearing helps considerably.
Square bases are mandatory, and the only way to get them is to bump them square at the bottom of the lubricator stroke if using an in and out sizer, or with a flat pusher punch and sizing nose first if using a Star sizer. The stop plug for the other three sizers must be machined, in a lathe, with a small cup in the center of the end where the bullet makes contact, and a tiny flat rim around it's perimeter, about 1/32 wide, which is easily impressed into the gc and bullet base, insure dead squareness. Be sure whoever does the lathe work understands exactly what I'm saying and feels comfortable that they are giving you a square end to within .0002 inch. I do them for $5 each plus postage, if you want to send them to me. Best deal is to send the plugs from all the dies you have, for all calibers, so the postage per each is minimal. Contact me by email if you want this service. LBTisAccuracy@localnet.comi
