Something else I need to get clear on

[ScottJ]

If I have long, hair-thin lead shavings in the barrel rather than smear in the grooves it's a fitment issue rather than a velocity or lube issue, right?

[fecmech]

The only thing I've ever seen that in was a 9MM with the fast (1 in 10) twist and running up around 1100-1200 fps with acww bullets. What caliber, velocity etc are you talking about??

[Doc Highwall]

Almost sounds like burrs on the rifling, maybe fire lapping will cure it.

[ScottJ]

It's a Taurus Millenium Pro .45 ACP I bought back in Jan. I've posted about it here before.

All my cast .45 ACP is sized .451 because that's all that'll feed in my 1911. But I got the shavings in the Taurus.

I loaded up a magazine full (6 rounds) of the same boolit as cast (.4525, RCBS 230gr round nose) to see if they'd feed and they did but I still got some of the shavings.

Many weeks went by while the Taurus was down with a broken mag catch so I didn't investigate any more. I was doing inventory and found that I'm down to about 250 rounds of loaded .45 ACP so I decided to try again to find some way to run the same cast fodder in the 1911 and the PT745.

I need to try another nose profile. I think the 1911 would feed .452 if the profile weren't as straight-sided as the RCBS. I know it won't feed any sort of truncated cone. In factory stuff it runs Golden Saber and Win White Box hollowpoints just fine but not the Winchester PDX1 or Federal Hydra Shocks.

My load is 4.7 grains of Bullseye but I was thinking of trying somewhere between 4.5 and 5 grains of HP-38 since its pressure curve isn't as abrupt as Bullseye. But I'm guessing that still won't solve the Taurus' issues.

[Bloodman14]

If the gun is relatively new I would guess burrs on the lands, too, like Doc Highwall said. Try firelapping, or slugging with an abrasive-coated boolit.

[ScottJ]

It's a 2008 production, Gunnerd. I bought it used so round count is unknown but fire-lapping is easy.

[randyrat]

The .451 problem could be solved by a different die set. I had an older RCBS die set and it gave me a headache.
I had to use FCD to size it down (or they wouldn't chamber), the seating/crimp die wouldn't do it. I bought a new LEE die set for the 45 acp and problems went away. Now I size all my 45 boolits .452 and seat the boolit so the rim is even with the rear hood.
Could be my older die set was out of spec or worn out.

I also will join the fire lap camp.

[geargnasher]

The only times I've had the little hairs in the bore were in a revolver with a bad forcing cone restriction and in a rifle where I exceeded the stress limit of the soft alloy I was using. If the .4525" as-cast boolits stilll leave shavings, I would think it is NOT a fitment issue, but possibly a throat issue (meaning that it doesn't actually have one, but has sharp lands ending right at the chamber, or a lube issue. Or possibly an ALLOY issue. But I won't rule out a burr, either.

Those little hairlike strips are usually laid down in the crevice of the leading edge of the lands by gas-cutting, from either the boolit skidding the rifling too far or undersized boolits. Sometimes soft boolits skid too much, sometimes really hard boolits don't flex enough to completely seal the bore, sometimes it's a lube issue, sometimes it's a barrel issue, sometimes the powder is too fast or too hot, sometimes the charge weight is to much.

Gear

[Eagles6]

Yeah, I agree, give fire lapping a try and then move from there as long as it shoots good.

[malpaismike]

Hello the camp! FWIW, I run 4.9-5.0 HP38 w/ 230 Meister LRN in my Taurus with no problems. I had a couple issues with the Taurus as recd, but the company took care of them toot sweet. Hope this helps. mm

[chris in va]

I get those 'hairs' in both my CZ 9mm and Sig 45. Probably something I can do about it, just never bothered.

[BD]

I'm with gearnasher on this. Lack of throat causing the lands to carve strips of lead.

BD

[ScottJ]

Just took it apart and looked closely at the throat. It has one. Short but it is there. I do have tooling marks and the lands are really sharp-edged.

Maybe I need to run more than a couple mags through it and see what I wind up with.

Randyrat, for my 1911 I'm not sure it's dies. I'm using a Lee 3-die carbide set so I should be getting a proper taper crimp. My mold is RCBS.