Leading help with commercial LSWC

[inthebeech]

I get a mild amount of leading that shows up in the first half inch or so of my K-38 (actually a 14-2) after about thirty rounds. After 40, accuracy is affected so the gun would not go the full 90 rds of a Bullseye match without scrubbing with a steel wool wrapped brush, which one does not have time to do. It isn't a long term solution anyway and I know you guys will have some sound ideas.

I've been a caster for many years and know the typical adjustments to be tried to reduce leading but can not use most of them in this case. I think I'm limited to polishing/lapping the barrel / throats which I've not done so need some input.

I don't (and will not) cast for my Bullseye gun. I buy .3575 (Speer) or .359 (Rem) HBWC's. My throats are all a uniform .358 and groove is .357 so not much improvement needed there as we all know; very good dimensional relationship. Rules do not permit altering the revolver anyway. I should also not mess with velocity (and therefore pressure) since my 680 f/s loads will punch a ragged hole at the short line. I suppose accuracy would not be too far off if velocity were altered a small amount but the Smith's are famous, given their relatively slow twist, for having a narrow band of optimum accuracy. If you guys think it worthwhile, I am willing to try loads up to maybe 740 f/s. I know that while working up to my load, leading got worse (though accuracy got better) than when I was at the slower speeds (600-650 ft/s) but I suppose the 'obduration' theory might reverse things at slightly higher speeds. If accuracy falls off though I could not call that an acceptable solution.

I suppose I could mess with seating depth and if that might improve
things, just adjust charge later to get me back to my sweet spot (670-690 ft/s). I currently seat a hair over flush and put a medium (Lee factory) crimp over the small radius of the flat nose. I guess I could also try a faster powder to boost peak pressure as long as MV stays in my sweet spot, but don't have experience here either. I've used Bullseye for twenty years.

I do have experience with custom, match grade barrels, my PPC gun (another Smith14)has one and I can tell you guys who have never experienced it, the gun NEVER leads with any load and when you scope the barrel and forcing cone, you can see why. Match grade barrels are a thing of beauty. Unfortunately in the Distinguished Revolver class, no alterations are permitted so I have to work with what I have.


Any and all ideas are welcome guys. This model 14 is everything they are claimed to be so I want to stick with it.
Thanks,
Ed

[salvadore]

The last time I loaded hbwc I seated the bullet just shy of the throat, I don't know if this will with your leading. I do like the idea of lapping the barrel if that's allowed.

[Silver Jack Hammer]

You say you don't want to cast, but would you consider running your store bought boolits through your sizer-luber and just applying a small amount of lube on your boolits? I'll bet this'll fix your leading problem.

They sell spray on lubes too, although I've never tried them.

[44man]

Boolits are way too soft. Sorry but you must cast a better boolit. Why do you buy when you cast?

[dubber123]

I'd strongly suggest slugging the bore, and pay very close attention to where the barrel threads into the frame. I have a 1952, and 1967 K-38, and both showed thread choke right there, and would lead in the first part of the bore. I firelapped both, and both now shoot leading free, and MUCH more accurately than before. The 1967 model has shot under 1" at 50 meters, and averaged around 1.5" at 50 meters, (iron sights). The 1952 just got lapped, and I only tested at 26 yards resting off the car roof. One of the very first groups was a .8", followed by a 1.0" group, again MUCH better than it has ever done.

I also have a scoped, 8-3/8" K-38 that never was a winner, guess what I'm going to try next? :)

[inthebeech]

Sal and jack,
Good, low cost suggestions. Thanks. I can certainly give this a try.
Sorry 44 man but trigger time is much more important given the limited amount of hours in all of our day.

Dubber123, please tell me more about fire lapping? How, materials, suppliers... If you're evaluating groups at ISU distances then you "get" the needs of a Bullseye shooter. PM me if you don't mind and thanks all for the input. I knew I was in the right place. Meanwhile I may try running this current batch of Speers through the sizer to get a thin coat of lube,as an interim fix.

[dubber123]

Pm sent..

[44man]

Sal and jack,
Good, low cost suggestions. Thanks. I can certainly give this a try.
Sorry 44 man but trigger time is much more important given the limited amount of hours in all of our day.

Dubber123, please tell me more about fire lapping? How, materials, suppliers... If you're evaluating groups at ISU distances then you "get" the needs of a Bullseye shooter. PM me if you don't mind and thanks all for the input. I knew I was in the right place. Meanwhile I may try running this current batch of Speers through the sizer to get a thin coat of lube,as an interim fix.
You ain't telling me nothing, I get up, spin twice and it is getting dark. The whole year is almost gone again. Never retire, days turn into seconds. Better to stare at the clock at work. That thing never moved! :coffee:

[Alablam]

Those soft lead swaged things might need a bit of help in some but not all weapons. I have never liked the lubes they used but a little liquid alox helps. Probably the best of the lot were Hornady because I think I remember Midway saying that they had 2% antimony, but they leaded without the LLA. The Hornady squished lead hollowpoints are of limited use because the lead is brittle and the mushroom just breaks off at about 950FPS to create a wadcutter.

[Stonecrusher]

I had the same problem myself with some 158 grn RN Speers that I have had for decades. No matter what speed or powder they leaded every gun I put them through. I asked about tumble lube on here and someone said to try it, it couldn't hurt. They suggested I could tumbling over the factory lube. I didn't feel brave enough for that so I washed the old lube off with some mineral spirits before tumble lubing with White Labels 45-45-10.
First time for tumble lubing and I didn't hold much optimism. I was proved wrong, very wrong. I am using up all my old powder pieces and parts and they all work fine with no leading. Right now I am using 4.3 grns Unique and loving it. I had resorted to using a handful of these bullets as flux but now I have several thousand boolits I don't have to cast.
The 45-45-10 works great and isn't stick if you don't use too much. I use two coats and just enough to think you might have some coating. One day I'll try it on something else. I just have a hard time believing it works!

[Black_Talon]

I've used all the factory (Speer, Hornady, Remington, Winchester) swaged 148gr HBWCs over the years in my various Model 14s. The only ones that I can get to consistently not lead are the Remingtons.

I run them at around 770 fps (2.9gr BE, 2.7 gr WW WST, 2.7gr VV N310) for best accuracy at 50yd and experience no leading. I resize WW brass with a 38 Super size die that leaves the case ID at around .358" and do not use an expander. I only bell the mouths a few thousandths. I seat flush and use a slight (.004") taper crimp only.

FWIW, I currently have 3 Model 14's. All have throats at .3580-.3585", as measured with pin gauges.