drive band size

[bradb]

Is having just the rear driving band on a Keith style .44 boolit sized to the revolver throat diameter adequate to prevent leading? For instance, my throats on my ruger srh are .432 and the barrel groove dia. is .4295, if the rear band on my 429421 boolit is at .432 and the front 2 bands are .430 will it be ok or is it a try it and see what happens deal? Thanks

[Wayne S]

Leading is caused by one or more of many bad conditions. Two are undersized bullets which you have covered, another is using an alloy that is not matched to your load.Two examples are using a hard alloy to cast wad cutters and shot in a 38 Spl. with 2.3 gn of bullseye , the other extreame would be use pure lead for your SWC and load them over 24.0 Gn's of 296.
As you suggest, try what you have and see.
What I had a SRH I quickly found out that I liked 9 gn of Unique, much better that 22 gn of 2400

[runfiverun]

you'll be fine try a few.
i'd run them through my sizer just to keep everything straight.
but it's worth a shot.

[44man]

Yes, they will be perfect.
I can't explain leading because I shoot from 50-50 to very hard alloys now and then and none lead my guns. I also shoot undersize in my .44, from .429" to .432" with different boolits and my throats are .4324".
I just don't know how to judge the perfect fit stuff????
Undersize throats to the bore is bad, skid is bad and slump is bad. A good lube helps prevent leading. Beyond that I do all kinds of things I am not supposed to do. I think my .44 is going on 2-1/2 years since I cleaned the bore. I made two long range, perfect shots on deer this season.
The hardest thing for me is to tell anyone how to prevent leading and it will never be because of a hard boolit because the best accuracy from my Keith was at 30 BHN.
Many feel a low pressure load of fast powder is best but when you consider all the pressure is "right now", low pressure does not mean anything. My idea is that as you slow the burn rate you can go with softer alloys.
But then I am considered a crazy old coot! [smilie=1:

[bradb]

I'll give them a try, hopefully they will work ok. I may call on you guys for more help. Thank-you

[Mal Paso]

Is having just the rear driving band on a Keith style .44 boolit sized to the revolver throat diameter adequate to prevent leading? For instance, my throats on my ruger srh are .432 and the barrel groove dia. is .4295, if the rear band on my 429421 boolit is at .432 and the front 2 bands are .430 will it be ok or is it a try it and see what happens deal? Thanks

Ah. A Lyman mold owner. I had the same problem and finally used diamond powder to lap mine larger and square. Nothing wrong with shooting it as is. If you want enlarge the bands, search Lapping, Beagling, and I think Erik's Hollowpoint Service will do it for you.

I like one to two thousandths over groove and shoot .431 boolits even in the Redhawk with .432 throats.

[runfiverun]

many benchrest rifle swagers strive to have a rear drive band on their rifle bullets that fills the barell completly.
there is some other things they do to a bullet that would make it appear alien to storeboughts.
sometimes what's there is unseen by the naked eyes and they just look paralell sided with a funky ogive shape.
the tape tells the real tale.

[kbstenberg]

I think I am missing something. How do you get the front 2 bands at .430 and the rear band .432? Does your mold cast them that way? Kevin

[runfiverun]

that's what i make of it.

[bradb]

The deal with he mold is that it was casting all band at .430 and I was getting leading in the throats and just after the forcing cone in the barrel. It seemed the right thing to do was have a bullet that was .432 same as throat diameter. I screwed around with beagling but couldn't get a consistant size and usually the boolit was still small at the parting line. Being a toolmaker I finally said to heck with it I'll just cut the bands larger in the mold and be done with it. I then wondered if all bands need to be larger or if just the rear one would be sufficient. Enlarging the rear band was easy but the others will require a little more care and work but still not a big deal. As it is now with the rear band enlarged it still leads the throats. I'm guessing now that because the the rear band is not long enough to be in the throat before it leaves the case mouth that I need the second band at .432 also. I tried different charges of universal clays, and alliant 2400 and all yielded the same results, I also tried air cooled ww and water quenched ww, no difference. I feel the first thing I need to resolve is the cause of the leading in the throats then work my way forward.

[runfiverun]

okay let me see if i have this right..
you have a ruger.
it's leading the cylinder throats..

you are having the same issue sam was having.
he needed a longer front drive band. [something like .150]
ruger messed up his throats in his revolver a couple of times.
look for a couple of threads by grey wolf it delves into the rugers having these issues.

[bradb]

Thanks! I'll check it out.

[MtGun44]

What lube? Like 44 Man, I have run a bunch of different designs and from WD wwts to 8 bhn
range scrap and zero leading. Accy varies with powder and boolit design and the individual
gun, but NO leading. I DO make sure they are pretty close to or over throat diam and ONLY
use NRA 50-50 or LBT soft blue, or a good red lube from 357 Max here. I suspect lube issues
as much as anything.

Many of my ejected cases show a paper thin ring of lube ~ 1/8" long at the case mouth, exactly
molded to the tapered area from case diam to throat diam, clearly showing that this
soft lube is filling this funnel area and preventing leading there. Clearly the lube is
pressurized at launch and as soon as the front edge of the lube groove clears the
case mouth, lube fills this void full.

Bill

[leadman]

Elmer designed that boolit with a smaller front band. Must be he had a cylinder with smaller throats and was using the larger rear band to help prevent rearward gas blow-by.I lapped out my mold so it casts a .432" front band to match the throats in my gun and all is good now.

[bradb]

I'm getting real close to having a srh for sale real cheap, love the gun but it's getting to be more pain than its worth. I did some more tinkering and also read "gray wolf's" threads about his ruger. My situation is similar to his but I get leading more in streaks up the throats and a little forward of the forcing cone. With some patience and beagling I was able to cast some boolits that had all three bands large enough to size to .432. I then seated them far enough out so the upper band was engaged in the throat and loaded them with a light load of H universal clays. I think the leading was a little better but still there. I did not use a crimp on those rounds and when I pulled a bullet the bands still measured .432.
44 man's theory of the bullet not being hard enough and slumping as it enters the throat sounds plausible but the load I used is a " cowboy load" and doesn't generate much pressure, this is straight wheel weight lead air cooled. I can surely try some water dropped ones though.
Now, on to the lube thing. 44 man is gonna cringe, I been using the 45-45-10 mixture and tumble lubing because I don't have a lubesizer and tumbling is so dang easy. One of my pet peeves is not being able to use something that others have success with ,but on the other hand I realize it's probably not gonna work in all situations. I will try something else for lube too, I can panlube for now.
The only lead boolit Ive had any success with so far is the lee 310gr rf gas check boolit, I get very little leading from this. I worked the mold over so I can size to .432, load it to the lower crimp groove so it engages the throats and use a hornady gas check. Does this tell us anything? Thanks for the help so far.

[bradb]

My understanding is that if it were a lube problem it would lead more towards the end of the bore, is this correct? I have some bear poop brown lyman stick lube, is that worth trying?

[runfiverun]

no you do not run out of lube.
look at where you are having the leading issue and measure stuff.

[bradb]

Have measured things several times, throats are .432 +or- .0002, bore grooves are .4295 Chambers look much like gray wolf's did with the throats being quite a ways forward of the case mouth.

[runfiverun]

the gas check fixing things indicates a harder alloy would help.

[fredj338]

Well despite some other's exp, I can tell you undersized bullets lead most revolvers. My RSBH in 45 colt had .0450" throats & leaded badly in the first 2" of bbl. Opening the throats to 0.4515" pretty much errased the leading & my accuracy improved quite a bit, so I am convinced bullet fit matters more than alloy for leading. I would think you'll be fine w/ the driving band larger as that is what is sealing the bore, but if you are getting leading in the cyl throats, sounds like you want to go slightly larger fornt band too. I woudl think beagling would work, does for me aon a couple molds, but I size all my bullets.

[bradb]

Still having leading problems in the throats, here is what I've tried so far.
Air cooled wheel weights
Water dropped wheel weights
All bands on bullet are sized to .432
Bullet seated so front band is engaged in throat
No crimp
I made an expander plug that expands case to .0015 under boolit diameter.
I've tried 45-45-10 tumble lube as well as pan lubing some with lars 50/50 nra lube.
I've tried varying weights of H universal and Alliant 2400 powders.

The only luck I've had is with trail boss powder, it doesn't seem to lead with that. What does this mean? Thanks

[bradb]

Just wanted to update for folks who may be interested in this debacle. I finally had some sweet success, which is good because I was about to throw the gun in the trash. The lars lube definitely worked better than the 45-45-10 but it was still leading. This particular boolit is an rcbs 44-250-k that I recut the bottom band in the mold to give me a large enough boolit to size to .432, that combined with beagling which made the other two bands larger, I thought I should have a usable boolit. However, in my expirience beagling still leaves you small at the parting line. Finally I said the heck with it and re-cut all the bands in the mold to cast a nice round boolit at .4335 - .434 diameter. I then made a expander plug for my lee expander die that was similar to a lyman M-die expander, it expands the case to about .001 under boolit dia. then has a small area that expands the top .050 or so of the case to boolit dia. or slightly larger so the boolit starts straight in the case, then a slight flare at the mouth. I tried these with the lars lube and trailboss powder for mouse fart loads and viola, no leading! I then tried them with 45-45-10 tumble lube and still no leading, cool! I was looking for a plinking load and I can tumble lube to boot. I then wondered, hmm, can I push this bullet hard without leading? I loaded some up with a healthy dose of lil-gun and fired them off. Guess what? Still no lead! I finally feel like I accomplished something with this. I would say the moral of the story with this gun is bullet diameter. It seems to be happy with boolits that have all bands .001 or so over throat dia. Thanks for all the ideas, and hopefully this may help someone else.

[runfiverun]

i love a happy ending.
it does show diameter matters.

[LAH]

Great report