Ok why is my barrel leading???

[whiplash]

I thought I had this leading problem figured out. Apperently not...Here is the info...Taurus M44 (4in barrel, 2in actual barrel, and 2in of compensator) 44Mag, 240gr Laser-Cast SWC BB (.431 dia), no gas check, 24gr H110, CCI 350, Win brass. Cylinder gap is .011. Cant check groove dia because of the compensator, and havent slugged the barrel yet. The throats are .429 (if I remember right, i am at work). There is leading all the way down the barrel, with about 20 rounds fired. Any clue? To hot (H110 is supposed to be pretty hot, or should I say no more than 3% from max)? To hard? Need a gas check? any suggestions?

 

[farmall]

Whiplash,
I suspect your troubles may be caused by the bevel based bullet. To push a cast bullet that hard, it should be gas checked, or have a square base, but I'm sure someone here might dispute this.
I have never had much luck with commercial cast bullets....they are usually too hard, in my experience. It would be helpful if you could slug your barrel, but you might try sizing some to fit the throats.
The fact that the leading is the length of the barrel makes me suspect gas cutting, or perhaps lube failure of some sort.
Good luck, as there is a bit of "Voodo" involved here, but the results are usually worth it!
Andy

 

[Scorch]

24.0 gr of H110 puts your load just below max load for a jacketed 240 gr bullet, and would push a 240 gr jacketed bullet at 1,350 fps. Several issues here:
* You are using jacketed bullet data for loading cast bullets. Cast bullets do not need as much pressure to achieve a given velocity. Use cast bullet data to load cast bullets.
* Cast bullets should be kept around 1,000 fps or less unless you are using hard cast or gas-checked bullets.
* H110 is too hot for cast bullets, it will gas cut the base of the bullets and will cause severe leading. You will do better using something like Unique, Universal, HS6, or similar burn rate.
* Now you have a severely leaded barrel. You wil need to remove the lead before shooting jacketed bullets.

 

[whiplash]

* You are using jacketed bullet data for loading cast bullets. Cast bullets do not need as much pressure to achieve a given velocity. Use cast bullet data to load cast bullets.

The H110 (24gr as max) data came straight from Oregon/Laser-Cast tech support, w/ faxed load data from their manual.

* Cast bullets should be kept around 1,000 fps or less unless you are using hard cast or gas-checked bullets.

They are pretty hard, and a gas check might be in the future.

* H110 is too hot for cast bullets, it will gas cut the base of the bullets and will cause severe leading

Not going to dispute that there might be some gas cutting going one, thats why I might be looking at gas checks.

* Now you have a severely leaded barrel. You wil need to remove the lead before shooting jacketed bullets.

I definately agree with you on that....time to go "get the lead out!"

 

[James R. Burke]

I believe Scorch has it correct. I bet if you do what he says that should take care of your problem. Not much I could add to it.

 

[FrankenMauser]

I definitely agree with too much velocity. Back off the powder charge a bit, and see where that takes you.

Was the barrel broken in before using this load?

 

[cornbush]

Scorch and Frankenmauser got it, slow down or go to jacketed bullets. A rough barrel could also be a factor.

 

[paratrooper]

Gas check .

 

[Travis Two]

It could also be a case that the cylinder throats are smaller .429 and the barrel is larger ( say .430-.432) in which case the .431 bullet is being swagged down but not swaging back up to fit the rifiling and you are getting gas cutting. I run a hard cast with 24 grs of ww296 without those issues but evrything must fit. The cylinder throats may need to be opened up to .431 diameter ( at least as big as the barrel dimension or slightly bigger) and then the bullets can size down a bit insuring a good seal without blowby or gas cutting.

 

[Russ5924]

Is this a brand new gun if so run a hundred or so FMJ and smooth the bore out. And lead bullets don't like to be pushed to fastI I try to keep mine below 1000fps

 

[Unclenick]

Travis has it right. I know of no revolver firing cast bullets even at low target velocities that will not lead if the throats are not at least half a thousandth over the groove diameter of the bore. Also common with revolvers is the famous barrel constriction where the barrel screws into the frame. You need to slug the barrel to find out if you have a constriction?

Your compensator should not be a slugging issue. Buy a box of Hornady .433" round lead balls for muzzle loading. Clean the gun. Run one lightly oiled patch through the bore, then wipe the lead ball with it. Drop the ball into the muzzle and let it find the center. Use a short length of wood dowel or better yet, a brass rod to act as a punch. Tap on it with a plastic hammer until the ball just gets in the muzzle. Push it the rest of the way through slow by hand, using a longer piece of the rod or using a cleaning rod. If you have a constriction, you will feel it. Such a constriction will have to be lapped out before the gun will shoot lead without fouling unduly. Firelapping is one approach that can work.