41 MAG is leading need advice

[WARD O]

My S&W 657 is leading with even a light load. 215 SWC .411 as purchased in quantity over 7 gr Green Dot for around 900 fps from 6" barrel. Same with another bullet/powder at around 1,000 fps.

Cylinder throats are all a snug .410 as measured with a set of minus plug gauges. I was going to slug the barrel but with the five groove rifling it makes it difficult to get at good reading.

Perhaps the throats are a little tight??? Anyone been down this road with S&W 41 mags?

thanks
ward

[FN in MT]

I think you are going to be told to slug the barrel as well. tough to figure out the solution without knowing all the info.

My 657 has been lead free, but most of my loads are 900-1000 max. Size mine to .411 with .410" throats and a .410" barrel.

FN in MT

[missionary5155]

Greetings
Would not be surprised to read the groove on that S&W is fatter than the throats. "J" thangs can run pressures up real fast. But leave a bit of windage about the base and pressure leaks right on by. Sad but accuracy with cast boolits is not high on the list of some revolver manufactures.
Mike in Peru

[Larry Gibson]

215 SWC .411 as purchased in quantity

Commercial cast with a hard wax lube? Try TL'ing in straight LLA.

Larry Gibson

[2 dogs]

Just because the box the bullets say .411" doesnt mean they are exactly that. Measure them with a micrometer to be sure they are the correct diameter.

[WARD O]

Thanks all,

My error - label says .410 not .411 sorrry. Measure four with the mic and the numbers are running from .4103 to .4112. Commercial cast with a hard wax lube - perhaps relubing with the liquid alox will help - I'll try to pick up some of that and give it a try.

J bullets shoot fine - just don't want this to be a J bullets exclusive.

ward

[theperfessor]

I'd suspect the bullets before I blamed the gun. I have a 57 and have no leading problems with the right size bullets using the right lube. I have had problems with commercial cast crayon lubed bullets.

[Southpaw 72]

If they are commercial cast, they are probably cast from a harder alloy. Maybe a little too hard for the pressures you're running.

[44man]

The groove must be measured and throats MUST be a little larger by about .0005". But exact is OK too. Throats a little larger lets you use a boolit just over bore size.
Whatever, a .410" throat and .410" groove should shoot a .410" boolit. It does no good to go .411" if the throats size the boolit.
What is forgotten is the fast powders peak right quick and can leak along the boolit before it is even out of brass.
It is hard to explain that light loads with fast powders are more prone to leading and also more prone to boolit skid at rifling start.

[kweidner]

I have a Dan Wesson I know not the same design etc. However I found unique was the powder for mine and sized .412 acww with felix lube 210 grain swc design from Tom. Just something to think about. Do you have a die that will go .412? If so send me your address and I will send you some to try unlubed as felix probably won't ship too well. I also have a 200 grain lee design. Send a PM if your interested.

[WARD O]

Yesterday I took it to the range again. I was trying hard bullets. 230 gr SWC Leadheads with a BHN over 20 sized to .411.

Tried some around 1000 fps over 4756 and got some smeared leading starting pretty much right in front of the forcing cone. I cleaned it out completely and then switched to a full/heavy load of 296 with Fed 155. This time I got leading again but it didn't start until about half way down the barrel. Again it was looking rather smeared on the barrel.

Last night I took some .430 round lead balls and forced them through the cleaned, lubed barrel with a wood dowel. I then tried passing the slugs through the cylinder throats and they went through freely without pressure so the barrel slugs smaller than the throats.

I am somewhat at a loss here. Could a lube change help this??

kweidner - thanks for the generous offer - I may wait a bit to answer.

ward

[HATCH]

I size 411 and use magma lube.
8.5 grains unique 220 grain boolit
no leadding at all.

[44man]

I use Felix lube in all of my revolvers.
Leading is something hard for me to deal with because I have no problems so I have no answers. It just might be the hardest thing for me to answer.
Now I have had bad leading over the years. The worst was with wad cutters in the .38. Then with Alox in my big bores. Lead too soft that slumped or skidded.
Then when I found the best for revolvers leading went away and I can use different alloys and lubes. I do see a difference in accuracy between alloys and lubes but I can go a few years without cleaning a bore.
I just can't explain it or cure leading problems. I have used LBT lubes and can tell one from another for accuracy. I used many of Glen's lubes like CR with good results.
I really am at a loss to help. But does the leading hurt? A few pieces will not hurt a thing. If the next boolit pushes it out and just leaves a little for the next boolit to push out, does it matter?
When it thickens is the worry. When grooves fill up is the worst.
To get a sliver on a patch would not concern me.

[WARD O]

The leading I am experiencing is not just a sliver. I have only been shooting a couple of cylinder fulls before checking and I'm finding lead pretty much top, bottom, left and right side of the bore for maybe two inches of complete coverage - clearly visible with sunlight reflecting up the barrel from the recoil plate. I don't like cleaning it so I don't let it go any further.

I think I have a Lyman mould for the 41 so I guess I'd better get busy and try some of my own and see what happens.

[HATCH]

Send me a pm with ur addy and i will send out some of my 220's for you to try out.
I have some lube with magma green and come with bac red.
Also got some mixed too... Lol