New Blackhawk Leading Problem

[November]

Picked up a new .45 Blackhawk last week and took it to the range to put some handloads thru it. Loads were 255 grain SWC over 9-ish grains of Unique in Starline brass with a CCI 300 primer. I put about 30 rounds thru it and it shot way high and left. I also noticed heavy leading of the forcing cone and about 3/4-inch into the bore. Throats too tight?

 

[louiethelump]

Could be. Could also be too hard bullets if you are using commercially cast. they are often too hard, and don't bump up and fill the rifling, and gas blows past and blasts lead onto your bore instead of keeping the expanding gasses behind the bullet. Bevel base bullets the commercial casters make (they are easier to mold and feed better in automated machines) make it worse. That is not a real hot load, and "cowboy" hard bullets (pretty soft) work best at lower velocities. Also, is the CCI 300 a standard primer? I don't know all the numbers, but Unique (what I use exclusively) does not need or do as well with magnum primers. Can you recover any of your bullets? If you can, check the bases to see if there are signs of them being melted by hot gas blowing by.

I have had this problem with commercially cast 158 gr 38 bullets. You just about have to shoot them at magnum pressure to get them to bump up.

Just some ideas. NOT gospel

 

[November]

I believe these are standard primers. I used this exact same load (same batch) in my Uberti Cattleman with no leading at all. Also the cases dropped free from the Uberti, but stuck in the Ruger. The chambers seemed somewhat tighter on the Ruger.

 

[Rclark]

Your load is just fine. CCI-300s are standard primers used with Unique.

First thing is to check your cylinder throats. Does the .452 bullet you are using push through the throats (clean throats first) with finger pressure. If they don't then you have to small of throats and need to get them reamed. Second would be the bullet hardness if throats ok. May be to hard. You want something in the range of 10-15 BHN. Third you may have a bore constriction which is common in that area. The easy way to take that out is with fire lapping. I'd make sure of the first two before heading down the fire lap route.

Hope that helps.

 

[Flash]

Hey November, haven't heard anything from you in a long while. Sounds like the issue has already been discovered. I'd measure all the throats too.

 

[eagle55]

My BH 45 Colt did the exact same thing with regards to leading in the forcing cone and first inch of the barrel with .452 Dardas 200 and 250gr (which are 16BHN) , and 8 to 9gr of Unique. First I reamed the throats to .4525 but the forcing cone leading continued with .452 cast and the groups were not great. Then I ordered 100 Dardas .453 and just like that the leading virtually vanished and the groups tightened at the same time. I am planning on ordering some more .453's and experiment further but it seems I may have found a combination my 45 likes.

 

[November]

Thanks everyone for the suggestions. If I get a chance tomorrow I'll see if a .452 slug will fit thru the throats and go from there.

Hey Flash, how you doin'?

 

[63November]

You might try bumping the load up a grain and see if it shoots cleaner and a bit lower. Possibly less barrel time will give the recoil less time to act on the bullet enroute through the barrel. It might also give the bullet just enough more of a shove to help it fill the grooves. But the throats are a good place to start.