Ruger GP-100 - Leading with no solve to date

[robertbank]

This has to be the place for an answer to my dilemma.

Challenge: To develop a .38spl load running at a power factor (Bullet wight X vel.) of + 105 for IDPA.

Problem: Leading in the first 1/8th of an inch in the rifling. I also get lead splash on the outside of the forcing cone. Forcing cone is still 5 degrees. I intend to have it cut to 11 degrees.

Throats on the Ruger are all now .358

Accuracy using lead, jacketed & plated is excellent or as good as I can hold from a rest.

To date I have tried WC WW alloy and air cooled pure lead boolits with similar results.

Powder is 2.8 gr of Clays.

Bullet is 160 gr RCBS RN .

Take Care

Bob

[Maven]

Bob, Are you using .38Spl. or .357Mag. brass? Also, are you sizing those CB's to .358", .359" or .360"? The reason I ask is that my ~18yr. old Ruger BH doesn't shoot at all accurately with .38Spl. brass (or even match WC ammo) or with CB's sized less than .358" (.359" is best for it). However, it certainly likes Clays, especially 3.1gr. with WC's in .357Mag. brass. Are you willing to try the longer brass + the slightly heavier charge of Clays to see if things improve?

[subsonic]

Have you tried water dropped wheel weights? You never know till you try.

What kind of lube?

[ReloaderFred]

Or, you could just gas check the bullet with one of Pat Marlin's Plain Base Checkmaker dies. You can make your own gas checks out of aluminum or copper and apply them to any plain base bullet. That should solve your problem.

You can find his information in the swaging forum on this board.

Hope this helps.

Fred

[Wally]

I have a SS Ruger Blackhawk Cal .357 Mag..does the same thing...only gas checked bullets prevent leading. If I use plain base bullets I use a cloth pach covered with aluminum flyscree..a make shift Lewis Lead remover, if you will, to de-lead it after so many shots. It just takes a few sceonds and the bore is clean again. It shoots so well and is accurate, I just live with it.

[phaessler]

+1 for Maven, my wifes GP100 can be a soldering iron if using 38 cases in the 357 cylinder, I also found water dropping to help a little but not enough.

Pete

[bhn22]

Have you considered a mild firelapping to (perhaps) smooth the transition from the forcing cone to the rifling? It might just be a slightly rough edge.

[phaessler]

Appears valid to me bhn22, but its hers...lol, heaven forbid I change anything.
It appears the forcing cone is rough in mine, and it would probably benefit greatly.

Pete

[robertbank]

Many thanks guys for the replies. I have tried water quenched WW and almost pure lead and pretty much get the same results. Accuracy is real good. I size all my boolits .358 ( I reamed my throats out to .358. I have yet to cut my forcing cone to 11 degrees which may help. If nothing changes I will resign myself to getting another Lewis Lead Remover and just putting up with the problem. I may try using .357 cases to see if that helps. The longer cases are a tad more difficult to reload with under pressure but my reloads can be timed with a sun dial now so I doubt I'll notice much difference.

Take Care

Bob
ps I normally use the Chor Boy method for removing lead but in the case of revolvers I think the Lewis might do a better job at keeping the area clean.

[GP100man]

Bob if your useing WC boolits how many grooves do you lube ???

I have a wc with three lube grooves ,I leave 1 off & set the boolit out & crimp in the 1st groove when I used 38 brass so the boolit does`nt have to jump so far & gives gas less chance to scoot by .

This is 1 reason I use 357 brass , but I know 357 brass is`nt as plentiful as it is here in the south & 38s are easier to line up with a speed loader

[robertbank]

The bullet I am using is the RCBS 158 gr boolit without the bevel base making it a 160 gr boolit. I crimp over the last driving band by just eliminating the belling on the case. I'll try loading them in .357 cases and upping the charge to compensate for the increased volume and see if that stops the potential for gas cutting. As you point out it may slow down the reload a tad but I am pretty inept on my reloads anyway so I doubt any contribution to slowness will have much effect in the greater scheme of things.;-)

I am busy getting ready for our IDPA Provincial Championships but will have time after the 30th to do some testing.

Take care

Bob