That Ruger Stainless must be some tough stuff, I sent 30 rounds downrange today trying to lap out the choke in the Ruger Stainless Flattop 45 convertable and there's still some there. Use 320 grit silicone carbide in grease on 200 gr swc over 3 gr Green Dot in the 45 acp case. Rolled the bullet between two steel plates with a fair amount of pressure after spreading the compound on the drive bands and some on the plates. Loaded into fired cases they were a slip fit, so I single loaded each round and fired to make sure the bullets didn't move. Left the fired case in the cylinder so I would be sure to use all chambers equally. Cleaned and checked after each cylinder full. I was getting some leading with the lapping rounds, but that eased off quite a bit on the last batch. I can still feel some choke with a tight(maybe too tight?) patch. We'll see how things go after this.
Fire lapping thread choke
- Thread starter Ole_270
- Start date
Sandspider500
Member
Have you checked with pin gauge?
Haven't any access to pin gauges, but have slugged the bore both by pushing a .490 round ball about half way down from the muzzle and another all the way through. There was a bit more than half thousandths difference. Tight patches feels more than that so the test should of been repeated for consistency.
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Sandspider500
Member
pin gauges should be able to tell you how much thread choke you have.
Ian
Notorious member
9 BHN should be good enough. Rifles with snake/egg syndrome really benefit from dead-soft lead because it won't lap the parts that don't need it.
I worked my SS New Vaquero over with firelaps and hand laps too, then lapped the forcing cone with a rod, then firelapped some more, all I managed to do was put some scratches in the forcing cone area. Finally gave up, it doesn't lead all that badly and if I don't clean it all out it doesn't get much worse. I've never seen SS that was so abrasion resistant in any other form, but it makes me feel good when I pull the trigger and know the revolver is made out of some TOUGH metal.
I worked my SS New Vaquero over with firelaps and hand laps too, then lapped the forcing cone with a rod, then firelapped some more, all I managed to do was put some scratches in the forcing cone area. Finally gave up, it doesn't lead all that badly and if I don't clean it all out it doesn't get much worse. I've never seen SS that was so abrasion resistant in any other form, but it makes me feel good when I pull the trigger and know the revolver is made out of some TOUGH metal.
Kind of what I've threatened to do. I can shoot say 50 rounds of PC'd bullets at roughly 900 fps and see some lead streaks. A couple patches of Ed's Red, a few strokes with a chore girl wrapped brush and most of it is gone. Sometimes though I'll push a really tight patch through and come out with 3 or 4 quarter inch long strips of lead. Work on it a while and bring it in the house to use the borescope and there is still lead in the corners of the land/groove junctions. Not much, but it bugs me. Probably the start of the next smear of lead.
Throats have been honed to .4525. The forcing cone has been cut to 11 degrees. When I slugged the bore I got .4508 in the front half of the barrel. I've got 2 sizing bushings, one throws .4514 bullets, the other .4527. I've been mostly shooting the larger sized bullets.
Throats have been honed to .4525. The forcing cone has been cut to 11 degrees. When I slugged the bore I got .4508 in the front half of the barrel. I've got 2 sizing bushings, one throws .4514 bullets, the other .4527. I've been mostly shooting the larger sized bullets.
Try a PC bullet sized in the smaller die.
I firmly believe the worse thing we can do with PC is shoot them thru something that scrapes the coating off the bullet.
When shooting a .4527 bullet they .4525 throats you are likely shaving off some coating.
One of the oddities of PC is that it sometimes does better sized a little smaller than normal.
I firmly believe the worse thing we can do with PC is shoot them thru something that scrapes the coating off the bullet.
When shooting a .4527 bullet they .4525 throats you are likely shaving off some coating.
One of the oddities of PC is that it sometimes does better sized a little smaller than normal.
Petrol & Powder
Well-Known Member
I don't know what steel Ruger uses but their stainless is tougher than woodpecker lips.
A few years ago I had a Ruger GP-100 that was a problem child from the start. One of the issues was thread choke and I fire lapped the barrel to correct that problem. After shooting more abrasive coated rounds than I was comfortable with, it still had thread choke. I finally got it to shoot better and I stopped the fire lapping. I never got all the thread choke out but I certainly didn't harm that barrel in the process.
That's some of the toughest steel you will ever find in a gun barrel.
A few years ago I had a Ruger GP-100 that was a problem child from the start. One of the issues was thread choke and I fire lapped the barrel to correct that problem. After shooting more abrasive coated rounds than I was comfortable with, it still had thread choke. I finally got it to shoot better and I stopped the fire lapping. I never got all the thread choke out but I certainly didn't harm that barrel in the process.
That's some of the toughest steel you will ever find in a gun barrel.
Bull in a china shop!
Ordered some 220 grit to help things along. While waiting I cast some of the 452-255rf in the 9 Bhn alloy to see if having more bearing surface would cut faster. This evening I decided to go ahead and roll some in the 320 grit to have ready for finish when the 220 gets here. Using an old gong that split in two to roll with, doped it up and got to rolling. When I picked the first on up it felt like it had a cupped base. Measured it and got .448.
Lighten up Francis!
Makes me wonder how many went through the bore undersized the first time.
Ordered some 220 grit to help things along. While waiting I cast some of the 452-255rf in the 9 Bhn alloy to see if having more bearing surface would cut faster. This evening I decided to go ahead and roll some in the 320 grit to have ready for finish when the 220 gets here. Using an old gong that split in two to roll with, doped it up and got to rolling. When I picked the first on up it felt like it had a cupped base. Measured it and got .448.
Lighten up Francis!
Makes me wonder how many went through the bore undersized the first time.
I tried Brads idea of the smaller size die, better but still not good. This afternoon I ran about 50 rounds through of lubed acp loads from the 1911 that seems to hate PC. Very light leading, mainly just "sparkles" on the first patch. Now to find out if it's the lower velocity or a PC issue.
I run PC in 3 different rifles, up to 2450 fps in the 308 with no leading. Probably a thousand or better through the 25-20 at just under 1300, hunting loads in the 38-55 up to 1600 with no trouble, both of these plain based. I set an oven thermometer in the middle of the tray of bullets and start a 20 minute timer when it reaches 400 degrees. I've hammered them to the thickness of a dime with no flaking. Just seems like there's got to be something scrapping the surface away.
I run PC in 3 different rifles, up to 2450 fps in the 308 with no leading. Probably a thousand or better through the 25-20 at just under 1300, hunting loads in the 38-55 up to 1600 with no trouble, both of these plain based. I set an oven thermometer in the middle of the tray of bullets and start a 20 minute timer when it reaches 400 degrees. I've hammered them to the thickness of a dime with no flaking. Just seems like there's got to be something scrapping the surface away.
waco
Springfield, Oregon
You guys got me wanting to check my new Ruger Lipsey’s Blackhawk 45 convertible. A .442” pin would not enter the bore. A .441” glides nicely all the way down with zero constrictions. Happy camper. Most cylinder throats take a .451” gauge but two only do a .450”
I size my PC Bullets to .451” and have had zero leading after somewhere in the neighborhood of 400 rounds through the gun.
I size my PC Bullets to .451” and have had zero leading after somewhere in the neighborhood of 400 rounds through the gun.