Setting a GP100 for Lead, Gunsmith needed!
- Thread starter lowburb
- Start date
A common modification with revolvers when shooting lead. “Better accuracy”, less fouling, and less "splash” on the cylinder face. Not necessary but can help.
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- Location
- Alberta, North America
not necessary, what is your gain? for what, plan/use?
You can shoot lead all day in factory config. Forcing cone should be left alone and do not ream the chambers.
One possible improvement (and might be what you meant by ream) is a tiny tiny tiny chamfer on your cylinder for easier loading, especially when using speed loaders. The soft lead can sometimes snag or be cut/shaved by the sharp edges of the chambers. Just the tiniest amount to smooth that edge makes a pleasing improvement in reloading.
One possible improvement (and might be what you meant by ream) is a tiny tiny tiny chamfer on your cylinder for easier loading, especially when using speed loaders. The soft lead can sometimes snag or be cut/shaved by the sharp edges of the chambers. Just the tiniest amount to smooth that edge makes a pleasing improvement in reloading.
I would agree with curseyou and suggest the cylinder chamfering is the only particularly useful thing to get done, and even then I'd only spend the money on that if I wanted to compete with it or had a real desire to use speed loaders. If it's just a range toy that you load each round individually into the cylinder I would spend the money on something else like more ammo.
Just check your cylinder throats. If they won't allow a .358 lead bullet to pass through them then you should have them reamed out ot .358 to reduce leading and to maximize the guns accuracy. The 11 Degree cut on the forcing cone will eliminate a lot of lead splash and build up around the forcing cone. Nobody suggests you can't shoot lead through cylinders that are tighter than the barrel but nobody suggests it has no effect on the guns accuracy. Rugers are famous for having tight cylinders. Check yours out by pushing a .358 bullet through each one. Any gunsmith with a set of reamers can do the work for you. My Smith 686 no dash was fine. My Ruger GP-100...not so much. Fixed now....accuracy difference was noticeable. No leading and little to no lead build up at the forcing cone.
If you are only going to shoot plated bullets do the test with .357 bullets and leave the forcing cone as is.
Take Care
Bob
If you are only going to shoot plated bullets do the test with .357 bullets and leave the forcing cone as is.
Take Care
Bob
Now I acknowledge that this group was not shot with lead. These are full loads, jacketed 160 gr. shot at 25 yds. However, if the GP100 will do this with jacketed, I am thinking lead rounds should do just as well, especially if they are lead target loads. I have some CamPro plated wad cutters that I am going to try with Bullseye next. Can let you know if interested how they worked out.
If you are going to spend money on the GP100 I would spend it on fibre optic sights. That is the only mod to this revolver and it made a difference. For me, anyway.
If you are going to spend money on the GP100 I would spend it on fibre optic sights. That is the only mod to this revolver and it made a difference. For me, anyway.
Rugerman and others if you shoot plated and jacketed bullets that are typically sized .357 you are not going to see issues with cylinder throats that are .357. If you shoot lead bullets you likely will see leading in your gun due to gas cutting. Too, whether your gun has cylinder throats that are .358 or even .357 are not much concern to me when mine were <.356 and <.357. Accuracy was adequate but not great with jacketed bullets and less than adequate shooting lead bullets that should be sized .358 to fully seal a bore of .357. The gun did lead up though with 100 rds shot through it. Opening up the throats to .358 made all the difference in the world as did cutting the forcing cone to 11 degrees. I now experience no leading using either .357 or 38spl loads.
I love my Rugers and use the GP-100 in IDPA Revolver Division but they do tend to be kit guns.
To the OP if you do decide to send your gun to a 'smith order a set of hammer and trigger shims they do add to the quality of the trigger pull. The Match Champion comes with them the regular GP-100 does not. Until you get a FO front sight flouresent orange paint is a very good substitute over a white base coat. I put the original sight on the gun when I carry mine in the bush. I put the FO on for competition and target shooting.
Take Care
Bob
I love my Rugers and use the GP-100 in IDPA Revolver Division but they do tend to be kit guns.
To the OP if you do decide to send your gun to a 'smith order a set of hammer and trigger shims they do add to the quality of the trigger pull. The Match Champion comes with them the regular GP-100 does not. Until you get a FO front sight flouresent orange paint is a very good substitute over a white base coat. I put the original sight on the gun when I carry mine in the bush. I put the FO on for competition and target shooting.
Take Care
Bob
easyrider604
CGN Ultra frequent flyer
- Location
- Greater Vancouver, BC
101% Correct/\
My GP100 does 1/2 inch groups at 15 meters with 357 magnum loads of 158 grain Speer jacketed hollow points over 14 grains 2400 powder.
Best groups it can do with .358 sized home cast (Lee tumble lube) 158 grain SWC over 4.1 grain 700X are 1.5 inches.
I believe my GP100 will benefit from reaming and 11 degreee cut.
You will cut that group down to an expanding single hole with the throats opened up and the cone cut. At 4.1 gr of 700X you are pushing that 158 gr bullet right along. I use 3.4 gr to make 125 PF using RCBS RN 158gr bullets cast from WW Alloy in 38spl cases. They run just over 1,050 fps sized .358. Accuracy is excellent and good enough for IDPA. I go through a lot of them practicing. I shoot everything from 148 gr RCBS WC bullets to the 358430 200 gr RN bullets. The RN 158 gr bullets are my choice for IDPA. I tend to use Clays under either the lead RN or BDX/Canfor plated. Clays is a bit cleaner with a bit less smoke when shooting a large match.
Take Care
Bob
You didn’t even understand what these modifications are for now your giving advice on the matter?!? Again, the keyboard warrior emerges. Just like your input on the rain gear thread, unreal.
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Finally another with real world experience with these revolvers, i had a similar experience and found it dis make a substantial difference in MY gun
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Those are great groups, I will add to my last post that I was talking about light load 38sp, not lead 357M loads, I could see mods for those.
And a bit of trigger works makes a big difference on Rugers, thou I shoot the older models.
And a bit of trigger works makes a big difference on Rugers, thou I shoot the older models.
Folks lets not get carried away. Before you start modifying your gun permanently, for lead, you should take a look at your bullets and loads first. 10k+/- lead rounds and I dont have leading or splash issues and my groups are just fine thank you. I am a fan of light lead loads because the gun will last forever with minimal care. My barrel is like new.
Why ream and cone cut when you haven't even tried powder loads, lead hardness mixes and moulds. It is a 100% no brainer to change the bullet before you change the gun.
To ensure optimal obturation and minimize leading you need to balance bullet diameter, lead hardness and powder charge. You can get a number of press attachments to swage your bullets to the right size and leave the gun factory.
What was shown in the iowegan guide can be done. But not without consequence. There is a very large body of factory config shooters evidence that this is overkill and there is a well known tweaker effect where people have to do something special as retail therapy and bragging rights at the club with their buds.
Change the bullet before you change the gun.
Why ream and cone cut when you haven't even tried powder loads, lead hardness mixes and moulds. It is a 100% no brainer to change the bullet before you change the gun.
To ensure optimal obturation and minimize leading you need to balance bullet diameter, lead hardness and powder charge. You can get a number of press attachments to swage your bullets to the right size and leave the gun factory.
What was shown in the iowegan guide can be done. But not without consequence. There is a very large body of factory config shooters evidence that this is overkill and there is a well known tweaker effect where people have to do something special as retail therapy and bragging rights at the club with their buds.
Change the bullet before you change the gun.
curseyou before you change bullets your advice should be to check the cylinder throats. If they are .358 there is nothing to do but consider the forcing cone. If they are .357 or less then reaming the cylinders out to .358 is a no brainer to use your terms. You likely know that a six shot revolver is essentially six guns. Each cylinder must be considered. The fact one gun shoots lead without any issues makes little difference to the next. It may or it may not. In my guns case I had three cylinders that a .357 bullet would not pass through and three that would not allow a .358 to pass through. Left as is I would have three of the six bullets originally sized bullets bouncing down the barrel sized <.357 and three <.358. What would be your suggestion? Mark the cylinders and cartridges and load for each set of cylinders.
You turn the exercise into into a quest for the Holly Grail or just do some simple tests (measure the throats), assess the data and make the adjustments. Reaming out the cylinders to a even .358 tales no more than 10 minutes and the forcing cone less.
Properly sized lead bullets with a decent lube to seal the bore is the answer to leading assuming the barrel doesn't look like it was chipped out with an axe.
To make IPSC Minor 125 power factor you have to load to +P levels. IDPA did a study when they reset the PF requirements down to 105 for one of their revolver divisions. Seventeen brands Factory 38spl ammunition was tested and ran from 95 to 117 PF for standard loaded 38spl ammunition. They settled on 105PF down from 125 so their shooters were not forced to reload if they chose not to.
You enjoy shooting light loads through your gun and I suspect pursue accuracy. Great! Some here will just like to plink at tin cans if their range will allow them to do so. Others are happy to hit a sheet of paper frequently at 15 yards. Other to compete in action shooting. Others carry their revolvers under their Wilderness Permit as part of their work. The OP wants to shoot lead bullets and asked where he can can certain work done. To date nobody has bothered to respond because some here have no appreciation for why he is asking.
To the OP I would call Dianne at P&D Enterprises, they are a sponsor of this site, and ask er if she can direct you to a gunsmith or machinist to do the work for you. You can buy the kits as you noted. Like you, I opted to have my 'smith do it. One has to know ones limitations. There likely is a gunsmith that will do the work for you. I suspect mailing your gun back and forth, if necessary, will cost you more than the work involved. Let us know how you make out.
Take Care
Bob
You turn the exercise into into a quest for the Holly Grail or just do some simple tests (measure the throats), assess the data and make the adjustments. Reaming out the cylinders to a even .358 tales no more than 10 minutes and the forcing cone less.
Properly sized lead bullets with a decent lube to seal the bore is the answer to leading assuming the barrel doesn't look like it was chipped out with an axe.
To make IPSC Minor 125 power factor you have to load to +P levels. IDPA did a study when they reset the PF requirements down to 105 for one of their revolver divisions. Seventeen brands Factory 38spl ammunition was tested and ran from 95 to 117 PF for standard loaded 38spl ammunition. They settled on 105PF down from 125 so their shooters were not forced to reload if they chose not to.
You enjoy shooting light loads through your gun and I suspect pursue accuracy. Great! Some here will just like to plink at tin cans if their range will allow them to do so. Others are happy to hit a sheet of paper frequently at 15 yards. Other to compete in action shooting. Others carry their revolvers under their Wilderness Permit as part of their work. The OP wants to shoot lead bullets and asked where he can can certain work done. To date nobody has bothered to respond because some here have no appreciation for why he is asking.
To the OP I would call Dianne at P&D Enterprises, they are a sponsor of this site, and ask er if she can direct you to a gunsmith or machinist to do the work for you. You can buy the kits as you noted. Like you, I opted to have my 'smith do it. One has to know ones limitations. There likely is a gunsmith that will do the work for you. I suspect mailing your gun back and forth, if necessary, will cost you more than the work involved. Let us know how you make out.
Take Care
Bob
