Gp-100 seize up

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Savage12

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I've loaded some:

158 grain speer lead semi wadcutters, over 6 grains hs7

And my gp's cylinder starts to cease up after 20 rounds or so, even after a good normal cleaning. I can't find a source anywhere for a complete dissasembly, just the basic take down. What could be causing this? I'm stumped.
 
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I think it has to do with the relativly soft (pressed) lead bullets from Speer compared with hard cast...there could be a build up from lead shavings around the forcing cone...
 
polaris said:
I think it has to do with the relativly soft (pressed) lead bullets from Speer compared with hard cast...there could be a build up from lead shavings around the forcing cone...
Click to expand...

I would tend to agree. I have shot mostly hard cast lead and some copper jacketed for the really hot loads. My GP works like a swiss watch, smooth as butter.

I couldn't find reload data on HS7 powder. Are you below 1200fps? If you are near or over 1200fps, you need to use a gas check to avoid heavy lead fouling. Lowering your powder charge or changing type of bullet should fix your build up problem.
 
When I first started reloading for pistol, this happened to me. I thought that I was loading 2.7 grains of Bulseye. Turns out, the scale's large weight was bumped up a notch. So, the load was actually 7.7 grains. I got off three rounds before the gun seized up. If you looked inside the cylinder, you could see the notches pushed out a little. A new cylinder fixed it. That's what you get don't pay attention when you switch loading from rifle to pistol.
 
my GP100 did the same thing, seemed to have a VERY heavy pull on it, after it got dirty- was getting crud into the pawl somehow
Take the trigger group out, and clean all the inside out, and the area where the cylinder goes into the frame
 
You shouldn't need to remove the cylinder to clean it or around it. Ruger doesn't put it in their manuals as they don't want anyone doing it but their factory guys.
Where is it seizing when it ceases to work properly?
 
Give the front of the cylinder and the forcing cone a good scrub with hoppes and a bronze brush.Once it is clean,get a set of feeler gauges and check the
cylinder /barrel gap.Im not sure of ruger specs,but it shouldnt be much less than .003".You can also hold the gun up to the light and cycle the action,looking for any binding of the cylinder/barrel.also,with the cylinder open,check that the cylinder spins freely with no binding,and put a bit of oil onto the crane/cylinder interface to ensure it rotates smoothly.

HS6 can be a bit dirty and there may be a build up,change to a lighter load and see if this helps.Other things to look for are high primers with reloads,binding onto the breech face,dirt in the chambers not allowing proper seating of the round etc etc.Check that you have cleaned the gun well under the ejector "star",dirt buildup here can also cause binding.Less likely would be things like timing issues with the gun(unlikely with a ruger)

My guess would be to give the gun a really good clean,good lube and try another load and see if this helps
 
As an addendum,Ive noted that the speer lead bullets are extremely soft and leave alot of residue,they are best suited to really light target loads(eg at 700fps),try a hard cast bullet rather(or jacketed or plated)
 
Can't reduce hs6 much more than 6 gr, but I like how it fills the care for constant igintion. It is dirty stuff, but causes everything to lock up after 50 rounds or so. Will investigate other powders.
 
sevoman said:
As an addendum,Ive noted that the speer lead bullets are extremely soft and leave alot of residue,they are best suited to really light target loads(eg at 700fps),try a hard cast bullet rather(or jacketed or plated)
Click to expand...

I think those bullets are very soft and may be leaving a lot of residue. I have had similar problems with a Security Six, they do not seem to tolerate getting too dirty.
 
I have a GP 100 stainless that I just bought from a fellow gunnut . I don`t fire any lead out of any of my guns . That is one the big problems with lead it is very dirty . plus they wax lub the stuff which also builds up on the forcing ring . as far as striping it down go to the ruger web sight , they will help you out with any questions you have . Joe
 
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