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Folks,

Wanted to let you know that I posted my experiences with improving SP101 sear on THR. Here is the link.

I want to once again thank Gary / Iowegan for IBOK and for sharing his enormous experience with me.

Gary asked to emphasise that changing sear angle is a dangerous thing for a novice to do. It is indeed a very delicate operation and any mistake will cost big $$$$$.

Mike
 

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hoptob you rock I just ran downstairs and grabbed one of my files and did this mod. In two minutes I have a trigger that rivals my best smith wheel gun.
thank you so much. I had already done the IBOK and polished the gun and heated the top two coils on the main spring but this really smothed out the double action trigger pull. now I need to go put a box of ammo through it to make sure it actually goes boom reliably.
 

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Took it to the range yesterday and she goes bang X 1 box of ammo. now if I could shoot it as accuratly as I can my Baby Eagle 9mm. Are there any tricks for accurizing the SP101's??? At 7 Yards I can put 10 rounds in the target the size of a quarter with the baby eagle. The
SP101"s accuracywith six rounds at 7 yards is about 6 inch groups. My buddy who is a much better shooter than me cant seem to make the groups shrink either. His theory is that the unburnt powder from the Mag load coming out of the Barrel is messing with the bullet flight. Any help would be appreciated.
 

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hoptob, I've done the same modification on several SPs ... but only on guns with extra generous carry-up timing. Ever wonder why Ruger won't sell you a hammer? Well, that little lip in your link's graphic is the reason. It is the "adjustment" for DA carry-up timing and is hand fitted at the factory for optimum performance (not trigger pull). Some SPs have a very defined tip while others are nearly smooth. That's also why one gun "feels" better at DA let-off than another. With slight differences from gun-to-gun, there has to be a way to delay DA hammer release until the cylinder is locked in place by the cylinder latch. Additionally, wear is a major consideration ... almost like tread on a tire. As the tip of the pawl and ratchets wear, carry-up timing begins to retard. At some point in the wear cycle, the cylinder will fail to carry up (cylinder won't lock up in DA before the hammer releases). The little "lip" is the extra tire tread that keeps carry-up timing within spec, even after thousands of rounds have been fired (or dry fired).

Though removing or reducing the tip definitely improves DA let-off, it will shorten the lifespan of the revolver. Carry-up in your gun may be good now, but I'll bet it gets out of spec long before it should.
 

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I am impressed!!!! I pulled out the Dremel and shaved just a bit off and then used a polishing disc to smooth it out. It feels better than my old S&W Airweight. Thanks for the info.
 

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Folks,

Wanted to let you know that I posted my experiences with improving SP101 sear on THR. Here is the link.

I want to once again thank Gary / Iowegan for IBOK and for sharing his enormous experience with me.

Gary asked to emphasise that changing sear angle is a dangerous thing for a novice to do. It is indeed a very delicate operation and any mistake will cost big $$$$$.

Mike
Thanks much Mike! I love it when diagrams/photos are used to show precisely where cuts, filings, etc are to be done. This helps dummies like myself decide the right course of action. :)
-Bruce
 

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It smooted mine out, but wish I had left it alone. The hammer will fall after the cylinder locks when I tried to let pressure off of the trigger. For example if I pull the trigger double action until the cylinder locks then let a little pressure off of the trigger the hammer will fall resulting in the gun firing. Do I need to send it back to Ruger for hammer replacement, or is there something I can do to repair this condition.
 

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Interesting, I'll have to keep this in mind when I pick up my SP101 next week.
 

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It smooted mine out, but wish I had left it alone. The hammer will fall after the cylinder locks when I tried to let pressure off of the trigger. For example if I pull the trigger double action until the cylinder locks then let a little pressure off of the trigger the hammer will fall resulting in the gun firing. Do I need to send it back to Ruger for hammer replacement, or is there something I can do to repair this condition.
Does the hammer drop when you push on it in SA (unloaded of course)? I think in post #1, Mike's last sentence is extremely crucial. Even if it does hold in SA, you have changed the geometry of the sear enough to make the weapon unsafe.

You can get used hammers at Numrich, but I quote Iowegan... "SP-101 hammers are a factory fitted part so Ruger doesn't sell them as spare parts. Buying a used one is a crap shoot. Maybe it will work ... maybe it won't."
 

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Does the hammer drop when you push on it in SA (unloaded of course)? I think in post #1, Mike's last sentence is extremely crucial. Even if it does hold in SA, you have changed the geometry of the sear enough to make the weapon unsafe.

You can get used hammers at Numrich, but I quote Iowegan... "SP-101 hammers are a factory fitted part so Ruger doesn't sell them as spare parts. Buying a used one is a crap shoot. Maybe it will work ... maybe it won't."
No the hammer does not drop. I'm not comfortable with it the way it is. Thanks for the info. I think first i will call ruger and see how much it will cost to replace the hammer.
 

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The purpose of the "hump' identified in hoptob's link is twofold. First, it is the factory "adjustment" for carry-up timing in DA. Filing it down will allw the hammer to drop before it should. The second function is "hand-off". When you pull the trigger in DA, the cam surface has to position the DA sear where it will transfer from the cam surface to the DA sear, better known as DA hand-off. Any alteration to this "hump" may prevent the DA sear from handing off properly so the hammer will fall as soon as the trigger's cam surface tip slips off the hammer dog. This is NOT the place to be filing unless you really know what you are doing.
 

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Thanks everone for the great info. I feel I messed up, but I learned something in the process. It usually cost money to learn (especially if you take college courses). I got to learn, by doing somthing I love doing.
 

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That was a great write up man. Not brave enough to do the work but it helps that much more in understanding what is actually going on in the SP101 trigger, sear area. Great pics and diagram too. The warnings came accross very clear as well, as I will not be trying this mod just yet. I think I will just deal with my IBOK trigger and get good with it through target practise.
 

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I have a possible cure for you. I bought an extra hammer to bob. When I polished and installed it, my SP was doing exactly what yours is. I tried to visibly compare the two hammers and noticed the hammer dog on new hammer did not extend out as far as old one. I ground down the back top of the dog to let it stick out a little farther on bottom at rest, matching original hammer. Cured!
Steve
 

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Good info. When I have to smooth-out a D-A pull, I shoot-in the weapon, a few hundred rounds, clean and re-lube, then I'll carefully accelerate the break-in of the pull's travel, using a piece of latex tubing, pushed down onto the hammer spur. I use maybe a six-inch piece of heavy slingshot band. Pull slightly up, and forward, and squeeze the trigger through against the tension of the band. After twenty fairly squeeze-thru's, remove the band, and check fer progress. I've read of similar methods, but the latex tubing seems to work well, fer me. In the case of the Ruger revolvers, at least, you then disassemble, and strop the affected surfaces, using green rouge, on leather.
 
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