[Zero Knives]

I picked up a beaten Hi-Standard Sentinel R-101 .22LR pistol for next to nothing on Gunbroker with the idea of parting it out for another experiment. Seller stated very plainly the timing was off and the cylinder needed to be manually indexed to line up correctly.

In one of those rare instances, it seems the malfunction is not as bad as the seller stated. The timing is in fact off about 80% of the time, but even then the cylinder locks into place when the trigger is pulled.

My question is, is this a safety risk? If not, would it be worth removing the pawl in hopes of peening it out the 2mm it's running short? I was a knifemaker in a past life and still have a well equipped shop, but I'm used to taking steel off, not stretching it out...:D

Thanks in advance,
Ram

[dfariswheel]

Depends on how bad it is.
Usually, as long as you pull the trigger normally, or cock it normally, the cylinder will free-wheel to full lock.
If it doesn't, or you fail to operate the action with enough force to get it to full lock, the gun is going to be firing in an unlocked, unaligned way. Not good.

Stretching the hand is a valid technique, but good luck on RE-assembly. Disassembly is reasonably easy, it reassembly that gets tough.

Here's some High Standard exploded views. One of these should be close enough to get an idea of how it is assembled.

http://www.stevespages.com/histandard.html

In most cases, the hand is stretched by peening about in the center, unless there's a notch or recess to work inside of.
The best tool is a 1/2" chisel with the face ground flat and very smooth and the edges slightly rounded off.

[Zero Knives]

Thanks again, dfaris!

By my guerrilla measurements, the cylinder is falling short by about 1mm, 2mm at most. So close fact that any quick movement and it clicks into place. Pulling the trigger drops it into place every time. It's that chance it doesn't that bothers me. I've read of revolvers shaving lead when they're out of time and it's something I hope to avoid, if not for safety then for accuracy's sake.

I hear ya on reassembly. I work on small parts for a living but none of them include setting off powder in my hand. :D

Worst case, I do have the equipment to make a replacement part, if not the skill. If I was to open this sucker up I'd prefer it to be to replace the pawl. Judging from the parts diagram it looks like a flat part. Are pawls normally hardened steel?

[rcmodel]

How much is 1mm, 2mm in thousandths?
I don't have a conversion handy.

Gunsmiths work in inchs, fractions, and thousandths, not mm's.

rc

[Zero Knives]

1 mm = 0.04 in (roughly), so I'll round up and say it's about 3/64 off, looking at my tap/drill chart. I wish I could upload a video at work, it really is just a smidge.

[dfariswheel]

The hand, or pawl is hardened steel, or at least harder steel.
You can buy new one's from Gun Parts Corporation and other parts houses so there's no need to make one.

[Zero Knives]

Holy cow, I may have been looking at the wrong part all along. Using this parts diagram (http://www.histandard.info/manuals/hprevolvers/0090D150R.pdf) I assumed the part I needed was the Hand (7138), which is out of stock at Numrich. Is the part I actually need the Hammer Pawl (7129)?

[Jim K]

No, I think the part you need is the hand, but I note they have two types, and it looks like 7138 is for the 100 and 7185(?) is for the 101. The hammer pawl (aka "strut" or "lifter" in other gun brands) has to do only with DA fire and I don't think it is the problem.

Also check out the ratchet on the back of the cylinder. It is of a rather unique type that almost never wears out, but not to say it can't.

(If you have a decent shop, you should be able to make a hand in an hour or so. Make it overlong, then cut and try until you get the indexing right, then finish it and harden it. But not too hard; they are supposed to be softer than the ratchet, on the theory that the cheaper and more easily replaced part will wear first.)

Jim

[Zero Knives]

Thanks for the clarification, Jim. It doesn't look like Numrich has either, but at least now I know the proper terminology.

Everything looks good on the back of the cylinder, though I just noticed the spring on the ejector is weak.

I've got some O1 tool steel that's pretty easy to draw back. I'll give it a shot this weekend. All I've got in-house is a Bader-type belt sander and I'm worried about the flatness of the part, but mainly disassembly and reassembly as I test the part. I guess if these little projects were easy they wouldn't be fun... :D

[Zero Knives]

I worked on both my little .22s today and decided to shoot a video of the timing of my Sentinel R-101. My next course of action is to first try to get the part somewhere. Failing that, I'll try to stretch this out.

That is, if anything's even necessary. As you can see from the video, the cylinder falls into time with the pull of the trigger. What do you wise guys think? :D

http://www.youtube.com/watch?v=klO6n-KPHf4

I've also attached a picture of the sorry state of the hand...