View Full Version : Bolt drag
June 20, 2010, 08:51 PM
I recently purchased an R&D conversion cylinder for my 1849 Uberti Pocket and the cylinder needed to be fitted right from the get go.
I spent a good bit of time fitting the bolt and hand, and it now cycles and locks up PERFECT. However, I'm beginning to notice a line around my cylinder which I think would indicate the bolt is dragging.
I'm a bit confused because I can visually see the bolt pop up and retract freely within the frame with the cylinder removed and there is absolutely no "slop" with the cylinder installed. Everything seems to be working perfect, but again ... I'm beginning to notice a drag line around my cylinder. :confused:
Can anyone tell me what causes this and how I may correct it?
June 20, 2010, 09:00 PM
With the gun disassembled (cylinder removed), place the gun on half cock. You should be able to see if the bolt is fully retracted into the frame or not.
If you lower the hammer from half cock (such as when using the safety pins) you will create a drag line. If this bothers you, always fully cock the hammer before lowering it again, and forget about using the safety pins. Just keep the hammer lowered on an empty chamber.
June 20, 2010, 09:35 PM
If you lower the hammer from half cock (such as when using the safety pins) you will create a drag line.
That's EXACTLY what's happening.
If this bothers you, always fully cock the hammer before lowering it again.
So, I'm guessing folks who use the Kirst Konversion cylinder with the loading gate really have no choice since the hammer has to be at half-cock in order to load the cylinder, huh?
Thanks so much for your response.
I thought I really screwed it up this time. :p
June 20, 2010, 10:31 PM
Dino, you can highly polish the TOP of the bolt and that will cut down on drag line creation quite a bit. I've given up caring about drag lines as long as they're not ugly scratched looking things (a polished bolt top helps there) and when they become bothersome to the eye a bit of cold blue will blend them back away if one is careful about it.
June 20, 2010, 11:27 PM
A drag line "around" the cylinder is the result of the bolt not retracting far enough to completely clear the cylinder. Lowering the hammer on the safety pins will not cause a drag line if done properly. With the hammer still in half cock line up a pin in the hammer notch then lower the hammer. The bolt will rise and be against the cylinder but when you cock the pistol the bolt will have retracted before the hand picks up the ratchet to start revolving the cylinder.
June 20, 2010, 11:45 PM
Dino all you need to do is try backin' off the trigger/bolt spring screw about 1/8 of a turn at most(adjust as required)...the problem should go away...as it also lightens the bolt hitting the cylinder too hard. No lines or gouges...and certainly you'd want the bolt head shiney.
June 21, 2010, 12:00 AM
With all due respect, backing off the trigger/bolt spring screw may make it take longer for a drag line to show up but it is not a cure for the problem and may cause the lockup at full cock to be somewhat loose. The problem is caused by the leg of the bolt that impinges on the hammer cam being slightly too short. The cure is to replace the bolt with one having a slightly longer leg. The bolt should nearly completely retracted into the frame at the point the hand picks up the cylinder ratchet.
June 21, 2010, 12:32 AM
Denster you are mistaken that ain't how it works...it drops the bolt head height also...I been at this for a spell and wouldn't offer a fix that I din't know would work. Besides he's already said all else has been done so what's left? It's simple thing tha most don't think about doing if they haven't tried it.
As the sayin' goes, " don't knock it till you've tried it. I've lost count as to exactly how many I've done that to but of my own Revs about 150 over the years. It's the first thing I do with a new one out of the box or new to yupo or me...:cool:
June 21, 2010, 12:45 AM
Smokin Gun. I now you've been at this a spell and so have I. You are correct it will drop the bolt head height, but only where you don't want the height dropped ie: full cock and hammer down. Think about the cycle for a bit and you will see what I mean. It will not drop the bolt head lower as the weapon is cocked as that is controled solely by the hammer cam contact with the bolt leg and nothing else. It will lighten somewhat the spring pressure against the bolt as the cylinder drags by but it does not correct the problem.
June 21, 2010, 03:04 AM
Thanks for all of your responses.
You guys really know your stuff. ;)
Long story short ...
After further inspection, I determined that the bolt was a wee bit too tall.
Not by much at all, but just enough to leave hints of a drag line.
So I removed the bolt, filed it down a bit. Sanded and polished it real good and reinstalled it.
I believe the problem has been solved.
Thanks again for all of your responses.
I've learned a helluva lot from you guys. :)
June 21, 2010, 03:06 AM
Denster, that;s why I stated to adjust ads needed... backin' off the TG/Bolt spring srew won't make the differance that you mentioned. I basically jus' barely back off the screw...all you need to do is lighten the snap went it hits the cylinder...with the clyinder removed I use my thumnail as it were the cylinder. Ifi hurts yur thumb back it off till I don't and be sure you the have bolt head up high enough on lock up. But I'm with you on if the bolt drops significantly you certainly will not like the way it'd try to lock up.
I know it ain't Rocket Science, it's harder to explain than to do or show ya know... :O) But it does work and it's an excellant starting point with any revolver new to a Pard or with a ring/gouge around the cylinder.
Very good point you made Denster ...that's a bit deeper than what I was talkin' about.
So ifin what I said don't do it for ya you have a lil bigger problem. You need to go to Part 2 when it's needed, what Denster is speakin' of.
That's for Part2...Denster you can post it as I'm typin' with one hand and my whole good arm in a cast :O)
June 21, 2010, 03:17 AM
I believe the problem has been solved
That's a job well done Dino.
These Revs well some look real simple but adjustment are not always simple or easyily acheived. Seems to me to be an ever learnin' process.
Must be why I like Old Revs.:cool:
June 21, 2010, 06:24 AM
Bolt drop is determined by the interaction between the leg of the bolt riding on the cam on the hammer.
Reducing bolt spring pressure well lower the bolt a very small amount, SG's method. Changing the position of the bolt leg well do the same, denster's method.
It's fairly common to see the bolt return spring to have more pressure than it needs. This well dent/peen the cylinder and sometimes cause a drag line.
It's not uncommon to have to tweak both those parts to get a nice smooth action.
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