Hi all,
First, although I am a S&W owner, this post is not about a Smith, it's about a Taurus. The fact that it's a Taurus is not important, as you will hopefully see. I am asking here because everything of value that I learned about canted barrels has been on this forum. I value the knowledge of the posters here and I hope you can answer my question.

This revolver's barrel is slightly canted to the right (looking down the sights)...meaning that to center it, one would have to turn it clockwise, tightening it. The unusual part is, there is a clear mark on the frame, presumably where the barrel used to be. If the barrel were to align with this mark, it would be perfectly straight/level. I only noticed this after firing 15 rounds through the revolver, I don't know if was like that when I got it, but I think it was, since the mark is "dirty" and not "new looking."

My question is...what are some of the things that can explain it? Was it centered at the factory but under-torqued and loosened during proofing or test firing? Should I be watching for further loosening?

Is there anything else that could account for that mark?

Here are some pics (for the safety minded, those are snap caps in the cylinder):

I can't tell from the pics but apparently screwing a barrel on straight is a difficult task because gun manufacturers, even quality manufacturers like S&W, seem to have difficulty with this. I'm just going from memory but I think people have said that the factory specs are +/- 5° and if your barrel is within this range, they will send it back to you unchanged rather than running it by the torquer again to straighten it out. It's pretty tough when you can tell if it's crooked by eyeballing it better than someone can when using a dedicated machining fixture.

I realize that tighter tolerances are more expense, but it should be really difficult to tell if a barrel is canted just by looking at it. It's kind of like a car manufacturer assembling a nice car except at the very end of the cycle they put the hood on crooked. I guess I'll get off my soap box now.

Thank you for the reply, but my question is specifically about the mark.

I learned a lot about canted barrels from reading this forum, thanks to people like you. Thank you.

I'm not concerned about the barrel so much as I am curious about the mark. At one time or another, that barrel was straight! The mark proves it. I'd like to know how this is possible.

Oh, and one thing I did not specify, the gun was purchased new.

For example, if the barrel was perfectly straight but vibrated loose after firing, then it is undertorqued and will get looser with time, and I need to send it back. If not, I can live with it.

My guess is that in shooting the gun, the spin of the bullets going down the barrel torqued the barrel slightly loose (that is, if the loosening of the barrel and the twist-rate are going in the same direction).

I've seen that condition before while a practicing pistolsmith. As stated above the torque of the bullet spinning down the barrel is gradually unscrewing the barrel from the frame. Get it fixed as it will only get worse with more shooting. .............. Big Cholla

"Too tight" but shoots fine: No worries.
"Too loose": Keep an eye on it!

Easy check. Grab the barrel with one hand and the frame with the other. (Cylinder open.) Try to unscrew! If you can't move it using your own strength, then it's OK to shoot some more. But do the same check after each of several range sessions.

Whilst shooting watch for zero shift to the left that's not caused by a change in grip, trigger technique, etc.

Not a bad check to perform before purchasing any revolver, BTW. Have had two or three fail since '89.

You guys are great! Thank you.

Is there anything else this mark could mean?

Assuming it was like this when I bought it (I noticed it after 15 rounds and it hasn't moved since), could this have happened in the factory? Do they test fire their guns?

jaymore,
I'm fascinated by the "too tight but shoots fine no worries" bit. Are you saying an over-torqued barrel can somehow be detected by the way the revolver shoots?

Too tight would mean the threads were stretched and only removing it would tell. Could be something was wrong with the first barrel and they removed it and put on another or recut the shoulder and reinstalled the barrel. If the barrel is tight enough to mark the frame it most likely isnt unscrewing from shooting. You need a wrench for the frame and a barrel vice to keep from twisting the frame to do the work. I would want to make the correction. Your back sight must be way over to compensate.

__________________
A republic if you can keep it

Just about every .44 I own has a "too tight" barrel, but their sights center up fine. Don't know how many that would be, lost track years ago!

As noted, "too tight" might mean your rear sight is cranked way over to the left.

Or that accuracy is impared due to bore/rifling distortion. (Most often seen on those "big for their frame size" calibers.) I.e.:


A .40 caliber L frame Model 646. But given it's usage that bore imperfection doesn't adversely affect its utility. Have never shot this one past 30 yards or so, unlike the .44s!

Heck, I've a Python that's not perfectly plumbed and bobbed, and folk seem to think they're special...

Oh wow! That's...noticeable!

So what about all this talk of barrels failing and flying off at the frame joint from being overtorqued? Either from the factory or from gunsmiths tightening barrels where the sight is canted to the right as mine is? If THAT barrel doesn't explode the second you pull the trigger from being overtorqued , then what about an overtorqued barrel without such distortions?

All the talk is just things that get your attention over the years. Rare, but once seen, not forgotten.

Basically, just shoot until something happens. Which it probably won't.

As noted above, the usual "overtorqued" barrel will perform just fine.

The two worst case scenarios:

1) Over tight barrel breaks off. Accuracy goes to pot. Mostly because there's no front sight!
(Have yet to see this one in person.)

2)Undertight/bad thread barrel gets really loose. Barrel either unscrews to the point where it's noticable and something is done or (bad threads), it too goes sailing downrange. See photos below:

Again, accuracy isn't so good...




Oversized threads in frame AND poor machining on the barrel shoulder.



Recent trade-in at a LGS. I unscrewed the barrel by hand. Unfortunately, the oversized frame threads made this one essentially scrap. Would have been a good project gun, otherwise. Great timing and an excellent trigger. The previous owner probably just screwed the barrel back in after launching it, and made a quick swap!


Safety-wise, the user is in no particular danger except that misses aren't useful.

Don't overthink this sort of thing. Let the revolver tell you whether it's OK or not by using it.

And we see one more reason two, or three piece barrels are superior to single piece! The one thing that made the Dan Wesson GREAT was the end-user being able to remove the barrel and reinstall it...considering all the hoopla that goes into perfectly indexing and (over)torquing a barrel into a frame, how hard, and how expensive would it be for manufacturers to go to the DW system?
In this age of CAD-CAM...I can tell you...it's not "hard" at all...but it the makers think it would drive sales of new guns down...so here we sit in the 21st century buying revolvers with 19th century "tech," yet 20th century tech has already shown the way forward!

jaymore,
Thank you so much for your replies! You have a way of slicing through the fog to reveal the truth of things that is rare online.

I went out shooting my new 686+ 3" and saw that the front sight is way to the left, hitting 6-8" to the right at 10-15 yds. Sent an email to S&W to see what they will do about it if anything.

I bought a 629 classic hunter from g.b. guess what, over tightened barrel . It was enough that the rear sight had to be moved all the way to the left and still was not hitting the center of the target. I called smith, They sent a pick up label and said it would take 9 months. OUCH!!! just have to sit back and see what happens.

9 months is a long time for something that left the factory messed up

I called them today and they said I would be contacted by mail with my estimate. Did anyone notice the loaded cylinder in the first picture. hope the hammer wasn't back also. OOPS!!!!!!

I saw the last line. sorry

Forgot to update this! I got my S&W back a week after I sent it out, barrel is lined up and shoots great!! No hassle or fuss from S&W at all.

I got my M60 back a week after I sent it in. Getting the shipping label only took less than a week.

Great service.

My gun was new, however, so they may be giving new purchases priority.

Overclocked by more that the OP's picture, but fixed perfectly by S&W.

Dave