I recently purchased a M66-1, 4 inch bbl, Mfg. 1971.
The gun is in very nice overall condition. I have had it to the range twice now, tried various types of ammo in both .38 and .357.
The issue is that the gun just will not shoot straight. One shot is high left and the next might be low left. Just no consistency.
The lock up looks to be good. I do not see any obvious problems with the gun.
My question is does anyone have a suggestion of what to look for??
If left to my own troubleshooting, my first step is to have a gunsmith re-crown it.

Before going to a gunsmith, it will be well worth your time to do the following:

1. Benchrest the revolver, with the butt on sandbags. You may even want to rest the barrel, to insure there isn't an involuntary "yip".
2. Run several types of ammunition through it, both .38 Special and .357 Magnum.
3. Are the sights adjusted incorrectly?
4. Try a variety of bullet weights.
5. Have a friend assist you, and insure that he/she also shoots the same mix.
6. Insure that you are not pulling the trigger incorrectly. Incorrect trigger pull will cause pulling to the left, especially for a right hand shooter. You could be involuntarily flinching. Flinching in single- or double-action shooting will cause a left and/or low, left pull.
7. Try bore-sighting if you have one available.
8. Try a drill in which you don't know if the gun is loaded, and shoot your regular routine. Have the person helping you determine if the cylinder is loaded, so you are shooting blind to the recoil.
9. Is there any apparent damage to the crown? Nicks, dings, etc.

I know some of these are very basic tests, but I don't know your skill level, and my recommendation is to start at the lowest knowledge level possible, and work your way up. Good luck.

Greetings-

You did not say, was the pistol rested on sandbags or clamped in a shooting vice during this test? Also, what size of group was involved at what distance. Depending on the ammunition/distance involved this can vary greatly.

If the pistol was not rested/clamped one could look at two things- grip and trigger pull. If the grip doesn't fit your hand, and you are changing your hold, this will change shot placement. Also, if the trigger is heavier/lighter than you are accustomed to it may cause you to break the shot at different times, leading to the differing shot placement.

Note- these are common issues for Bullseye shooters.

Good luck!
m19862

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Member, OGCA.

Excellent advice from Dennis; I'll add only two things:

1) When you use the rest, be careful blast from the front of the cylinder doesn't singe the rest or you, and

2) Use single action to determine accuracy; it'll help dial out the greater room for operator error inherent in double action.

Hard to offer much helpful input.

What distance are you shooting?

How far from poi ?

Are you shooting from a rest?

I would be reluctant to start carving on the revolver until I'd shot it at 25 yards from a good bench setup.

If it's unsatisfactory after that, I'd sell it and find another: chasing something like this can be a real money pit.

Thanks for the replies-let me answer some of the questions raised.
Bench rest-yes
Different bullet weights-yes
Different ammo mfg.-yes, both factory & reloads.
Shot at 50 feet.
Shot single action-yes
Loaded & unloaded chambers-yes (no noticeable pulling or flinching.
Different grips-yes
The impacts can vary 4 to 10 inches between shots.

Crown damage-I have observed some tool chatter marks on the crown. How much is too much? I don't know. I have read elsewhere that re-crowning can make a significant difference if the original crown is damaged.
I have several S&W revolvers and have never had one that shot like this one. Also, I have been shooting a long time.
Someone mentioned selling it. That is a possibly but I don't like the idea of passing along a problems to another person.

Let somebody else shoot it . . .

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Wisdom comes thru fear . . .

Every revolver and pistol I have goes through periods of not shooting straight. Ruger no longer answers my e-mails. Smith & Wesson has threatened legal action if I don't stop harassing (their word) them about it, and Colt simply hangs up on me soon as they realize who they're talking to.

Someone from Glock did return one of my phone calls, but he was speaking German and I couldn't understand him. He sounded sort of angry, though. Does anyone know what trottel means? What about narr?

I'm at my wit's end.

Is there anything that is loose, such as the rear sight? How about excessive lead in the barrel?

Hats off to the OP for being reluctant to sell the problem to someone els

Have you checked to see if the sights are loose?

My first step would be to send it to S&W. You must have an accurate diagnosis BEFORE you begin surgery.

Is this suppose to help the OP and his problem ?

If what you say is so ( and I have no reason to think otherwise) My suggestion is to send it to S&W. Darn shame, but that's the path of least resistance, and we pay for quality and Smith & Wesson backs their product, in my experience.

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Halfway and one more step

My question for OP, since you didn't mention it, is what is your basis for comparison? Are you an experienced shooter who normally obtains good accuracy from revolvers, or is this your first handgun? If it is as bad as you seem to infer my first guess would be an experience issue. Handguns aren't as easy to shoot as many think they are!

Give us a bit more to go on. I can tell you it is not an issue with the crown! This would put all shots off in basically the same direction, not all over the place.

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Gunsmithing since 1961

well,one way could be that if you belong to a range or club see if you can locate a Ransom Rest with proper grip inserts and test it that way. If it were me i'd try to find someone that is a verified better pistol shot than me and have them shoot it.

10. Are the sights STABLE? Make sure they're not loose. A friend once wasted a bunch of target .22lr hitting nothing before he realized that the front sight on his rifle team issue Remington 40x (shared with beginning college rifle classes) was loose... when it FELL OFF.

To address some of the additional comments---
Yes, I am an experienced shooter. I have several other S&W revolvers-models 18,19,27,36,327,586,657,686,642 and of course this M66. I have not had any issues with any of the other guns. If fact some are very accurate.
I usually shoot initially from a rest at 50 feet to benchmark the gun.
I save my targets after the gun is sighted and scan them to a file.
I reload so as I change powders, etc I can evaluate the differences.
I have shot this gun with both factory ammo and reloads. Also,both 38 & 357 ammo.
Someone mentioned that a crown issue would causes all shots to be off in the same direction. That is a good point. I will add that most all of the shots are off to the left but some are high and some are low.
Mentioned also was lead in the barrel. I closely re-inspected the barrel this morning and I see no evidence of leading.
I do plan to have some else shoot the gun when I can arrange it.
I have access to a couple of gunsmiths that I will get an opinion from soon.
Thanks for the comments to date. If anyone else should think of something please let me know.

You might want to check the cylinder throats. Virtually all .357s that I have checked have throats that are right at .357 plus or minus very little, maybe .0005 or so. BUT, I had one 627-2 that would throw a bullet far from the rest. When I measured the throats, one was a full .01 large. Smith replaced the cylinder, shoots consistently now.
One other thing to check is how the chambers line up with the barrel. The best way to do this is with a range rod, that is available from Brownells. Almost all Smiths line up well, but since you seem to have an unusual gun, something is out of whack! (Technical term)

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Richard Gillespie
FBINA 102

10. Are the sights STABLE? Broken windage screw making the sight blade move around? Stripped threads on the blade? Wicked bad leading? Dunno. Good luck.

Nope, sure isn't. That's just silly ol' me trying to inject a bit of humor, that's all. I sure hope that answers your question.

Looking through the thread, I don't see any suggestions, constructive or otherwise, offered by you, either.

We have this quaint old expression down around where I live...something about people who can't take a joke. Wish I could remember how it goes.

It's called "humor"

humorVariation | Phrase
Houghton Mifflin

n.noun

The quality that makes something laughable or amusing; funniness.

That which is intended to induce laughter or amusement.

a writer skilled at crafting humor.

The ability to perceive, enjoy, or express what is amusing, comical, incongruous, or absurd.



I had a similar problem with a revolver one time. It turned out that the barrel was completely fouled with lead. It was hard to see with the naked eye, but when I started to clean it, I couldn't believe all the junk that came out. Once I had removed the fouling, it shot like a dream.

And an observation: OP if your revolver is indeed a 66-1 it has to have been produced some time in the late seventies. I have a no dash 66 and SCSW puts it's date of production as 1976. The serial number on mine starts with a 9C25XX.

FWIW I picked up a very nice used 66-2 at a gun show some years back. Couldn't get it to shoot for beans. Thought the barrel wasn't clocked quite right, so boxed it up and sent it in to S&W. When it came back it shot much better with all loads. About that time I noticed that the muzzle was worn slightly egg-shaped, presumably from ridiculously enthusiastic cleaning. Screwed up my courage and seriously recrowned the muzzle to where it looked like a GP-100. But it worked. Now it's one of my best shooters.

Sometimes it takes all hands on deck. The elves at S&W are good at what they do.

Revolvers are not simple machines!

Good luck. There's a good gun in there somewhere, trying to get out...

I think I'd order a Lewis lead remover.

So you are just having an elevation issue, or is it also windage ?
Since you are an experienced shooter I am probably insulting you by
saying the .357 magnum rounds will typically impact about 10 " lower than the .38 at 50 feet (50 feet is a long way btw) .That's normal .
So are you saying that if you stick with one brand of ammo , same grain etc. your shots are all over the place even when shooting single action from a rest , OR are you saying that you are shooting all kinds of ammo, loads, grains and the shots are all over the place ?
What happens if you bring it in to about 30 feet and strictly use one one type ammo ?


Lewis

Am I interpeting correctly , up to 10in groups @ 50 feet ?

Nick, it is sure intended to help. You’ve have forgotten that misery loves company. Ole Watchdog just wanted to let the O/P know he was not the only miserable person in the world.

Added:

Jim, I remember how it goes. Ya want a hint?

Update--The sight(s) are not loose. The barrel does not have leading.
Today I took the gun to a very well respected gunsmith. He said the crown looked like someone had tried to clean it up but also said it did not look to be a problem. I told him to recrown it anyway.
He said the forcing cone looked rough. He will also address that.
He will also do an overall check of the gun.
I expect it back in a couple of weeks.
I will eventually post the results.

Night owl may be onto something. While your gunsmith is checking make sure he sizes the cylinder throats. I've only had one revolver that had similar issues with accuracy. In that case the cylinder throats were all small and different sizes. Thus each bullet fit the barrel differently. When all were properly sized, accuracy returned to what it should have been. BTW, my example was not a Smith. None of my dozens of S&Ws ever had an issue with cylinder throats. In fact, I have never had any such issue with a S&W. Other major manufactures, yes, but not S&W.

Update--I have received my M-66 back from the gunsmith. He cleaned up the crown which he said looked like it had been tampered with and also cleaned up the throat area which he said was rough. Everything else looked good to him.
Range report-I shot about 100 rounds on Saturday. 38 special factory and reloads and 357 reloads. I am pleased with the results. Very much improved accuracy.
I also had someone else shoot the gun and the results were good.
I have to say that the gunsmith fixed it. I cannot tell if the major problem was the crown or the forcing cone (throat area) but is now a keeper.

I sure like happy endings. Glad it all worked out

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SWCA # 2887