Slugging the bore

[Darth]

Hey !!! New member here and I don't want to sound "whiny" but ...

I've recently bought a 637 (Airweight) and I haven't been entirely impressed. I bought this NEW from a dealer in my area. Since I want a light practice load, I've been loading mild loads for this thing.

Well, I slugged this thing tonight and I came up with .3545 to .355 ??? ... I've slugged a number of bores over the last 35 years but this one surprised me ... so, I did it a second time ... same thing. It seems to get tighter as I pushed the slug (pure lead) down towards the forcing cone. Which is another issue. The forcing cone looked like it was machined with the sharp end of a claw hammer.

Now, I know that bores can get a tad tighter where they are inserted into the frame of the firearm but ... this one is aluminum. I fully expected this barrel to be around .357" ... not .355.

It also "almost" bound up as you approached the SA sear because the cylinder hand was about .010" too long.

Also ... the hammer and rebound springs were clipped on one end. I was told that S&W came to their facility and did some trigger work on all of the "Airweights" that were in their stock. This is a highly reputable dealer in my area ... so I don't suspect them at all.

 

[Kernel Crittenden]

I was told that S&W came to their facility and did some trigger work on all of the "Airweights" that were in their stock.

S&W has a traveling band of Service Techs that just show up at stocking dealers to do trigger work and spring clipping on their inventory? I highly doubt it. Per diem costs alone would kill them. If something was wrong, S&W would issue a recall and ship the product back to Springfield. This don't sound right.

 

[Darth]

Yea ... I really wish the guy hadn't told me that ... what made me look was a Failure To Fire in the first 25 rounds. The primer strike was real light. I tried it twice and it still didn't fire. When I got home I pulled the bullet and tried it in another revolver ... POP !

I did send an Email with pics to S&W direct ...

When I get a reply, I'll let ya know what the verdict is. I ordered Wolf springs to correct the situation and told S&W that as well.

I've fixed all of the issues except the bore size ... and I guess I might have to "lap" that to size as well.

I cleaned up the forcing cone as best I could but, there are still radial groves in it here and there from the machining.

 

[Darth]

OK ... I got a response from S&W ... and a very clever one at that !!!

"Dear Jim,

Our sales reps are not armorers and are not qualified to do that. If you change to Wolff Springs, please keep your original springs in case you need to send your revolver in for repair. "

So, "Our sales reps are not armorers and are not qualified to do that." ...OK ... so who did it ??? Did the armorers at the factory do that ? We now know the S&W reps can't. My guess is yes ... why would a large dealer take the time to disassemble a bunch of revolvers that far and cut the springs. I think the sales person at the dealer was feeding me BS about the trigger work and doesn't even know the springs are cut.

"If you change to Wolff Springs, please keep your original springs in case you need to send your revolver in for repair." This doesn't make much sense to me either ... They are neither admitting to the cuts or denying ... actually, to me, this is an admission of the springs coming that way. How could they honor a warranty if the springs are cut ?

Oh well, no matter ... I'm just going to move on. I was really hoping to find the answer but I guess it's not that important.

 

[Kernel Crittenden]

My guess would be they sold you a used revolver. First owner bubbaed it, brought I back for a refund. LGS resold it as new to you. Or someone at the store plays around with their inventory, bubbaing parts here and there (hey, they're doing YOU a favor, because, you know, they're so 'skilled'), then selling the guns as new.

 

[Warren Sear]

"Trigger work" does not equal clipping springs.

 

[John R]

My guess would be they sold you a used revolver. First owner bubbaed it, brought I back for a refund. LGS resold it as new to you. Or someone at the store plays around with their inventory, bubbaing parts here and there (hey, they're doing YOU a favor, because, you know, they're so 'skilled'), then selling the guns as new.

This would be my guess too, I'd be having a talk with this dealer and it's owner.

 

[Darth]

That's very possible ...

But why wouldn't S&W say the springs should not be cut ? You would think that they highly recommend getting a new stock set ... not evade the whole situation ... or they could say, "send it in and we will install a factory new set of springs" ...

I don't know ... this whole thing is pretty weird. I'm beginning to be sorry I ever looked into it. There are way more questions than answers.

And, I can't be absolutely sure but, there was a dab of red locktite on the crane retaining screw ... it seemed pretty fresh and undisturbed.

 

[Darth]

I agree on the "Trigger work" does not equal clipping springs" ...

quite the opposite in my book ... all it does it cause the spring to curve and drag on stuff ...

It just seems weird that S&W wouldn't say anything ... other than their sales reps can't do that ...

It's probably a very lightly used gun and I "sorta" got taken ... there wasn't even any sign of ringing on the cylinder.

 

[Coastie762]

What is the age of your 637 and what type of rifling does it have? Mine dates from 2007 and has the newer ECM rifling. Between that and the fact that most S&Ws come with an odd number of lands, this could make your bore slugging chore harder.

 

[k22fan]

Vader,

I didn't ask earlier only because you are new. How did you measure the plug you drove through the bore? Due to their odd number of lands and grooves, even with S&W's discontinued square cornered broach cut rifling you could not get an accurate measurement with only a micrometer. Like Coastie762 pointed out, S&W's current rifling created by eroding away metal with electricity has round corners which decreases measurement you'd get with only a micrometer. You have to lay the plug in a precision ground V block then measure from the bottom of the block to the top of a groove's imprint on the plug.

 

[Darth]

What is the age of your 637

It's dated 10/2014 ... well, the box is anyway ..

Since it is new ... it probably is a result of the Electro Chemical Machining ... It's just that the slug slides uniformly in the first 1.25" (or so) of the barrel and then gets pretty tight as I get close to the forcing cone.

I have a .356 sizing die I can double check it with ...

 

[Darth]

Vader,

I didn't ask earlier only because you are new.

LOL !!!

It's OK ... I'm just an older dude who has always loved shooting and working with guns since I was a young Jedi (LOL !!!) ... and Kaw Triples !!!

I'm not above criticism, correction or a good ol' scolding ...

 

[jtcarm]

If it's 5-groove like most Smiths, you don't have opposing grooves and a simple measure of diameter won't cut it. The measurement will come in small.

I don't know how to measure odd-grooves since I've always shot cast boolits where throat diameter is the critical measurement. Google or wait for an expert to show up to find out how.

I freaked over the same thing about 30 years ago when I did a bore slug of my 24-3 that came in at .427

 

[Darth]

I just put the slug through my .356 sizing die and it goes through with no effort at all ...so, I'm at least a tad smaller than .356 ...

Even a freshly sized bullet offers a good deal of resistance going through a second time.

I did one of my throats ... .3578 .3579 somewhere right in that area ...

 

[Nightowl]

With that many issues, I think I would just send it back to be fixed. Warranty work is usually turned around pretty quickly, according to testimonials on this forum.

 

[Darth]

With that many issues, I think I would just send it back to be fixed. Warranty work is usually turned around pretty quickly, according to testimonials on this forum.

I've got all the other issues resolved at this point ... other than the barrel size.

I'm going to slug the front section only and see what that is ... if it's correct (which I bet it is) then I'll probably just lap the forcing cone section in and call it good. I REALLY do like the fit and feel of this thing.

Like my son says ... I worry too much !!!

 

[Alk8944]

Darth,

First, it is not possible to measure a bore slug from a barrel with an uneven number of grooves without the appropriate gauge block for the specific number of grooves. The block for a 5 groove barrel has an included angle of 108 degrees.

The situation you describe of the slug getting tight as it passes through the frame area is typical of what is usually referred to as frame-choke or thread-choke. This is not usually found with EDM/ECM barrels, but it does reduce the bullet when found. It can be fixed/helped by fire lapping or hand lapping, but I wouldn't worry about it unless the barrel won't stabilize your bullets or is wildly inacurrate. Even a barrel with a thread choke will often shoot relatively well with jacketed bullets, even if it won't with cast.

I don't have an explanation for the cut springs other than possibly the gun was sold, Bubba played with it then returned it for something else/refund without revealing what he had been done. I can tell you with no fear of error that it did not come from S&W that way. As for the story about the factory reps. doing the work, this is absolute BS! I thing you place too much faith in the dealer!

The hand is not too long! S&W lockwork does not work that way. Final locking is on the side of the hand as it bypasses the ratchet lugs. A new gun being a bit snug is not uncommon, it will loosen fairly quickly with a bit of shooting.

 

[Kernel Crittenden]

Regarding S&W's response to your email. I think you basically just got a Form Letter reply. They weren't going to address your issues point-by-point, or speculate on what happened or who did it. Probably barley looked at what you wrote and your pictures.

The only thing they heard was something about putting in an aftermarket spring kit. They said if you do, keep the original parts incase it ever has to go back to the mothership. They'd replace your Wollff springs and you'd never see them again. If you disable the lock they void the warranty and send the gun back on your nickel (or so I've been told).

 

[Darth]

Thank you all for the wonder and extremely helpful responses ...

I have taken it all to heart. I believe I'll just leave the barrel as it is for now and just shoot the thing.