S&W 29-5 problem

[waco]

So I have never done any serious shooting with this revolver. I'd like to change that. I measured the cylinder throats tonight and they all measure .429"

I have never slugged a barrel until tonight. I've always been scared to try it. Well I cast a 44 slug from pure lead and gave it a go. all was fine until I got right in front of the forcing cone. MAJOR barrel constriction......

To the best of my abilities the slug mics out at around .423"-.424" So now what? Fire lap? If so, what does that process involve? Can some one give me step by step instructions and hold my hand through the process?

That seems WAY TOO SMALL for a 44 barrel....

Any help would be great. I'm sure I'm not the first guy to run into this problem.

Walter

 

[waco]

This is the tool I used for measuring the cylinder throats along with a mic.

 

[Brad]

Got access to pin gauges? That is what I would use to measure throats.
As for firelapping, it is controversial at best. I have done it and gotten good results.

Use a fine grit, maybe 320, grease based lapping compound. I bought a couple cans of Clover brand from a shop that sells machine tools. Use a soft, like even pure lead, bullet. You want a bullet that gets squeezed down in the constriction and doesn't bounce back in size. This lets you lap the constriction but not the bore beyond it. Roll the bullets in the abrasive with some force. Get the grit embedded into the bands. Use unsized cases and seat bullets by hand or with a 7/8-14 bolt. Light powder charges. Shoot for just enough to get bullets to exit. Shoot at a target or berm so you KNOW the bullet exited the bore. Shoot 6 then clean the chambers and barrel. Shopt maybe 24 rounds, clean well, and remeasure. It isn't a fast process at all. I actually did it in my garage shooting into a 5 gallon bucket of wet dirt covered by a couple layers of drywall. The drywall kept the dirt in the bucket and left me see holes to know I got bullets to exit.

Goal is to just remove the constriction, no more. Might even try 24 then clean well and shoot a baseline load. Does it lead? Any change in accuracy? Of course this means you shoot before starting the process with a known load.

 

[Brad]

Oh yeah, use bulelts that are a slip fit thru the throats. Let the grit lap the bore, not the throats. Based on your measurements that shouldn't be an issue.

 

[waco]

Ugh.......

 

[waco]

Thanks Brad.

 

[Ian]

Bill just fixed one by cranking off the barrel, facing off a thousandth, and screwing it back on. Never heard of that trick before but he said the choke pops right back out.

I have a 429-3 that's choked at the frame, bulged in front of the frame, and somewhere in-between the rest of the way out. If it weren't for that bulge, it would already have been converted into three Rugers.

 

[Pistolero]

I don't think you should fire lap. All that you need to do is unscrew the barrel, take off about .001 to .003 from the shoulder
and screw it back in with hand pressure and blue Loctite. I have done, or watched done, multiple excamples, and
the restriction goes away when the excess tension is removed.

If you don't have a lathe or access to a lathe, it is possible to remove this material with a file if you are VERY careful,
work with a fine cut file with a safe (smooth edge) and use colored marker on the shoulder, then with perfectly smooth
and regular strokes, just remove the color evenly. Then check fit, and do it again until it will screw up into clocked
position by hand.

If you have a lathe, make a brass pin from 5/8 or 3/4 brass, cut it to bore diam plus .005" and tap into the muzzle. It
will engrave on the rifling, will not harm the barrel. Grip this in the chuck and put a live center in the forcing cone end.
Take off .001 from the shoulder, and .002 from the area outside of the shoulder contact ring. Then check fit. Repeat
until it clocks with no heavy torque. Either way do NOT cut a sharp inside corner as you do
this, leave a radius.

I just did this to a Model 14 and it has zero restriction now, had about .002 before. Never seen it fail to work, the metal is
still in the elastic range, will spring back if you let it.

Look at my post in "Projects" - S&W Kit Gun, not what you think.

Bill

 

[gman]

My Super Blackhawk Bisley was constricted like that. Also had a really big cylinder gap. After removing the barrel to make the cut to set it back for a tighter gap we slugged the barrel again. The choke was gone. We hand tightened 12 degrees before TDC then tightened. No choke. Worth checking out for sure.

 

[JSH]

As mentioned a pin gauge is a bit better way to measure. You need the ball end gauge, yours looks to be flat? Won't give a true measurement.
I have seen SW with a lot of thread choke. One of the guys here took just a bit to much off the shoulder,most people would not have noticed it. He used red lock tite and got it where he wanted it. No choke and it has had thousands of rounds through it with no problem. A good soak in some solvent and then to a heat gun or hair dryer and it will come loose.
FYI on the thread choke, he sent it back and SW said there was nothing wrong with it, with in specs.

 

[9.3X62AL]

S&Ws have 5-groove barrels, you'll need a tri-poise micrometer or a V-block/conversion chart and conventional mic to get the actual groove diameter.

WHY S&W began crush-fiiting their barrels in lieu of pin-fitting c. 1980 is another mystery from the dawn of time.

 

[Ian]

Bean counters. You need them to make a company efficient, but they can cripple what some consumers will consider valuable product quality. Making money in the general civilian gun market seems usually to be about minimum deliverables, not about unnecessary refinements. The unfortunate fact is that an overwhelming majority of these choked revolvers will never be known by their owners to have any problem. Can hit bucket at ten feet? Check. Never shoot those nasty lead bullets because they lead up the barrel? Check. Don't shoot more than one box of jaxketed every couple of years? Check. There ya go.

 

[waco]

WHY S&W began crush-fiiting their barrels in lieu of pin-fitting c. 1980 is another mystery from the dawn of time.

Okay....I now understand why sellers stress the fact the revolver has a "pinned" barrel......

 

[Ian]

Most sellers who stress that also wax poetic about "recessed" cylinders. Maybe they know why it's desirable, maybe they're just parroting sales rhetoric, but at least YOU know now.

 

[Pistolero]

yActually, the crush fitting is just cost savings. It costs time (= money) to fit the barrel shoulder
and clocking correctly. Most folks shoot jacketed, and a frame constriction isn't as critical for a
jbullet. Add in the fact that most folks are really poor pistol shots and many/most customers
can't tell the difference. The get the clocking to within about 45 degrees and then crank it in
with a big wrench. Most customers can't shoot and can't measure the restriction, so they get away with
the cheapo method.

The pin doesn't do much. Starts to engage after 10 deg turning on most. Meaningless, actually.
Blue Loctite is the real solution. Put the pin back in to look pretty, if it has one.

Recessed cylinders are a reliability problem -- crud can build up in the recesses, holding a
round out and preventing closing or smooth rotation. A flat cyl lets the crud fall or wipe off.
Only in a rimfire is the rim carrying pressure, so it is not stronger with any centerfire round.

If you can unscrew the barrel, cut about .001 to .002 off the shoulder face - whatever it needs
to clock up with hand pressure - and reinstall with blue Loctite, the frame restriction will be
gone.

Bill

 

[waco]

If you can unscrew the barrel, cut about .001 to .002 off the shoulder face - whatever it needs
to clock up with hand pressure - and reinstall with blue Loctite, the frame restriction will be
gone.

You guys make this sound way too easy..........I have my doubts........

 

[Pistolero]

As the great American philosopher Harry Cunningham said, "A man has to know his
limitations." Maybe you can do it, maybe not. Only you can judge.

If you have and know how to use a lathe, it IS straightforward work, maybe not easy. The crux would be making a
frame wrench if you don't have one. Using a contour gage (bunch of pins in a friction fit bar
housing), make a pair of oak blocks which fit the frame at the front. You can clamp them in a
bench vise with these blocks, but be careful, you CAN crunch the crane and/or bbl hole in the frame if you
get horsey with a vise. If you make vise blocks, then drive out the pin (if it has one) and using a crecent
wrench with leather or heavy cardboard against the lug, unscrew the bbl.

Make the brass muzzle insert, turn 5/8 or 3/4 brass rod about 1.5" long to bore diam (not groove)
plus about .003-.005, a bit of bore diam pilot, say 1/2" long is good, too. Tap into muzzle, chuck
brass rod in lathe, indicate in if your chuck won't hold better than .003 or .004 without it. Put a
live center in tailstock (it IS correctly centered, right?). Face off .001 from bbl shoulder and then move
out wards the width of the frame collar (around 1/8 radial) and take off another .001, so only the collar
can hit the frame. So the rod is: ~ 1/2" long full diam., 1/2" long bore diam + .005, 1/2" of bore diam pilot

Remove from lathe, screw in bbl by hand. If it will clock up with hand or maybe light tension with padded
crescent wrench, clean threads, add blue loctite, tighten bbl. You need to verify clocking by looking down
sights VERY carefully. You can put a straightegde against the naked grip frame and then sight this edge against
the front sight.

If it won't clock, repeat the "remove .001" part until it does.

It really IS that easy. --- If you have a lathe and know how to use it.

It can be done with a safe-edged fine cut file, but you need to be a smooth, confident filer. Taking
off .001 with good uniformity is possible, but not the first time you ever did good file work.
I have been filing to fit things since a kid, so I would do it, but I a fairly good lathe and access to
even better ones, so don't have to.

Careful work, a lathe and a bit of skill.....it works. Not for the 'get a bigger hammer'
kind of person. You need to judge your skills. The methods are exactly as I have described,
no magic, but it takes a bit of skill, many can do it, many cannot. I can't judge your skill
set.

One more point. No big deal if it clocks past too far by say 10-15 degrees. Just put red Loctite
on and clock it. The Loctite will hold it just fine.

Bill

 

[Ian]

I never thought about attempting that job with a file, but I just might. I have a good feel for a file and know the basics like clean the pins every stroke, how to keep it flat, etc. Doing a few barrel dovetails with a safe-edge triangle file will test your skills. I'd think if you can dovetail properly you could set back a revolver shoulder.

I wonder about lapping in the last 5 degrees or so of the shoulder/frame face with valve lapping compound? Also, coating the mating surfaces with threadlocker would make for a 100% contact, and if you put a layer of grease over the outside to take the air away it will actually cure.

How about roughing the frame blocks with coping saw and rasps, then dabbing on some epoxy and "bedding" them to fit the frame? Probably not necessary but it might eliminate pressure points.

 

[Pistolero]

I do frame blocks with a router to a marked line, then fit with a rat tailed file and
60 grit paper on blocks and dowels. Need a decent fit, but not perfect. DON'T CRUNCH
THE FRAME! You are just holding it, no need to do much past removing the slack. Just
enough so it doesn't fall out. I would say about 80% contact is good enough. Sloppy fit
near the bbl threads is OK, get your best fit farthest away from the threads, that is where
the real torque is applied, near the bbl threads nothing much going on, waste to fit it
super well there. Need wide contact patch, well distributed down where the crane
pivot is, get uniform pressure there.

I wouldn't lap, don't want grit there. If you make a tube which fits the OD of bbl threads on the
inside and cut some rings of 320 or 400 grit wet or dry, you could hand polish off .001 or so pretty
quickly and evenly, too. Get Brad to make you a tool, spun by hand. A 5 minute lathe job.

If you can fit a dovetail, it shouldn't be hard to file. Like you said, clean the file, hold it flat. Mark with
Sharpie, cut off one layer. Check fit and then mark again with Sharpie. One file stroke on each place,
or two, but the exact same number of strokes then move the file. You are removing a TINY
amount of metal.

Just thinking, soot the bbl shoulder face with candle, check fit, file only on high (shiny) spots second time
around.

Don't overthink this. Get it to clock 5 deg short and use a wrench, you will get no measurable
crush. Even 10 deg is probably OK to wrench down, but if you can get closer, do. My .38 bbl
factory clocked to above 45 deg, had about .001- .0015 crush.

Bill

 

[GaryN]

All I can say is WOW!!!! Lot of good info. in this thread.