New Model 21 vs 629-1, some observations.

[dbriannelson]

My new nickeled M21 leads like crazy, where the old 629-1 hardly ever does, using the same .431 bullets I cast back in the '90s.  So I took a look at it more closely, once I'd scraped the lead out.

The forcing cones of each are 18 degrees, best I can figure out.  The new M21 has a cone that looks like it was machined with a broken file shard, all stepped and ugly.  The 629-1 has been shot with Keith loads for 15 or more years and the cone is slick and shiny.  I figure 3000-5000 full, hot loads have polished it some, but I can't remember it ever being that bad.

The chamber throats of the 629-1 mike out to .432, while the M21 is somewhere close to .427 or .428.  That would probably work OK with jacketed bullets, but I'm pretty sure it's way too tight for the .431 Keith bullets.  The throats (and chambers) also show gross machining marks.

So I've ordered an 11-degree forcing cone cutter from Brownells (along with the gauge) and a throat reamer and plan to fix it. 

In addition to that, I've changed the lube on the bullets from an antique mix of Alox and motor oil to a dry lube that should act as a sealant as well as a lube. 

I'll let you know how this all works out once the mods are made.

It's great to be back fiddling with my Smiths.

-Don

[dbriannelson]

On the Model 21:  Well first, one can't cut an 11-degree cone from an 18-degree cone.  There's nothing but air there.  I'll keep the cutter - maybe it will come in handy some time.  And I'll buy or make a lapping cone to fit the factory 18-degrees to smooth it out.

Jeff Quinn convinced me to let S&W have a chance to make the revolver good.  I wrote them and am waiting for a reply.  If I don't get one I'll go ahead and ream the throats myself.

Flitz!  Everyone talks about it and today I bought some.  Gets the lead out!  I guess leading isn't all that annoying anymore.  Also bought one of those Pro-Shooter lead cloths which seems to do the same thing. 

On the other hand, I shot 50 rounds of .44 Special and 30 of .44 Magnum out of the 629-1 today and cleaned it and put it away within 45 minutes, only using the cloth for the front of the cylinder and the tight spots between the aft end of the barrel and the top strap.  Lead just doesn't stick to that slick old gun.

-Don

[dbriannelson]

I got tired of waiting for S&W to answer the email on fixing the new M21 and went ahead and reamed the cylinder throats to .431 using the Brownells tool.  Slick!  Used the .4280 guide and some cutting oil and the throats came out MUCH smoother than they were from the factory.

Haven't had a chance to go shoot it yet, so I figure while I'm at it I should slug and lap the bore and polish the forcing cone.

-Don

[dbriannelson]

Just got back from a road trip and headed to the range with the Model 21 and it's fresh throats.  I shot 150 rounds of mixed old and new loads, cleaning the bore every 6 or 12 rounds.  Apparently I didn't scrub it well enough, as the grooves just forward of the forcing cone and the throats were leaded when I got it home and did the real cleaning.

This morning I'll get the last bits scrubbed out and head for the range again.  Primarily I want to chrono some loads through both of these revolvers, but I figure the more bullets I put through the M21, the better it will get.

So...reaming the throats wasn't the complete answer.  I talked to a well-known gunsmith in White Sulfur Springs, Montana, when I dropped off an OM Ruger for conversion to .44 Special, and he seemed to put a lot of weight on fire-lapping.  We'll see how it goes this morning, but I may have to do the lapping eventually.

-Don

[AtlLaw]

So...reaming the throats wasn't the complete answer.

I read this thread with great interest!  It seems your primary concern is leading, but please tell me about your accuracy!

I have a 2" Taurus that I got to scratch a 44 snub nose itch.     Accuracy at 25 yards isn't what I would call acceptable, even with my old eyes!     I just slugged the barrel for the second time and, again, it measures .430.  The throats all measure a pretty uniform .428.  I'm shooting 240 gr. Keith's and RNFP's cast from WW's and sized to .430 as well as Hornady swagged SWC's.  I was thinking of (maybe) having the throats opened up to something like .4305.   

What was your accuracy like before and after you opened up the throats?

[dbriannelson]

The throat reamer I used was 0.431" and the only one Brownell's listed.  I think that's probably what you want for the throats.  They should be 0.0-0.001" over actual bullet diameter I understand.  You could probably size the reamer down five tenths, but I'm not sure what you'd gain.  The groove diameter should be a smidgin smaller than the throats too, so it looks like your Taurus would fit the bill with the throats reamed.

And yes, my primary concern right now is leading.  As I don't scope handguns and can't shoot off-hand well enough for an inch at 25 to make a difference, I don't measure accuracy of handguns.  (The only revolver I own that doesn't shoot as well as I do is the 351PD in .22 WMR.)

Message me if you want to borrow the reamer.

-Don

[dbriannelson]

The grip frames of the two revolvers are different, of course.  The Model 21 has the recent round butt and the older Model 629-1 had the square butt with the grooved front and backstrap.

A long time back I rounded the butt on the 629 by cutting off the heel and contouring the frame to fit my smallish hands.  The backstrap grooves were continued with a triangular file, Sambar stag grips (now nicely yellowed) fitted to the frame, and a Tyler T-Grip adapter added.  The toe of the butt was made concave as a place for my little finger to fit and the whole thing is my idea of the best possible combination of fit and looks.

The Model 21 comes with reproductions of the pre-Magna scales made by Altamont.  They are nicely checkered and finished glossy.  But you can see that they weren't fitted by S&W on the round butt frame.  They overlap the frame.  And because they don't fill the void behind the trigger guard they are difficult to use, particularly shooting classic one-handed offhand. 

So I've been thinking about what to do about them.  Yesterday I ordered another Tyler T-Grip in polished aluminum and will use it with the factory Altamont scales.  I'll strip the glossy finish off and fit the contours to the grip frame (not touching the checkering) and hand fit the T-Grip to get a tighter interface with the frame and scales.  The result should retain that old-timey look of the nickeled revolver, yet still be functional. 

Other options that crossed my mind were to go purely functional with smooth wood boot grips, or to go completely pimp with mother-of-pearl scales. 

The next thing to think about is a holster.  Currently it rides in a black crossdraw I made from skirting leather for the 629 about fifteen years ago.  Looks good, but not really period.  I would like to come up with something more 1920-ish for it.  A fancy-tooled Tom Threepersons from El Paso Saddlery would be nice, but there are other options I'll think about.  The 629-1 rides in a Jordan Border Rig copy I made using skirting leather.  The belt seems to have shrunk over the years though.

Obviously I plan to keep the Model 21, despite the initial problems encountered.  It is a pretty revolver.

-Don

[AtlLaw]

Message me if you want to borrow the reamer.

Thanks Don, that's a very generous offer.  I have never done anything like that before.  Is the job idiot proof?  I'd rather spend a few dollars then take any chance on messing up a throat!   

[dbriannelson]

I suppose one could screw it up, but it's unlikely.  The tool consists of the reamer, a handle to turn it, and several pilots in diameters meant to fit snugly into the existing throats. 

Put the handle on the reamer, select the pilot by finding the largest that will fit the throat, pull the c-clip with a needle nose and put on the right pilot, lube the tool generously in cutting oil (about $2 at any hardware store), insert it into the chamber end of the cylinder and turn clockwise slowly.  No forcing or effort required.  Add cutting oil once in awhile by dribbling it down the reamer while cutting.  When the reamer comes out the throat end, clean it off by blowing or with a brush, as you don't want to drag chips back through the throat and scratch it.

Repeat five more times.

The tool is self-aligning and actually does a better job than it needs to.  Many people effectively do the same thing by chucking a slotted dowel in a hand drill and using fine emory cloth to enlarge the throats.  That works too, but isn't as precise. 

-Don

[dbriannelson]

The continuing saga of the M21 and leading.  I put 100 rounds out the barrel yesterday.  Leadhead 250-grain Keith bullets over 7.5 grains of Unique - the classic Skeeter Skelton load.  I did some scrubbing after 30 rounds, again at the 60-round point, and before I left the range.  Yet, alas, there was leading.

This time the lead mostly peeled off nicely with a slightly oversized patched jag.  Some more stubborn deposits remained but the lead cloth and Flitz removed those quickly.

I think there's been some improvement, but there's room for more.  Still thinking about hot-lapping.  Also thinking about loading some jacketed bullets for a bit to see if they affect the machining marks.

On the grip front, I stripped the factory Altamont scale grips to see if I can fit them more closely to the frame.  They were heavily varnished, so it isn't quite done yet.  I'll reshape them to fit the grip frame AND to fit the T-Grip.  The T-Grip itself has such a bad profile that I don't think I can shape it to fit the wood, so we'll go the other way around.

Anyone know what happens if one mills a nickel-plated revolver for adjustable sights?  Does the plating chip?  Nickel is softer than steel, so maybe it mills just fine.  I don't know.  That tiny, shiny rear sight is pretty primitive, but the Model 24 isn't legal in California (probably S&W's unwillingness to part with sufficient examples for the state to destroy in "testing").

-Don

[dbriannelson]

Recent stuff done with the New Model 21:

The T-Grip now stays put.  I stripped the grip scales and subtly reshaped the front to better fit against the T-Grip, and it seems to be working pretty good.  Need to finish the scales and should probably go find some tung oil. 

-------

This evening I installed a Patridge front sight blade on the Model 21.  All S&W pinned front blades are interchangeable and replaceable.  They don't tell you that it's tough to get the old one out, and when you order a blade you've got to drill it to fit.  The drill size is something like 0.053"  It also has some fore-and-aft location choice, so it's got to be positioned where you want it. 

I had a couple of 0.056" bits and stoned down one of them, and also a tiny punch to push the roll pin out (put it in a baggie - if you lose it and don't have a replacement, you're screwed).  The old blade was pulled with pliers using some leather under the jaws, after the pin was punched out.

The base of the blade has zero slack in the slot.  In fact it's a slight interference fit, so it must be tapped in with a wooden tool (I used a hammer handle).  It can then be tapped back and forth to find the position you want. 

Once I had the position that looked best, I used the stoned-down drill bit to mark where it was to be drilled, pulled the blade back out, put it in a vise and drilled it slowly with a hand drill, checking squareness and using cutting oil frequently.  Then I hammered it back in place with the wood handle, tapped it to line up the holes and tapped the roll pin back in place, gently using a brass punch, so as not to scratch the nickel finish or damage the pin.

Looks pretty good, and it will go a long way to helping me see the sight at the indoor range where the light is bad.  The Patridge is about 0.02" taller, so groups should be about 3.5" lower at 25 yards.  Don't really need that, so I'll see how it really shoots, then drawfile the sight down to where I want it with the Skeeter Skelton loads.

--------

And due to the on-going leading problem, I finally ordered some hot-lapping bullets.  Cleaning IS getting easier already, but it's still nothing like the 629s, where lead doesn't stick much, but if it does, it peels out with a nylon brush.  As I don't have any empty brass, lapping will probably be a job for after I've been back to the range with it.

-Don

 

[dbriannelson]

Today I ran all five grits of hot-lapping bullets through the Model 21 to once again try to fix the serious leading problem.  I have no leading problem at all in either 629-1, so it's been bothering me a lot.

The results are good, so far.  The rifling lands are mirror-smooth now.  They weren't bad before.  The grooves still have the longitudinal grooves-within-the-grooves, but the lateral stutter marks are almost polished out.  Not completely, but much, much better.  No lapping appears to have been done to the chamber throats, but I had reamed them to 0.431" earlier and as the lapping bullets provided are standard jacketed bullets impregnated with compound it's not surprising they didn't expand to fill the throats - particularly as the instructions were to load the rounds to the manual minimums.  I used 5.7 grains of Unique under these 250 grain lapping bullets.

There is also no effect on the nasty forcing cone "machining marks."  I had expected that the forcing cone-to-rifling juncture would be cleaned up better.  From the factory, that part looked pitiful.  It still does, though maybe a little shinier.  You can still see where the cutting of the forcing cone upset or smeared parts of the lands, rather than cleanly cutting through them.

Shot six, cleaned.  Shot six one grade finer, cleaned.  Etc.  Brought the revolver home and cleaned it thoroughly, a little surprised to see copper in the bore.  Shouldn't have been, as these were jacketed bullets, but as I only shoot lead, it surprised me a little.  I hate to use one of the heavy-duty copper solvents in this nickel gun, so I'll continue with Hoppes and scrubbing until it's gone.  Then next weekend or maybe tomorrow I'll go shoot it seriously and see if there's a noticeable improvement in the leading situation.

And I'll also figure out how much to lower that new Patridge front sight blade.

-Don

[dbriannelson]

...and today I put 80 rounds downrange.  These are the Skelton loads using Leadhead Bullets' 250-grain Keith over 7.5 grains of Unique.

First off, felt recoil was noticeably lower.  It was this way for about the first thirty rounds, then recoil started feeling sharper.  I know this is subjective, but it was distinct enough that I thought it should be mentioned.

After 50 rounds I swabbed down the bore and chambers with Hoppes #9, as usual.  Scrubbed with a nylon brush several times, then used a jag to run a few patches through the bore and for a couple cleaning passes through each chamber and throat.  Then I shot another 30 rounds, wet the bore and drove home.

The result of the hot-lapping is all positive, but it didn't solve everything.  The lands of the bore don't lead at all anymore.  Nada.  The grooves still lead up, but are significantly easier and faster to clean, cutting bore cleaning to less than half the time previously.  (The lateral chatter marks from the factory broaching tool are almost gone now due to the fire-lapping.)

Chamber throats are as they were.  Hot-lapping didn't show on those and they lead up.  Not as much as before I opened them up to 0.431" when the factory machining marks were horrible, but still they took some scrubbing.  At least I can use a nylon brush on a cordless drill on those.  I may get that throat polishing tool from Brownell's.

Because all the bore leading is right afore the forcing cone, I am considering just breaking the cone/bore junction with the 11-degree cone cutter.  That's where the rifling was smeared or upset by the factory cone-cutting tool, rather than being clean cut through the lands.  I figure knocking off that small confusion of metal can't hurt and might reduce leading even further.

I can't say a thing about accuracy.  I was shooting worse than usual today, as I couldn't focus on the front sight at all, even though it's that new black Patridge.  When I did get momentary focus, I couldn't judge the top of the nickeled notch back sight under indoor range lighting.  I really need a good black adjustable rear sight.  I don't think there would be any trouble milling and drilling the top strap for it.  I can use a milling machine next door.  Maybe a J-Frame sight assembly?  I need to do some looking around...

-Don

[docmagnum357]

I had similar problems with a vintage pre model 29 44 mag.  Ironically, it is nickel, too.  I used a little bit of valve grinding compound on a brass jag wrapped in steel wool.  I know, I know, this isn't "proper", but irt sure cut down the leading.  i get almost no leading now with a bullet cast from an ideal 421 429 mold.  It is just big enough, as cast, not to push through the throats.  I am going to make a proper lap, and try that, as the gun has zero collector value.  One question i have, maybe related, maybe not.  I have one cylinder that seems to refuse to release brass.  The only load i use is 9.3 grains of unique, in a magnum case, standard primer, aand the 250 grain keith, cast from ww.  If i didn't know better, i would swear the chamber is shaped like a bell, because the brass will start out of it, and then stop, after about 1/8th of an inch..  The other five cases simply fall out.  It didnt do this when i got it, but it seems to have started since i got the gun.  If I had bulged the chamber through an accidental double charge  (would 18.5 of unique bulge a chamber?) wouldn't there have been some other simptoms?  Would the darn thing even revolve?  The chamber does seem really rough compared to the others, and I have lapped it with 1500 grit wet dry sandpaper on a dowel.  that helped a little, but not much. Ideas?   

[dbriannelson]

My guess is that a double load like that could bulge a chamber.  Do you have a way to measure inside diameter like a hole gauge?  Something you can stick into the front of the chamber, lock and see if it comes out.  Might want to check a used tool store that carries machinists' stuff to see if you can get one cheap.  Otherwise something you know to be a straight edge that fits inside with a strong light from the other end.  I'd try busting a razor cartridge for a blade.

If the sides are parallel, then it's got to be a matter of roughness.  I'd be real careful about using anything coarser than rouge cloth to polish.  Brownells sells a chamber hone that looks just like a tiny auto cylinder hone.  I don't have one yet, but it's getting closer - I still need something like that for the throats.

Good luck.

-Don