S & W Model 29-2 Cylinder Throat Size

[goodwrenchldj]

If fortunecookie45lc on YouTube is correct, when determining the correct size cast bullet for a revolver the diameter of the cylinder throats is more important than the barrel diameter. He suggests dropping progressively larger bullets into the chambers until one is found that requires a small amount of pressure on a dowel push it out. That works for my model 19-2 4" and on my model 38. However, the chambers in my 4" model 29-2 seem to be much too large. Lyman 429421 bullets sized at .4327 go right through. Has anybody else encountered this?

[376Steyr]

First post, Welcome aboard! Yes, you are on the right track about matching the bullet to the throat diameter. And yes, S&W throats can be larger than we would like them to be. I have to ask, did you use a good micrometer to measure the test 429421 bullets? Dial calipers aren't meant to measure to 0.000X inches, so you might have smaller bullets than you think you do.

[Old School Big Bore]

As-cast .433 boolits are a press-fit rather than slip-fit in the throats of my '70s M29-2 as well as my 624. Boolits sized to .432 will push through both. As 376Steyr sez, if you don't have a mic, borrow or buy one and use that.
Ed <><

[DeadWoodDan]

I'll just add also possible previous owner has opened the cyl. throats up. A member on this board, DougGuy, has done plenty for me and others.

[6thtexas]

I have a a M29-2 that I bought in the '70s. The chamber throats are large (.432-.433) and the 2 or 3 others I have seen from that era run large as well. I shoot .433" bullets through it. I used to just shoot soft .431" through it and they would slug up, but the .433" diameter bullets shoot better.

[Outpost75]

I also have a 29-2 from the 1970s. Throats pin out .433"

I shoot Saeco #441 as-cast and unsized, lubed with Lee Liquid Alox but otherwise straight from the mold with 16 grains of #2400 and it works well.

276314

[45DUDE]

I also have a 29-2 from the 1970s. Throats pin out .433"

I shoot Saeco #441 as-cast and unsized, lubed with Lee Liquid Alox but otherwise straight from the mold with 16 grains of #2400 and it works well.

276314
What size boolit does the #441 drop? My 29-2 has .443 throats but shoots a jacketed ok. I found some Factory .432 gas check Remington's at a gun show in big D.

[Outpost75]

What size boolit does the #441 drop? My 29-2 has .443 throats but shoots a jacketed ok. I found some Factory .432 gas check Remington's at a gun show in big D.

My old, old Saeco mold drops at .433. Cannot speak to their current production, but Tom at Accurate can cut a .433 mold for you.

[NuJudge]

I have a 29-2 from the late 1970's. I have measured the cylinder throats with pin gauges on it, and they are all .428". Most cast bullets I have shot in it are .429", or a little larger.

[243winxb]

Sized bullets at .430" to match .4295" groove diameter for me. M29-2 . Throats about .432"

Recently tried .4315" as a test, got leading.

[murf205]

If you do order a mold make sure that you get one to fit the largest cylinder you have, in your case, you really don't know yet. If you really want to know, you will need a mic like 376Steyr said and I will add that a set of about 6 or 7 pin gages, from .428 through about .434, are a big help too. They are not expensive and you can buy individual pins and not have to buy the entire set. I have seen people slug the cylinder throats with a soft led slug but the thought of beating on a 29-2 is not something I would do personally. Those big throats are not a bad thing. 2 of my most accurate 44's have .432 cyl's and .429 barrels. Welcome aboard, you will enjoy this site. Lots of really great people here.

[6string]

Historically speaking, .432-.433" could likely be taken as the "correct" diameter for .44 caliber as far as S&W is concerned. Phil Sharpe made a comprehensive list of bullet diameters for factory handgun ammo in the 1930s. Remington, Peters, Winchester are amongst the brands he measured. Of course, this is for the 44 Special. Just off the top of my head, the .432"-.433" range was the norm for 44 Special.
S&W pretty much stuck to that, based on the samples of pre-model number revolvers I've encountered in 44 Special and Magnum.
Nothing more than personal opinion really, but I have long suspected that the trend towards jacketed ammo beginning in the 1960s found the reduction in bullet diameter to be a useful way for the factories to keep pressure down while impressing consumers with high muzzle velocity figures. Does that mean that the assumption that .429"-.430" is the "correct" value constitute some type of revisionist history? (just a personal theory.)
In any case, experienced bullet casters have often found that the as-cast diameters using older molds from Lyman, Ideal, etc to be a good match to S&W throats.

[DougGuy]

I have a 29-2 from the late 1970's. I have measured the cylinder throats with pin gauges on it, and they are all .428". Most cast bullets I have shot in it are .429", or a little larger.

They might have been larger when you assembled the rounds, but they came out the front of the cylinder at throat diameter..


However, the chambers in my 4" model 29-2 seem to be much too large. Lyman 429421 bullets sized at .4327 go right through. Has anybody else encountered this?

If they are consistent, and you get a slip fit with a .433" boolit, I would suggest sizing to .433" it usually works best if you size to fit the throats.

[shooting on a shoestring]

Goodwrenchldj, welcome and I like your taste in revolvers!
Got your bases covered there in J, K and N frames.

Yep those should be fed a steady diet of cast boolits.

I’ve got a Colt SAA that has to have 0.434” boolits to fit its throats. Don’t worry if your 29 needs bigger boolits than what some people consider normal.

Heads up on getting bigger boolits and keeping them that way.

To get fat boolits the popular options are:
1. Get a mold cut from Accurate (or any custom maker) at any diameter you need (based on what alloy you’ll use).
2. Use a typical Lee/Lyman/RCBS/Redding and “Beagle” it. Beagle would put a strip of aluminum adhesive air duct tape on the inside of the mold blocks to space them out further apart and hence gain some boolit diameter, albeit a little oblong. Being oblong really doesn’t matter much bc they often get more round in sizing and sure enough get round when fired.
3. You can add a thousandths or two by controlling casting temperature, alloying and aging. Too much info for me to put in this post. There’s plenty of reading on the topics if you search.

Then after you get your boolits fat enough, the next step is to keep your reloading dies (and sized brass) from squeezing them back down too skinny during loading. Things to control there are:

1. The diameter of your neck expander, probably will need to have a bigger one. Sometimes the RCBS Cowboy dies/expander or Lyman M die is good enough. Sometimes you’ll need to get the expander for next caliber bigger and reduce its size to what you need.
2. Often though just hardening your boolits can give them the ability to resist being squeezed in loading.
3. Also annealing (softening) the necks of your brass can help.

The single biggest factor in getting cast boolits to shoot both accurately and without leading in your revolvers is to have the boolits start their journey filling the throats as they leave the cylinder. Get that right and the rest gets easy.

[Petander]

Shooting cast, uniform cylinder throats just make life so much better.

I had no idea until I bought my first reamer. I mean, I understood the concept but grossly underestimated the benefits in real life.

[murf205]

Unless you are a lot more dexterous than me (which wont take a lot) I recommend a micrometer holder. They don't cost much and it keeps the mic still instead of trying to manipulate the boolit and mic and then tighten the mic screw. I think I paid around $20-25 for mine.276395

[Rick B]

Pin gaged several 29-2's. Cylinder throats run .433.
Rick

[goodwrenchldj]

Thanks so much for all of your responses. I am absolutely amazed at the amount of information that you have freely shared. When I called S & W and gave them my Model 29’s serial number they told me that it was made in 1972. All of my measurements were taken with an inexpensive Chinese micrometer that I believe is accurate. When used to measure ten .430 Hornady XTP 240 grain bullets one was .4298, four were .4299, three were .4300, one was .4301 and one was .4302. Each Hornady was placed nose down on my bench for measurement as were my BHN 15 Lyman 429421 bullets. Within a few days I will measure some of my as cast Lyman’s, will try again to determine my throat size and will post the results.

[DougGuy]

You can always size to fit the throats, light drag fit, check for consistency, that is the single most important thing about a cylinder. Can't size to uneven throats.

[murf205]

goodwrenchldj, First and foremost question is how does your 44 shoot? Have you experienced any leading with the .4327 boolits you described? I have seen S&W revolvers with the throats the same size as the barrel that will shoot like a rifle. Never know until you shoot it.

[243winxb]

SAAMI lists a LEAD .432" bullet diameter & a barrel groove of .429" But there are tolerances listed. Comes down to, What works, works.

[Cosmic_Charlie]

My 24-3 has .432 "+ throats and does just fine with powder coated .431 boolits.

[zarrinvz24]

Thanks so much for all of your responses. I am absolutely amazed at the amount of information that you have freely shared. When I called S & W and gave them my Model 29’s serial number they told me that it was made in 1972. All of my measurements were taken with an inexpensive Chinese micrometer that I believe is accurate. When used to measure ten .430 Hornady XTP 240 grain bullets one was .4298, four were .4299, three were .4300, one was .4301 and one was .4302. Each Hornady was placed nose down on my bench for measurement as were my BHN 15 Lyman 429421 bullets. Within a few days I will measure some of my as cast Lyman’s, will try again to determine my throat size and will post the results.

You can get a nice Starrett or Mitutoyo Micrometer on the 'bay for a good price. I picked up a Starrett T230xfl-1 for $21 shipped last week. That's carbide anvils, friction thimble and USA made - doesn't get much better than that. While quality tools aren't cheap keep your eyes open for good deals. I try my best to operate under the "buy once, cry once" mentality; this has been reinforced over the years as I've been forced to upgrade to better tools - it would have been more cost effective to just buy the good stuff at the beginning. Good tools and equipment can make a dreaded task bearable. Just ask anyone that's got a Giraud case trimmer . . . :-)

[44MAG#1]

Let me throw this out here. Since it is known reasonably well the early S&W 44 Mag's had large chamber throats why did Mr Elmer Keith recommend sizing bullets to .429 inch? He carried an early S&W 44 Mag 4 inch gun and took Flying Fish, Flying Birds, Coyotes at a quarter mile, Mule Deer at 250 yards with it.
Was he just lucky to hit anything with a bullet sized to .429 inch in large chamber throats since it is the rage now to size to chamber throat dimension?
Could it be possible that he was just lucky and not really that good since he didn't know he was doing it wrong?
What could he have done if he had done it right?

[Outpost75]

Keith used soft alloys which slugged up. He knew exactly what he was doing:

Sixgun Cartridges and Loads (1936) on pgs. 69-70 states:

“For most revolver cartridges, including all light and normal pressure loads, there is no use to having the bullets harder than one part tin to twenty parts lead for really heavy loads a one to fifteen mixture is hard enough… For automatic pistols, the bullets should be very hard, consisting of about one part tin to ten parts of lead, in order for them to slide up easily out of the magazine into the chamber… A mixture of part tin and part antimony works very well for some heavy loads, but such very hard, brittle bullets are not needed for any revolver load except in the case of extreme penetration, where no upsettage or expansion is wanted.”



I have found Keith's suggestions to work in my last 50 years experience following them.

[44MAG#1]

Are you assuming theyalways slugged up concentric and in perfect alignment with the center line of the bullet?

[44MAG#1]

While I am not very smart, I know some alloy slugs up more than others due to hardness when run at a given PSI.
Now can anyone give me evidence that each and every bullet cast from a given alloy sized a given amount, fired with a given load will slug up the EXACT same amount bullet fired after bullet fired?
Will the bullet shorten the exact same amount slugging up the same exact amount to prevent the COG from varying and that the driving bands slug up the same exact amount to keep the axis of the bullet that it rotates around after it leaves the barrel exactly the same as to prevent unnecessary yaw which would affect accuracy. Especially at long range.
If anyone can point me to a detailed study to answer my questions I would appreciate it.

[Petander]

My simple observations regarding mod 29, yes,often large throats.

I only have one at the moment, a 29-3 with .433-4335 throats. I slugged the barrel too but can't remember it any more,it was not large though... all I know I'm shooting the same .432" bullet that my 629 with reamed .432 throat likes.

That 4" 629 rings a 75 meter bullet trap with every shot. The good old 10" 29, maybe three times out of ten. No matter how fat a bullet I feed my 29, the barrel has the last word for a good size.

There's not much one can do with oversized throats and a standard bore. I just shoot my 29 and live with it, accuracy work is another thing altogether.

I have a -84 Redhawk with nice throat / groove ratio... I just wish it had a S&W trigger...

https://i.postimg.cc/FRqGtRTF/IMG-20210206-011645-791.jpg

There is no limit for better accuracy. I almost quit all shooting ten years ago when I wasn't good enough, my 300 meter 1" BR groups were bad, my timed 0,5 sec pistol doubles were bad, nothing was ever good enough.

Just go shooting and enjoy your 29.

[mtgrs737]

I have measured several S&W 29's and a few 629"s and the blued 29's always seemed to have throats in the .433 - .434" diameter. The 629's were mostly undersized at .428" to .430" range. I suggested that if their owners wanted to shoot cast in them the 629's cylinders would need to be shipped to Doug Guy and have him open them up to .431" which he did and they shoot well now with cast which is what their owner was into. Leading was a problem with the tight throats. I have three pin gauge sets that cover diameters from .011" to .500" and are +.000" Minus .0001" and use them for precise measurements of throats. You can as someone here suggested just buy individual pin gauges in .428" thru .435" and you should have good coverage. In my experience stainless cylinders seem to run undersized when compared to blued steel cylinders probably due to higher wear of the stainless and companies trying to cut costs by re-sharpening reamers which can reduce their diameter. I recommend pin gauges and Doug Guy to fix your cylinders for you. A local machinist might measure your throats for you as a favor or for a six pack if you know any.