.44 Chamber Mouth Diameters

What is interesting is that the early S&W 44s-by "early" I mean before 1970-were designed to shoot cast bullets. In those early days, cast was mostly what was available-unless you were going to military, or high powered rifles. Cast bullets then were often "oversize" compared to modern jacketed creations, so the larger throats. Throats were not payed close attention to-unlike today, where they are heavily scruitinized. One other thing interesting about larger throats, they generate less velocity than tight throats.
So, next time when you are looking at older load data, remember those 44's bled off a bit of gas-and thus pressure-before the journey down the barrel.
Have to smile at that Ruger number. For years and YEARS they made throats seriously smaller than minimum dimensions. Lead spitting, hopelessly inaccurate they were. Now, it seems they are going the other way. "Bout time!

For what it's worth,  here are some additional cylinder throat measurements I've taken (the Heavy Duty and the .44 Spls are recent snags):
 
S&W  '46-'47  .38/44 Heavy Duty:          .3580
S&W "early" 686:                                  .3570
S&W Model 19-4:                                  .3570
 
S&W Model 629-3:                               .4310
S&W Model 624                                    .4310
S&W Model 24-3                                  .4310

While I am not set up to measure chamber moouths to ten-thousandths, I have emasured my collection, and here they are to the thousandth:
S&W 1950 Target
Cimarron Bisley
Ruger SBH circa 1976
2 Turnbull Cowboy Classics
All measure .430 and all shoot well with no leading with Lyman 429421 and 7,5 gr. Unique. In the S&W, I usually load 16.5 gr. 2400.

My pin gauges only measure to five ten-thousandths, to be clearer. So I could be off just a little bit, but not so you'd notice, probably.
 
Never would have expected such a range of guns to measure to .430 as yours do.  Nice. And thanks for the load comments, too. Be interested in your load velocities if you've chronoed them.
 
 

Amity;
I will be chronographing soon, I hope. I keep thinking that retirement should be slow and easy, except every morning there is a new calamity to deal with. Day before yesterday it was finding that some fool had replace the lock on the gate to one of our properties with their own lock. I called the idiot brother in law to see if he knew anything about it. Of course not. So, I stated that I would blow the lock off with the 577 NE and hunt for the miscreant. The woods in this county are full of meth labs and Mary Jane farms. When I went up yesterday. the gate was open. So, I guess he did know what was going on. I spiked the other locks, put my own on,  and did a quick traipse through the hundred acres of thorn trees and briars. Today I am going to take another look. The joys of living in a fourth world society. My wife had me put up a POSTED sign. My thought us that people know if some land belongs to them or not. I digress. Hopefully, I can get in some shooting time today late in the afternoon when it cools off.

Mike

You won't be needin' to shoot any of those varmints. Chris

Calling them varmints would be an insult to the local skunks. My wife is a hell of a lot tougher than I. A few years back she used the Ithaca Featherlight 12 method of interrogation on one of them to find out who had been cutting the fence for their ATV. He sang like a canary.

I am thankful my talents with my artillery haven't been tested but it's good to know how others have handled these situations. Stay safe. Chris

Mike:
That'd definitely get my pot boiling, too, somebody staking a claim on my property like that. Sorry to hear about the meth and MJ. Nothing but the highest quality folks involved with that stuff. Plenty of both in Western Oregon. Not so many meth labs as previously;  now it comes up from Mexico ready-made. Fights plaque and promotes a youthful complexion, too.
 

I'm way behind on getting chrono results for my family of .44's. Being retired is no sit back and take it easy session. We have had visitors from all over the civilized world (USA above 4000 ft.) for the past month. Hopefully, I can get it done this coming week. 
I have been making visits to the outer property every few days, and I think the local ringtails have noticed. Also, been unlimbering the cannon several times a week testing loads. Gets their attention when their windows rattle.

Mike

OK. I finally got out during a brief period when it was not over 110 deg. and 110% Hum. Set up the Chrony F-1 in the pasture and let my grandson take down numbers while I shot.
Load 7.5 Unique    Lyman 429421          sized .430            lubed Lee Liquid Alox
Turnbull 748DT                                       Turnbull117DT                            Cimarron Bisley
        4 3/4                                                                  4 3/4                                                 5 1/2
 
        Ave
     958                                                                       963                                                        972
 
Didn't do the S&W 1950 because I ran short of loaded ammo. Now I have a plan for the weekend: Cast and Load.

MW,Thanks for the results.
Remembering we now have a new Unique, yet the powder seems to be stalwart. Your results are right up there, since this load has produced the mid-900's in velocity for many decades. A solid load.
How was accuracy?
Second thought, how is that Cimarron/Uberti Bisley?

Accuracy on all my 44's with this load is great. But, by far, the S&W and the Bisley are the most spot-on. I have had the S&W 1951 since the week after I read Sixguns in 1980. It shoot everything well. The Bisley I have had for three years. It shoots to point of aim at 30 yards, and keeps a nice, tight group. I haven't measured groups yet, but they are very good. The Turnbulls give nice groups, but go left for me. I am experimenting with my grip before I turn the barrels. The original owner told me that they shot to the right for him.
The Bisley is a bit stiff on the cocking end. I haven't tried a new mainspring in it because of the mainsprings odd shape. I may just try some delicate grinding and polishing. I have disassembled it and checked for areas in need of polishing. I really need to put more rounds through it first, though.
All my shooting will probably be put off for a few weeks when it starts to cool a bit. I have an inside shooting bench in the shop, but, when it is this humid, I am loath to expose the shop by an open window.
I am still using my cache of 15-to-20-year-old Unique. I have never found it to be "dirty". I bought a new 8 pound keg a few months ago at a gun show, so I may experience the new stuff sometime this year.
I need to do all the same with my 45 Colts. One is the S&W 25-5, and the other is a Beretta Stampede.
 
Mike

So, this is the old Unique you are using?
I have worked with new formula, changed a couple years back. I have tried a number of powders, but for some reason, probably having nothing to do with practicality, I keep going back to Unique.
IMHO, Unique is a little dirty, but it is certainly not onerously so. Now, real black powder, THAT is dirty!
I wonder if the mainspring on that U.Bisley is a leaf? If it is, you can shave it on both sides to reduce the pull. Only problem is, if you shave too much, and loose positive ignition, you can't put it back!

MAK;
I have tried Red and Green Dots, 800X, and of course, 2400. Indeed 2400 was the first and only powder I used in the Special for many years. 16 1/2 gr. worked like a charm. WITH linotype 429421's it penetrated like lightning. However, my Scots blood wants to use less powder, so I use Unique for both 44 spl and 45 Colt.
 
The mainspring on the Bisley is a leaf. However, it has a gooseneck in it, so Wolf probably doesn't make a reduced power replacement for it. So, I think I could do trial and error slimming on it. If I screw it up, I can replace it with another factory spring.
I need to load 250 r0unds for 44 tomorrow, I hope. I have enough bullets, so it should be short work with the Hornady LNL.
 
Mike

Mike,  thanks for the chrono info on the .44 loads. seems like Skeeter scaled down to 7.5 gr. Unique from 8.5,  and from your data that seems like a just-fine load.  I'll give 'er a try too.