Top break latch?

[model3sw]

Think of the evolution of the revolvers in USA. The Colt Walker, Dragoons, 1851 Navy and 1860 Army had NO top strap. The barrel held in solely by a tapered wedge and a line up pin.

Makes you wonder how much stress is actually placed on top strap and latch on the top breaks. Also, the frame / barrel assembly when fired with proper loads.

I've seen and handled many "well used" top break revolvers. Yes, the average, utilitarian or military use revolvers get loose and sloppy over time ... to a much lesser extent the Schofields.

Big mistake that S&W didn't want to pay the royalty to Gen. George Schofield to continue using the Schofield type latch / catch assembly.

However, a well cared for and maintained top break provides many years (to decades to now centuries) of faithful service albeit they have not been in daily use all that time.

 

[BMur]

That's very interesting about the topbreaks making it to WWII. I stand corrected. I could only find one in the model 5 hammerless 38 that made it to 1940. The perfected model sold almost 60,000. I'd say that rates for some popularity. My research of antique firearms transitioning to the new era of smokeless actually did see some form of change. Not necessarily to outward appearance but metallurgy and bore dynamics that must be mic'd to be understood. As an example, the .38 special was introduced and remains at .358. The original 38 S&W mic'd at .361. These changes were purposely done by the industry to protect the older guns when using smokeless powder to introduce lower pressures. I have not performed a bore study of the Smiths but this must have happened also or dangerous pressures would have been introduced to the older guns having black powder lands and grooves vs modern guns having narrow lands and grooves and reduced bore size. I would like to see a later model topbreak post 1900 and compare the bore rifling. Would be willing to bet that the rifling changed significantly. "Without Smith telling us about it". This to reduce pressure spikes from Smokeless powder use.

 

[coyotejoe]

That's an interesting thought on the change of bullet diameter to afford a pressure reduction but I'm not sure it applies since the SAMMI specs for .38 S&W still specify a .361" bullet diameter and most other cartridges retain their original diameter.
One pressure reduction practice I have observed is with the typical "Saturday Night Special" revolvers by Harrington & Richardson, Iver Johnson and such. All of those I have examined have unthroated chambers, meaning the chamber is bored full case diameter straight through. If you remove the cylinder from one of those you'll find you can drop a cartridge into the front end as easily as the rear. That of course makes accuracy hopeless since the bullet has room to wobble through the oversize chamber to strike the forcing cone off center and crooked. But it no doubt also reduces chamber pressure by allowing powder gas to blow by past the bullet.

 

[BMur]

Yes Sir, I did not perform a study on the Smiths. There were additional methods used by manufacturers to reduce pressure. Changes to land(rifling design) was by far the most common. Black powder barrels having wide lands (for the most part) there are always exceptions. All of the top break Smiths that I have examined have the black powder lands. But my study on them isn't really a study at all but the old and most common "eye ball test". You would have to perform a bore dynamic comparison with the early models as compared to the later models. Also a close examination of the rifling. Bottom line is there "must be" a difference. It might be subtle but it's there. Maybe when I get a chance I'll slug a few late models and post my results in a few days. I do have a perfection model that dates to post 1900. I'll dig that one out and compare the bore dynamics to the earlier Black Powder era variations. At this point though based on research from other firms, I'd put money on there being a detectable and consistent change with my caliper.

 

[coyotejoe]

I guess I don't understand why you say "there must be a difference". Most of our revolver cartridges and many rifle cartridges were originally loaded with black powder and smokeless powder loads were introduced for all of them. Even such outdated numbers as the .44 Henry rimfire were factory loaded with smokeless powder before finally being discontinued. Those smokeless loads were intended to be safe to use in the existing firearms of the day.
While smokeless powder certainly "can" produce higher pressures than black it does not have to do so. The ammo makers did much experimenting and testing before releasing new loads to the consumer. They made certain their ammo was compatible with existing firearms of the day, even if that meant settling for somewhat lower velocities than the full black powder load. Even today many factory loaded cartridges fall short of the velocities of the original black powder loads in order to assure pressures are safe in original firearms.

 

[glowe]

Yes Sir, I did not perform a study on the Smiths. There were additional methods used by manufacturers to reduce pressure. Changes to land(rifling design) was by far the most common . . . Bottom line is there "must be" a difference. It might be subtle but it's there . . . I do have a perfection model that dates to post 1900 . . .

Sorry, but I believe you might be reaching for straws here. You will find no difference in the rifling between pre-1898 and post 1898 top breaks. Many top-break S&Ws were made well past 1900. 32 DA mfg. 1919; 32 Safety mfg. 1927, 38 DA mfg. 1911; 38 Safety mfg. 1940; 44 SA (NM3) mfg. 1913; 44 DA mfg. 1913. These revolvers remained the same design, same materials, and the same rifling. The only change was that the post 1900s guns shot smokeless and the pre-1900 guns shot BP, all without concern over the small differences in ballistics.

I checked my antique 38 Double Action revolvers and compared them to my collection of 38 Perfected revolvers to find no difference in rifling, twist/pitch, lands or grooves. Also, you will notice that I did not call the 38 top-break with a thumb release a "perfection", but rather by the name both the company and collectors call it.

 

[BMur]

Ok, the wife went shopping so I managed to get some time in the shop. I pulled out the Perfected model and several earlier models.(Not perfection My fault: I was in the Utility business(explosive gas trainer) for 33 years and terms tend to co-mingle). I didn't eyeball the rifling but I did get out my multiple calipers and slugged 6 barrels in all. The land and groove design is visibly the same. But that's not what I'm trying to convey. The caliper is telling me that there is a difference between the earlier & late variations. I slugged and mic'd the models II and III.( I'm not hammering on my near mint model 1 thank you)..I also slugged and mic'd the perfected model. The earlier models have a .359 groove diameter. Matched on the model II and III's. With a land diameter of .353,.352,.352,.353, &.352. This variation is due to normal rifling wear. The Perfected model mic'd at .356 groove diameter with a bright and perfect bore having sharp but visibly shallow .354 rifling. This represents only a preliminary test. In order to perform a more accurate test I would have to slug and mic at least 20 of each variation. I would also like to slug the later models that date to 1940 or close to it. But this test not only suggests the bores are different but that the earlier variations had larger grooves and taller lands as compared to the grooves. You would also have to compare earlier black powder manufactured rounds, which we already know would mic at .361. To the later light loads of smokeless. Heeled vs hollow based? .361 vs. say .358/.357? I know, it's not a "HUGE" difference but it does in fact consistently register on a caliper and it was obviously done on purpose!
I also performed a "complete" and thorough test for the .41 caliber derringers of the black powder era. This was performed for a book that I wrote on the .41 rimfire short. "Huge difference" in Groove and Land Diameters. In fact that B.S. stigma associated with the Remington Double derringers being under powdered??? 400 FPS normal. That's wrong! There was a groove change on those that took place about 1896. I documented that in my book on 41's. It's obvious and yet nobody has bothered to mic the bores on them as well. They changed from .406 to .399!!! groove diameter at the turn of the century...Hense the smokeless era. The bullets also changed for the .41 rimfire from (.405-.411) to .401 in diameter at the same time. All this published info on the low velocity of the .41 is simply based on shooters using the "wrong" (Undersized ) bullet for the bore in question. This just further supports that the industry did in fact make changes to bore dynamics to protect the earlier guns from smokeless powder issues. That's all I'm saying fella's.

 

[BMur]

Here is a photo from my book on .41's. You can see the bore change without a caliper. This took place during the industry's change to smokeless powder. About 1896.

 

[glowe]

I have to stop doing all these side jobs, since I am retired and have too many fun things to do. Measured about 15 guns, both sides of the 1898 date. I can find no correlation between antique and post-antique guns. Certainly nothing that a soft lead bullet cannot handle with little or no difference in pressures. As I mentioned before, no change is design or barrel rifling and diameter by what I am observing and I have never read any accounts of barrel changes made during or after the transition from BP to smokeless.

The chart below includes models, serial number ranges, measurements, and ship dates.

38 Perfected, 1st Model . . . . . . . . 8,XXX . . . .361 . . . .1912
38 Perfected, 1st Model . . . . . . . 38,XXX . . . .359 . . . .1913
38 Perfected, 2nd Model . . . . . . .57,XXX . . . .360 . . . .1919
38 DA, 3rd Model . . . . . . . . . . .222,XXX . . . .361 . . . .1889
38 DA, 4th Model . . . . . . . . . . .485,XXX . . . .362 . . . .1906
38 Single Action, 2nd Model . . . . 14,XXX . . . .362 . . . .1878
38 Safety, 2nd Model . . . . . . . . . 72,XXX . . . .361 . . . .1893
38 Safety, 3rd Model . . . . . . . . .115,XXX . . . .360 . . . .1902
38 Safety, 4th Model . . . . . . . . .200,XXX . . . .360 . . . .1906
32 Single Action . . . . . . . . . . . . .56,XXX . . . .312 . . . .1871
32 Safety, 1st Model . . . . . . . . . . .4.6XX . . . .312 . . . .1889
32 Safety, 2nd Model . . . . . . . . 217,XXX . . . .312 . . . .1920
32 DA, 2nd Model . . . . . . . . . . . .20,XXX . . . .311 . . . .1881
32 DA, 4th Model . . . . . . . . . . . 247,XXX . . . .310 . . . .1905
32 DA, 5th Model . . . . . . . . . . . 272,XXX . . . .311 . . . .1905

 

[glowe]

View attachment 303361

Here is a photo from my book on .41's. You can see the bore change without a caliper. This took place during the industry's change to smokeless powder. About 1896.

I know that early 41 RF, and many other RF and centerfire cartridges, used heeled bullets, meaning that the bullet was the same size as he outside dimensions of the case. Later designs inserted the lube rings into the case, making the bullet smaller, while still being able to use the same size casings. This allowed the use of the modern ammo in older guns, since the chambers did not have to be altered. It is also reasonable that the new guns would reduce the bore diameter to accommodate for the smaller bullets. I do not believe that it had much to do with smokeless powder, but rather there was much criticism about outside lubed bullets picking up dirt and debris and losing their lubricity over time. References have been made that the Russians facilitated the change from the 44 American (heeled bullet) to the 44 Russian (internal lubed bullet) caliberr for that very reason.

 

[coyotejoe]

BMur, sir, I think you are confused in regard to the transition from black to smokeless powders. It was not necessary to adapt the guns to lower the pressure of the new powder since ammo makers loaded the new powder to pressure levels safe in the existing guns. It would serve no purpose to adapt new firearms for smokeless powder when those smokeless loads would still be fired in the old black powder guns, such as we are still doing today.
Your measurements show the newest revolver having a groove diameter of .356". Now how is that going to reduce pressure when the SAMMI standard bullet diameter remains a .361"?
I know nothing about the .41 rimfire except that being a rimfire the shooter has no choice but to shoot the bullets the ammo maker provides, there is no option of matching bullet to bore.

 

[BMur]

Hey Fellas, Please be patient. I don't know how Gary performed his research so fast. I'm not that fast. I'm in the process of pulling bullets from the black powder era 38 S&W's vs. smokeless and will present my findings as soon as I can.
As far as the .41 rimfire. I don't need to perform any more research for that round or the history there of. The .41 rim fire was introduced with the .41 Moores derringer in 1861. (Not 1863 as found on the internet). The first variation was actually a centerfire and introduced in late 1860. Found to be defective the Moores firm converted the model's 1 & 2 to .41 rimfire because that was a more reliable cartridge primer at that time in history. I performed close examinations of over 60 single shot and double shot .41 derringers and found a huge variance in groove and land diameter of early production derringers. The reason for this was "Black powder use" and also the fact that the firms were in no way standardized. In other words they did what ever they wanted without uniformity. They simply hired out a specific firm. Example: Remington hired out Union Metalic Cartridge Co. to engineer a special cartridge/bullet for their needs. Other firearms firms did the same for their specific firearm designs. The result was chaos with bullets, powder loads, case lengths, and bore dynamics. The only reason they got way with this was with the use of Black powder.
With the introduction of semi-smokeless powder in the early 1890s you will notice specific changes that took place with bullet types. Outside lubricated bullets now eliminated in favor of inside lubricated "Hollow based" bullets. Gary mentioned only one reason for this. Dirt getting on the lubricated bullet. But in reality the bullets were grossly undersized for both the 38L cal and 41L cal. They relied on expansion of the hollow base to seal the bore. This design did also reduce pressure.
With the 41 rimfire the industry decided to reduce bore dynamics and bullet size of the modern derringers. Primarily with the Remingtons since that variation was one of the only surviving examples to make it into the smokeless era. This bore reduction and bullet reduction to solve the same problem. Pressure!! Remember, This is 1898, not 2017. They did not have the plethora of smokeless powder types that we are fortunate to have today. The smaller bullet would still function in the older guns but the performance would be reduced considerably. The industry didn't care about that! All they cared about was safety and liability with the older guns. So if you shoot a smokeless round through an older Remington derringer it will function safely but the performance will be reduced considerably. The post 1898 derringers, That I posted a photo for all to see! has a smaller bore that is engineered for the undersized smokeless round and will produce significantly higher velocities since it has the correct size bore. They are .399 groove with the standard and post 1900 .401 bullet. I can't make that any clearer. I documented this change. My data is accurate.

What I'm working on now since I mentioned early on that I did not conduct a study on the Smiths, is a close examination of the bullets. I'm going to present photos of bullets, powder, cases, etc when I'm through with my study. Please be patient.

 

[BMur]

Ok Fellas, I decided to perform manual reference research prior to a bullet/cartridge inspection. I'm glad I did. Over and over again in my early loading manuals they list a bullet change for the original 38S&W from .361 to .358/.357. My loading reference is from the following manuals.
Ideal volume/circa;
5 1892
6 1894
8 1895
10 1898
17, 26,32,34,36,37,38,39,41 through 45, Lyman cast bullets reference circa 1955

Speer 1,3,6,7 &10....Very interesting reference to the early 38 S&W and I quote: The following loads listed are intended for and should be used only in modern solid framed revolvers. For safety sake, all hinged frame revolvers made prior to WWII should be placed in honored retirement. The 38 S&W sees little use and is fast fading into retirement. (just like us)

All of the listed loading references depict a ".358" bullet change from the original .361 bullet. This includes bullet molds post 1900! 358 being the first 3 numbers on the mold. Identical bullet design but a smaller diameter bullet. I also mic'd an original lead bullet from an ideal loader from the 1880's and found the original bullet was in fact .361. Right at the beginnings of the smokeless era for some reason the bullet was reduced to .358/.357.
Simple truth: The original .361 bullet was reduced in size to .358/.357 in the 1890's with the introduction of the semi-smokeless era. I can pull modern loads to further the point but it seems mute to me at this stage.
As far at groove diameter changes. Later variations would almost certainly have groove diameter changes with metallurgy improvements to match the .358 bullet. My Perfected model is a late serial number and mic'd at .356....That also makes sense. I would be interested in examining the latest variations that date to 1940 but I think I already know what results would be at this point.

 

[coyotejoe]

SAMMI cartridge specification as of present time.

 

[BMur]

Very cool drawing. You will notice at the base of the head an obvious taper on the brass shell(The bottom)? This is symbolic of a "balloon head" case. In other words, a black powder case. Ballon head cases had a deeper inner shell that surrounded a large primer pocket that stood up inside the case. Looking like a small tower inside the case. Shall I post a more modern smokeless diagram? As seen in all of my reloading manuals except for the very early antique manuals? I wonder if you might also post the written info on the page and where you obtained this drawing please.
The modern drawing will depict a "solid head" case. These cases have a squared off rim with a line above it milled into the case. Like a .38 special case. Also, if you look inside the case you will see a flat area at the base with a small primer hole. The Solid head case has been used basically since the beginning of the smokeless era. Modern cases also have no taper on the base of the head. They are designed for more pressure. The pressure you would see with smokeless loads. I collect cartridges also. They are really getting pricey. Especially the older ones like the example in your drawing.

 

[coyotejoe]

It's a drawing, not a photograph, none of the revolver case drawings show a groove ahead of the rim, that is shown only on auto pistol cartridges. Even such as the .41 magnum which certainly was never loaded in balloon head cases. It is the current specification for the cartridge, visit the SAAMI site and see for yourself, I'm surprised you didn't go there already.
Bad Request

 

[BMur]

ANS-SAAMI is a voluntary reference that was first established in 1979. The drawing on the 2015 website does not in anyway look like the photo of the drawing that you posted. They reference a maximum bullet diameter of .3610 with a tolerance of .0060 deviation. You can see the same reference with the .38 special. .360 with a tolerance of .003. Also the old 45 Colt they list with a bullet diameter of .456. That diameter is the "OLD" bullet as I have shot the 45 Colt many times in the SAA. Modern bores are 452-454.
Assuming that you reload for the .38 S&W I'd also like to know where you got your .361 bullet mold? If it's not too much trouble. I looked at my reloading log and found that I used a 105 grain SWC pure lead .358 bullet and saw excellent pattern shooting at 15 yards with a model 3 DA TB. Using Black powder. I also used a 148grain WC .358 bullet and saw very similar results. The only option that I am aware of for the .361 bullet is the antique Ideal field loader or the target 38/44 of later manufacture.

 

[BMur]

It's a drawing, not a photograph, none of the revolver case drawings show a groove ahead of the rim, that is shown only on auto pistol cartridges. Even such as the .41 magnum which certainly was never loaded in balloon head cases. It is the current specification for the cartridge, visit the SAAMI site and see for yourself, I'm surprised you didn't go there already.
Bad Request

Where did you see me reference your "Drawing" as a photo?

 

[coyotejoe]

I said "Drawing not photo" because a specification drawing shows only dimensions which are specified. SAAMI does not specify an extraction groove ahead of the rim of any revolver cartridge. Whether or not you like it that is the current specification for .38 S&W cartridge.
The bore of my .38 S&W mikes .361" groove diameter as nearly as I can measure a 5 groove slug. When I start to reload I will first try .358" bullets because I already have a bunch of them. If I feel the need for .361" bullets I can get them here:
ttps://www.grafs.com/retail/catalog/product/productId/21168
Or here:
.361" 145 Grain Round Nose Hand Cast Soft Lead Bullet 20-1 Alloy SPG Lube Bullet Box of 50 - Buffalo Arms
Or I can get the .360" bullets Magtech currently produces for their factory loads from here:
Magtech Bullets 38 S&W (360 Diameter) 146 Grain Lead - MPN: BU38SWA
Ain't the internet a wonderful thing?

 

[BMur]

Thanks for the info on the cast bullets. I did ask for available molds? I will get to work right away on correcting all of my manuals from 1892 - present day and correct them to circa 1979 Sammi "The Bible" of loading standards. God Bless The internet!