Velocity difference in .45 Colt Black and Smokeless mo

Traditional ballistics charts show the full black powder .45 Colt round as having a 250 grain bullet at 910 FPS.

The smokeless load lists as just 860 FPS, BUT the BP round was chronographed in a 7.5 inch barrel The smokeless in 5.5 inch barrels.

If the smokeless load is fired in a 7.5 inch barrel, will it equal the old BP load?

I've always read that the smokeless load is milder. Who has chronographed both? In both barrel lengths...

What are you shooting it out of. My old Speer #10 shows for the 7 1/2" Blackhawk or Contender a max of 1262fps with W296 and a max velocity of 904fps out of a 5 1/2" Colt single action with HS5.

I've never loaded 45 Colt.

A 2 inch difference in barrel length can make a substantial difference in velocity, but there is more to it. Differences in bore and groove diameter and the smoothness of the barrel will also affect velocity. Chamber variations can affect velocity. Then there are differing methods of measuring velocity and the distance from the muzzle of that reading.



Ballistics by the Inch used a test barrel, cutting it back 2 inches at a time and it looks like the difference in velocity between a 5 inch barrel and a 7 inch barrel is around 125 fps, so I'd say that, if anything, the black powder loads might produce a little less velocity than smokeless powder.

I went to the Alliant powder co. website . They list 9.5grs of Unique equals 941 fps using a 5.5" test barrel with a 250gr speer bullet ( soft lead) and not exceeding SAAMI specs of 14K psi . I hope this helps , Regards, Paul

You guys aren't understanding the question. I'm not talking about what can be done by modern handloaders, some using Ruger - only .45 specs.

What I want to know is: in the early 1900's, when BP loads were still on the market in factory ammo, how much, if any, would a man lose velocity if he fired the smokeless cartridges.

And I wonder what difference there is now in BASIC .45 loads by the major makers, when fired in the different barrel lengths common in the Colt SAA. I haven't found tests along those lines.

Elmer Keith inferred the .45 BP load was hotter, again in ammo from major makers, in the early 20th Century.

And I wonder how current loadings fare.

Texas Star said:

You guys aren't understanding the question. I'm not talking about what can be done by modern handloaders, some using Ruger - only .45 specs.

What I want to know is: in the early 1900's, when BP loads were still on the market in factory ammo, how much, if any, would a man lose velocity if he fired the smokeless cartridges.

And I wonder what difference there is now in BASIC .45 loads by the major makers, when fired in the different barrel lengths common in the Colt SAA. I haven't found tests along those lines.

Elmer Keith inferred the .45 BP load was hotter, again in ammo from major makers, in the early 20th Century.

And I wonder how current loadings fare.

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Considering any commercial load as to be on the downside of blackpowder pressures, for fear of being used on an antique revolver. I'll tell you, without even trying, they will be under 150 fps or more than the blackpowder counterpart.

I did not try .45 Colt, true, but I did try .44-40. in a 5 1/5 barrel. BP load of .35 grs FFFg, 200 grs lead, around 1050fps. Remington "high velocity" 200 gr softpoint jacketed , 830 fps.

Bear in mind that velocities in a test barrel will always be higher than in a real revolver. There is no cylinder to barrel gap and the barrel tolerances will be tighter than in any revolver.

Edit. Removed the .38-55/.357 Win part of the post, being proved wrong about it. See BB57's post #8 below.

Which smokeless powder?

You can get velocities that are under the original black powder load, as well as velocities that exceed it, using different powders, all within SAAMI pressure specs.

Kurusu said:

.../

/...About pressure liabilities. In the late 70s Winchester blundered with their "Big Bore 94". Their "new" cartridge had very similar dimensions as the old BP .38-55 round , and could be chambered, and fired (with catastrophic results ), in a old 1894 in .35-55.


.38-55 Winchester.

.375 Winchester.

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Actually no, Winchester got it exactly right and did so very intentionally.

Let's look at the dimensions:

The bore of the .38-55 Winchester has a .379" groove and .373" land diameter.

In comparison the .375 Win used a .366" land diameter and a .376" groove diameter.

In addition, the chamber diameter at the case mouth of the .375 Win is .4015" in diameter with a diameter of .3785" at the start of the throat, at 2.1229" with a straight section to 2.1929" before starting a very long and gradual taper to bore diameter.

In contrast in the .38-55 the case mouth diameter is .3949" in diameter, tapering to .3943" at the throat.

The distance to the start of the throat in the .38-55 is also 2.1182", compared to 2.1229" in the .375 Win. That makes the .375 Win very large and long throated compared to the .38-55, particularly in regard to it's smaller .375" bullet diameter.

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What this all means is that a proud new BB 94 owner, upon discovering that .375 Win ammo was very hard to find (which was precisely the case and one of the ,major reasons the .375 Win failed commercially), could shoot factory .38-55 ammo in the .375 Winchester BB 94 without blowing anything up.

Why? Because the .375 Win's generous chamber (.4015") and throat (.3785") dimensions allowed the longer .38-55 cartridge to chamber with ample room for the case to release the larger .378-.379" diameter bullet, which in turn would enter the throat and be sized down .002" to .003" to the .376" groove diameter in the long tapered throat.

That sizing of the bullet does potentially increase pressure in the case above the 30,000 CUP limit for the .38-55, but it is still well under the ability of the modern .38-55 case to contain. (The .30-30 case walls are identical and it operates at 38,000 CUP.) Just as importantly, the pressure is well under the 52,000 CUP pressure limit of the .375 Win round so there is zero risk to the rifle.

Conversely, if the proud owner of a trusty .38-55 happened upon some .375 Win ammo and fired it, the shorter 2.080" case would easily chamber in the longer 2.118" .38-55 chamber and when fired, the smaller .375" bullet would essentially rattle down the .3943" throat, and into the .379" bore with minimal engraving (.001") from the .373" rifling. Which means the pressure generated in the chamber would remain within the .38-55's 30,000 CUP limit.

Winchester didn't authorize it, and warned against it for legal reasons, but they were smart enough to know it would occur on a regular basis and designed the .375 Win round and chamber accordingly.

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If larger .380-.381" cast bullets are used in the .375 Win, the larger but softer bullet still sizes in the long throat. The problem with cast bullets in the .375 Win however are related to the large .4015" throat. Ideally with a cast bullet the cartridge will be no more than about .001" smaller than the chamber at the mouth - just enough for a clean release, and the bullet will be about .001" larger than the throat, providing rapid obturation to prevent gas cutting. Those conditions are just not met in the .375 Win. It also has a much faster rifling twist rate, which tends to increase leading with cast bullets.

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Below are my .38-55 Model 94 rifle and my .375 Win BB94 carbine.



I enjoy shooting them both. I save dedicated jacketed .375" bullets and both Winchester and Starline .375 Win brass for full pressure .375 Win loads. However I also occasionally shoot .38-55 cast bullet hand loads in my .375 Win, but it's rare as they shoot much more accurately in my .38-55.

@ BB57( by the way, is this USS South Dakota related?)

I stand corrected.

But I seem to remember reading about blowing up a .38-55 using .375 WIN in it. Maybe I got things mixed up. I've been wrong before.

Back to the OP's question: years ago, there was a column in a gun mag about this. The writer tested the 40 grain black powder load with the 255 grain factory type bullet and got just over 900 fps with a 7 1/2 inch barreled Colt SAA. I believe there was discussion in the article about balloon-head case being used for this. Sorry I can't remember more. By the late 1940's my W. H. B. Smith "The Book of Pistols and Revolvers" was listing 870 fps (429 ft. lbs.), in a 5 1/2" barrel. Not too shabby!

Excellent discussion. During my very active years in cowboy action shooting I collected quite a few Model 94 Winchesters in varying calibers. During a period of time when I was no longer really active in that game, and became interested in other things, like S&W revolvers, I sold all of my 94s except for two - and I had some nice ones! The first I kept was a plain Jane .30-30 that I bought in the early 1980s that was pre-USRAC but post-64 and is still one of my favorite guns.



The other one that I kept was a Big Bore 94 in .375 Winchester. I need to take a picture of it. Simply gorgeous rifle and fun to shoot. And I have an ammunition supply but if I can't find .375 Winchester now I know I can shoot .38-55 in it!

Groo here
1 the smokeless are lower pressure due to old guns..
2 there were many loads military and civ.
3 the black powder load , a full case to the bottom of the boolet,
gives a true 900 + from the 7 1/2 inch P model colt.
Much of todays Bp is of a lesser quality to the older stuff,[english was best]
Bp burns much faster than smokeless but has a pressure limit
it can't exceed., unlike smokeless.
The pressure applied to the gun is much faster with BP
but over a much shorter time span..
Smokeless powder has a longer "time" to bend old guns....

Early BP .45c loads where loaded in balloon head cases. Modern solid head .45c cases have less powder capacity, hence you cant get "old time" velocities with traditional BP in modern cases.

The original 40 grain BP / 250 grain bullet load did not last long as a service load, and was most found as a reduced velocity load as issued.

I think most standard factory loads tend to try to duplicate this slightly less velocity load.

Larry

The problem with .45 Long Colt is that due to its lineage as a Black Powder cartridge, factory loaded Smokeless Powder ammunition is often downloaded just on the off chance that Bubba inherits an original Colt Single Action Army or something which predates Smokeless Powder and ignorantly stuffs it with modern Smokeless Powder cartridges.

As you can probably imagine, Smokeless Powder loads would have to be substantially downloaded to be safely fired from a Black Powder firearm, and while most companies skimp just enough to make sure that in the event that it is fired in a BP firearm it won't turn into a literal hand grenade when fired, others seem like they're trying to make it safe to shoot indefinitely out of a BP firearm.

So while most factory loaded .45LC Self-Defense ammo is loaded hot enough to have similar performance to .44 Special or .45 ACP, there are target loads which are honestly downloaded to the point that they offer similar performance to .38 Special. Honestly, there was a YouTube video on Military Arms Channel in which while testing various magnum cartridges, Tim chronograph's some Federal American Eagle .45LC target loads which it calculated as delivering a whopping 200ft-lbs of energy, which is roughly equivalent to Standard Pressure .38 Special or .380 ACP SD loads.
Fortunately, some manufacturers offer true SAAMI Spec .45LC loads which can push a 255gr bullet at 1050fps, delivering a good 555ft-lbs of energy, and is safe to shoot in any modern Smokeless Powder firearm, although sadly most of them are Boutique loaders like Buffalo Bore, Barnes, Cor-Bon, etc, so they command a premium.

Hence why most folks who like .45 Long Colt get into handloading in the first place, because factory loaded ammo is expensive, and target loads can be loaded so darn weak that in some cases it isn't even good for training, yet handloading allows for truly powerful full SAAMI Spec loads which leave otherwise respectible SD cartridges like .45 ACP in the dust all the way up to high pressure loads which can duplicate .44 Magnum performance with significantly lower chamber pressures, provided you have a firearm beefy enough to handle such loads.

Bubba inherits an original Colt Single Action Army or something which predates Smokeless Powder

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Referring back to my cowboy action shooting* days again, I must note that I had the great good fortune to be an active writer for the Single Action Shooting Society's* monthly newspaper, the Cowboy Chronicle*. As such, I was able to contact various firearms manufacturers and request guns for testing. I tested a variety of handguns and rifles such as the Beretta Stampede, various iterations of the Charles Daly SAA replicas, Uberti 1886 50-110, and similar guns. I did send them all back but for one. I bought the prettiest one to keep.

Anyway, I cannot recall which or what any longer, there were quite a few, but I do recall one particular SAA replica in .45 Colt (which brand and such I really CANNOT remember) that I decided to test with modern Corbon ammunition instead of lightly loaded cowboy ammunition. I don't think it took more than two or three rounds for the ejector rod housing screw to shear right off and send the whole contraption down range.

Very embarrassing. I had to get the range master to call a cease fire so we could retrieve the thing.

My point is, even in modern SAA replicas, shooting modern ammunition, especially self defense ammunition like Corbon, IS NOT A GOOD IDEA! Err on the side of safety and keep your pressures low.

Let's be careful out there...............


*Cowboy action shooting, SASS and Single Action Shooting Society, and the Cowboy Chronicle are all SASS trademarks.

The one I kept:

According to Wikipedia there were three old loads. So the question is which one did the early smokeless try to replicate?

"Colt began work on their 1873 Single Action Army Model in 1871. Sample cartridges submitted for Army tests were made by UMC, using the Benet cup primers; commercial ammunition used the Berdan-type primer, followed by the more common Boxer priming. Original UMC loads used a 40-grain (2.6 g) powder charge and 255-grain (16.5 g) bullet. This was reduced to 35-grain (2.3 g) of powder, and later, by the Army, to 28-grain (1.8 g)."

@ISCS Yoda

Replicas are an exception to the rule as they are mostly aimed at the Cowboy Action Shooting demographic which perfers to use Black Powder loads, (or substitutes like Pyrodex) or at most specially loaded Smokeless Powder loads, aptly named Cowboy Action Shooting loads, which tend to be on the lighter side.

When I say; "any modern Smokeless Powder firearm" faithful replicas and conversions made with CAS in mind don't necessarily fit the bill. I'm more talking about things like a S&W Model 25/Governor, Charter Arms Bulldog XL, Taurus Judge, Ruger Black/Redhawk, etc.

Remember to take into account that black powder era .45 Colt brass had what are called " balloon-head " cases that did not have the thicker brass in the bottom around the primer in the web area. This gave them more volume, sacrificing strength, which was ok for black powder pressures. Modern .45 Colt brass holds a few grains less of powder.
Just be sure you are comparing apples to apples.

Kurusu said:

@ BB57( by the way, is this USS South Dakota related?)

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That's exactly the reference. I grew up in SD and I'm a big fan of that class of battleship in general.

Texas Star said:

...Elmer Keith inferred the .45 BP load was hotter, again in ammo from major makers, in the early 20th Century...

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As I recall, EK wrote if he were to be limited to factory ammunition, he would carry a SA revolver in 45 long Colt with Remington black powder loads. After he passed, just that combination of revolver and ammunition was found among his collection of loaded revolvers.

I was influenced, a lot, by his writings. One of my first revolvers was an Italian SA revolver, 5 1/2” barrel, chambered for the 45 long Colt. I loaded it with a 255 grain SWC and black powder. It was and would still be a heavy hitter. I used it to take several Ohio whitetailed deer. Never recovered a bullet.

Kevin