Pistol caliber loads in a rifle.

[corvette8n]

Correct me if my thinking is wrong, but wouldn’t a slower pistol type powder shot in let’s say a .45 Colt through a rifle be a better choice than a faster powder that was designed with a short barrel pistol in mind?

I have a lever gun w/16” bbl in 45 Colt but no pistol so I can’t test my theory
Has anyone done testing? short vs long bbl?

[runfiverun]

if you are burning power beyond the length of your pistols bbl you would see an increase of velocity in the rifles bbl.
of course not having the cylinder gap alone will get you 50 fps.

[Rocky Raab]

That is one of those common sense ideas that perversely turn out to be untrue.

The optimum powder for a cartridge will be optimum in long and short barrels. You will gain velocity in a longer barrel because the expanding gasses have more time to push on the bullet, and in revolvers there is the gap factor as well. But the optimum powder will produce the highest velocity (compared to other powders) in a given barrel length.

The powder charges in most handgun rounds essentially cease combustion within an inch or so of bullet travel. Some (the 9mm Para for example) burn out before the bullet leaves the brass case. But "powder still burning past the muzzle" is largely false even in mega-magnum rifle rounds.

[felix]

Maybe largely false, but not entirely. If you see flame, that is as immediate reaction. The implication is that the powder did not burn completely within the barrel because of the lack of oxygen to burn remaining "trash". Now, that trash might not have any useful energy to do any good, anyway. I suspect that is true because oxygen is going to be sucked into the barrel somewhere. In the case of a revolter, that's a no brainer. But, in a closed breech, any oxygen appearance while the boolit is still in the barrel would be something to investigate. The implication would be the cartridge neck did not expand and hold firm for the boolit's duration. So, I actually like to see a smattering of flame at boolit's exit when shot in the dark in my bolt guns, at least. ... felix

You want the most accurate load possible without regard to flame. A night stand gun prolly could benefit with a powder that is known to suppress flash. Those containing some inorganic sulfate that is more than a couple of percent will vastly temper the flaming reaction. The old Alcan #5 had the best reputation of producing good energy without flame. ... felix

[Rocky Raab]

Felix, all smokeless powder burns in an oxygen deficient manner (or "rich" as an engine guy says.) Flame past the muzzle is the result of the remaining flammable gasses - mainly carbon monoxide, elemental carbon, hydrogen and some others - mixing with air and reigniting because they are still way above auto-ignition temperature. Photos show clearly that the muzzle flash begins quite some distance beyond the muzzle, proving that it is NOT burning at exit.

I didn't understand what you meant by oxygen getting sucked into the bore. Surely you don't mean while the bullet and powder gas are still there under high pressure, do you? Because it would have to overcome pressures of at least 10Kpsi to get in, and that's not likely.

But because the burn is oxygen deficient and pressure dependent, the actual burning has stopped long before bullet exit. In fact it is decreasing with extreme rapidity the whole time past pressure peak, which generally marks peak burning.

[felix]

That's right, Rocky, what you said. ... felix

[LeadThrower]

I understand corvettes notion, but don't understand the counter-statements. Pressure = force/area and impulse = force*time, so impulse = pressure*area*time. Can't a slow burning powder produce a given (maximum) pressure over a longer time than a faster powder, and therefore a greater impulse?

What am I missing?

[Rocky Raab]

LT, the only thing missing in your statement is the mention of the optimum powder. Powders that are too fast or too slow will simply not produce as good a pressure curve as the best one.

What you are describing is the total impulse, known as the "area under the pressure curve" because the longer pressure is sustained, the higher the bullet acceleration. Faster powders drop off too quickly and slower powders never reach enough peak. (The interacting factors of bullet friction, diameter and weight, expansion ratio and several other things make this complicated, so I'll limit my words to just powder for simplicity.)

So, all other things being equal, a powder that's is faster than optimum, OR slower than optimum will achieve less velocity that the best powder could. That is unrelated to barrel length, except that a longer barrel will produce a numerically higher velocity than a short one.

TWO things there are true: The optimum powder will always produce the maximum velocity, regardless of barrel length. And, a given barrel length will produce the highest velocity with the optimum powder. Regardless of barrel length, it's the SAME powder.

But if you start changing powder for barrel length, you will no longer produce the highest velocity possible.

[LeadThrower]

Rocky, thanks for taking the time to clarify!

[Rocky Raab]

No problem, my friend. The only thing that irks me is when I fail to be crystal clear in the first place.

Just to muddy the waters, however, let me say that we have so many powders to choose from today that a given load combo might be equally good with two or even several powders of almost the same burn rate. They all might produce the same velocity within a meaningless few feet per second, but one might produce less muzzle blast, or deliver better accuracy, or have some other indirect benefit like being cheaper to buy. So several powders might all be optimum - and reloaders might disagree which is "more optimaler" and all of them be right!

[shdwlkr]

Rocky
I am just thinking here and want to be sure I have not forgot something. If I have say a 357mag you are saying that the best charge of powder is or could be the same for a 5 1/2 inch barrel, a 18 1/2 barrel and 24 inch barrel. I am asking because I have that caliber and in a pistol with a 5 1/2 barrel and will have the same caliber in a 24 inch barreled rifle.
here is my question would you use the same powder charge for both or would you use more in the 24 inch barreled rifle?
I am hoping I have been following what has been said and that I would use the same charge of powder for both. The reason I am asking is I don't want to have a bullet left in the longer barrel and then fire a second round as it would be most unnerving to have the barrel open up because of a barrel obstruction.

[TCLouis]

Just a thought shdwlkr and contrary to all the things you calculated to a gnats hair in the past, load, shoot observe.

Over time I have found that sometimes in the reloading/cast boolit game things work out as hoped and sometimes not even close.

Get ready for some fun attempting to get a common load. May well turn out to be easy!

[shdwlkr]

TCLouis
that is what I was wondering. It is a terrible thing to hang a bullet in the barrel because you didn't give enough push to get out of the barrel. Ha Ha

[bobk]

OK, now I'm a little unclear about something I thought I understood. Why do slow burning powders bend an M-1 op rod? I'm thinking about this as I write this, but I'd like to hear what those more knowledgeable on the subject say before I say anything else stupid. :confused:

Bob K

[Rocky Raab]

Okay, two things to answer. Yes, you can use the same load in the revolver and carbine. There will be absolutely no danger of sticking a bullet. Cast bullets slide pretty easy once they are engraved, for one thing. And there's no cylinder gap to bleed off pressure for another. Your muzzle residual pressure will be plenty high enough to still accelerate the bullet.

And that segues right into the second question. Slow powders will damage an M-i op rod because a slow powder has a slow tailoff of pressure, and when the gas port is uncovered by the bullet, the pressure is still so high that the cartridge is still tightly gripping the chamber. The high force on the op rod and piston at the muzzle end cannot move the bolt at the chamber end, and the rod bends from the "squeeze."

That's why you want a faster burning powder for a gas-operated action: you want the residual pressure at the gas port to be low enough that you don't overstress the mechanism. In the M-16 family, slow powder causes the extractor to rip right through the rims of rounds that are still tightly gripping the chamber, and then because the bolt was slowed doing that, you get either a failure to feed or a jam against the chambered empty.

BTW, residual gas pressure can be as low as about 6-8kpsi in a rimfire rifle to as much as 35kpsi in a short-barreled magnum rifle. The sudden release of that amount of pressure is what we call muzzle blast. It is higher in handguns, obviously due to barrel length, and especially so in revolvers. The peak of pressure occurs right as the bullet is clearing the cylinder gap in a 357 or 30 Carbine revolver, which is one reason why both are so bleeding loud.

[missionary5155]

Good afternoon Because of barrels length differnces I would dought you could have just one load that would be THE best for lets say both a 20" carbine and a 5.5" revolver.
You certainly CAN find a load that is Very good in both IF the boolit is compatable in diameter to both barrels.
My 20" winny 44-40 and my Colt New service 44-40 both shoot 8 or 9 grains of Unique with the Saeeco 433 Very nicely. BUT the Winny really shoots 10 grains some better and the Colt will not safely handle more than 9 grains.

[shdwlkr]

Missionary 5155
You are thinking and shooting kind of like I think I will have to do. My rifle has a 24 inch barrel and the pistol has a 5 1/2 inch barrel so I think I will have to load differently to get the most out of both and my bullet. The only thing that will be the same it looks like is the bullet which will most likely be a 358429 pb and hollowpoint.
Guess the wife will just have to give me some more time at the range to get them both working when I get the rifle off layaway. Such is the life of a lead bullet caster. Cast, load, shoot Cast Load shoot cast load shoot and then just shoot once a good load is found for each and then i will have to buy more lead, more powder, more primers there goes the pension check. Ha ha

[EDK]

Go to Glenn Fryxell's article on 1894 MARLINS at lasc.us for suggested loads and boolits for lever guns.

You will probably find out that 358429 has too long a nose to feed reliably in 357 brass. I'm using 357446, 358156 and 358665 in my 24 inch MARLIN and assorted VAQUEROS/BLACKHAWKS and several 627s. For "generic loads" I use TITEGROUP or HP 38 and the "rifle specific" get IMR 4227 with those boolits. I prefer 357 brass, but do use 38 special brass for the long nose boolits that wouldn't feed otherwise. If you alter the carrier on the MARLIN (I haven't yet,) you may have better results.

:cbpour::redneck::Fire:

[shdwlkr]

Edk
Thanks for the ideas and I will go find glenn's article