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.45 ACP loads for 16" bbl?
bigcitybill
Member Posts: 4,912 ✭✭✭
Seeking advice for shooting 230gr. hardballs in a carbine. What powders might work at .45 ACP pressures and still burn slow enough to accelerate all the way down the bore?
Thanks, Bill
Thanks, Bill
Comments
Powders that burn slower than standard for a cartridge will produce less than optimum results because they never achieve the pressure they are designed for.
The optimum powder for a cartridge will give the best results regardless of barrel length.
Or, saying that another way, the powder that produces best velocity in one barrel length will give the best velocity in all barrel lengths.
alone. One of the biggest factors I think you are leaving out is the size and shape of the .45acp case. With that short [compared to bore size] case, I don;t believe ANY powder will "burn" more than 10 0r 12 inches of barrel length. I have used Red Dot powder in plinking/practice
target loads for the .45acp, and noted about the same amount of "burn"
in 4" and 7" barrels. With almost all acp type of cases, .25 thru .45,
you are probably at the end of useful burning somewhere about 10 inches.
Now if you had say a .357mag...loads could be altered from a 3 inch snubnose revolver to 18" lever rifle. bob
It takes extremely slow powder combined with an extremely low expansion ratio (think smallbore magnum cartridge) for the pressure peak to occur as much as nine or ten inches down the bore.
psi than a powder that "flashes" as the bullet is just leaving the case.
Many hand loaders know of powders and loads that are killers on the barrel throats. I will be glad to donate a chambered barrel to anyone
that will drill a row of holes spaced every inch along the length of it and install pressure transducers and then try different powders in the case and record the readings. bob
I said "essentially no burning" rather than an absolute, because although pressures and temperatures drop fast enough to prevent any additional powder ignition past the peak, there is still a very short "tailoff" of powder that's is already burning. But that is both very small and very short in duration.
The answer to the original post remains the same: regular 45 ACP powders will operate best at the pressures that round develops, and produce more than enough gas to accelerate the bullet all the way down a 16" barrel.
are just too many loads out there that are "flamethrowers", to think that "burn" rate is not critical as many internal ballistic experts want us to believe. Lets hear from some others that are advanced handloaders on this subject please....bob
You only need one transducer or strain gauge, for the same reason you need only one pressure gauge on a tank - it will record the pressure throughout the system.
I said "essentially no burning" rather than an absolute, because although pressures and temperatures drop fast enough to prevent any additional powder ignition past the peak, there is still a very short "tailoff" of powder that's is already burning. But that is both very small and very short in duration.
The answer to the original post remains the same: regular 45 ACP powders will operate best at the pressures that round develops, and produce more than enough gas to accelerate the bullet all the way down a 16" barrel.
Rocky,
I am in agreement with Babun here. What you are describing is a static measuring method in a dynamic situation. The pressure will peak at some point after firing then decrease as the bullet travels down the barrel. You can change the peak pressure point and total pressure with choice of powder, case or primer. The trick is to find what will work best for this 'long for caliber' barrel. My choice for your situation would be AA No. 9.
The problem with the .45 case is that there is such a small window (read: small case, even though it's fat,; small potential.) to load up in velocity in comparison like you would a rifle. You're going to hit the wall of diminishing returns when you extend the burn time and get less initial push on the bullet to help velocity. The #9 is one of the slowest double base pistol powders I can think of, so it should work for this circumstance. If not getting the desired velocity (and not infringing on pressure limitations) move back to No. 7
-good luck
I have and use a strain gauge system. Trust me, it is at least as good as the transducer systems used in the labs, and it makes a copper crusher seem like reading chicken innards by comparison.
A copper crusher is probably the least responsive measurement system. Not only is there serious lag in response, but it can only record the peak, but none of the character of the buildup or tailoff.
To the 45 ACP: the problem with going to a slow powder is that we fail to take its optimum pressure range into account. AA#9 is designed to ignite and burn properly at pressure far above the maximum allowed for the 45 ACP. So even though we can pack more of AA#9 in there, it would burn poorly if at all. Result: even lower velocity.
While it might add a few feet per second to load a very slightly slower powder, there simply isn't enough room to add enough of it to matter. And then the huge expansion ratio guarantees that little if any of it burns because the pressure drops so fast as the bullet moves. A too-slow powder simply can't burn under those conditions.
very heavy bullet weights for the 6.5 mm.? I want to try to work up some ultra long range target loads for a friend's 6.5 Creedmore. This powder is said to be slower and with more energy than the norm. bob
Previously shot N135 and N140. I'll stick with 540.
*Let's ask the board
No experience with any VV powders, babun. There simply isn't room in my powder locker for everything, and I passed on the whole VV line as a result.
One pound of VV N550 through my 6.5x55. Excellent velocity, but I didn't renew the prescription as I don't want to erode the barrel prematurely. I haven't and don't buy anymore 500 series VV. I do buy and stick with the 100 series.
The fire marshal would not be happy.
quote:Originally posted by bigcitybill
Seeking advice for shooting 230gr. hardballs in a carbine. What powders might work at .45 ACP pressures and still burn slow enough to accelerate all the way down the bore?
Thanks, Bill
quote:Originally posted by Rocky Raab
Here we go again. There is essentially NO burning past the pressure peak. If there were, the pressure would continue to rise or at least maintain its peak. It doesn't; it falls abruptly. That proves there is no added burning past that point. In most handgun rounds, that peak occurs about the time the bullet clears the case mouth. In some rounds like the 9mm, it happens before the bullet leaves the case. All the powder that is going to burn has done so by then.
It takes extremely slow powder combined with an extremely low expansion ratio (think smallbore magnum cartridge) for the pressure peak to occur as much as nine or ten inches down the bore.
Bob, last time I counted, I had more than 75 KINDS of powder!
The fire marshal would not be happy.
Speaking of that...my kid caught my house on fire last week when I was last down in Chicago.[}:)] It took most of the siding off on that side of the house...the side where my reloading room is, with more than 160 lbs of various powders.[:0] I joked that I could just see my wife's lily white butt flying through the air and landing in the next suburb.[;)][:D] She didn't think that was funny, ...I did[:D]
On a more/less serious note, I have to go with I wanna username in than a slower powder will produce more pressure down the barrel. Whether it be fast pistol powder or slow rifle powder. And of course the length of the barrel has an effect on the useability of that pressure created. Of course the powder can't be so slow it won't generate enough power to push the bullet out to the required speed.
Seeking advice for shooting 230gr. hardballs in a carbine. What powders might work at .45 ACP pressures and still burn slow enough to accelerate all the way down the bore?
Thanks, Bill
When I was in Tanks, we used the same .45 Cal. Ball rnds. in the .45 Cal. Auto-Grease guns ( M3 or M4 ??) I don't remember how long the barrel was, but they cycled as long as the trigger was pulled. I'll have to look that up!
Ski