45 ACP in a strong pistol, ho far we can go safely?

[Onty]

My knowledge about semiauto pistols is on low side. However, I am posting this in hope that more knowledgeable folks will correct me if I omitted something.

Here is the website with info about 45-08 round: http://www.armco-guns.com/what's%20new%20at%20armco.htm , scroll down to first half. As a matter of fact, I am aware of 45 Super, 451 Detonics and 45 Rolland, so 45-08 looks similar. One of the loads listed is 200 gr at 1350 fps. If suitable powder is available, that energy level should be the same as for 250 gr at 1200 fps, or 265 at 1165 fps; assuming that pistol could take this loads. In Guns & Ammo, 2000 ANNUAL HANDGUNS, there is a load for 45 AR from S&W M25-6.5”; Lyman 454424, 255 SWC (I think that 265 gr is the real weight), with 14.5 gr of 2400 going 1137 fps. I have no such bullet to verify its protruding length, but similar one from SAECO has .370, so OAL of the loaded cartridge should be within OAL spec for 45 ACP. Appropriate LBT bullet or jacketed FP (better than HP) would be also a good choice. There is no information what is the pressure, but considering that thickness of the cylinder wall on this revolver is about .065” v/s .110” on 1911 barrel wall, barrel itself is more than enough to take such pressure in strong case like 45-08.

I am aware that this kind of load must be hard on 1911, however, bit more conservative approach and on sturdier platform, could be the answer. The pistols I have on my mind are 5” 4-digit S&W; 1006 and 4506. As far as I know, 1006 is a strong pistol, designed from the ground up to handle hot 10 mm cartridge. Load such 200 gr at 1150 fps looks like normal for it. Its 45 sibling, 4506 should be the same strength. If 1006 could lunch 200 gr at 1150 fps, equivalent energy level from 4506, with 250 gr bullet will be 1028 fps; assuming that strong case like 45-08 and suitable powder are used. A well designed LBT 265 gr cast bullet should reach this velocity, and probably more, without the problem.

So, if I have it right, 265 LBT at about 1000-1050 fps should be serious hunting or backup load in relatively compact firearm when compared with 45 LC revolvers, even with 4-5/8 barrel. I would prefer it any time over any 200 gr at 1150 fps.

Thanks, Onty.

 

[1911Tuner]

Hot Rod .45

With a 265-grain bullet at 1150+ fps, you're into .44 Magnum territory on pressure and recoil impulse.

I strongly suggest a hand-fitted barrel with 100% vertical lug engagment and
all three lugs taking a share of the brunt horizontally, (Equalized lug engagement) and a limited amount of such ammo.

I'd also recommend using a 23-25-pound mainspring with a .075 inch radius on the firing pin stop. (EGW square-bottomed stop. Oversized/Fitting required) Will probably require a 24-pound recoil spring and extra-power magazine springs to keep up with the slide velocities.

'Bout all I can tell ya....except good luck!

 

[LHB1]

What type of chamber and case are you planning to use for these hot loads? The standard 1911 chamber leaves a portion of the .45 ACP case unsupported and the brass case thus becomes the weak link in pressure containment. Am not sure how much, if any, additional support a ramped barrel provides but may be an improvement. Sounds like you will need a FULLY supported case before venturing into high pressure loads.

Must admit I don't understand the rationale in trying to use the wrong tool for a job. Why not just use a .44 Mag or whatever will provide the power you want? I want to keep my eyes and hands/fingers intact for a few more years.

Good shooting and be safe.
LB

 

[Car Knocker]

Onty is contemplating using the S&W 1006 and 4506 for this project, not a 1911 platform. I have no knowledge of these two S&W pistols so will offer no commentary.

 

[gazpacho]

With a small powder capacity, generated pressure may actually be higher than 44 magnum.

I would first test 45acp brass in a Ruger Blackhawk 45 Convertible, to make sure the brass is up to the job. Further I would recommend triming dow a 45 Winchester Magnum case instead of using regular 45acp brass. According to the Reload Bench, the 45wm has thicker walls.

The Ruger should be strong enough since it can handle all of those 45lc "Ruger" only loads. That said, I'd also recommend a ransom rest and a long string.

 

[LHB1]

Hi Don,
I don't know anything about those two pistols either. That is why I used the 1911 chamber to illustrate my concern/point about possible dangers with unsupported brass cases at high pressure. It may or may not apply to the guns/chambers he is planning to use.

Good shooting and be safe.
LB

 

[Vern Humphrey]

I have shot .45 Super loads in a Kimber M1911. I replaced the recoil and firing pin return spring with a set from Wolff (28 lbs.) I have driven a cast 185 grain bullet across my chronograph at 1350 fps.

I've only shot a little of this stuff, and finally put the old recoil spring back -- with a 28-lb recoil spring, you risk a finger every time you chamber a round -- sort of the M1911 version of M1 thumb.

 

[1911Tuner]

Brass

The original question dealt with the 45-08 variant, which would...as the numbers indicate...be handloaded from cut-down and reamed .308 rifle brass. That would make the unsupported area forward of the case head a LITTLE less of a concern...but still not to be disregarded.

A good, tight barrel fit...as described...along with minimum static headspace,
and the understanding that when the pistol is fired, the lugs will be under at least twice the SAAMI standard pressure as the .45 ACP generates. This pressure and recoil energy will deform the lugs and set them back much faster than the standard ACP round. As the lugs deform, headspace increases and case head support is reduced.

Just upping the recoil spring to 28 pounds in a stock gun and letting fly with this double-pressure ammo is risky and carries the potential not only to damage the slide and barrel beyond repair, but to damage YOU beyond any reasonable repair too. Yeah...I know. Many have done it and gotten away with it. Some people also handle Western Diamondbacks for years without takin' a hit.

Quote: (paraphrased)

"The amount of pressure required to accelerate a 185-grain bullet to 1350 fps in five inches of barrel is more than enough to blow your eyes through the back of your head."

Please please! Proceed with extreme caution...

 

[Vern Humphrey]

The original question dealt with the 45-08 variant, which would...as the numbers indicate...be handloaded from cut-down and reamed .308 rifle brass. That would make the unsupported area forward of the case head a LITTLE less of a concern...but still not to be disregarded.

A good, tight barrel fit...as described...along with minimum static headspace,
and the understanding that when the pistol is fired, the lugs will be under at least twice the SAAMI standard pressure as the .45 ACP generates. This pressure and recoil energy will deform the lugs and set them back much faster than the standard ACP round. As the lugs deform, headspace increases and case head support is reduced.

Just upping the recoil spring to 28 pounds in a stock gun and letting fly with this double-pressure ammo is risky and carries the potential not only to damage the slide and barrel beyond repair, but to damage YOU beyond any reasonable repair too. Yeah...I know. Many have done it and gotten away with it. Some people also handle Western Diamondbacks for years without takin' a hit.

Quote: (paraphrased)

"The amount of pressure required to accelerate a 185-grain bullet to 1350 fps in five inches of barrel is more than enough to blow your eyes through the back of your head."

Please please! Proceed with extreme caution...

There are two separate issues here, the brass and the gun. I used Starline .45 Super brass. As for the gun, the Kimber is a tightly-fitted gun. I don't recommend a steady diet of these loads, but there's no problem with a few magazines full now and then.

The worst part is the possibility you'll pinch a finger when you release the slide.

 

[grendelbane]

Methinks Tuner gives good advice here!

I have experimented with hot .45 loads off and on for several years now. There are several levels. Standard .45 ACP, which we have had for about a century now. Then, the next step up is .45 ACP, which dates back at least to the 1930's.

Then, within the last 2 decades we have the .45 Super, and the .460 Rowland. Both use thicker walled brass, and are loaded to higher pressures. In the case of the .460 Rowland, much higher pressures. This cartridge requires a barrel with a compensator to lower the slide velocity to acceptable levels.

In addition to Tuner's recommendations about springs, firing pin stops, and lug engagement, I would like to add one suggestion.

Don't use wooden grips. If a case head lets go, they will splinter. I speak from personal experience. Brownells sells steel plates which will fit under regular grips, or some Pachmayr grips have steel inserts inside their rubber grips.

Looking at smoke coming out between your fingers is a sickening feeling. All I lost was a nice pair of walnut grips, and respect for the strength of .38 Super brass. I have hot rodded .38 Super for a quarter of a century, and this was the first time that a case head failed. It was not even a hot load!

 

[1911Tuner]

Smoke gets in your Hand

Grendlebane said:

>Looking at smoke coming out between your fingers is a sickening feeling. All I lost was a nice pair of walnut grips, and respect for the strength of .38 Super brass. I have hot rodded .38 Super for a quarter of a century, and this was the first time that a case head failed. It was not even a hot load!<
******************

Refer to the part about full-depth, equal lug engagement and lug setback issues...and standard .38 Super is plenty hot, thank ya very much.

Not tryin' to bust anybody's bubble here...especially Vern's. Just takin' a trip down memory lane and relating some of the experiences that I've had with friends and customers who destroyed some nice pistols during the old .451 Detonics craze. Well...I tried to warn'em...

As you were, lads!

 

[HSMITH]

I would add to the recommendations of Tuner a quality barstock hammer, and make it the heaviest hammer you can find. That short radius firing pin stop and slide velocity are going to be HARD on parts. A bull barrel would also be a good option, its weight is essentially added to the slide for the first .100" of slide travel. A tungsten sleeve barrel would be better yet.

ALL of my recommendations are aimed at reducing slide velocity and delaying unlock, either one in too great a quantity will be damaging to you and/or the gun.

 

[RyanM]

Was that guy using a stock barrel? That's nuts. Just get a .460 Rowland conversion unit, if you want that kind of power. Much safer. Also, Longshot is supposed to peak suddenly in pressure, towards the upper end. Alliant Power Pistol or IMR HiSkor 800-X would be safer powders to hot-rod with.

 

[Azrael256]

Of course, it's all about bears. I don't know why, but it's always about bears.

There is no information what is the pressure, but considering that thickness of the cylinder wall on this revolver is about .065” v/s .110” on 1911 barrel wall, barrel itself is more than enough to take such pressure in strong case like 45-08.

I wouldn't come within a mile of one of those things without detailed pressure specs. Just 'cause it doesn't blow up a revolver doesn't mean it won't blow up a 1911. There are far more variables to the pressure (or sudden and dramatic reduction thereof) equation than the chamber wall thickness.

As far as I know, 1006 is a strong pistol, designed from the ground up to handle hot 10 mm cartridge.

Yeah, fair enough. The 10mm pistol will probably do okay as far as Newton cares, but Pascal may still bite you in the butt. Pressure specs. Seriously.

 

[1911Tuner]

Pressure

Pressure really isn't the issue. If the barrel has full lug engagement in both planes...vertical depth and equal bearing on all three lugs...the gun will stand the pressure, assuming no defects in the chamber. The problem is that, when the lug engagement isn't optimum...
and only one lug is handling the load with say...80% full vertical...that you start running into trouble. Horizontal end-play also figures in. The more
end-play, the harder the lugs slap together when the pressure hits...which accelerates deformation. As the lug or lugs deform, the breech actually opens just a little when the gun is fired...even though the barrel is still technically locked to the slide. When the breech opens that tiny bit, the case backs out of the chamber until it stops against the breechface.
As the deformation increases, that amout of breech opening increases until the case head becomes so unsupported that the case begins to bulge.
The deformation progresses with each round fired...and because that deformation also increases the amount of barrel end-play, it accelerates.
When the case is able to back out of the chamber far enough to expose the
thinner brass just ahead of the web, it ruptures.

Starting with a good barrel fit with minimal endplay and minimum-spec headspace works to delay this by providing the maximum locking strength
that the design will allow...and thus greatly delays the onset of lug deformation.

Very few production barrels provide more than one lug engagement in the horizontal plane...and not very many give full depth of engagement horizontally. Same goes for drop-in replacements and conversions.

 

[Onty]

Thanks to all of you! NOTE: I am not suggesting to anybody to reload 45 ACP at such level. All that I want is to discuss. If I am ever going do something like this, I’ll get first 45 ACP barrel for TC-Contender (I already have 357, 44 Mag. and 45 LC barrels), put strain gages and test the pressure. Also, for the same reason, I am considering making pressure gun from 98 Mauser receiver with replaceable barrels and strain gages attached, and everything hooked up on Oehler instrument (http://www.oehler-research.com/model43.html ). I have credible information that some of custom reloaders are testing their loads this way. Unfortunately, Oehler is bit pricey so its purchase is going to wait for a while. Until I have hard evidence what’s the pressure, I’ll stick to standard SAAMI loads.

The only way I MIGHT consider would be S&W 4506. If 1006 in 10 mm is at home with 35,000+ psi, 4506 should have the same case thrust at 27,500 psi. Again, assuming that case could take such load. For that reason, I was even thinking of making the same cut-out on test barrel under the case as is on pistol barrel. The next step would be to see what would be total recoil, to keep slide to frame battering under control That could be done by using Ransom Rest and compare side by side 4506 with 1006; full recoil of 1006 could be used as a yardstick and proceed with 4506 until the same recoil is reached. Not 100% scientific but it will give comparable value.

Again, I was just asking for opinion. Yes, I am aware that this is enchanted territory. So it was 45 LC. Everybody was crazy for 44 Magnum and 45 LC was declared as an obsolete, dead round. Well look at this old obsolete round now; 45 LC “for Ruger, Freedom Arms & T/C only” is well establish and proven today, and with 300+ gr. bullets it’ even better than 44 magnum. In other words, 10 mm form S&W 1006 is a very nice, powerful combination, but I believe that properly loaded 4506 could be even better…

 

[stoky]

1911? JMB would just say no.
Don't go down this road. Remember the Delta Elite 10mm's problems?
Get a Desert Eagle or a Wildey.

 

[1911Tuner]

10mm pressures

Again...Pressure isn't the only concern. The top weight bullet for the big 10 is around 200 grains. Some .45 Super and .460 Rowland hot-rodders will use bullets of 250 grains or more at equal or higher velocities as the 10/200 standard. The recoil energy absorbed by the barrel and slide lugs increases with bullet weight, just the same as bullet impact energies go up with more weight at an equal velocity. This is a multi-faceted issue, and everything has to be plugged in to the equation.

 

[Marcus]

Why plague yourself trying to get .44 magnum power out of a std. 1911 only to beat the snot out of the poor thing? Just buy an LAR Grizzly Mk1 .45Win.Mag. and and you`re done. Shoot all the 250gr/1300fps you like through it and don`t worry about it. For big nasty critters CorBon has a lovely 325gr.HCRN/1150fps. My Griz also soaks up the recoil pretty well,making it more controlable than you might think. If that`s not enough for ya get a Mk5 in .50AE. BTW 80% of the parts are interchangable with normal 1911s and the remaining parts are build like a tank so that shouldn`t be of any concern. Marcus