Super hot .45 ACP? Is the ACP "downloaded"?

[halvey]

Ok, I'm posting this over here since my thread on the 1911 forum went way off...My question wasn't if a new caliber/gun would be a better idea, my question is can the .45 ACP be loaded hotter than we think?

----------Anyway, here's the original post-----------------------------------------

This thread got me thinking:
http://forums.1911forum.com/showthread.php?t=60635
Since .45 Colt seems to be way underloaded, or CAN be loaded a lot hotter, couldn't the same be said for the .45 ACP based on the higher pressures of the .45 GAP?

If the GAP can match the performance of the ACP (let's assume that is correct for sake of argument) with a shorter case; and the .454 Casull can have a GREAT performance increase with just a slightly longer case over the .45 Colt, couldn't the same be said for the .45 ACP?

Another thing: I was told the .454 Casull uses the small primer pocket to increase the amount of metal in the case because of the higher pressures. Well, couldn't the same be done for the ACP? Maybe there's a use for the NT brass now? If I wanted to get super hot on the ACP, wouldn using the NT brass, because of the extra metal, help squeak out a bit extra performance?

So using that logic, maybe we've been downloading the ACP all these years? Any insight is appreciated.

 

[Zak Smith]

So using that logic, maybe we've been downloading the ACP all these years? Any insight is appreciated.

From a pressure standpoint, yes.

SAAMI spec on .45ACP is 21,000psi. 45ACP+P is 23,000psi.

9x19, .40SW, 10mm, and 44RM are all between 35,000 - 38,000.

That doesn't mean you can double your .45ACP loads. The system must be adjusted.

-z

 

[Desert Dog]

.45 ACP +p is 23,000 PSI
.45 Super is 28,000 PSI

Yes you can up pressure your .45 as long as you have a modern (read new) firearm to shoot it in, and a barrel that fully supports the case. That is where .45 Super came from.

You WILL need a stronger recoil spring on any gun you shoot with higher pressure .45...

Where is Clark when you need him?

YMMV,

 

[ClarkEMyers]

It's been done time and again

What you can't do is fire the higher pressure loads in existing 1911 or 1917 guns. When you go to guns that can fire the higher pressure loads why bother with the .45 ACP?

Review the Detonics story or read Dean Grennell on the .45 Super or start with BR cases today if you want a small primer pocket and trim to .45 ACP length.

Notice that the .45 Rowland pretty much needs the ported barrel to work well in everybody's favorite the 1911, not necessarily in a revolver. Guns for the .45 Win Mag don't seem to be all that popular. I certainly have never picked up a Grizzly and said I'm not giving it back.

Ace's Customs puts limits on .45 Super loads and guns for assorted applications including ported barrels and limited pressures for some guns.

There are big strong revolvers out there to shoot high pressure .45 loads in. Often with cylinders to cover a range from .45 ACP throught .45 Colt and on to Casull. I'd love to have one but I'll never try to match the performance in a 1911 - I do have a 9x23 in a 1911 though for a high pressure round.

To sum up - what's to gain? what would I want to shoot it in?

 

[halvey]

Where is Clark when you need him?

Actually, Clark's post about the Kel Tec .380 got me thinking about this. He loaded the .380 to like .380 +P++++++++++++++++++++++
I mean that thing was WAY overloaded, in a relatively poor setup.

I was thinking a .45 Super + that would mimick the 10mm performance in an autoloader would be nice - with a .45 diameter bullet.

Doesn't Ace build the the .45 super in UNsupported guns like the Colt? I thought I read they wanted better .45 performance in an unsupported chamber,

Any low cost .45's with ramped barrels one could recommend for this project?

 

[ClarkEMyers]

Ace is the place for .45 Super but H&K works

Yes of course the .45 Super conversion by Ace on the 1911 is not normally ported. As a custom gun you can ask for changes I suppose. There is a web site and a man to deal with who can answer questions far better than the rest of us about the .45 Super.

The long barrel Springfield in .45 Super is factory ported. Lots of information available from Ace and other sources. For some people the energy figures (500 foot pounds at 100 yards or something like that) for legal hunting in some jurisdictions matter as well.

For do it yourself see the web for tales of high spring pressure, flat bottomed firing pin retainers and so forth and so on.

The big H&K's are also said to be, and I believe, entirely suitable for .45 Super loads. There may be some tapering off with smaller H&K pistols. I might be willing to shoot high pressure loads in Thompsons and in grease guns as well.

If time and price are important buy the Springfield or the H&K and have a Super out of the box experience. For me I'll go N frame when I want a magnum.

 

[saands]

Be careful when comparing the pressures to which different cartridges are loaded!!!! Pressure generates a force ... and everything but the chamber sees the resultant force, not the pressure. If you have 37,000 psi acting on a case head the size of a 9x19, you have a LOT less force on the breech face than you would with 37,000 psi acting on a case head of a 45acp.

Saands

 

[ClarkEMyers]

Or remember to carry out the operation times si

That's why I shoot a 9x23 for rifle pressures in a 1911. Reminds me of the difference between pressure on the ram and hydraulic pressure in a press. The total ram pressure would blow the hydraulics if it were applied to each square inch. There are tales of what a 90 pound woman can do when she puts all her weight on a spike heel.

 

[stans]

45 Super does have at least one major pitfall, it operates at 28,000 psi max and is dimensionally identical to the 45 ACP that operates at 21,000 psi. You certainly would not want to start shooting 45 Super in a gun that is not set up for it.

Ace will convert Glocks, 1911's with 5 inch barrels and S&W 645 and 4506 pistols to 45 Super. You can also do the conversion yourself. A heavy recoil spring, firing pin spring and magazine spring; for the 1911 you need an EGW flat bottom firing pin stop and you might want to actually increase the hammer spring by one or two pounds to further slow the unlocking of the pistol. A Sprinco recoil reducer will help minimize frame battering. Now the real trick, when you increase that operating pressure you accelerate the slide faster which is going to place more pressure on the locking lugs, so getting tight lockup of the barrel to the slide is going to improve durability and longevity. If the locking lugs have little engagement, as is seen with a great many 1911's, then the slide is going to be applying all that pressure to a small section and a sheared lug may be the end result.

You can match and exceed 10mm ballistics, at least at 50 yards, with the 10mm's better ballistic coefficient, it will outperform the 45 Super beyond 75 yards. So at 50 yards or closer, the 45 Super has the edge and can get real close to matching the ballistics of a 41 magnum.

I am giving serious consideration to converting my 4506 to 45 Super.

 

[Double Naught Spy]

To answer the question in the title proper, the .45 ACP is NOT downloaded. The requested design was for a weight of slug in .45 with a specified velociity. Since the criteria for for certain parameters, the design is NOT downloaded. It isn't uploaded either. It was what worked. The PSI in the barrel was not a consideration as far as I know. The the original was 'properly' loaded as it met the requested design parameters.

With that said, it can be uploaded some, but NOT because it was downloaded, but because the original design allowed for a lot of variation.

 

[redneck2]

Go to

Realguns.com. Joe shows you how to SAFELY run a 1911 at 45 Super pressures...for something like $20. Also, a lot of stuff that is done on "conversions" really isn't necessary...flaring ejection ports and stippling the front of the grip has little to do with how much pressure a firearm can stand.

http://www.realguns.com

 

[Clark]

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

The 45acp is based on the Mauser case head: 7x57mm to 8x57mm to 30-06 to 45acp parentage. But the modern brass is not going to wait to 77 kpsi to loosen the primer pocket like the thick webbed rifle brass. The 45acp brass has evolved into a lower pressure and lighter weight design.

The problem I have found with 45acp taken to it's potential in a pistol is that the recoil becomes horrific. The bones, joints, and nerves in my hand cannot take the pounding of lightweight slides hitting the frame.

After reading the realguns article on 45 Super for $7 in a Kimber, I paid $180 to AIM and got a 20 ounce Patriot and worked up to 460 Rowland pressure with 45acp mixed brand once fired brass. It gave me a flinch of punching my right shoulder forward every time I pulled a pistol trigger. A 42 pound triple recoil spring assembly was just right for +P, but with 460R loads, made the remainder slide velocity batter the frame at a low engouh level that my flinch went away.

The 17 pound 45acp Mauser rifle I built can easily shoot 460 Rowland loads in 45acp brass with mild recoil. When the primer falls out of the case it is academic, and not a jamming threat.


CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.


CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

0) 45 acp................. 185 gr. 7.6 gr. AA#5 jams w/stock Patriot spring
1) 45 acp..................185 gr. 10.2 gr. AA#5 1100 fps 18,000psi
2) 45 acp +P...............185 gr. 10.8 gr. AA#5 1200 fps 21,700 psi
3) 45 Super................185 gr. 12.4 gr. AA#5 1312 fps 28,000 cup
4) 460 Rowland............ 185 gr. 14.5 gr. AA#5 1500 fps 38,800 cup
5) Easy extraction ........185 gr. 15.0 gr. AA#5 1868 fps 35kpsi *rifle
6) Case starts to stretch..185 gr. 15.2 gr. AA#5 1886 fps 37kpsi *rifle
7) difficult extraction ...185 gr. 16.0 gr. AA#5 1956 fps 42kpsi *rifle
8) primer falls out .......185 gr. 16.5 gr. AA#5 1998 fps 45kpsi *rifle
9) accurate heavy bullet...230 gr. 13.0 gr. AA#5 1662 fps 52kpsi *rifle

 

[Vern Humphrey]

Quote:
---------------------------------------
What you can't do is fire the higher pressure loads in existing 1911 or 1917 guns.
----------------------------------------

Actually you can -- in the M1911A1, certainly.

The "weak point' in the M1911A1 is the throat -- where it is slightly cut away to form part of a ramp for feeding. This area leaves the brass unsupported, and this is where high pressure loads blow out.

.45 Super brass has a thicker head, so that there is no thin wall at the throat -- just solid brass. To shoot .45 Super in an M1911A1, change the recoil spring for a 28 lb spring (about $10 from Wolff). Add a buffer if your gun is reliable with buffers.

 

[Rockstar]

Question for Clark or anybody else who reloads: How do Clark's figures that he's posted here relate to reloading for any handgun, regardless of how that handgun is modified?

 

[ClarkEMyers]

Oh you can take it farther than that

There are lots of misconceptions about recoil springs, and some of them eminate from the factory I think. Suffice it to say that I have fired 1911's with no recoil spring in place with no harm done.

Ned Christiansen

It is a locked breech, not a blowback.

Some find the return to battery with a 28# a trifle too quick for a cartridge to rise in the magazine and so balance magazine springs, and firing pin springs and mainsprings and the proverbial flat bottomed firing pin retainer and so forth and so on.

If your lugs engage properly and seat properly and everything is as it should be you can do a lot of things.

I can't speak for 1911's in general as being super strong compared to other pistols but rumor has it that some of Glock kabooms are out of battery firings because the lugs were battered - there is the odd locking block failure in other pistols - I'm reluctant to expect a run of the mill 1911 to live as long as a Super as it will with SAAMI ammunition - but that's not to say I have a problem with shooting guns loose - I've done it enough.

 

[Clark]

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

.45 Super brass has a thicker head,

When I cross section a piece of 45 Super brass, I find the web no thicker and the walls no thicker than 45acp brass.

I called the man at Starline, and he said that the 45 Super and 460 Rowland brass have the same shape as 45acp brass [the 460 is slightly longer], but have a superior heat treat. He says they are for pistols with good case support. He says the Starline 45+P is for pistols with poor case support.

When I cross section the 45+P brass I confirm his statement about that, but the 45 Super brass allows the primer to fall out at an overload exactly the same as all the brands of 45acp brass I have tested.

The web of 45 brass is .180" thick, of my 45 pistols, the Patriot has case support at .180", the Para Ord P10 from .235", and the Colt 1911 from .225".



I have been able to shoot 45 Super levels in the Colt and P10 by using +P brass.
I have gone beyond 460 Rowland in the Patriot with mixed 45acp brass.

 

[Vern Humphrey]

Quote:
---------------------------------------
When I cross section the 45+P brass I confirm his statement about that, but the 45 Super brass allows the primer to fall out at an overload exactly the same as all the brands of 45acp brass I have tested.
---------------------------------------

Interesting -- my .45 Super brass was made by sawing down .308 cases and inside reaming, so it is definitely thicker at the base. I assumed Starline was the same.

I guess this means I need to buy 45+P if I buy new brass.

 

[1911Tuner]

Interesting Thread

Ned Christiansen said:



quote:
--------------------------------------------------------------------------------
There are lots of misconceptions about recoil springs, and some of them eminate from the factory I think. Suffice it to say that I have fired 1911's with no recoil spring in place with no harm done.
--------------------------------------------------------------------------------


Which nails it right on the hittin' spot.

The recoil spring has nothing to do with containing chamber pressures
and very little to do with barrel linkdown/unlock timing. Since the barrel
and slide move together for a short distance...about 1/10th of an inch,
the bullet is gone and pressures have dropped by the time the barrel starts to unlock. .100 inch of movement from the in-battery static position
would increase recoil spring tension maybe a quarter-pound...or not enough to have any real effect on linkdown timing and unlocking.

The recoil spring does control the rearward speed and momentum of the slide in recoil, and likewise on the return to battery. The pistol can be fired
without a recoil spring at all...repeatedly...and returned to battery manually. I don't recommend the practice due to the frame absorbing the
full impact of the slide, but other than that one issue, the pistol will work just fine.

 

[stans]

my .45 Super brass was made by sawing down .308 cases and inside reaming, so it is definitely thicker at the base. I assumed Starline was the same.

Never assume anything, especially with firearms, ammunition, or reloading components.

 

[Clark]

Let me say this about recoil springs.
I think of myself as a really tough guy.
I would like to say recoil has no effect on me, but with the 20 ounce Patriot and 460 Rowland loads, I got a flinch. I would punch my right shoulder forward eveytime I pulled the trigger, of any pistol.

I made the 42 pound triple spring recoil spring assembly, and it was just right for +P ammo with the very light Patriot slide.

That pistol has great case support, but I could not use it, until I changed the springs.

 

[Rockstar]

Anybody got an answer to my simple question?

 

[Clark]

Loaded hotter than we think?
What do we think?

 

[SteelEye]

After shooting hot rod loads, 1350 fps 180 gr bullets, in my Smith 625 and seeing this was loads of fun, I began to think that I was wandering into a dangerous zone. I could see myself loading hotter and hotter, eventually blowing up the gun.

One must think of suitability. As Clark and demonstrated, the 45 ACP/AR will take an enormous amount of punishment but you must think of after effects. The gun was never intended for this purpose.

If you would like to shoot heavier loads, get a more suitable gun. In my case, I ended up with a very strong 44 mag. My 625 has reverted back to 45 ACP/AR loads.


SteelEye