45 acp pressure question

[osteodoc08]

Just a theoretical question:

With today's modern steels, modern casings, etc; what is the reason that 45acp pressures are kept as they were 100+ years ago. Is there any other reason (besides wear and lawyers) that the 45acp can't handle more pressure with today's modern steels and casings, ala 45/70 and "ruger only" loadings in 45 Colt?

I don't intend on hot rodding the 45acp. I'm aware of the 45 super and 460 Rowland. This is purely academic.

[3leggedturtle]

I have hot-rodded (sorta) a 45ACP in a 18" Contender. Was shooting the HNDY Lead 185gr SWC at over 1300fps. The slug lost velocity so quickly that it just aint worth it. Was trying to get a reasonable "flat" load that I didn't have hold over alot from 50 yard sight -in to the 200 yard gong. Just alot of extra powder and noise for very little gain. YMMV

[376Steyr]

Almost all 45 ACP handguns are recoil operated autoloaders. Since higher pressure=higher velocity=more recoil impulse, you would quickly set yourself up for malfunctions as the "timing" of the operations (extraction, ejection, feeding from the magzine, chambering) would be changed from the original design. While you could undoubtedly build an autoloader around "+P++" ammo, it probably wouldn't work worth a darn with standard ammo. I'm sure others will chime in pointing out the relative lack of chamber support in various models. I have personal experience with a 45 ACP case blowing out at the web in a 1911. It wasn't pleasant.

[dudel]

I recall some issue with the 45ACP case design. The LP left less meat in the 45 ACP base. Glock addressed the issue in their 45GAP (which BTW shoots great). The 45GAP brass looks like a shorter 45ACP case. 45GAP runs at higher pressures than 45ACP; but uses a SP.

[country gent]

There are several reasons for keeping the 45 ACP at original pressures. 1st is all of the older guns out there that arnt newer steel and tolerences ( actual some due to wear may not be as strong as original). Another is the number of pistols still being made with original style barrels that may not fully support the case head. Ammo manufacturers will always err on the safe side due to these older firearms. I have seen and shot +P factory loadings now being offered for self defense and wasnt all that impressed. Also keep in mind a heavy diet of heavy loads wear the gun much faster than standard pressure loads do. The 45-70 loads are for specific firearms. saying for a certain year range of 1911 or pistol would be very confusing to most to say the least.

[reed1911]

As stated above it has more to do with the platform and less to do with the strength of modern steel. Really, the steel used is not terribly new or hi-speed, most of the advances in metal are elsewhere and/or not the steel used in firearms. What limits most in terms of pressure is the mechanics of said gun.

[Outpost75]

The limitation in the 1911 is not pressure, but at what point increased recoil impulse hastens frame cracking. The .38 Super and 9x23 operate at higher pressure and the guns handle them no problem, but in. 45 ACP I can tell you that a steady diet of 260-grain loads at over 850 fps cracks frames and when you use heavier loads than the gun is designed for, you need to start tweaking other things which start to impair reliability and safety.

[Moonie]

At handloads.com there is an article on making ruger only 45acp loads, they are 45 super level loads in regular 45acp brass. The theory sounds great except for 2 things (for me anyway). In my family we have 5 1911's in 45acp and 1 45/45 convertible NMBH. If I were to load regular 45acp cases with 45 ruger only loads I would be terrified one would make it into one of the 1911's. Also, why should I worry with it when I have a 45 Colt cylinder...

[gray wolf]

I recall some issue with the 45ACP case design. The LP left less meat in the 45 ACP base. Glock addressed the issue in their 45GAP (which BTW shoots great). The 45GAP brass looks like a shorter 45ACP case. 45GAP runs at higher pressures than 45ACP; but uses a SP.
The base of a 45 ACP is one solid mass of brass throughout the case head, I doubt that is a factor.
The gap is a different animal, most 1911 pistols even when throated for SWC Do at least support the case to the beginning of the web. Sure not fully supported but enough for normal pressure.
Only a theory on my part, but a hot load could/may/ possibly start the slide back while letting some of the case head out of the chamber blowing a hole in the case just beyond the web.

Like I said just a theory, I agree with the other post about the frame battering and lets not forget the barrel link and link feet.

[MtGun44]

The pressure limit is actually the unsupported area of the brass case head at the feed ramp,
nothing to do with the guns, as a general rule - speaking about MODERN guns in good
condition - not 1917 S&Ws and Colts, or old original 1911s - although the old 1911s MIGHT
be OK. I suspect that the old revolvers are just not strong enough for the pressures,
regardless of the cases.

The .45 Super is just stronger brass designed for higher pressures, a 1911 can be modified
to shoot this stronger brass.

OK - according to Wikipedia (not necessarily a reliable source!) there are changes in the
support of the case head in the chamber design in the feed ramp area, too. So, I suppose
a .45 Super barrel is required in addition to the stronger brass.

Look up the .460 Rowland - it is some sort of a ".45 ACP Magnum" round - not really familiar
with the particulars - seems like it could also be put in a 1911 with some mods.

I do know as a hard fact that with overpressure the failure is always in the
brass at the feed ramp area where it is unsupported. I have double charged a .45 ACP
ONCE, and have seen it done a number of times. This is the real world pressure
limit of the cartridge in semi-autos. In a steel 1911, not much damage, usually,
split grips, stung palms, ruined mag. In a plastic gun - total disaster, and significant
more risk to hands. A member here double charged a Sig .45 ACP and totaled
the gun - bent aluminum frame rails and slide rails a lot, no injury, tho.

In revolvers - they are not so much brass dependent as design and materials. If
I had a hankering to push it in the .45 ACP, I think the Ruger Blackhawk is the way
to do it safely - strong, modern steel, fully supported brass in a gun well known to
digest very hot loads with no issues.

Bill

[35remington]

Gw, case can't move back when pressure is high. Case stays in place and does not move because barrel stays locked to slide and will not unlock until bullet and pressure are both gone.

[gray wolf]

Gw, case can't move back when pressure is high. Case stays in place and does not move because barrel stays locked to slide and will not unlock until bullet and pressure are both gone.
Double face palm, I should have known that. Thanks for the tap on the head.
But hey , I did say it was only a theory.

[osteodoc08]

Interesting reading guys.

Like I said this was purely academic.

[bandmiller2]

The 45 acp has enough power, designed to have manageable recoil and enough power to serve its intended purpose. It was not intended to take out the great bears and bull moose, that's why we have the hand cannons. I enjoy shooting mil spec hardball especially from my Ruger convertible. Frank C.

[Scharfschuetze]

As Mtngun notes, the unsuported area at the feed ramp is one reason pressures are kept low. Handloaders have blown cases in this area trying to hot rod the old gal.

You can buy a "ramped" barrel that supports the case head in this area better. You have to modify your frame, but a competent pistol smith should be up to the task. Still, even with a ramped barrel, you still have the issue of cracking or prematurely wearing out your 1911 with excessively hot loads.

From the Clark web site:

"Ramped models feature an extended, integral ramp that fully supports the case head to end head separations and bulged cases. Rounds feed directly onto the ramp, no frame-to-barrel gap for bullet noses to hang up on."

I found this photo on the internet, but it shows the unsupported area blown out when one gets too aggressive with his reloads.

[williamwaco]

I would NOT recommend it but if you decide to try it,

Get a Thompson Contender or a modern revolver. I would select the Ruger.


Better yet . . .

Get a .45 Colt.

.

[leeggen]

Why change something that is so close to perfect in relation to what it was built for. inclose and personal combat.
CD

[osteodoc08]

I would NOT recommend it but if you decide to try it,

Get a Thompson Contender or a modern revolver. I would select the Ruger.


Better yet . . .

Get a .45 Colt.

.

Like I said guys, purely academic. I don't reload outside of published data and value my digits and eyebrows.

I was reading about Keith's 38/44 loadings and how that lead to the 357Mag. Granted he was known to have a few KB himself, it just got me thinking. I know it's not the same (auto vs wheel gun) but the idea of going outside the published is still at play. I wonder what would of happened had EK been an auto guy and Jeff Cooper a revolver guy? Hmmmm. Now that would be an interesting debate.

[Dhammer]

Don't know about know but when Ruger first came out with their 1911's they were not rated for plus P. I read several articles where they were aditment about it too.
Every agency in my area where 45's were authorized for carry, they issued plus P ammo.
I talked to the LT who got to make all the final decions for what duty ammo we carried. He had acrsss to some very cool govt studies and ammo manufactures studies. He bascially said the plus P in 45 despite not being a whole lot more. (930fps ish?) Compared to other 45 ammo in the high 800's just really stood above and beyond in certain parts of the study. It was night and day. Sadly, I don't recall which part of the study anymore. Ive got some short term memmory loss since I got hurt.
My dad used to hot rod some 45 jacketed HP's for his 1911 Remington Rand. Wasn't plus p but was up there and he finally cracked the slide. He attribuited it to too many years of hot loads.
One of my 1911's is basically a colt commander that's called a TLO. It was limited run for the FBI and enough hot rounds through it will cause crack's in the frame at the weak points. We had people with low round count with plus p crack frames on bran new 1911's of various alloys. One had three frames in a row too from a certain manufacture before they got told your getting a steel frame. I imagine the hotter they push the more likely more issues from certain model if not many too.