1911 Warm Loads / .45 Super & Springs

G

Gregory Gauvin

New member
I have been reading up on .45 Super conversions. There seems to be some controversy in the method of re-springing the 1911 to handle the higher recoil. The mainstay of replacing the firing pin stop with a flat bottom makes sense to me, but this also goes in hand with beefing up the mainspring itself. Now, from what I'm seeing, there seems to be some who throw in a 28LBS recoil spring (slide return spring) and leave the mainspring alone. There is another group who believe the recoil spring is simply a slide-return spring. It needs to be set effectively to reliably chamber a round and adjusted not to slam the slide closed too hard. These guys run beefed up mainsprings and 18LBS or so recoil springs.

Running a flat bottom FPS and upping the mainspring makes sense to me in order to increase lock-time. Increasing the recoil spring alone will not increase lock-time, only, lower slide velocity (on the way back) but increasing the spring weight will increase slide velocity going into battery. Obviously, you can't increase the mass of the slide. So, changing the recoil spring to a 28# or 30# alone does not cut it, otherwise, the same theory would say you can put a stiff recoil spring in a blowback pistol (let's say a 9x18 makarov) and start running 9mm Luger power levels. Obviously, you can not do this.

So, from the horses mouth...what is the proper way to set up a 1911 for .45 Super?

I'm running the standard spring weights in my 1911. I have no need for .45 Super but I have thought about pushing some 230 grain Hard Casts to their upper end. Running them at 859ft/sec with a dose of HS-6 is the limit to where I'd run them sprung with standard springs, as, this is where I do run them and they are most accurate. But anymore and I feel that I would be beating the gun. For fun, I was thinking of working up to a +P loading which some others have done, and running them up to 1050ft/sec. That's just a bit past velocities of some +p loads with FMJ. 18 or 20# recoil spring I'm thinking...?
 
I do not claim to be an expert.Over the years I've built a few 1911s and shot a few.To try to build them right,I've studied them.
John Browning made a good,robust tool .Its not grossly over engineered.
It was designed to work well with the 45 ACP and the 38 Super.

It has surfaces designed to slow/stop slide velocity and absorb recoil in the recoil action.That dust cover doohickey on the underside of the slide.Where the recoil spring feeds in.The rear face of that contacts the frame.
It has other parts that absorb slide velocity after feeding,as the slide returns to battery.
For my self,the way I see it, A 16 lb recoil spring is a stock spring.Just me,my approach,no science,I feel comfortable bumping up one step.An 18 lb spring.

I might use a 20 lb to figure out where I can trust the slide stop to function reliably with a given warm load.,then return to the 18 lb.

I don't spring to the load,I load to the spring.If 18 is not enough,use less powder.

The squared off firng pin stop is JMB's original design.I would not be afraid to use it.A 28 lb mainspring is spec per Kuhnhausen.No problem.

There are two issues with heavy recoil springing.,well,three.
One,cycle time.Your magazine needs time to feed.Heavy springs cause the slide to outrun the feed.

But,IMO,the worst is the destructive effect of the increased recoil spring.The slide and barrel mass serve as a hammer flying forward.
Look carefully at what the "anvil" for that hammer is.
Your smith carefully fits and tunes those two little barrel feet to properly climb up on and stop on the slide stop pin.That is what stops the slide.Thats why it is called the slide stop! Slide transfers energy to the barrel,barrel feet to slide stop pin,slide stop pin to frame. Those holes you put the slide stop through.
Not much surface area.And maybe Rockwell 24 C.Not all that hard.

Think of the weight of your slide as a hammerhead.Look at the steel that absorbs the force.

The recoil spring will lose some energy to feeding a round.That is constant,16 lb spring or 24 lb spring. 50 % more spring swings the hammer(slide mass) a lot harder.

Factors one and two,feed reliability and wear on the gun.

Factor three: A slideslamming shut with a 24 lb spring will drop the muzzle more than with a 16 lb spring.

You will either shoot slower or miss more.. You did say your pursuit of velocity was primarily for amusement.
That's all up to you.
I suggest pursuing overall effectiveness.Adequate power,to defeat your target,reliability,longevity,and controllability to get more hits quicker.

One way to get more "power" out of the 1911 is the path the race gunners use.The compensator.Its part of the .460 Rowland story,too.The compensator slows the slide.(No,not an e-bay "bushing comp" .A real,tuned compensator designed to use gas to hold the bbl/slide )
My brother is shooting a 38 Super racegun built by Guncrafter for a top competitor in the 70's.Its been shooting high round count,over 40,000 psi loads for over 40 years.Its still tight,sweet,like a fresh gun.
My brother set up the springs by using high speed video.Slow motion.He selected springs that allowed the gun to run with the least disturbance to the muzzle.

He's shooting over 1400 fps with a 125 gr bullet and using a 12 lb spring.Its not only reliable and effective,the 12 lb spring is very gentle to the gun.

Once again,if I need a spring heavier than 18 lbs for my 1911,I will try a lighter load.
 
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Oh, thanks, excellent information! How about mainsprings? Some guys run 19 or 21# springs, primarily, to make for better trigger pulls. I am running a stock 23lbs. Of course, my Springfield has a 28LBS mainspring in it because from what I understand their ILS system. I guess what I am getting at is...upping the recoil spring or mainspring is going to reduce rearward slide velocity. I'm trying to correlate a relationship between slide velocity and respective springs.

For example: Given a load, say, GI ball, assuming the bullet leaves the barrel before any movement of the slide and other variables such as hammer weight are fixed - Lets say with a 16# RS and 23# MS the average slide velocity is 300 inches per second. Using the same load, but an 18# RS and 23# MS will be 300 - x inches per second. Is there any relationship to then a 16# RS and 23 + A# MS to equal 300-x?
 
:D Well,Gregg, I never was the guy with the quick draw scientific calculator rig,the charged spare battery pouches,the Dockers,or the Izod shirt.

That guy would come to me with a drawing of something he needed.

I did a little trig on my TI.

I'm more the guy who runs the saw,the mill,the lathe,the surface grinder,the EDM,and a file.

Same team,different position.

I have noticed that "assuming this,assuming that" can lead to overlooking significant variables,helping to jump to questionable conclusions.

IF I had really good reason to do all the work,and you provided the $,we could make a gol durned apparatus!!.Hi-speed cameras,accelerometers, run through a bunch of springs,shoot a bunch of bullets,and have a good time.

You could tell me what it all means.
 
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HiBC pretty much covered what needs to be covered and gave a wonderful explanation. I don't like upping recoil springs past the 18# recommendation either, mostly because of beating the slide stop pin holes in the frame.

As an aside, when you up the weight of the mainspring you are almost certain to increase your trigger pull weight. Would you rather have a nicer trigger, or push 230 gn pills faster than they were meant to be pushed.

For fun, I was thinking of working up to a +P loading which some others have done, and running them up to 1050ft/sec
Click to expand...

I think that's a bit much for a 1911, personally. I think 950fps is realistically achievable with cast. You already get a velocity bonus with lead anyway, and there is some +p load data somewhere pushing a 230 gn cast bullet to about that level with HS6. I believe it's in a Lyman #49, but can't remember off hand. I would still rate 950fps with a 230gn bullet a VERY warm load.

I would definitely go with the square based firing pin stop, and likely an 18# recoil spring. An increased power mainspring would help, but again your trigger pull may suffer some.
 
I also forgot to mention, I don't know that I would push much harder than you already are with normal brass. I've seen here where at least a couple of 45 super shooters are using starline +p brass with success. I actually want to get some to play with a little.
 
I have a few hundred rounds of .45 Super experience, and generally agree with HiBC; make some easy mods that reduce or eliminate the need for heavy recoil springs.
The reduced radius FPS and heavy mainspring are more nearly a free lunch in comparison.
I'm running a 25# main and . . . 22# recoil spring in my Super. I did run into trouble with the slide outrunning the mag, but it was my choice of a flush-fit 8rd mag that created the problem; a 7-rounder or modern, extended-tube 8-rounder would have been fine.
Even with full-power Super loads I am getting 6'-8' ejection, I could reduce the recoil spring a little, but I've always run 23# and 24# springs in my 10mm, and have not had functional issues there, either.
For a 5", .45 I prefer a 14# recoil spring, so I'm definitely no advocate for heavier than necessary springing.
 
HiBC, very well written, excellent info.
Most people do not understand the difference in hardness of the parts involved in stopping the forward momentum of a 1911 slide barrel assembly, the frame is the softest part.
I've preached for years the effects of forward battering.

I also have a lot of experience with compensated 1911 pistols, I've done some loads in 45ACP that were well past +P+ loads (239 power factor) and the gun I shot them thru was using a 15 pound recoil spring, 18 pound main spring.

Best Regards
Bob Hunter
 
I run 45 super in my Sig Extreme 5" gun. Harrison Design flat bottom firing pin stop, 18lbs flat wire recoil spring, a 34lbs mainspring, and a xtra xtra power wolff firing pin spring. Tames my 230gr HST at 1250fps pretty well. I use a regular short GI spring guide and a GI plug without issue. I checked my barrel lugs to ensure good solid engagement prior to running them hot. I would suggest you do the same.

My 45 super load is an Extreme Bullets 230gr FN coated bullets or Federal HST bullets over 10.5gr of Alliant Power Pistol with CCI large pistol primers and Starline 45 Super brass. Empties are landing 8-12 feet away at approximately the 4 o'clock position.
 
Printed load data suggests a max load of Power Pistol with a 230gr bullet is 9.4 grains.
Your velocities are higher than what I get with a max load of AA#7 out of a six-inch barrel.
 
I found a large variance in printed load data when I first started my 45 super journey. I started low and worked my way up. Zero pressure signs until I was at 10.8gr, obviously your mileage may vary from gun to gun. My velocity is not much higher that Buffalo Bore velocities.
 
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I do not know where things start to go bad.Your setup might be fine(squared off FPS and 32lb mainspring) I'm not saying there is a problem.

But at some point,there is a limit to how much you can ask from a hammer pin,hammer,and the holes that support it,too.

As you change the geometry (fulcrum,lever arm,etc) It IS harder for the slide to begin accelerating to the rear.

There is no free lunch.The hammer velocity into smacking the grip safety goes up,the load on the pin,frame,and the thin sections of the hammer go up,too.

Maybe they can handle it.I do not know
 
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Tames my 230gr HST at 1250fps pretty well.
Click to expand...

:eek::eek::eek:

Sounds like the 357 ROF almost! How's the brass holding up? I've thought about starline 45 super brass for some +p loads. Not 230gns to 1250fps though.
 
Brass is fine. The brass I used above 10.5gr was discarded and I inspect my brass prior to reloading. I have a couple hundred pieces of brass with 4 loadings on em without any signs of fatigue or damage. I will probably discard them after 8-10 cycles.

As for the no free lunch, you are correct. I keep a good eye on the frame abutment, hammer pin holes, ejector, etc. I have probably only run 1500 rounds of this load through the gun and have observed no peening of the abutment or wearing on the pin holes. I have however knocked an ejector pretty loose. I was lucky enough to catch it before it broke so it was an easy fix.

The gun is not a 100% factory sig. The fire control is all Wilson Combat bulletproof tool steel parts as is the new ejector. I run 230gr Federal HST +p for my everyday carry and duty ammunition. My target load is a 230gr FN plated bullet at 800fps and they just cycle without issue while dropping the empty about 2-3 feet away at my 4 o'clock position.
 
Guys, you know you can buy a .44 Mag off the shelf and you won't have to destroy a good 1911 gun to get more power, Don't You?
 
Sure, but while I can buy a 1911 in .357 Magnum, I can't get one in .44 Magnum.

And since LAR quit making 1911s in .45 Win Mag, there's not much to do other than go to .40 or .45 Super or .460 Rowland.

If someone made stretch frame and slides I'd be all over a 1911 in .44 AMP; I'm already set up to load that. And 10mm AMT Magnum, and...
 
I have yet to destroy a 1911 or any other perfectly good handgun by playing with these hotrod loads. Besides, as a reloader why would I want a big ole 44 mag when I can cook up loads in a semi auto with minimal work to the pistol that can compete? Just takes attention to detail, working up slow, and setting the pistol up correctly. I never got into the 44 mag thing like some. I have several 45 colt loads that equal 44 mag offerings. Advantage being I can use a lot of the same bullets as I use for my 45 acp and 45 super.
 
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