Is a 1911 in 10mm as reliable functioning as one in .45?


March 26, 2004, 03:34 PM
Seems like operating at such a different pressure would take the 1911 so far out of spec that it would have lots of problems. Ie: stronger recoil springs and increased slide velocity making slide lockback on the last round more "iffy".

How long do they last? If they really take three times the beating that a .45 does......

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The Tourist
March 26, 2004, 04:12 PM
I've had three 10mm's in my lifetime. A Dornaus and Dixon Bren Ten (number 313), A Colt Delta Elite, and a Colt Double Eagle.

The Bren was finnicky when new. A few stoppages, and then one day the slide came back and sheared the hammer off. Mr. Dornaus, a former Pachmyr employee and gunsmith, tore the pistol apart, replaced half of the parts and returned it. From then on, it was the smoothest cycling firearm I had, short of a full Tussey custom. I sold the pistol (after Miami Vice became popular) for $4,500.00, with numerous spare parts, magazines, springs and screws that Harlene was gracious enough to provide. For this part of your argument, the Bren was a 'handmade' pistol.

The Delta Elite was basically a Colt 1911 with a stronger recoil assembly. It did have a plastic spring guide, which I assumed cushioned the pounding the slide was taking. I never shot any of the original Norma rounds through the gun, just handloads which amounted to .45 +P. The pistol never had any stoppages.

The Double Eagle was a similar pistol. It had a tighter fit, it felt heavier to pack, and I never shot it much. I had a Colt Double Eagle just like it in .45 ACP, and a load all dialed in. Both of these guns were just toys for fun, and I never used them as house defense guns.

I enjoy experimenting with the 10mm load, usually down in pressure. I have tons of old brass. In reality, if I was going to fire something different than a standard .45, I'd shoot my H&K USP in .40 SW instead of the 10mm's.

March 26, 2004, 04:18 PM
I'm also having trouble justifying $800 or whatever for a gun that's gonna beat the crap out of itself everytime I shoot it.

Sean Smith
March 26, 2004, 04:34 PM
I've owned 2 custom 1911s in 10mm Auto. I've also owned a Glock 20C and a Witness 10mm. Oh, and a 610 revolver. Here is my take on it.

Pressure by itself is less of an issue than you'd think. Since a 10mm is basically a de-bored .45, you get thicker chamber and barrel walls by default. That only leaves case support as an issue, and since the 10mm case is very strong, you don't really need alot of case support unless you are determined to load above the 37,500 psi SAAMI limit. Which is really pretty pointless. If you think you need to overload a 10mm (with the exception of the 610 revolver), you really need something more like a .44 Magnum revolver.

Note that you can have a ramped barrel installed in the 1911 to get more case support, by the way. At that point it is as good - or better - than any other 10mm autoloader. Note too that 10mm Glocks have ramped barrels, but very little case support.

The big problem with the pressure is that it seems to make extraction more difficult, since it causes the cases to "stick" in the chamber more. Me and a friend of mine have each had 10mm 1911s kill conventional extractors in short order. We both went to AFTECs, which haven't failed yet over a few thousand hot rounds between us. High-end conventional aftermarket extractors would probably do just as well, but my best luck has been with the AFTEC in this application. Dan Wesson Razorbacks use Caspian extractors, incidentally, which are extremely good parts. I'd assume that external-extractor 10mm 1911s with the huge claws would have no problem, either... they'd be basically like a Glock in that regard.

You hear some people say that the 10mm cartridge is too long to feed reliably. To be blunt, they are full of crap. The 10mm works well in a 1911 precisely because it is loaded to exactly the same OAL as other cartridges designed for the 1911, the .45 ACP and .38 Super. Oddly enough, you don't hear twits complain that those calibers are feed-unreliable in a 1911. Incidentally, ALOT of people handload .40 S&W ammo to near-10mm OAL so it runs more reliably in their .40 S&W 1911s. Go figure. ;)

You do need heavier recoil springs for 10mm, but not as heavy as most people think. 20-22lbs at the most. You can do other things to stack the deck in your favor, like use an EGW firing pin stop to delay unlocking a bit, and a good shock buff. Similarly, full power mainsprings are called for here.

Never have seen problems with the slide not locking back, or feeding issues, in 10mm guns. Haven't seen exessive wear and tear on them, either. What I have seen is some lower-quality magazines cause PREMATURE slide locks, and factory extractors breaking on 10mm guns.

How long will a 10mm 1911 last? Beats me. I think you are going to seem SOME accelerated wear over a .45 ACP if you shoot lots of hot ammo; there is no free ride with anything. Properly maintained, a 10mm 1911 is going to last a LONG time.

Pistolsmith Richard Heinie's take on it goes like this:

I have a Delta Elite that I have shot, I am guessing in the neiborhood of 25000 rds., I don't keep track, and it is not battered. I have shot mostly loads that were in the 180,000 Power Factor Range. I shoot downloaded 10MM, because I had this Pistol before the 40 was a hot item. Frank James has a Delta Elite, that I hate to guess how many rounds he has thru his, and Frank doesn't shoot wimp loads in his. He has the ugliest Heinie in existance. It is his daily companion. I see it about every 3 years. He sends it back to me to go over it. The only thing we have replaced has been the Tritium Front Sight, and that has nothing to do with the 10MM. However, changing springs and shok buffs on a regular basis is very important. You don't take a multi-thousand Dollar Race Car and change the oil once a year just for the Hell of it. I think you are trying to get an answer to a question that really doesn't exist. If you like the 10MM, get one and shoot it. If you think it is going to come apart then don't. I still think it is a very versatile Caliber, that is why I have it. Everyone I know that has a 10MM, has it for the same reason. Mine is the one gun I would never get rid of.

Mr. Heinie arguably knows more about making custom 1911s than anyone on Earth, incidentally.

March 26, 2004, 05:57 PM
Well, I have not put tens of thousands of rounds through my Delta Elite, I have way too many toys to spend that much time with just one! My experience with my Delta has been highly positive. Feed reliability? Would you believe that the factory mag will feed resized empties 100 % of the time? So will the two additional Colt mags that I picked up as used parts. Live ammo feeding? Never a problem. The Colt plastic recoil spring guide and 23 pound dual spring set up, well, all I can say is "what were they thinking?" A steel guide rod, and I do prefer a full length for my 10mm, and a 20 to 22 pound spring with a CP Bullets buffer and the factory mainspring work very well. I am sure the EGW firing pin stop helps even more with delaying the unlocking of the pistol and this is on my short list of parts to buy. Don't buy into this thing about the Delta Elite being too weak for 10mm. Sure, if you want to push the 10 beyond SAMMI specs you will need the added strength of the S&W 1006 or 610, but for sane 10mm loads the Delta Elite is hard to beat. Recoil? Really not that bad. About like a six inch barreled 357 Magnum firing 158 grain loads, at least that's what it feels like to me.

March 26, 2004, 06:20 PM
It's not because the design is in danger of ka-booming. Jim Keenan
proved that beyond any doubt. I've immersed GI and commercial Colts
in water up to my armpit and fired them..7 rounds to slidelock...with no ill effects. The pistol is amply strong to take the pressure. It's not even
the pounding that the impact surfaces of slide and frame...It's not really
so much the lower lug/slidestop pin going south under the heavier recoil springs.

The point that has the potential for being the most destructive is the amount of locking lug engagement in the slide. 75% engagement for
a .45 shooting hardball or the equvalent will do pretty well. For a Big 10
with full-power loads, it will do...but not for long. Even with the .38 Super,
the locking lug engagement is more critical than with the .45 ACP.

The barrel fit in the slide gets more critical as the pressure goes up, and as
the amount of use increases.

Just FYI...


March 26, 2004, 06:25 PM
My 6" Python with silver tips in it kicks worse than my DE. I don't think theres a comparison at all.

March 26, 2004, 06:55 PM
Hey I would like to get a standard diameter colt recoil spring guide to go with my newly ordered wolf main recoil spring. Where would I find one? also interested in picking up shock bumper? if thats the right termanology.
I'm kind of new to the lets start playing with the internal parts of the gun other than to clean them:D . Any suggestions are appreciated

Sean Smith
March 26, 2004, 09:31 PM
The point that has the potential for being the most destructive is the amount of locking lug engagement in the slide.

I'm not to worried about the lockup on my 10. But my barrel is slightly... non-standard. :cool:

Hey I would like to get a standard diameter colt recoil spring guide to go with my newly ordered wolf main recoil spring. Where would I find one? also interested in picking up shock bumper?

You can probably just order one from Brownells. The Delta Elite can use standard 1911-style recoil bits in place of the stop double-spring setup without modifications. And it is a shock buffer, not bumper. And you can get those from Brownells too. I like the CP ones best.

March 26, 2004, 10:18 PM
Thanks, & off he goes...:D ahhh more money spent:evil: wife is gonna scalp me. Thanks Sean.

March 27, 2004, 06:36 AM
Hey Sean,

What recoil spring rate do you use to compensate for the extra mass?

Sean Smith
March 27, 2004, 08:02 AM
The recoil spring is a 20 pound variable from Wolff.

March 27, 2004, 08:23 AM
Sean said:
The recoil spring is a 20 pound variable from Wolff.

Ahhhh...Thanks Sean. I'll add that to my database. Soon as I can find a
ramped bull barrel to weigh, I'll plug it into my figures to see where to
start tunin' springs for various barrel designs/weights. Tryin' to pin it
down to an exact science here...and probably over-analyzing.
:rolleyes: But that's just how an obsession works.:D
I'm assuming that you also use the EGW square stop...and a 23-25 pound mainspring...?

Seems like just when I get somethin' nailed, they change the rules on me.



Sean Smith
March 27, 2004, 08:51 AM
I'm assuming that you also use the EGW square stop...and a 23-25 pound mainspring...?

Yep. :D

All the specs on the gun are here:

March 27, 2004, 09:21 AM
Looks good from here! Yost is flat good, ain't he?

The combination of the 20-pound variable, square EGW stop and heavy mainspring serve to reduce the battering in recoil without sendin' the
slide back to battery at warp-speed. This bears out my theory that
one can have his cake and eat it too with the right combination of parts.:cool: ...which just pleases my mule.

On that FP stop...did you leave it mostly alone except for breaking the corner, or did you put a small radius in it? I've been hesitant to just break
the corner on those....just seems to be a bit too brutal to me...and
generally use a radius that matches an early firing pin stop that I
found in a parts box at a show back in the late 70s. That stop is
what set off the light bulbs in my head on controlling slide speed
with somethin' besides the recoil spring. Up to that point, I'd been using
heavy recoil springs with the attendant extractor and magazine timing problems. Remember, this was in the day before Wolff mag springs and EGW square FP it got to be a little frustrating at times. I welded up a few firing pin stops and re-cut'em, and later on, after learning to use a mill, even made several.

Thanks for the information. It'll come in handy.


Sean Smith
March 27, 2004, 11:24 AM
It looks to me like Ted put a small radius on it. Supposedly pre-A1 1911 guns had a more square firing pin stop, but I haven't seen one firsthand to check.

Sean Smith
March 27, 2004, 11:41 AM
Using Power Factor (weight in grains times velocity in feet/sec divided by 1,000) as a rough recoil estimate, the 20 lb recoil/23 lb mainspring/EGW FP stop combo seems to come into its own around a PF of 200+. Much lighter, and the gun starts to feel sluggish (relatively speaking) & get on target more slowly.

March 27, 2004, 12:01 PM
That's pretty close to the one I use with a .45 GM, a 23-pound mainspring, and a 14-pound recoil spring. Thousands of rounds with ZERO frame/slide battering, and I haven't used a shock buff in years. For Commanders, I
step up to a 25-pound mainspring with a Wolff 16-pound GM recoil spring
cut to 23-23.5 coils. No extractor issues...No mag issues on the last round,
and the empties hit the ground about 5 feet from my right foot.

Like you noted, after a point the gun feels sluggish, but generally speeds up some right after a change of springs.

Interesting stuff, spring wot?

Sean Smith
March 27, 2004, 12:13 PM
Actually, I mean thas as the ammunition gets less powerful, the gun starts to feel sluggish. Too little oomph to work the gun. :)

Mags are strictly 8 rounders with Wolff XP mag springs.

March 27, 2004, 02:17 PM
Sean said:

Actually, I mean thas as the ammunition gets less powerful, the gun starts to feel sluggish..

Understood, but since I stick with hardball equivalent, and never download, I've noticed the same thing if I use the square stop...and the
full-power recoil spring...and a 25-pound mainspring, even with "hot" hardball...or loaded to the upper end of spec at 850-860 fps.

For a 5-inch .45 caliber pistol, a 16 pound recoil spring with a stock FP stop stop and a 23-pound mainspring produces the same feel as a 14-pound recoil spring, a 25-pound mainspring, and a square stop.

Moreover, a Commander with a square stop, a 25-pound mainspring, and a tuned/trimmed 16-pound GM recoil spring seems very close to the "standard" of stock FP stop...23 pound mainspring and 18-pound recoil spring.

Wish I had a way to measure slide velocity in recoil with the various combos...That would be more science and less "Seat of the Pants" feel.

For a real eye-opener...In Brownells Colt parts section, the recoil spring for the .45 and the .38 Super have the same part number...Standard for the Super is 14 pounds.:scrutiny:

March 27, 2004, 04:25 PM
if you are comfortable with a 10mm, then a 1911 is more accurate, and fires like a bixxh...i shoot my friends delta and kimber all the time, and recently ordered a witness in 10mm...the 10mm is in my opinion a nicer round for the 1911 format...

March 27, 2004, 08:25 PM
I have often considered a Witness in 10mm, but there seem to be very few custom parts available for the Witness as opposed to the 1911 design. Also, the 1911 is an incredibly simple design and so easy to home gunsmith, the Witness strikes me as being quite a bit more complicated.

Parker Dean
March 27, 2004, 10:16 PM
Y'all were talking about case support with a ramped barrel. The picture posted illustrated a barrel with a certain amount of throating which, in turn, resulted in some of the case side being exposed.

Just posted over on 1911Forum was a (terrible) pic of a barrel from one of the DW Bobtail Commanders in 10mm. The thread is here ( and the pic I'm talking about is Feed Ramp0001. The pic doesn't show any case side exposure. I wonder how well it runs?

Jerry the Geek
March 28, 2004, 05:21 AM
In 2000 I bough an STI "Edge" (1911 with a full dust cover) in 10mm for IPSC competiton in "Limited" division. I had been shooting a Kimber Custom, but I was getting really tired of the 10-round magazine limitation. With the 10mm I could use double-stack magazines and get 19 rounds in a magazine, which is a significant competitive advantage.

When I got the gun, I didn't have any ammunition. Folks in my section who had been shooting 10mm revolvers gave me their ammo. It was seriously full-power, and the first thing I did was to break the Tungsten guiderod. I notified STI ( and while I was waiting for them to replace it on warranty, I borrowed a steel guiderod. No problems, and the replacement has lasted since then.

Next thing I did was to break the front sight. Actually, the tiny pin which holds the front sight broke ... twice .. until my local gunsmith replaced it with a threaded screw.

I also broke the pivot pin on the rear sight, replaced it with a paper-clip to finish the match, and STI sent a replacement which held for a while.

Then I took it to the "Make A Wish" match in Waco, and while shooting the match I noticed that both the front and rear sights were wobbly. I was squadded with Dave Skinner, owner and CEO of STI. He took the gun to work with him on Monday, brought it back in time for me to make my flight to Oregon that afternoon, and I've never had any problems with sight pins breaking since.

Six months later, I broke the retaining pin on the ejector. Sent the gun to STI, they returned it at the end of the week and I have never had any breakage problems since.

The reason why I am listing all these small-parts breakage problems is to high-light the difference between a 10mm and a .40 S&W. I shoot about a thousand rounds a month in IPSC competition and practice, and that's a pretty good test of the things that are going to go wrong on a gun. I have never had a problem with a KaBOOM!, or any major malfunction, shooting the 10mm.

But when I shopped for the gun, I was looking for a double-stack hi-cap Limited, and I had heard of a lot of problems with the .40 S&W. Some internet research showed me that the .40S&W is the 9mm wrote large. That is, the same gun ... frame, slide, everything ... is used for the .40 S&W as is used for the 9mm. However, the functional parameters for the .40S&W is closer to that of the 45ACP than the 9mm parabellum. And most of the pistols then available didn't have fully supported chambers, which means that when you loaded the .40 with hot loads, you were exceeding SAAMI specs.

On the other hand, when you use the 10mm and load it to major power (at that time, 175 power factor), you are actually loading the cartridge DOWN, instead of UP. This means that shooting a .40 you exceed the parameters for which the gun is designed, and I didn't want to do that. I chose the 10mm so I didn't have to worry about the cartridge blowing up.

I received the first IPSC-Limited Legal STI in 10mm, and as such I served as something of a 'test' subject. We soon found out, as you have seen, that you can't use the same small-parts (pins, especially, and certainly tungsten guide rods) on a 10mm as you would use on a 9x19.

Okay, that's all the problems I encountered. Here is where I started to learn the advantages of the 10mm.

After I had tested the gun with full-power ammunition, I started to load ammunition that was a lot 'softer'. I pulled the load down until I was shooting right at the NEW major power-factor floor of 170pf. I discovered that, due to a lower pressure factor, I wasn't getting reliable feeding. I bumped the load back up to 175pf, and found that this was working the slide hard enough that it would feed reliably ... every time.

I tried 180 grain bullets, and found that they didn't work as well as 200 grain bullets. Part of this was because of the ogive of the bullet. The magazines were allowing an OAL (Over-All Length) of the cartridge which wouldn't allow me to seat the bullets on the straight edge. They were seated so short, in order to feed through the magazine, that the case was being crimped on the ogive instead of the straight side of the bullet. Montana Gold Bullets, however, loaded within an acceptable OAL, and the ogive of the bullet is so short that I wasn't crimping on the ogive. This dramatically improved feeding reliability.

You should be aware that the STI magazines for the 10mm are the same magazines as used for the .40 S&W, and that allows a maximum OAL of 1.250. I found that I could load the MG 200gr jacketted flat-point round-nosed bullets to 1.245, they would feed reliably ... and I never had to worry about pressure spikes. I use 4.8 grains of Vihta Vourhi N320 powder, and it works absolutely swell!

So why did I go through all that fol-de-rol trying to get a reliable cartridge configuration for the 10mm? First, I was awarded by a gun that holds a lot of rounds in the cartridge. Second, it works all the time, every time. Third, when I shoot the gun it looks like it's bolted to the floor. The muzzle-flip ... biggest obstacle to fast double-taps ... is almost negligible. People who watch me shoot this gun tell me that it looks like I'm shooting a compensated gun, which is of course illegal in Limited division. My split times are .16 to .25, depending on the distance to the target. The median average is .18 seconds split-time for double-taps.

I shot this gun for over 3 years, racking up 35,000+ rounds (I didn't shoot as much the 3rd year as I did the first two, but I was shooting about 1,000 rounds a month.)

A bit over a year ago, my eyesight degraded to the point where I was no longer able to see iron sights, so I switched to an Open Gun (a compensated STI in.38 Super with an electronic red-dot C-more sight, 21 rounds in the 140mm magazine, 26 rounds in the 170mm Big-Stick magazine. Woof!)

Now I don't have to worry about seeing a good sight-picture, and especiallly I don't have to worry about sight-alignment.

But frankly, the $250+ extra cost of buying a gun with a compensator isn't the reason why I switched. It was the sights, that's all.

I can get the same performance from the STI EDge (in 10mm) as I could from the .38 Super, in terms of muzzle-control. I got the same performance from the 10mm as I did with the .45ACP in terms of power. Magazine capacity is significant in defense situtions, but the double-stack 10mm is similar to .38 Super, and MUCH superior when compared to the single-stack .45acp while it is similar to the double-stack .40 S&W.

Ultimately, the 10mm has ... in my opinion ... proved itself superior to the .40 S&W because the 10mm is more reliable, handles over-charges better (the 10mm cartidge is a much more robust design), and provides similar magazine capacity. It's better than the .45ACP only because of magazine capacity. And it's probably better than the .38 Super because it's a harder-hitting bullet, and with the full-length dust cover you don't need a compensator to make it a flat shooting gun.

If you don't want to use the hotter .38 Super load (no advantage without the compensator and the electronic sights), I think that the 10mm is inarguably better than the 9x19, holds more rounds than either the .40 or the .45.

Get the full-dust-cover 10mm from STI. Lots of power, lots of bullets, strong frame and less perceived recoil.

Besides, you don't have to deal with those puny Small Pistol primers, which do NOT feed as well in my Dillon XL650 as the large pistol bullets used in the .45 and the 10mm.

March 28, 2004, 08:53 AM
1911tuner, Sean, Jerry---thanks! Lots of good info here for those of us who love the 1911 and 10mm. Just the sort of thing that keeps me reading this forum every day.


March 28, 2004, 10:12 AM
...and the 10mm congregation said... AMEN! Bless the Father, (John Moses Browning) and of the son, (Irving Stone) and of the spirit, (John "Jeff" Cooper.) All praise the 10mm Automatic Pistol cartridge! :cool: :D :)


Sean Smith
March 28, 2004, 10:50 AM
Y'all were talking about case support with a ramped barrel. The picture posted illustrated a barrel with a certain amount of throating which, in turn, resulted in some of the case side being exposed.

There is almost always going to be SOME case exposed. The quesiton is how much. Compare my picture to a Glock or typical unramped 1911 and the difference is radical.

Oh yeah, here is the pic he's talking about:

Just posted over on 1911Forum was a (terrible) pic of a barrel from one of the DW Bobtail Commanders in 10mm. The thread is here and the pic I'm talking about is Feed Ramp0001. The pic doesn't show any case side exposure. I wonder how well it runs

Actually, it shows about the same case support as my gun. The picture is so dark and grainy that it is hard to see it, that's all... the shadow from the case blends into the top of the feedramp. I'll post another pic of my ramp from the same angle as the pic of the DW ramp on and you'll see what I mean. Got to charge my camera's batteries first. :D

March 28, 2004, 10:58 AM
A subgun chambered for the 10...A '27 Thompson would be nice, albeit
a bit heavy...but an MP-5 or an Uzi would be a natural, and doable
with just a bit or re-engineering. Another good one would be something
on the lines of the old Marlin Camp Carbine, designed to take 1911
magazines...mainly for economy. A doublestack would be even better.
maybe an M-1 Carbine conversion kit? Doable...and the added thump from a longer barrel would lend some serious mid-range authority to the
Big Ten. Just think, the ballistics of a hot-rodded .44 magnum in a neat
little carbine AND commonality of ammunition with your sidearm.

Gunmakers! If you build it, they will come...:cool:



March 28, 2004, 12:09 PM

I WANT ONE (or two or three)

March 28, 2004, 06:09 PM
Thanks to everyone who has replied to the thread so far, it's been a very interesting read.

March 28, 2004, 06:36 PM
I just saw a 1927-A1 Thompson, in 10mm, at the gunshow in Puyallup last week. The dealer has had it in his rack for a while now. I didn't look at Monroe yesterday to see if he still had it.

I'll look next week in Puyallup if anyone is interested.

March 28, 2004, 07:19 PM
Trying to recall exactly what John Jardine said last night... something about the slide needing to be set back 110 thousands, and the ejection port needs to be made a little longer, and a long extracter helping a bit... thinking about getting a 10mm 'upper' made for my Valtro.


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