1911 extended barrel question

[Grizz]

what is involved in putting a 6" barrel in a mil-spec copy 5 inch 1911 ? just wandering. wondering. curious . . .

thanks

Screenshot 2024-01-08 080447 1911 long slide.png

this would be my lottery ticket BBQ gun

I have $200 into my 1911, which makes me want to scrounge parts . . . at least get to the roadside picnic grade . . .

grizz

[Grizz]

what is involved in putting a 6" barrel in a mil-spec copy 5 inch 1911 ? just wandering. wondering. curious . . .

thanks

Screenshot 2024-01-08 080447 1911 long slide.png

this would be my lottery ticket BBQ gun

I have $200 into my 1911, which makes me want to scrounge parts . . . at least get to the roadside picnic grade . . .

grizz

.
OK OK I'M WAY PAST THAT NOW . . . Going to get a few pesos worth of parts and start shooting 45 Super in it . . . gets the ballistics into the 10mm range . . .

https://www.youtube.com/watch?v=gbryB8XjO-A

fun stuff, Yeah ?

[COSteve]

what is involved in putting a 6" barrel in a mil-spec copy 5 inch 1911 ? just wandering. wondering. curious . . .

thanks

Screenshot 2024-01-08 080447 1911 long slide.png

this would be my lottery ticket BBQ gun

I have $200 into my 1911, which makes me want to scrounge parts . . . at least get to the roadside picnic grade . . .

grizz

.
OK OK I'M WAY PAST THAT NOW . . . Going to get a few pesos worth of parts and start shooting 45 Super in it . . . gets the ballistics into the 10mm range . . .

https://www.youtube.com/watch?v=gbryB8XjO-A

fun stuff, Yeah ?

I might be able to help a bit.

I purchased a custom German steel 6" Longslide and a blued Jarvis custom 6" .45 barrel for my Gen 3 Glock G21 from Lone Wolf Distributors back in early 2004 and I really liked the feel and balance of the longer slide but even my hottest .45 ACP +P loads didn't give me the increased performance I was looking for.

G21 Longslide.jpg

By that summer I was doing some research to see if I could make it into a convertible 45/10mm as all of the lower parts were the same between the G20 and G21. Jarvis wasn't interested in a custom barrel so I talked Kevin at KKM precision into making me a custom, 1 off stainless steel 45-10MM conversion barrel for my G21. He said that he couldn't guarantee that it would work in my G21 and I agreed that if it didn't, I'd eat it.

It turns out that with a G21 all one has to do is machine a barrel with the chamber hood about .050" wider as the breachface on the .45 is wider than a .40 or 10mm one. The barrel outside diameter, chamber and everything else on the G20 was designed to allow them to machine a .45 cal breach and inside barrel diameter. The LCI version extractor introduced in the Gen 3 models has a canted claw and grabs the smaller rim of the 10mm just fine. And, 10mm Glock mags fit right in just fine.

Anyway, when I got the custom barrel in the fall of 2004, I took this picture of the first ever Glock G20/21 Longslide (as I named it). (I guess that Glock finally got their act together when they came out with the G40 longslide 10mm some 11 years later!) The Jarvis barrel is in the slide and the 45-10mm custom barrel with both 10mm mags and ammo and .45 mags and ammo shown.

100_0777.JPG

So, I started loading some hot 10mm ammo for it and realized I needed a 24# recoil spring even though the longer slide and barrel added 4 3/4 oz to the weight of the slide. Using a powder like Power Pistol, the performance increase between my 6" barreled custom and my friend's stock G20 was significant with just the 1.6" longer barrel. Muzzle flip was very tame with the added mass at the muzzle and the flexible frame.

Anyway, after really enjoying my 10mm longslide for a few years shooting at steel plates at 200 yds to the amazement of the guys at the range, I decided to give .45 Super a try as I only needed the .45 Super brass to load some.

The results were not that great for my use as I really would need a muzzle break to load up .45 Super hot enough to get anywhere near the performance I was getting with the 10mm loads. The best I could get with hot .45 Super loads was with 200 grn bullets and they only produced 1,307 fps and 758 ft/lbs ME out of my Glock.

That is compared to my hot 165 grn 10mm loads that clocked at an astounding 1,589 fps and 925 ft/lbs ME and 200 grn loads that clocked at 1,383 fps and 849 ft/lbs ME out of the same Glock.

Of note is that my Glock has significantly more felt recoil shooting the 200 grn .45 Super than it does shooting the 200 grn 10mm. I have no idea why, it just does. Also, shooting the hot 165 grn loads is almost disappointing in that the recoil is no where near what you'd expect and lower than with the 200 grn loads. It's more like a hot .40 s&w load so I've shoot 200 rds of hot 10mm in an outing without any issues at all.

[4t5]

I don’t see why it wouldn’t work , you would have 1” of barrel sticking out the slide. I’ve had 1911’s in the past and can’t see a reason why it wouldn’t work, maybe a current 1911 owner could shed light on the cons ,.

[Grizz]

Thanks Steve. That's a really interesting setup. I've been comparing stats all day and I think I'll buy the internals for the 1911 and work up some loads into the 45 super or short magnum range. I have the dies and the parts swap is easy, so it will get me started, and I can see where it goes from there.

I sure would like to shoot the gun you built!
Thanks for the input, i printed it to my notes.

grizz

[Grizz]

I don’t see why it wouldn’t work , you would have 1” of barrel sticking out the slide. I’ve had 1911’s in the past and can’t see a reason why it wouldn’t work, maybe a current 1911 owner could shed light on the cons ,.

Yeah Thanks. I saw a 7" barrel today, makes me wonder where this is going. What I wonder about is how the bushing would function. my 5" barrel appears parallel sided, bit I haven't mic'd it yet. It would be something if I could get a velocity gain from a longer barrel, and reduce pressure a bit. I read one report of a 255Gr hard cast 45 bullet out of a 5" 1911 that penetrated 64" of gel. OH Well, will see what happens.

[Paladin]

There should be no problem like they said the barrel will just stick out. all of my suppressed guns have that problem. The Colt officers model just has a King Tappen Comp. The Browning is just missing the suppressor. I have a few with this problem.

[Grizz]

Thanks. I have some Underwood 45 Super ammo on the way plus the recoil and firing pin springs and a recoil buffer, and some magazines. Anything else I should swap? There is probably enough stuff to get started. The chamber is fully supported so it looks like it should go bang instead of boom.

grizz

[Paladin]

GO with what you got until you want to make the aesthetics better and decide then how you want it to look.

[Grizz]

GO with what you got until you want to make the aesthetics better and decide then how you want it to look.

Thanks, Yeah, It's way easier to work on something when it's in hand. The barrel I have is full support chamber, and I took the spring out to check the lock-up. It seems good, maybe could use a smidge more, but that's just a guess. The bushing is no work of art, but I don't know what the tolerances are.

What I'm saying is I have a whole lot to learn, which makes the project worth while.

thanks again