1911 conversion?

[Red9]

I've got a Springfield 1911, 9mm.
Would like to make it a 10mm. Do I need a whole slide? Or just barrel, bushing and recoil spring?
Have a Colt too. Same question.
Would love to have a 10mm 1911 but finding a delta elite in Cali is a bit challenging.
Tyia.

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[morrcarr67]

Read this thread https://www.1911forum.com/threads/10...ersion.259982/ They are talking about going from 10mm to 9mm. The issues would be the same, just in reverse.

Here's another one going 10 to 9 https://www.calguns.net/calgunforum/....php?t=1178993

[Red9]

Read this thread https://www.1911forum.com/threads/10...ersion.259982/ They are talking about going from 10mm to 9mm. The issues would be the same, just in reverse.

Here's another one going 10 to 9 https://www.calguns.net/calgunforum/....php?t=1178993

Hmmm. So I have a 80% chance a 10 mm barrel will fit, pending breach size?

Would it be easier to go from 45 to 10mm?

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[ojisan]

You need to get a slide in .40 or 10mm so the breech face is the right size and the extractor will properly grab the fired case.
The 1911 extractor is not a pivoting type so it can not work on a variety of breech face sizes.
10mm ammo and barrel will not work with a 9mm slide / breech face.

[Red9]

You need to get a slide in .40 or 10mm so the breech face is the right size and the extractor will properly grab the fired case.
The 1911 extractor is not a pivoting type so it can not work on a variety of breech face sizes.
10mm ammo and barrel will not work with a 9mm slide / breech face.

How about a 45 slide? Will it work with the 10?

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[Old Flash]

How about a 45 slide? Will it work with the 10?

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No. Use a 10mm/40 slide.
If you want to use a 10mm/40 cal bullet and keep the 45 slide, there's the 400 corbon conversion.

[JTROKS]

9mm, 40/10mm, 38 Super, use the same ejector and the extractors are also about the same. Back in the early 90s I had a 9/38 sup slide that will accommodate 10mm. I would have to dig in the safe to see if it’s Caspian or Springfield.

[RickD427]

The conversion is mechanically possible.

You'll need a 10mm/40cal slide. Most folks find it better to build up a whole new top end. Make sure that you match a Pre-Series 80 top to a Pre-Series 80 frame and a Series 80 top to a Series 80 frame, or that you modify the fire control parts accordingly.

But the real challenge is going to be with the recoil spring(s). Early 10mm's built on 1911 frames were notorious for cracking frames and the recoil forces were the likely culprit. Colt did a lot of work with the Delta 10mm to design a recoil system that could better handle the load.

Also keep in mind that the chamber pressure of the 10mm is far above anything from John Browning's days. If I were doing a 10mm build, I'd definitely look at using a ramped barrel. An in-battery casehead separation can be kinda spectacular. Everything blows out through the magwell and ejection port. If you are going to use a conventional barrel, then get the old-style Pachmayr grips (the ones made before they put the medallions on the grips). They have a steel lining that will help keep the grip splinters from going into your palm.

I didn't want to take the chances of cracking my Colt Deltas. I swapped them over to 40 S&W. All that took was a new barrel, recoil spring and magazine.

[Red9]

The conversion is mechanically possible.

You'll need a 10mm/40cal slide. Most folks find it better to build up a whole new top end. Make sure that you match a Pre-Series 80 top to a Pre-Series 80 frame and a Series 80 top to a Series 80 frame, or that you modify the fire control parts accordingly.

But the real challenge is going to be with the recoil spring(s). Early 10mm's built on 1911 frames were notorious for cracking frames and the recoil forces were the likely culprit. Colt did a lot of work with the Delta 10mm to design a recoil system that could better handle the load.

Also keep in mind that the chamber pressure of the 10mm is far above anything from John Browning's days. If I were doing a 10mm build, I'd definitely look at using a ramped barrel. An in-battery casehead separation can be kinda spectacular. Everything blows out through the magwell and ejection port. If you are going to use a conventional barrel, then get the old-style Pachmayr grips (the ones made before they put the medallions on the grips). They have a steel lining that will help keep the grip splinters from going into your palm.

I didn't want to take the chances of cracking my Colt Deltas. I swapped them over to 40 S&W. All that took was a new barrel, recoil spring and magazine.

Aww ok.
Thank you for the Intel. Your reply helped with alot of my questions. Yes I used my googlefu but answered are all over the place.
New slide it is. I'll try to find one for the springer as I don't want to crack the Colt frame.
Interesting about the grip panels. Thanks for that too.
Would not given that a thought about the high pressures cracking the frame. I'm guessing too high, stress frame, too low, stress frame. Sigh... If it was a free state the answer would be so simple[emoji3525]

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[RickD427]

Aww ok.
Thank you for the Intel. Your reply helped with alot of my questions. Yes I used my googlefu but answered are all over the place.
New slide it is. I'll try to find one for the springer as I don't want to crack the Colt frame.
Interesting about the grip panels. Thanks for that too.
Would not given that a thought about the high pressures cracking the frame. I'm guessing too high, stress frame, too low, stress frame. Sigh... If it was a free state the answer would be so simple[emoji3525]

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It's not the slide design, nor the chamber pressure that causes the frame cracking. You'll need the new slide so that breech face matches the cartridge head and so that you'll get proper extractor engagement. It's the combination of chamber pressure and cartridge head diameter that create recoil forces. The same chamber pressure in a .45 is gonna cause a lot more recoil force than in a .22. Too low of a chamber pressure ain't gonna crack a frame, but may cause the weapon not to cycle.

The 1911 frame design is pretty much the same for both Springfield and Colt. My experience with the cracking was relative to Colt manufactured frames since the Delta 10 was the predominant 10mm offering on a 1911 frame. If your Springfield was built on an Imbel frame (check your markings, a lot of Springer frames were not made by Springer), then you likely have a weapon that is more prone to cracking than a Colt. My experience with Colt v Imbel frames is kinda dated. I'll let folks with more current knowledge chime in.

The Pachmayr trick is often used by folks who try to shoot USPSA Major Class using 9mm. There is no legit way to meet the USPSA power factor requirements while staying within SAAMI load specs. Consequently, there several instances of case head blow-outs, and that make the older Pachmayr grips a sought after thing.

[MuayThaiJJ]

[Robert1234]

The Pachmayr trick is often used by folks who try to shoot USPSA Major Class using 9mm. There is no legit way to meet the USPSA power factor requirements while staying within SAAMI load specs. Consequently, there several instances of case head blow-outs, and that make the older Pachmayr grips a sought after thing.

Not commenting on anything but this guy's last paragraph.

It's FUDD.

You cannot shoot Single Stack in 9mm at major power factor. Read the rulebook before making ridiculous posts.

You can shoot Open in 9mm at major power factor, and a lot of cats do. These aren't Single Stack guns,, so nobody's using Pachmayer grips. There are not a lot of guns blowing up as a result. Very few guns are blowing up. In over 13 years of USPSA shooting, I can't recall a single Open gun blowing up. Not saying it doesn't happen,, but I've never witnessed it..

Lots of Production guns at minor power factor have self-destructed, more than a few PCCs, but no Open guns.

[dfletcher]

I've got a Springfield 1911, 9mm.
Would like to make it a 10mm. Do I need a whole slide? Or just barrel, bushing and recoil spring?
Have a Colt too. Same question.
Would love to have a 10mm 1911 but finding a delta elite in Cali is a bit challenging.
Tyia.

Sent from my T790W using Tapatalk

I'm not overly enthusiastic about Kimbers but their Eclipse is probably the easiest way to go for a 1911 in 10 mm.

[walmart_ar15]

Frame cracking is due to the force of the slide/barrel during unlocking. If the gun is not build correctly, the barrel lug is not going to sit or properly stopped by the frame, thus it will pull on the slide stop pin and potentially crack the frame at the slide stop hole since there are not a lot of metal there for strength. When the slide is at its full open, there should not be any pressure on the slide stop pin, and the barrel lug sits squarely on the frame, to most solid section of the gun. Using too strong recoil spring will also cause this problem as the slide forward movement is held by the slide stop pin alone. So when people build a full house 10mm, either the barrel is not fitted correctly or used strong recoil spring to tame the recoil, causing potential cracked frames.

9mm has different case head diameter compared to 40S&W, 10MM. So a 10mm round will not fit into 9mm breach face. Some manufacturer cheat and uses a 40/10 slide for 9mm build. It will work as the round is held in place by the barrel chamber. It is a bad idea due to how 1911 loads it rounds, a mismatch breach face can cause reliability issues down the road. People also tend to open up their barrel throat to "improve" loading due to badly built guns with wrong dimension, or try to shoot bullet not designed for 1911, hence the not fully support chamber.

Like other has mentioned, your best bet is to get a complete new top section. Look up Fusion Arms, they have complete build top ends for different calibers. You may still have to replace the ejector.

[ar15barrels]

Hmmm. So I have a 80% chance a 10 mm barrel will fit, pending breach size?

Would it be easier to go from 45 to 10mm?

You have a 100% chance that a 10mm cartridge will not fit in a proper 9mm slide.

Changing case diameter requires changing slides as the extractor presses the case against the side of the breech during feeding.

You can swap a 440 corbon barrel into a 45acp slide and shoot 40 caliber bullets.