I put together a custom 10mm/40 top end for my series 70 Colt 1911 45. I ordered a Caspian 40/10mm slide (there is no difference, at least from this vendor) all the top end components, wilson combat adjustables, a Kings 10mm recoil rod system, Metaform 40 and 10mm mags etc. I contacted Bar-sto for a 10mm and 40 cal barrels which were fitted by a talented gunsmith. Needless to say this setup shoots lights out in both calibers!! One and one quarter inch groups with each barrel. (You get what you pay for, and this project was quite expensive!) As long as you have the appropriate weight recoil springs 40/10mms should have fine durability. As a note, I have found the 40 S&W cartridge to be less reliable in the 1911 vehicle simply because of its O.A.L. However once the gun broke in and I found a recoil spring weight it liked it has performed awesome in 40 S&W. As RickB stated, the frame horror stories are 15 years old!! Us 10mm freaks smartened up and put REAL recoil springs and guides into our 1911 10mm street cannons!
It was mentioned previously that a 10mm Delta barrel will not fit in a 45 slide. This is true. Different hood dimensions. My question is: Why would you want to?
I understand the versatility and having the simple option of the two calibers (in my case three). My agency supplies me with an abundant supply of 40 S&W. so it is very economical for me to shoot. The 10mm gives a slight edge in power for hunting. My goal for this year is to take a deer with this 10mm setup. And of course the classic 45 ACP.
I aquired a Colt DE upper with barrel for a song a few months ago. I took the upper and converted my wife's series 80 .45 to 10mm with new DE slide, barrel, slide stop, recoil system, barrel bushing and magazines. I didnt have to modify/replace ejectors! They use the same ejectors! The gun is ultra reliable in 10mm & 45. I plan to replace the stock DE recoil system (plastic junk) with a full length recoil rod and a 24# wolff recoil spring ASAP!
My point is that I have done a few 10mm conversions and have talked to a great many gunsmiths concerning the projects. I first would check to see if indeed the DE 10mm barrel will fit in a Colt 40 slide. It should, and if I recall, Colt made a "Conversion Gun" which was a DE that came with an extra 40 S&W barrel. However this was a 10mm DE with an extra 40 barrel, not the other way around,
Some "experts" are stating that your 1911 wont hold up to the recoil of the 10mm. jtduncan stated " No. A gun made for 40SW does not have the pressure tolerances or the physical room for a 10mm" He is only half right IF he is right at all. I havent examined a Factory 40 1911 from Colt so I cannot state absolutely 100% that a 10mm barrel will fit. I believe a 10mm barrel should fit your 40s&w Colt. (If I am wrong, I stand corrected!)
However if you or jtduncan think your 40 cal wont hold up to the "punishment" of the Mighty 10mm, lets take a look at the psi the 38 Super generates! I know a few hardcore IPSC nuts who have put TENS of thousands of IPSC Major 38 super rounds through their 1911 with NO frame failure. The Major 38 Super operates at a higher pressure than factory 10mm ammo. I dont have the stats but Im sure someone can jump in here and back me up!
A gunsmith by the name of Burns makes a living converting 45s to 9x23mm. If you think the 10mm or 38 super operates at a high pressure look up the 9x23!! Hold on to your pacemakers!! By the way, this was a Colt 1911 factory caliber!! 9x23 fans where are you??!! Jump in any time!!
Make sure you can get an appropriate barrel, whether aftermarket (Bar-sto, Jarvis, Etc) or factory. Buy a few 10mm mags, a heavy recoil spring (24#+), perferrably a full length recoil guide and you are dialed! My opinion, you should have NO problem shooting 10mm out of that 40S&W.
Enjoy!