Colt Delta Elite- Chamber support?

[Rmiked]

I have a DW Specialist is 10mm. My best friend has a 45 ACP 1911, Remington R1. He shot my 10mm and now he is thinking about getting one. He doesn’t want to spend $1900, understandable. I like the Colt Delta Elite and considered it. I kinda moved toward the DW after reading about a non-fully supported chamber and a few other features of the DW I learned about here on PF. I only have one 1911. I have been reading about the Colt and it seems people are shooting 180 grain FMJ at 1250 fps and not having any issues. Is this the extent of limitations of the DE? I mean just don’t shoot any of the Underwood or Buffalo Bore loads that are greater than 700 ft-lbs of kinetic energy? Or is the Colt capable of handling hot loads as well? My DW owners manual says it can fire +P ammunition but it is not recommended in order to speed up break-in.

[farscott]

A Colt Delta Elite can shoot any factory loaded ammo that complies with SAAMI specs with no issues. It can even handle the Underwood and similar loads, but those loads stress the gun more than SAAMI-spec ammo. There is no SAAMI spec for +P for the 10mm Auto, so a cartridge marked as +P only means it exceeds SAAMI pressure spec. It does not indicate by how much the spec is exceeded. Brass from the "+P" loads will likely exhibit case bulges. If one does not reload, it should not an issue. If one reloads, full-length resizing will be required to remove the bulge and will lessen the number of times the case can be used.

My 10mm is a Yost Delta Elite with the factory barrel. No issues with any loads, but I do not push the limits of the cartridge in that gun. If I need more energy in a semi-auto pistol, I grab the 9x23 Winchester Harrison Colt Series '80 which runs at 5.56 NATO pressures without a supported barrel. The trick to that is the case walls are thick and it uses small rifle primers. If that is not sufficient, time for the revolver in .454 Casull. If that is not sufficient, time for a rifle as my wrists cannot handle .460 S&W power in a handgun.

[Bergeron]

It is hard to imagine a Delta Elite finer than a Yost-rebuilt example.

I've got my own lightly-touched DE with the factor barrel next to me while I type this. A 180 @ 1250 is a pretty common loading across a variety of ammo brands, and at a Power Factor (PF) of 225, it is a heavy load for a 1911 when compared the 230 @ 850 (PF of 195).

In a two-piece-ramp barrel 1911, as demonstrated by the 45 ACP/45 Super/460 Rowland family of cartridges, the safe pressure limit is a function of the brass cartridge case design. The 45 ACP is specc'd to 21kpsi, the Super to 28kpsi, and Rowland to 40kpsi, and all can be safely used in the traditional-original 2-piece-ramp format. The Rowland is even heavily recommended only for the those original ramp style. The upshot of all of that is the SAAMI-spec 10mm max pressure of 37.5kpsi is within the operating envelope of the case design and both "ramped" and "unramped" barrels.

Any differences might only be expected to show up when a max pressure excursion beyond 37.5kpsi is encountered. I don't know what the non-SAAMI loads max out at, but I also wouldn't want to shoot anything with more than SAAMI-spec max pressure. Any load that would "dimple" new-factory cases is one I'd want to keep out of my guns.

Almost all of the other questions about Deltas and heavy loads are similar to optimizing any 1911 for the heavy stuff- lowered, small radius firing pin stops, heavy mainsprings, etc. A bull barrel increases the locked mass of the slide-barrel system, and can be of slight benefit. I've had 4 different Deltas apart, and all had the frame rail cutout, as appropriate. The real Delta weakness was the original recoil spring system, which featured a plastic(!) guide rod. Easily remedied.

I am interested in the fully ramped barrel on a Delta, not because I want to shoot super-heavy loads, but because I'd like to start reloading 10mm, and the additional case support is just one more tertiary sort of "safety layer" in the case of an unintentionally overloaded charge or a weak case.

[farscott]

If you want a ramped barrel, there are two basic options:

1) Have the frame for an an existing 10mm pistol milled for a ramped barrel and have that barrel fit to the slide. I would suggest not using the Nowlin/Wilson version as the Para/Clark/Lissner version involves less stresses during the firing cycle. KKM Precision offers the the Clark/Para version, but the barrel is made from 416R stainless. I prefer carbon steel barrels as they bulge rather than burst. Kart offers a 10mm barrel for the Clark/Para version and the Lissner cut can be added; that would be my choice. The only issue would be finding a reputable smith with a decent lead time. All of my experience is with smiths who either closed their build list, retired, and/or passed away.

2) Purchase a pistol that comes from the factory with a ramped barrel. Slightly used DW Specalists and old STIs would be my choice. I had a .40 STI Trojan 6.0 that I foolishly let get away; a quick rechambering, a new firing pin stop, and a new recoil spring would have resulted in a great 10mm pistol. Never saw another one in the fifteen years since I sold mine.

The second choice is probably less expensive than milling the frame, sourcing a barrel ($230 minimum plus shipping), sourcing a new barrel bushing, fitting the barrel, and getting the pistol refinished, especially as it is so tempting to have more work done when the pistol is already on the smith's bench.

[Rmiked]

Thanks for the detailed explanation. Very informative.

[Corse]

It seems a shame to ruin a DE by putting in a ramped barrel.