Case head support in Colt Delta Elite.

 

In response to the flak that Colt has been catching over their failure to use a barrel with an integral feed ramp on their new Delta Elite so as to provide a fully supported chamber, I’ve been asked to weigh in.

First, a little history of the ramped barrel with the fully supported chamber.

In the mid-80s, when the doublestack .38 Super raceguns were dominating the open classes, it was because a few competitors discovered that they could make major with the old Super if…IF…they loaded 150 grain bullets to near centerfire rifle pressures, and it worked well until they started bursting cases with small powder charge variances, which got ugly in quick time when the hot gases and shards caused sympathetic detonation of three or four rounds in the magazine. Very ugly.

So, they turned to the aftermarket and had’em cobble up barrels with integral ramps which supported the case head as completely as can be done with a self-loading pistol. Problem solved! The higher than proof level Super ammunition didn’t blow their expensive shooting devices apart any more.

But it led to the belief such support was necessary in all calibers that the 1911 is chambered for…even the old low pressure .45 standby…and it just ain’t so. It does sell expensive ramped barrels and gunsmith services to install them, though.

But, the Big 10 is a high pressure cartridge, so they raised the cry that…like the .38 Super shooting devices used by the top guns…it also needed a ramped barrel and fully supported chamber.

Except it doesn’t. At least until some enterprising handloader decides that another 100 feet per second would make the 10mm just that much better…and sooner or later, somebody will blow up a stock Delta and offer it as proof that it “needs” a supported chamber.

As long as the headspace is within spec, and/or the barrel ramp…throat…hasn’t been cut so far into the chamber that it loses support forward of the case head…the webbed area of the case…the Delta Elites will fare just fine with the standard divorced feed and barrel ramps. The 10mm case was engineered around 37,500 psi, and will withstand proof levels which run to 25% higher than SAAMI standard pressure for the cartridge. Just don’t load to proof levels more than once per case. In fact, it’s not a good idea to exceed the maximum 37,500 under any circumstances.

As a wise man once noted: (paraphrased)

The pressures required to accelerate a 200 grain bullet to 1200 fps in 4.2 inches of rifled barrel are more than sufficient to blow your eyes through the back of your head.

If you need more punch than the 10 will deliver, go buy a .41 Magnum revolver.

Stick to SAAMI pressures and the new Colt will be fine. As this applies to the Delta Elite it equally applies to all 1911s.

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9 Responses to Case head support in Colt Delta Elite.

  1. Andrew L. Bresnan January 10, 2017 at 10:59 am #

    However if they produced the Delta with a ramped supported barrel that would put an end to the complaint if the unsupported chamber. They would also double their sales. I would even buy another Delta. Perception is everything. Without the ramped/supported chamber the criticism will never go away.

    • Hunter Elliott January 11, 2017 at 12:40 am #

      The people that have an understand of how a 1911 works do not worry about the standard barrel. You are expecting a company to change a product that is fine like it is, raising the cost without need. If you stick with SAAMI spec ammo the Colt Delta Elite is good to go, and I have no idea why people have so much trouble understanding this simple concept.

  2. Hunter Elliott January 11, 2017 at 12:38 am #

    The people that have an understand of how a 1911 works do not worry about the standard barrel. You are expecting a company to change a product that is fine like it is, raising the cost without need. If you stick with SAAMI spec ammo the Colt Delta Elite is good to go, and I have no idea why people have so much trouble understanding this simple concept.

  3. John Travis January 11, 2017 at 9:47 am #

    A belief is a funny thing, Hunter. A deeply held belief can border on fanatical.

    I mentioned the .38 Super’s pressures and the fact that Colt and other manufacturers have built .38 Super pistols for years…and it doesn’t make a dent.

    It’s like my salty old grandpappy told me.

    Once a man locks onto an idea or a woman…no matter how wrong or how bad…there just ain’t no shakin’ him loose from either one.

    • Hunter Elliott January 12, 2017 at 1:00 am #

      Thank you Gunny. I believe your grandpappy was onto something. Funny how wise that generation was and now look where we are.
      Thanks for everything.

  4. John Travis January 12, 2017 at 7:28 am #

    Just simple truths, Hunter.

    Examples of Marketing 101 are everywhere you look. Two recent ones are:

    “If your pistol doesn’t have this extractor, you NEED this pistol!”

    Despite the fact that the 1911 worked quite well with the original extractor for 90 years prior to the appearance of the “Power Extractor” put forth by Para Ordnance.

    “If you aren’t using these shock buffers in your pistol, you’ll destroy your frame!”

    Despite the fact that, in the half century that I’ve spent wrenchin’ on Johnny’s Toy, I’ve never seen a 1911 frame battered into an unserviceable condition.

    But just remember that if you use Brylcreem hair goop, the women won’t be able to resist your manly charms and if you don’t use the Capital One debit card, everybody will hate you at the grocery store for holding up the line.

  5. bmcgilvray February 2, 2017 at 4:17 pm #

    I’m fairly new to the 10mm Delta Elite game, having owned mine for a year coming up end of this month. It’s been a mild-mannered pony with the various factory loads as well as one mild cast bullet handload that have been fired in it. This includes several offerings from both Underwood and Buffalo Bore. I have no intention of running it full-throttle all of the time, but am I suppose to dither over the heavier 10mm loadings when I do use them. I’m seeing no indications that dithering is required when using heavy loads in the pistol.

    The thought of the 10mm cartridge and its ballistics appealed to me for a long time. I’m finding that it is worming its way into my affections even more than I expected. I just need to play with it more. I love handloading and the round appeals for handoading fun.

    • Hunter Elliott February 2, 2017 at 10:54 pm #

      Have no fear in running the hot 10mm Auto through your Delta Elite my friend. If the ammo is in SAAMI spec, and all ammo SHOULD be though some do not disclose that, you are good to go. I have run some hot handloads as well as plenty of DoubleTap (my favorite hot load) through the Deltas I have reviewed and have not had a single issue.
      Welcome to the world of 10mm, come on in the water is nice.

  6. Wade Landeche May 24, 2017 at 1:07 pm #

    I had asked in the past, companies like Underwood Ammo in particular, about the pressures from their ammo and their statements have been that their ammo is within SAAMI Spec. For all practical purposes this is what SAAMI 205 has set for the 10mm.

    Example of 205 10mm pressure MAP
    The specific loads of the test have to fit the MAP set by SAAMI.

    Here is a typical MAP as set by SAAMI
    Nominal Mean Instrument @ 15 feet with =/-90 fps from test barrel
    Maximum Average pressure MAP of 37500 psi
    Maximum Portable Lot Mean MPLM of 38700 psi
    Maximum Portable Sample Mean MPSM of 40500 psi

    The ammunition in test (10 rounds) would need to fit this established profile.

    Nothing in the sample over 40500 psi.

    PROOF PRESSURE
    Proof Pressures for 10mm are 130% minimum and 140% maximum as set by SAAMI
    The formula is based on the Maximum Portable Lot Mean MPLM of 38,700 psi
    38,700 x 1.30 = 50,310 psi and 38,700 x 1.40 = 54,180 psi
    Minimum and Maximum
    50,310 psi – 54,180 psi these would be rounded to 50,500 psi – 54,000 psi

    Why did I ask these questions?
    Doing the pull-down documentations have shown powder charges that exceed the published data that shows pressures below the 37,500 psi values.
    We know that, people can and do make mistakes for whatever reason while loading their own ammo and that may or my not lead to problems.

    Also the question of the strength of the brass comes into play. Malleability and alloy are the very important to a cartridge case. The stamping and production processes when brass casings are being made can be crucial to longevity and reuse.

    New Starline cases are usually softer as made with handloaders in mind, so they will not work harden as quickly. Other brands from factory ammo have been questionable for reuse. Things like SMILES, Fatigue, stress fractures have have been seen with the first firing of commercial ammo. Anyone who intends to handload accepts the risk and the important task of case inspection and preparations.

    Knowing your firearm and ammo in use, is also part of this safety.

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