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Thread: The Cobra Tests: Q&A

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  1. #1
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    The Cobra Tests: Q&A

    I guess this would be a good time to open a thread for comments, questions, and answers on the Cobra test, which is shown here:

    http://forum.m1911.org/showthread.php?t=47200

    Soooo....


  2. #2
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    I'm presuming the whole point behind the magazines is straight(er) line feeding that is somewhat less reliant on bullet shape and OAL to function with ammunition across the spectrum.

    As in, SWC target ammo from 1.175" or so to the maximum allowable?

    Can you indeed say that bullet shape is less of a factor with these?

    On edit: after reading the post you've updated on the magazines, how would you characterize this late release of the Cobras? Later than USGI mags? Later than the new Checkmate GI magazines? Later than hybrid?

    Maybe this late release compromises function with shorter rounds?
    Last edited by 1944Colt; 20th March 2008 at 19:56.


  3. #3
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    ]
    Quote Originally Posted by 1944Colt
    I'm presuming the whole point behind the magazines is straight(er) line feeding that is somewhat less reliant on bullet shape and OAL to function with ammunition across the spectrum.
    I assume that's one of the goals. I'll take a WAG that the other one is to make the pistols with less than optimum frame and barrel ramp specs and geometries less likely to suffer the ever-present 3-Point Jam.

    Quote Originally Posted by 1944Colt
    As in, SWC target ammo from 1.175" or so to the maximum allowable?
    I haven't tested any yet shorter than the ones that I've moulded...essentially a close copy of the excellent Hensley&Gibbs #68...mainly because I don't have any of the "snub-nosed" 185 and 200-grain SWC bullets. I may try a few of those at some point in the test, if I can find someone who is willing to sell a couple hundred.


    Quote Originally Posted by 1944Colt
    Can you indeed say that bullet shape is less of a factor with these?
    Not definitively as of yet. I'll have to reserve that call for another time.
    Quote Originally Posted by 1944Colt
    after reading the post you've updated on the magazines, how would you characterize this late release of the Cobras? Later than USGI mags? Later than the new Checkmate GI magazines? Later than hybrid?
    The release point is later than other wadcutter designs, and equally abrupt. It occurs at about the same point as with the hybrid-lipped magazines without the benefit of the gradual rise of the cartridge at the rear, and at about he same point as USGI magazines that have been adjusted to feed the #68 SWC...but later and much more abrupt than standard USGI "Hardball Only" magazines.

    My take is that Tripp has provided used the high position for a straighter shot at the chamber in order to match the feeding characteristics of the tapered/gradual release magazine without using tapered lips. It's a good idea, and will very liekly work well in most guns. In others...notably those with low feed ramp angles or slides and frame beds that have been lowered during the refitting...it could pose a problem. I'll put that theory to the test with a later group of pistols in which at least one of each conditions exists.

    So far, the magazines seem to be very good, and are delivering what Virgil promises.
    The fact still remains though, that....with any off-the-rack stocker...you have the best chance for trouble-free feeding with tapered, late/gradual release. The last group of pistols tested have been a trifle balky with the Cobras with some bullet types.
    These same pistols have proven 100% with the tapered/gradual design. Of course, these are old pistols that were built in a time before hollowpoint and SWC bullets, so we can't place the magazines entirely at fault...but they do very well with magazines identical to or close to the original specs...and that does mean something.

  4. #4
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    As an aside...Here are the links to a report from member Tony Bob relating his experiences with what was admittedly a highly problematical pistol that had been to Wilson Combat twice, without correcting the issues. He had to bring it to me twice in order to get the last of it resolved...so you can take my word for it that it was a real pill that really should be rebarrelled.


    You can view the entire thread on the Magazines forum...and I believe that the story on the gun is in the Gunsmithing area.

    http://forum.m1911.org/showpost.php?...47&postcount=1

    http://forum.m1911.org/showpost.php?...79&postcount=3
    Last edited by 1911Tuner; 20th March 2008 at 20:44.


  5. #5
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    "I'll take a WAG that the other one is to make the pistols with less than optimum frame and barrel ramp specs and geometries less likely to suffer the ever-present 3-Point Jam."

    I have just the pistol......the one that is the source of my username. It has a replacement Bar-Sto barrel that was originally fitted with a collet bushing. Possibly some ill advised work by (maybe?) the sergeant who sold it to Dad make it three point prone with bad magazines. The barrel/ramp clearance isn't all it should be.

    If the offer to send me some seven shot versions of this magazine comes through, I have some ideal and not so ideal cast bullets I'll run through them in reliability testing. From 155 to 255 grains in weight.

  6. #6
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    Quote Originally Posted by 1944Colt
    I have just the pistol
    First...Does it run with the Tapered lip design? If it does, it would make for an excellent side-by-side comparison.

    Quote Originally Posted by 1944Colt
    If the offer to send me some seven shot versions of this magazine comes through,
    I have three of Tripp's 7-round magazines. Since my testing mainly centers around the 8-round versions...PM your snail digits to me, and I'll send one that you can put to the test.
    Last edited by 1911Tuner; 20th March 2008 at 21:02.


  7. #7
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    does the cobra mag have a chrome finish?

  8. #8
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    Quote Originally Posted by dragonfire
    does the cobra mag have a chrome finish?
    Appears to be bright polished stainless.

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    Thanks for running a test in an organized fashion. It mirrors the experience of the only two local shooters I know; the Cobras generally work pretty well.

    Now, if we could get native 8 round magazines with the Cobra disguised protrusion which allows for more spring and a deep follower AND the Checkmate hybrid lips over a follower with proper pimple location...

    Or even not disguised, I have a couple of Metalform 45L-797s that just stick out about .40" with a little stamped overinsertion stop. They feed ok, perhaps in spite of the non-GI lip and follower shapes.

    (I shoot IDPA and while I agree that seven is best and enough for a sidearm, you really need 8+1 for competition.)

    I have about quit worrying about bullet shape versus magazine pattern versus gun layout. Roundnose is more reliable and I will leave my remaining supply of semiwadcutters for practice.

  10. #10
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    Quote Originally Posted by Jim Watson
    Now, if we could get native 8 round magazines with the Cobra disguised protrusion which allows for more spring and a deep follower AND the Checkmate hybrid lips over a follower with proper pimple location...
    I think Check-Mate is already on that one...but don't hold me to that.

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