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Thread: CFW-A Bolt and the M11A1 380

  1. #1
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    CFW-A Bolt and the M11A1 380

    What you should know about using your A bolt in the M11/380.

    My coil count on the recoil spring is 63 coils.
    Rate of fire is around 700-800 depending on ammo and use of suppressor.
    It the best accessory if you want a controllable machine pistol.


    video
    https://www.flickr.com/photos/407750...n/photostream/

  2. #2
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    Good lookin gal there Stobro. Still talking small magwell only right?

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    Correct. Tom has not had much luck with the slower ROF and the SWD large grip/mags.

  4. #4
    Registered User KickStand's Avatar
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    SMALL MAGWELL TIPS:

    1. My spring is right at 64 1/2. Donít be afraid to trim your spring a coil at a time.
    2. I tested several manufacturers ammo with the small magwell, all worked great.
    3. Iíve recently had the opportunity to test my CF-W A bolt in another small magwell gun. The mags or the mag catch needed to be filed a hair. If you have original mags DONT file them, file the mag catch, the cheapest part.
    4. When inserting the mag, I find it best to pull the mag down after insertion.
    5. No two guns are created the same, this is 100% true with MACS. What works for you gun might not work for mine.


    If I have time, Iíll edit some videoís with various ammo I tested and post in this thread. Worse case, Iíll just repost my old videos.
    Congrats to the new CF-W A bolt owners. This is the best upgrade for any MAC period.

    Frankly, this bolt is at home in my M11 (small magwell well).

  5. #5
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    Thanks guys!
    Based on spring data Strobro posted a while back, (can you repost in this thread please?), I shipped all A bolts destined for small magwell owners with 70 coils. That leaves plenty of room to clip and determine what works best in their gun. Hopefully we’ll have additional data points from the new owners in the weeks ahead.

    There may be good news for large magwell owners.
    Early on in this project, I had 300 recoil springs custom wound. They didn’t work as I’d hoped and I gave them the name wonder springs because I wondered what I would do with this large box of springs. Using the wonder spring and a slightly longer than standard ejector rod, one of our members has succeeded where I failed. The biggest problem I encountered during testing were failures to feed, but I did experience some stove piping. I have an ample supply of M-11/nine ejector rods and it’s a very simple matter to cut them to the correct length. The extra length creates earlier ejection during the bolt’s rearward cycle and should prevent this problem. I still haven’t tested this combo, but that’s planned.
    I’m hopeful this Uzi Talk member will weigh in with his experience.

    I have long said the smallest member of the MAC family were under loved and under valued. Their time may have come.
    Please visit my FB page for the latest CF-W bolt information.
    https://www.facebook.com/VegasSMG/?ref

  6. #6
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    I found the same result as KickStand with trimming the mag catch.
    If there ever is a next gen CFW -A Bolt, a tiny amount of material could be removed from the bottom of the bolt to allow it to pass through the feed lips without contact.

    Here is the link to spring experiment: http://www.uzitalk.com/forums/showth...ere-to-get-one

    Tom will tell you that he is selling the CFW 9mm A-bolt as a 9x19 conversion for the SWD 380 M11A1 SMG with the large grip and a 9x19 (9mm) mags and barrel as that is the most reliable configuration.

    I'm having good luck with the A-Bolt with and 9x17 (380acp) ammo. I have been using a RPB 380 SMG with a small grip and small metal mags.

    Here is the data I recorded earlier in the year.


    These ROF numbers tested with 1/4" neoprene buffer
    Future testing with 1/8" urethane buffer generated about 25-50 fps slower RPM.
    ROF - Rate of fire in rounds per minute
    #RT – Number of rounds tested

    Failure Codes:
    LPS - Light primer strike, rounds enters chamber but bolt speed/force insufficient to detonate primer
    MFS- Magazine feeding stoppage, rounds fail to feed up magazine before bolt closes due to drag from steel case or COAL in 380 magazine body
    FTF – Failure to feed, rounds fail to enter chamber completely
    FTE – Failure to eject, fired case caught between bolt and barrel
    FTS – Failure to strip, bolt/recoil spring does have enough speed/force to strip rounds from a magazine loaded to 30. Federal Champion functioned with 28 rounds in magazine.
    NA, Not available, unable to produce 10+ rounds of continuous fire to determine ROF
    * Remington UMC was tested with 2 boxes from 2 lots. One box was significantly more reliable than the second. One box was significantly unreliable. The cases from one box were cosmetically blemished and splattered with dark oxidation.


    If you want to run 9x19 (9mm) and 9x17 (.380) there needs to be two different length recoil springs.

    65-63 coils on the recoil spring for .380.

    90+ coils on the spring for 9mm.

    *Using 65-63 coil recoil spring with 9mm ammo could cause damage to the lower receiver.

  7. #7
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    Tom, I would Still like one of those wonder Springs and possibly one of the ejector rods if this combo works in the large Magwell. Hope all is going well in your new crib...

  8. #8
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    Well that is interesting info Vegas, hoping mystery tester steps forward. I thougth the primary issue was FTF though from mag seating the round incorrectly with .380?

  9. #9
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    I have quite forgotten what spring/ejector combo I have. But I have a dedicated A bolt for my large magwell babymac in 9mm, it works great. I donít have a stock on it and shoot it one handed as a machine pistol. Fortunately I have a second A bolt dedicated for one my m11/9s.

  10. #10
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    Thanks for the info. Took my small magwell A1 with Baby Ghost Upper and CFW-A (full-length spring) to the range this weekend and none of the 4 original mags I tried cycled after the first round.

    This gives me a starting point to trouble shoot.

  11. #11
    Registered User KickStand's Avatar
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    Testing StroBro32ís bolt (EXP CF-W A bolt)




    Testing my CF-W A bolt




    Accuracy test: Factory bolt vs CF-W A bolt with factory upper and sights. HUGE DIFFERENCE.


  12. #12
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    Been experimenting. I was getting runaways with 65 coils.

    Works perfect with 63. Still fast enough, but very controllable.

    First video is the CFW, second is native bolt. 30 or 32 rounds (canít remember).

    https://youtu.be/dqii2use9t4


    https://youtu.be/RVEKYDngUZg

  13. #13
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    The first video with the CFW-A bolt has a 787 RPM.

    That second video with the OEM bolt is faster than anything I've ever shot. I timed it. That's 30 rounds in .655 seconds which is 2748 RPM.
    Wow. That is fast.
    Last edited by strobro32; 06-19-2020 at 06:48 PM.

  14. #14
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    It felt a little too fast. I wonder if the oem cast bolt, without a cocking knob, the high back pressure silencer, and the 1/4” buffer might be a little much. Certainly a handful! My mind is struggling to believe your number, but I know your method is sound.

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