SIG Mosquito Rehash - FAQ versus Manual??

Discussion in '.22-Rimfire Forum' started by 45JHP, Aug 7, 2011.

  1. 45JHP

    45JHP New Member

    Aug 7, 2011
    I just bought a SIG Mosquito, followed the cleaning instructions, and took it to the range. Fired 250 rounds of Federal Champion (bulk) ammo. On 22 of the 25 magazines fired, I had a failure to feed or a case catch in the chamber exit on the first round only. Here is the rehash.

    The manual states "So to increase the round compatibility, we provided two slide springs for every pistol. The bigger bored version is designed for high-speed loads and is fitted in the pistol with delivery. The simple coiled smaller spring (marked white) is for standard loads and is supplied with the pistol."

    The Sig online FAQ states "The longer (light power – some are painted white) spring should be used with Standard or High Velocity (1000+ fps) ammo. Use the shorter (heavy) spring for Hyper-Velocity (1400+ fps) ammo."

    Read those statements carefully - don't they say just the opposite???

    After leaving the range and disassembling my Mosquito, I compared the springs. Neither spring has any white marking on it. The one that was installed at the factory is the smaller (by about 1/2 inch in length) spring. Isn't that the exact opposite of what the manual says?

    Has anyone else found this and does SIG know about their conflicting instructions? I can't find any Technical Support contact info on their website.
  2. raydcarter

    raydcarter New Member

    May 8, 2009
    There could be a difference between shorter and smaller (in diameter). If that were the case, I don't see a problem.

  3. CampingJosh

    CampingJosh Well-Known Member

    Sep 25, 2007
    This was the case with mine. I used the longer, lighter-weight spring (you ought to be able to tell by squeezing between your hands, anyway) exclusively.

    That said, mine never liked bulk Federal or Winchester. Worked 100% with CCI Mini Mags and probably 95-98% with Remington Golden Bullets.
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