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Patrol Rifle Thoughts

Discussion in 'GATE AR-15 Forum' started by CAcop, Jul 4, 2010.

  1. CAcop


    Jul 21, 2002
    We are about to loose our chief who has not wanted officers to have individual ARs on patrol. Now that a new, possibly more open minded, chief is coming we might be able to buy and carry our own. I wanted to pick your brain as to what should we look for when drawing up the policy. I and a few others have gone to Colt and ITRs AR-15 armorer's courses for the PDs pool guns (Colt LE Carbines) so we have a decent knowledge but not broad base of knowledge.

    What kind of things should we require AR-15s to have? Such as twist rates, staked bolt keys, shot peened bolts, etc. that gets tossed around the web.

    Twist rate? We currently issue 75gr Hornady TAP with Win 64gr Ranger as practice.

    I hate to get into brand wars but any that are a "don't let your guys buy crap" warning?

    Thank you in advance. I'm sure I will think of more or your answer will get me thinking.
  2. Constructor

    Constructor Moderator

    Dec 10, 2009
    Shooting the 75 Tap you will need 7 or 8 twist barrels to stabilize the longer bullets.
    Any brand MAY work for a weekend plinker but IMO you guys need to stick with professional grade rifles, I don't think you need a cold hammer forged barrel especially if it doesn't shoot as well as a 4140 or 4150 chromelined barrel but the overall quality/reliability of you weapons should be better than average. Colt and LMT would be 2 of the top choices, most companies do not make a 7 or 8 twist barrel so that eliminates many choices. There are several smaller custom shops that can build to suit with quality that exceeds large production companies.
    Staked carrier keys, MPI/HP tested Carpenter alloy 158 bolts or better, chromelined or nitro-carburized barrel, M4 feed ramps and chrome silicon extractor springs in the bolt are required IMO, some of the other stuff not so much. The main thing is getting them operating correctly and reliably with the ammo you intend to use to start with and teaching maintenance, keeping the carrier, bolt, trigger parts and buffer spring lubed is very important. If you need a SSS Op (buffer) spring and H2 buffer to control an over gas issue then use it but they aren't always needed and can even cause short stroking on some weapons. If a McFarland gas ring is needed to stop gas blow by then use it but sometimes they are so tight they can restrict bolt movement in the carrier enough to cause short stroking. The black O ring on the extractor spring isn't always needed either, sometimes it can make the movement too stiff to allow the extractor to snap over the rim of the cartridge.
    I am sure others will be along to give you their opinions.
    Last edited: Jul 4, 2010

  3. CAcop


    Jul 21, 2002
    Thank you. Your post was helpful. It helped put things in perspective.