I am looking for an experienced Law Enforcement or Military armor with Bushmaster experience in the Tyler area to look at several new Bushmaster Dissipator AR-15 rifles.  I have several brand new Bushmaster's that appear to be short stroking, causing a double feed and wanted to see if I could get them repaired local instead of sending them back to Bushmaster at $62.00 per rifle.  

 This isn't exactly the correct forum...so the mods may lock it....or let someone in the Tyler area contact you.  But I'll try to help you diagnose the problem

  I was a unit level armorer in the army, so I have a bit of experience with this.  
First, you're saying doublefeed, is the spent casing not ejecting completely?  Or, are 2 rounds being stripped from the magazine, trying to feed 2 live rounds?  Do the rifles have standard or collaspable buttstocks?

 What ammo are you using and have you tried a different ammo?  Have you tried new USGI magazines?

 Also, check with the proper sized allen wrench to make sure the carrier key screws are tight, Bushy has let a few get through with loose but staked keys.  Check to make sure the extractor groove/claw is clean and free of debris.

 The rifles were cleaned and lubed prior to use, right?  I've seen all sorts of interesting failures from people that were excited enough to take the rifles straight from the box to the range without cleaning and lubing.

 The actual troubleshooting forum is here, www.ar15.com/forums/forum.html?b=3&f=66.  But I think the mods may let this thread stay so you can find someone in your area to take a look at the rifles.

mm