M4/AR Upper/Lower "play"

[C-MAC]

Just mounted a KAC RAS and vertical grip on my Colt. It's a beautiful thing, but it made me notice some slight play between the upper/lower. Given I am always trying to tighten up the platform, this had me worried.

I received two opinions; one said that it was lousy machining by Colt and to get an "Accuwedge" to tighten it up. The second opinion was from a military armorer who said almost all Colts have that slight movement- don't screw with it or use the Accuwedge because it will bind the bolt and cause jams. The short-version reason this armorer gave for the "play" is that a good automatic weapon has a "measured amount".

Lot's of people trust this armorer with their life, so I am currently going with "armorer for $200.00, Monty".

But given there is generous experience and opinions, I would love to hear from the other experts.....

[Flesh Thorn]

I would go with the Accuwedge and if it causes any problem just remove it. Seriously, I don't see how using an Accuwedge could "bind the bolt and cause jams". Sounds like complete bs to me.

[C-MAC]

I would go with the Accuwedge and if it causes any problem just remove it. Seriously, I don't see how using an Accuwedge could "bind the bolt and cause jams". Sounds like complete bs to me.

Hey thanks. I really didn't get his point and thought there was something I was missing. He went into this whole (pretty logical) explanation to justify the play.

Even though I was USAF, as a 2A3x3 well fitting parts and gaskets were pretty important and logical. So I just could not get this straight in my mind.

[GoldCoast]

Works fine on mine, but needed a little tweaking to fit just right. No bolt binding or jams caused by accuwedge to report.

[Flesh Thorn]

Another solution, but more $$$: http://www.midwayusa.com/viewproduct/?p ... ber=339281" onclick="window.open(this.href);return false;

An article on the AccuWedge : http://www.fulton-armory.com/AccuWedge.html" onclick="window.open(this.href);return false;

[C-MAC]

Thanks for everything.

I would seriously like to call up Colt and give them a piece of my mind. I was considering other alternatives and almost pulled the trigger on a KAC SR15- but decided to go with the real deal. This type of crap just pisses me off- there is no excuse for poor machining on a weapon that our military uses every day.

[CWeber]

Accuwedge. Your weapon would allready be jamming if it was going to jam from the upper/lower slop. The slop is very common, hence someone coming up with the accuwedge. You could also remove your pistol grip and drill and tap a set screw that would come into contact with the rear takedown pin boss. Hope this helps.

[colt1rgr]

Three words............"Rock River Arms"

[Flesh Thorn]

I can give a thumbs up for Double Star.

[Parabellum]

I have used an Accu Wedge for years, personal and combat. They work great!

[C-MAC]

Thanks again for all the suggestions.

I finally got the Accu wedge yesterday for my Colt. I had to press down tight to get the takedown pin in and almost thought it wouldn't close. But perseverance and all that got it closed. Solid fit and I put about 90 rounds through it- no problems.

I have to also say, I like the idea of a tension screw. That is simply one of those smart suggestions that only an experienced operator or machinist would make (or incorporate into the weapon).

By the way, I am going to collect $50 bucks from the armorer. He bet me somewhere in the second clip I would feel a difference/issue in the action. Loser.