I took out my RRA 9mm carbine at lunchtime again today....so far I can't find a location up or down for my mag block that it likes. It ususlly feeds fine, but gets bound up by the bolt. I assume this is related to the ejecter. Once again when I loosened the set screw for the plunger and let the block "float"...it worked perfect. I wish I could use it that way and maybe add a small diameter pin in a larger hole to pin it in....so it can't fall out, but will still float.

My carbine has a Bushmaster lower with a post ban M4 style stock on it....everytime someone shoots it they are "tagged" with a black dirt/grease spot on their shoulder....anyone else seen this? Both of my shooting buddies are walking around work this afternoon with badges of honor:)

Im  having the same mag block problem as you,I guess we can pin or set screw the block thru the side,But id rather not do that,i adjusted the mag catch so that the mag will release but the block will not come out unless you push the button below the side of the lower, and the block still floats and mine runs fine with the block floating but theres got to be a better way..........let me know if you find something thats works,,,i dont mine "floating" the mag block as long as the block doesnt fall out when i do a mag change....After i ajusted the mag catch it wont fall out but im still looking for a better way that doent include pinning the block.......see vids of my 9mm here
[url]http://www.4matman.com/clan/downloads/video/Video032.wmv[/url]
UNDERDOG

I did have my mag catch screwed way in too...it did seem to help. I may shorten the threaded end that goes through the mag catch button to make it more user friendly. Do you get the dirt spot on your shoulder?

I think I figured this out. I wanted to somehow secure the block to the magwell and still have it float. I drilled a small hole in the front of the receiver between the pivot pin "Ears". I then tapped it. I located the same spot on the front of my mag block and drilled a larger hole. I then screwed a set screw into the receiver and into the larger hole in the mag block. It now floats up and down a little and can not fall out..period. When you have the upper on the weapon, you can't see the set screw. I am going to put a few rounds through it at noon today.

If anyone cares:

I did test fire at lunch today and it fired 3 full 40 rounds mags without one single hickup.

The block is free to move up and down a total of about 1/8" and it can wiggle side to side also. The set screw stayed put because it can't go anywhere since it is under the front pivot pin.

It cost me 25 cents to stop the dirt/grease from blowing out the small hole in the stock estension tube.....I used a quarter:)

I hope this info helps someone out there.

O M G, don't block the hole!!!  Don't grease up the F'n buffer....Use teflon spray or light coating of oil...  all that crap (grease, dirt, and the[b] quarter[/b]) will slow down the bolt and cause feeding problems!!!!!!Don't close the hole!!!!  You are making a air shock by closing the hole, the pressure needs to leave the buffer tube as the bolt flys back.  [stick]

After going through several different mag well blocks, I have settled on the ASA system.  It goes in from the top and is clamped in place by the upper.  It can't move.  Once the ejector is adjusted a little, it is very dependable.  The only flaw is it's inability to activate the bolt stop, and I have modified mine so it does.

As far as the "badge of honor" on the shoulder, I took a round toothpick and broke it off in the little hole.  No more grease spots on the shirt and many, many rounds later the rifle still hasn't faltered in .223, 7.62X39, .300 Whisper, 9mm or .22 LR.  The hole in the buttstock screw is a drain hole for water.  The earliest AR-15s didn't even have them, as illustrated on page 75 of "The Black Rifle"  by Stevens and Ezell.  Since I don't invade many beaches or ford rivers with my 16, I feel safe in blocking it off.

I was understanding that hole was for drainage too. I had changed the screw on a couple A2 stocked rifles with an allen head screw with no hole and they haven't skipped a beat for years.

Also...I've never greased up, oiled or did anything to the buffer...that was my description of the dirt/crud that was created from the dirty blowback operation of the 9mm.

 If your not having any problems, no need to fix it!

I figure it's an extra 25 cents incase I get stranded somewhere, I can make a phone call for Mom to come pick me up....wait, I better add a dime, payphone calls went up:)

I knew the hole could be used as a drain, but I swear I read/heard it changes ROF or short strokes....

HK_Dude.....I set screwed my mag block as you did only i drilled the block only slightly larger than the 10-32 set screw i used in the reciever...Range tested it yesterday and it worked perfectly,didnt jam, FTF or anthing else in 600 rounds....Thanks..........UNDERDOG

Yup, I drilled the hole in the block a bit larger too....Great, I'm glad it worked for you. It's kinda fun getting them to run right once it all comes together.

Roger that! yeah i used a 10-32 set screw which is like .185" or so and drilled the block At .190" so my block doesnt really float any more, which is good..Didnt really want to drill my lower but im happy with it,cant even see it....Thanks agian..........UNDERDOG

My Colts work great. [:D]