Well, after a couple years of putting it off, I finally got my ARMS #18 so I can scope my M1A NM.  The problem is that I have to remove the stripper clip guide before I can put the mount on, which requires me to disassemble the rifle so I can punch out the pin holding the stripper clip guide in place.  

The real problem is that my rifle is glass bedded and everything I've heard says that disassembling a NM M1A is a big NO, NO (could hurt the accuracy).  

Does anyone have any suggestions as to how I could remove the stripper clip guide without taking the gun apart?  Any other mounting tips for the #18 would be most welcome.

Thanks

You should be able to get away with just dropping the trigger group and tapping the pin right through. If you don't want to separate the barrel/action from the stock then I'd just tape it to keep everything together. It would help to have a set of stands to put the rifle in while you're tapping the pin.

I doubt if removing the action from the stock this one time will effect accuracy.  Best results with any mount is following directions.

I have an M1A National Match. I had a gunsmith put a Springfield Generation 3 scope mount just recently. This means the action was removed from the stock. Accuracy was not affected whatsoever.

Accuracy could only be affected by wear on the bedding or improper assembly. An occasional disassembly with care shouldn't affect accuracy. Worst case is eventually you would have to rebed the rifle.

I have a pre-ban NM M1-A with an armscorp mount and Springfield Armory scope. I broke the rifle down to install the mount and have fired it NUMEROUS times with no noticeable loss in accuracy.
    Shouldn't be a problem.

Really appreciate all the great feedback.  I feel a lot more comfortable taking the rifle apart now.  

If you haven't figured it out yet, I'm a relative newbie with the M1A.  Are there any other tricks to access the undernearth of the stripper clip guide (to remove the small retaining pin) without removing the barrel?  I have never disassembled this type of rifle and welcome all input; please don't assume I know anything at all about this process.  All comments are appreciated.

Thanks

Pull the trigger group, place stock bottom down on the bench (or  table) tap out pin, replace trigger group. you don't have to remove the reciever from the stock to drive out the roll pin and remove the clip guide.

OK, I got the trigger group out with no problem but am having trouble getting the pin to tap out.  I've tried, and bent, drill bits, small nails, etc.  Does anyone know of a good way to get the pin out?  Anybody know what diameter punch I need?  The hole and pin are very, very small.

Thanks

It's a 3/32" roll pin.  Length is 9/16" if you booger yours up and have to buy another from the parts store.  Chamfer ends prior to installation.
 
Your pin is best gotten out with a roll pin punch.  This type of punch has a tit smaller than the shank ,which engages the hollow in the roll pin and helps to stabilize things.  Size of the punch is called "#3 roll pin punch."  Your local hardware store may not sell them.  You can use a 3/32" pin punch, this will likely make it necessary to buy a new pin.  
 
The advice that you get about removing a bedded rifle from the stock is good.  This good advice begins to take effect when you can shoot well enough to notice the very small degrading of accuracy caused by infrequent removal of the barreled receiver from its bedding.  That leaves most of us out.
 
Removal of your receiver from the stock will cause initial changes in zero.  Not to worry, you can take care of most of that change by holdingthe rifle vertically and giving the buttplate a couple of good whacks on hard ground to settle things in.  Or you can use your buttplate to pound in the stakes on the portable targets that you use when traveling about and shooting on public land.

Prairie Fire,
Thanks for the great info - it amazes me how much you guys know about this topic.  I will try to locate either a #3 roll pin punch or a 3/32 pin punch tomorrow as I continue my quest to mount a scope of my M1A.  

Guess my next step is to find a good scope.  Lots of good threads currently on this topic as well.

Thanks to all