I just picked up a A1 upper with the pencil profile barrel. I wanted the barrel for another project which is a good thing b/c the MORON that I got it from attempted to drill the small hole out to make a big hole upper. Needless to say it is now out of spec, bad out of spec. When mounted to a lower you can feel the play. When upward pressure is placed on the bottom of the handguard you can actualy feel the upper move up and away from the lower. I've thought about trying to fill it and redrill but don't know if it's gonna' be worth the trouble. I placed it on a Cavalry Arms assembly and it seems to fit this lower the tightest with the least amount of play. What do you think, strip it of usable parts and scrap it or keep it and play with it trying to make it work?

I would find something you could use for a bushing and use it as a beater upper.  Something with the right ID.  Just my $0.02.

IDHunt
--
The Bill of Rights: Void Where Prohibited by Law

One of the few times I'd recommend JB Weld for a gun application. Fill in the takedown lug, mark the correct hole with your lower as a stencil, redrill.

Strip it and save it for a rainy day (as opposed to trashing it).  When TEOTWAWKI arrives you may need it

Use the O ring method of removing play beween the uppers by putting it on the lug where the push pin goes.

Sell me the whole mess. I'll JB Weld up the hole and use it with an M261 .22LR conversion, which should be just fine with it.

I'm not kidding. Let's make a deal!

what is a JB weld?

i have the same problem with one of my uppers.
someone tried hacking at it to make it a large hole upper.
they did a halfway decent job...as it fits the sp1 lower really good. but i'd like to make it a small hole and get a different upper for the sp1.

i asked a reputable gunsmith and he said he couldnt do anything about it.

JB Weld is a really excellent, inexpensive, commonly available 2-part epoxy--ask for it at any hardware store. It MIGHT be suitable for this fix for a .223 gun--but I'm virtually certain that it would hold up almost forever on a .22 conversion.

I had the same problem on a used Ebay upper.   A good friend with a garage machine shop pressed in (not welded, but simply pressed in and VERY tight) some metal, then drilled the correct size hole in the correct spot.   Fits and runs 100%.






Perfect fit:

One of these?



Whoever drilled it made the big hole in the wrong place.   I think they put the correct size drill in the middle of the small hole and bored it out to diameter, not knowing that it should have been slightly offset.   When placed on a large hole lower, you couldn't close the upper down.   Then they must have figured, "Ditch it on Ebay and it will be someone else's problem."  

Damn!!!  That's pretty good!

Quoted: Ditch it on Ebay and it will be someone else's problem.

Been there, still working through numerous cases of somebody's elses junk passed off as good.