My old Colt HBAR has developed side to side play at the front pushpin between the upper and lower receivers. It's not enough to cause a problem, but it is annoying. Does anyone make shims that will fit around the front pushpin and tighten up the upper/lower fit? Thanks!

I don't know if you would care for this but there was a thread in here about curing this problem by putting a small rubber O-ring around the front post. When putting the upper back on the lower have the upper at about 40 or 45 degrees when pushing the front pin in -- then when you close the upper down it squashes the O-ring and makes the whole thing super tight. The O-ring will need to be replaced from time to time depending on how much you like to take the rifle apart. The only problem is I can't remember the size of the O-ring that was recommended -- maybe someone will see this and remember the size. This was just a thought -- hope you can use it.

Tried the o ring ,ok but not great.I bought a feeler gauge at auto parts store.With front push pin halfway  in  slip feeler gauge in on other side ,use different sizes until snug fit.Drill hole in gauge to match pin diameter trim gauge to fit .drilling hole in gauge was tough to do  ,I used a dremmel tool.Line up shim push pin through, solid as a rock . If you need a few pictures send me an E-mail.zdn

Zdenstk, why didn't I think of that? I'll give it a try this weekend. Thanks!