Remington nylon model 66

[Poindexter85$]

Well, I’m stumped. I’ve had a model 66 nylon since 1973. Took it out after it sat for years, cycled flawlessly. Decided to take the barrel off to clean it well. Only took off the receiver cover so as to remove the barrel. Went to reinstall the barrel, it won’t go all the way in. There is a groove in the barrel that fits under a small clip, the barrel needs to go back about 3/8” to fit under the little clip. Just can’t get it back to do so. I took none of the works apart. Went to YouTube, assembly shows barrel just going in place no issues. Anyone familiar with these guns with some advice?

[MCPO_SOCM_RET]

Sounds like you have a misaligned barrel bracket and/or barrel support.
Even though you don't have to take out the barrel lock screw all the way to pull the barrel, might as well drop that all the way out to make sure its not a thread or two too high when you slide the barrel in.
It really should just slide right in - maybe a little wiggle force the last tiny bit, but it shouldn't hang up.

A picture is worth 1,000 words too.

Here's the Nylon 66 manual.

[Poindexter85$]

Thanks.
Took gun to local private gunsmith, problem immediately taken care of.