Does anybody know where to get these things other than allorings.com? I've checked locally at Napa, Autozone, Advance, Home Depot and Lowes...nothing. The folks at Napa actually gave me a couple of Weatherhead (?) heat resistant o-rings to try. Not sure they're the same size as a Viton 21 but I'll give them a shot.

Thx,

BC

The size, 21, is independent of the material, Viton. Viton is just one of many types of synthetic elastomer that 'O' rings are made from. Neoprene, butyl, just about any of them will work. You rarely see real rubber used in 'O' rings anymore, and any rubber you do see is synthetic also. A lot of people say use Teflon, but teflon is not an elastomer, and I have only seen teflon filled 'O' rings in very special applications, a lot larger than what we are talking. The main thing is oil resistance and decent heat resistance. Just about anything an auto parts place is going to have, will suit those two.
As long as it is thick enough and fits over the magazine tube it will likely work. How long it lasts may prove to be directly proportional to how much it got stretched to fit over the magazine.
Years ago I had a 20 gauge 'O' ring that looked like it got pinched on assembly, and had a string of material hanging from it. I went to NAPA (this was before Advance or Auto Zone existed) and got a replacement. That 'O' ring is still in the gun. I now have multiple 12, 20, and 28 gauge replacements. I carry one in my wallet when I go afield. All the 'O' ring weakness hype has even got me paranoid - I think it's an I-talian "B" gun led conspiracy! But that one 'O' ring is the only one I have ever seen the need to replace in 45 years and 7 1100s. I will admit my 1963 version has a metal 'O', actually a 'V' ring. I put an 'O' ring in that one if I go to the range to shoot light loads because they seal a tad better.

It's also a brand name.

If you have a Graingers in your area you should be all set... I bought 100 of them (unfortunately, that's the only way they come) for $7-something.

I've only had one o-ring let go... and that was on a sub zero day, and I'm sure the extreme cold made the ring brittle.

You can order them in lots off of ebay...

If you get into a jam I can give you some. I work all day in electro-mechanicals with hydraulics and pneumatics. Got all types of seals. That 021 "O" ring is nothing special. Most guys don't know about viton seals. A standard buna-N will also last half a lifetime in an ole' 1100. Let me know if you get hard up for some.

Thanks gents!

I got mine from the local Bobcat dealer.