I use barrel bands exclusively on my rifles, as I have an older 7mm TCU 21" barrel that the dovetail block pulled out because someone had mounted a sling to the forend. I also have it one my 21" 375 Win Barrel.
To me, that band size seems small without digging out the contender and measuring (though I could be wrong, I just measured mine with a caliper). What barrel is this for?
They were both Uncle Mikes. The Brownells Catalog is the best source, the website isn't as easy. Page 296 of Catalog 60.
You have to be careful, some are one piece bands that go over the barrel or tube magazine, could be a problem with a soldered contender site. These are intended for tube fed lever actions. You need to avoid these, the website doesn't tell you this. And there are no pictures for these either. A decent gunshop should carry these also.
However, the part should be for the size you are listing:
Brownells 593-107-100
Uncle Mikes 1071-2
Barrel OD 0.420 to 0.470
Here's the list from the webpage:
593-107-100
1" U22, Bbl O.D. .420"-.470" $17.20
593-134-100
1" RF, Bbl O.D. .430"-.445" $16.95
593-105-100
1" M357, Bbl O.D. .540"-.590" $17.20
593-133-100
1" CF, Bbl O.D. .645"-.660" $15.95
593-139-100
1" CFL, Bbl O.D. .640"-.675" $15.95
593-139-125
1-1/4" CFL, Bbl O.D. .640"-.675" $15.95
593-144-100
1" 760 BB, Bbl O.D. .645"-.660" $15.95
593-159-004
1" SG-4, Bbl O.D. .700"-.750" $20.95
593-159-003
1" SG-3, Bbl O.D. .750"-.800" $20.95
593-159-002
1" SG-2, Bbl O.D. .800"-.850" $20.95
593-159-001
1" SG-1, Bbl O.D. .850"-.900" $20.95