Can one use 22lr in a 22wmr gun?

So I've been looking at a Savage M42 22WMR/410 COMBO and was wondering if push came to shove would I be okay shooting 22lr in it?

http://www.budsgunshop.com/catalog/images/82907.jpg

No. They are close enough in rim and case diameter to look the same, but the 22WMR is actually bigger in girth in addition to the obvious extra length.

The 22LR won't seal correctly in the chamber, because it will be too loose. More likely to get a squib stuck in the barrel.

Thanks for the info. I think I'll go with the 22lr version then.

.22 LR WILL fire from a .22 WMR chamber, but a couple of things make it a not-so-good idea: As mentioned, the case diameter is smaller, so the cases split most of the time, and depending on your rifle, the extractor may have a hard time getting a hold on the case rim, so extraction is not reliable. In addition, the bore diameter is smaller, so accuracy is pretty poor.