Stupid Bore Swagging Question

[fireflyfather]

OK, I have a mosin I need to check the diameter of. I have no loose buckshot. I do have one spare round of .358 LRN from a batch of wax-lubed magtech bullets (set of a primer making a 99 round lot). That is a little larger than a .33 buckshot (00 buck), which I hear is the right size for swagging a barrel. Is that too big to use? If so, is there a way to downsize it to the proper size for ramming it through the mosin's barrel?

Thanks in advance for answering this admittedly stupid question.

 

[res45]

Try this. http://www.surplusrifle.com/reloading/slug/index.asp