Tried to slug my barrel for the first time...

[Robanada]

Hi guys, I tried slugging my barrel to see if I need a sizer/what size I'd need. The barrel is expected to be 0.365", so I picked up some all lead casting sinkers- size 3/8, whatever that means. I eyeballed them and they look to be about the same diameter as factory bullets, so I went ahead and started hammering it in. Unfortunately, I think the slug was too big. It only made it in part of the way before getting stuck and even hammering way harder than I was comfortable wouldn't get it to budge.
Here's a picture of the slug I ended up with:
71563

Some of the lands/grooves are visible, but not very much. My micrometer reads .3652" for the impression of the grooves. Since it's what I was expecting the barrel to be, can I roll with this? Or am I going to have to buy smaller sinkers? Your advice is much appreciated :D

[41 mag fan]

Try putting a screw in the end, put it in a drill and take some size off with sand paper and try again. Or smash it down some in a vice. It should be able to be hammered in and not get stuck.

[zidave]

I took crimp on sinkers and melted them in a casing from the gun I wanted to slug. Worked fine in my 40 and the wifey's 380

[fouronesix]

Sinkers are usually fairly soft so you can simply roll between two pieces of flat steel to decrease the diameter to something easier to drive through. Or you can put the oversized slug on a flat steel or anvil and hammer while turning to decrease the diameter. I usually start a slug with a brass rod that's slightly smaller than bore diameter. Tap it all the way in then continue with a one piece steel rod. Lube the bore completely before starting. I have no trouble starting even grossly oversized slugs into bores- the only thing that happens is a shaved off donut of lead with the rest of the slug going on through. If you start from the chamber end then the rod and surrounding lead may wedge tight as it enters the shoulder or throat constriction. That may give a good throat slug but it can cause a stuck rod or damaged throat or leade. Except for straight walled cartridge revolver cylinders that I slug from the chamber end using only a brass rod, I usually start at the muzzle for most everything else.

[nvbirdman]

Did you oil the barrel first?

[drinks]

Or at least lube the slug?

[Robanada]

Thanks for all of the suggestions, guys- I didn't have any lube or oil, so no, I just kind of went in dry. I didn't have any steel or sandpaper lying around either (just moved to a new city and didn't bring much with me). I ended up just using a flathead screwdriver I had lying around as a chisel and took off the excess. It wasn't pretty, but I was able to get it in further, and repeat the process until I got the slug all the way through. Ended up with a groove diameter of .3654". Thanks everyone, now to see what diameter my mold drops!