So a while back i posted about my Rossi 92 in .45 Colt. I was having bore diameter issues, trouble finding the right projectile, unburnt powder etc.
So I finally got around to getting some calipers so as I could measure the balls when I slug my bore. I slugged her, with readings at .450 and .451 at largest. I put the variability down to my inexperience with calipers.
This result was a surprise to me, as I assumed it was .454 or similar, due to it performing very poorly with .452 and the like.
I discovered the issue (I think) whilst slugging. The .454 round ball (From my Walker Colt) went in the bore tight as would be expected, but when approximately mid way along the bore, resistance on the rod pushing the ball dropped....it almost dropped several inches without any hammering, the when it reached the throat it got tight, tighter than when at the muzzle.
So, based on this and advice from someone else, this is my hypothesis; the bullet (whatever diameter) goes through the throat area and is sized down, then travels the rest of the bore not fitting properely as the throat has sized it down smaller than the rest of my bore.
If this is true, I am thinking I have 3 options; new barrel, chamber reaming, bore sleeve.
I would prefer to get a new barrel, but being a half round, half octagonal 24 inch, this might be tricky. The sleeve may be easier. Not sure about reaming, as the projectile may still allow gasses to escape past before it hits the tighter part of the bore.
What do y'all think?? It is such a dissapointment as I have done alot of work on the gun, slicking up the action, trigger lightening mods, refinshed the dark Rossi wood to a nice light finish. Plus it holds 13+1 of my favourite calibre AND I have just bought a brand new Uberti Cattleman in, yep, you guessed; .45 Colt
![Smile :-)](./images/smilies/icon_smile.gif)
Thanks for taking the time to look at my topic, even if you can't help, thanks anyway. I hope my grammar is clear enough.
theozzman from downunder.