Taurus ThunderboltI had this reproduction Colt Lightning (made by Taurus?) until my brother saw it and had to have it. Caliber was .45 Colt. It was a lot of fun, and worked great.
I just used the same cast lead round nose/flat point hand loaded ammo that I used in my Cimarron Uberti SAA revolver. 200 grain bullet with Unique powder.
If I had it to do over again, I would have kept the rifle. Oh well...

I have a blue one sitting unfired in the box and I have a stainless one that I threaded for a suppressor.
I run 400 grain hard cast, polymer coated projectiles at just subsonic speeds. Very quiet gun that can be easily fired from the prone position. One day I need to take some of the 45LC Long Guns to the farm and chronograph them
I have a spare stainless barrel on hand should the next owner ever want to replace the threaded barrel
As to the strength of a Modern Lever Action chambered for 45 Long Colt? I never really thought about it as I do not load to Magnum power levels. If I need more power I can grab my 45-70 Lever gun
I would have no problems taking hogs with a 400 grain 45 Long Colt projectile at subsonic speeds