I have a Ruger Redhawk in .45 colt.
I pin gauged the throats and they measure a tight .451. I shoot hardcast 300-325 gr LFNGC from CPB, and Beartooth bullets sized to .452.
Are my cylinder throats at .451 too tight ?
Thanks

Have you slugged your bore? Your 451 throats might be okay as long as the groove diameter is less than that, but I would prefer them to be the same or slightly larger than the bullet. I like to be able to push the bullet through with only finger pressure.

I have two Rugers in 45 Colt; a blued Bisley and a four inch Redhawk. Both guns pinned at .450 with groove diameters of .451. The Cylindersmith did the Redhawk when he was still in business and Doug at Cylinderhone.net did my Bisley. The Redhawk pins at .4525 and the Bisley at .453. I shot them both from the Ransom Rest before and after honing and there was a marked improvement, from 3+ inches at 25 yards to less than 2". Firelapping brought that down some more to under 1.5". Both guns shoot nice tight little clusters now with my cast bullets as well as factory Remington and Winchester loads. I am casting a Mihec 285 SWC and an Accurate Mold 300 grain WFN.

I would slug the bore first off. s4 is right, it may shoot just fine if your groove diameter is less than .451. I'd be surprised if it is but you never know till you measure it. How is it shooting right now with the cast bullets you're using?

If you want to ream them yourself I have a reamer for sale for $100. The reamer has been used to ream 5 cylinders.It is a simple process and leaves a smoothe finish that pins at .4525.It is hand turned and comes with all pilots and cut off colt brass for protective sleeves.When you are thru with your cylinders knock $10-15 dollars off and sell to another Colt user.

FAH, Had a new Ruger Bisley in 45 Colt and could not push a sized .451 cast bullet through ANY of the chambers.... Had the chambers recut and 11 degree forcing cone and now the gun is a darn good shooter... Would not be surprised if the original chamber size was .450"........

I reamed my Blackhawk with an adjustable reamer, go slow and keep measuring until it was .452, now shoots both cast and jacketed bullets much better !

Thank you for your response. The reason I asked this question is that a reputable handgun smith told me that I should not ream the throats, to leave them as they were perfect for my LFNGC 300 gr. sized .452. Do you think he is correct?

FAH, how does it shoot? Are you getting reasonable accuracy out of it?

As long as the groove diameter of the barrel is less than the throat diameter it may shoot just fine. You should slug your bore and see what you are dealing with.