They are for those persons who don't take the time or effort to open up the cylinder throats on their new .45LC single action Ruger revolvers. A normal .452" bullet, especially with a strong front driving band won't chamber in these cylinders with the undersize throats. Unfortunately this is a poor alternative (undersize bullets), because most of the Ruger barrels have groove diameters larger than thier cylinder throats.
I hope this answers your question! It's really nothing more than an option to make our bullets fit an ill-dimensioned firearm!
For cast bullets.
In an ideal world you would like to have the "throat" .001 to .002 thousands larger than barrel grove diameter, preferably .001!!
But Ruger spcifications are anything but a "perfect" world these days! You really don't know what you are getting untill you can slug the barrel and throats, measure and see if the gun can be reasonably (price) corrected to shoot "cast".
Other specifications (ideal situation) would be cylinder gap of .002 to .003 thousands, all chambers "line" bored relative to the barrel and highs and lows in barrel runout.
That said, the Ruger's are the buy of the centry in my estimation!!
If you want all of the above things done, contact "Bowen firearms" and check out the cost! That Ruger will look like a steal to you after you see what that kind of attention to detail and specifcations will cost.
Steve I am not sure who you are directing your question to.
If it is me, I would want to know what the grove diameter of the barrel is before making a recommendation. Slug your barrel and get back to me.
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