xtarheel
Member
I thought I might post some personal observations about Ruger cylinder throats. Several years ago I purchased a Bisley Blackhawk in .45 Colt. I had read in several places about the problem with tight throats on these pieces. When the gun arrived, I took it over to the gunsmith in this shop and asked to have the throats reamed. He said that he had no idea what I was talking about. Using a “snap gauge” and micrometer I determined that my throats were indeed tight. So, I went home and ordered a Manson reamer and pilots from Brownells.
After doing mine, I thought others might be interested in this service so I had a guy at work design and put up a web site, 45throatdoctor, which is no longer in operation. I thought if I got a few cylinders from others it would help defray the cost of my tools. People from all over the country started sending cylinders. In the two and a half years I was doing this, I did over 250 cylinders. About 95% were in .45 Colt and the rest in .44. In addition to Ruger single actions, I did a few Redhawks and a couple Smiths. Rather than simply reaming them and sending them back, I would prepare a report showing the original throat diameters before reaming them to .4525 (for the .45). I also asked the customer to let me know how the gun shot afterwards.
What I found was as follows:
All Ruger single actions that I measured had throats tighter than .4525. Redhawks and Smiths were not bad at all.
Throat diameter sometimes varied widely within the same cylinder! Throats measured from as tight as about .4496 to about .4518.
Reports back stated three consistent improvements, 1. Much tighter groups 2. Elimination of fliers. 3. Reduction of leading.
In my opinion the reason for these improvements were due to the following:
Tighter groups and elimination of filers comes from the throats being uniformly sized. Since the recoil impulse begins prior to the bullet leaving the muzzle, a variation in throat constriction will vary the place in the recoil impulse when the bullet actually leaves the gun. I could actually predict if a gun were throwing fliers if one throat was considerably tighter or more open than the other five.
Leading would seem to be worse if the throats were tighter than the barrel diameter. If passing thought a throat that swages down the bullet that tight, the cast bullet is going to “skid” for a certain length of the barrel until it can get a firm grip on the rifling. While skidding, it will naturally be shedding lead.
Again, these are simply my observations and conjectures which I thought I would share. Again, I no longer do this work..
After doing mine, I thought others might be interested in this service so I had a guy at work design and put up a web site, 45throatdoctor, which is no longer in operation. I thought if I got a few cylinders from others it would help defray the cost of my tools. People from all over the country started sending cylinders. In the two and a half years I was doing this, I did over 250 cylinders. About 95% were in .45 Colt and the rest in .44. In addition to Ruger single actions, I did a few Redhawks and a couple Smiths. Rather than simply reaming them and sending them back, I would prepare a report showing the original throat diameters before reaming them to .4525 (for the .45). I also asked the customer to let me know how the gun shot afterwards.
What I found was as follows:
All Ruger single actions that I measured had throats tighter than .4525. Redhawks and Smiths were not bad at all.
Throat diameter sometimes varied widely within the same cylinder! Throats measured from as tight as about .4496 to about .4518.
Reports back stated three consistent improvements, 1. Much tighter groups 2. Elimination of fliers. 3. Reduction of leading.
In my opinion the reason for these improvements were due to the following:
Tighter groups and elimination of filers comes from the throats being uniformly sized. Since the recoil impulse begins prior to the bullet leaving the muzzle, a variation in throat constriction will vary the place in the recoil impulse when the bullet actually leaves the gun. I could actually predict if a gun were throwing fliers if one throat was considerably tighter or more open than the other five.
Leading would seem to be worse if the throats were tighter than the barrel diameter. If passing thought a throat that swages down the bullet that tight, the cast bullet is going to “skid” for a certain length of the barrel until it can get a firm grip on the rifling. While skidding, it will naturally be shedding lead.
Again, these are simply my observations and conjectures which I thought I would share. Again, I no longer do this work..
