The Firing Line Forums - View Single Post - Uberti 1851 Navy London and Kirst Converter...Issues

Head Tomcat · January 5, 2020, 11:53 AM

Guys,

Continuing down the path of converting my new Uberti 1851 Navy London to fire metallic BP cartridges, the Kirst gated converter arrived yesterday in the mail.

Taking apart the pistol, I followed the instructions and slid the converter ring down the arbor and it properly set in place against the recoil shield. The surprise came when I slid on the conversion cylinder…and it would not slide in all the way! Once the ratcheted “neck” of the cylinder started to enter the ring it contacted the ring and would go no further. To make sure there was no contact with the frame I took the converter ring out and slid the cylinder onto the arbor and it went completely down to the recoil shield and spun freely…no frame contact anywhere.

Now this sort of mystified me that with no converter ring in place the cylinder would slide all the way down the arbor and rest against the hand, and in fact, would function correctly as I worked the hammer and observed the timing (which was fairly good).

Taking the cylinder off and re-installing the conversion ring gave the same results…with the ring in place the cylinder would stop when the neck started to enter the ring. For some reason, the ring/cylinder/arbor combination simply did not have the stacked clearances to allow the cylinder to seat all the way down against the hand.

This got me thinking that perhaps the arbor itself was not square to the recoil shield? Even though it is a new pistol and has never been fired, the fact the Kirst gated conversion assembly would not drop on is leading me in this direction. I am fairly sure the Kirst is not the issue as it is very well made.

A few days ago I took 45 Dragoon’s advice and re-checked the arbor length (it is a Uberti) and sure enough it was too short. Three #6 stainless steel washers dropped into the arbor hole “added” .087” of length and this was exactly what it took to get a correct overall arbor length. The wedge was filed a slight amount on one side and it now locks nicely into the arbor with a screwdriver handle tap, with the spring lip just extending out the right side.

And this got me to thinking….

Could the arbor have been bent slightly off-square to the recoil shield when the factory assembled the pistol and then forced the wedge in…which would have moved the arbor upwards a bit? In turn, this slight amount of off-square was more than enough to overcome the tolerances in the Kirst gated converter assembly such that the cylinder could no longer enter the converter ring?

Your thoughts are most welcome as the London is a truly beautiful pistol and if the arbor is in fact off-square to the recoil shield I would like to try and fix it.

Thanks!

Head Tomcat

January 5, 2020, 11:53 AM	#1
Head Tomcat Member Join Date: December 16, 2019 Location: Northern Virginia Posts: 31	Uberti 1851 Navy London and Kirst Converter...Issues Guys, Continuing down the path of converting my new Uberti 1851 Navy London to fire metallic BP cartridges, the Kirst gated converter arrived yesterday in the mail. Taking apart the pistol, I followed the instructions and slid the converter ring down the arbor and it properly set in place against the recoil shield. The surprise came when I slid on the conversion cylinder…and it would not slide in all the way! Once the ratcheted “neck” of the cylinder started to enter the ring it contacted the ring and would go no further. To make sure there was no contact with the frame I took the converter ring out and slid the cylinder onto the arbor and it went completely down to the recoil shield and spun freely…no frame contact anywhere. Now this sort of mystified me that with no converter ring in place the cylinder would slide all the way down the arbor and rest against the hand, and in fact, would function correctly as I worked the hammer and observed the timing (which was fairly good). Taking the cylinder off and re-installing the conversion ring gave the same results…with the ring in place the cylinder would stop when the neck started to enter the ring. For some reason, the ring/cylinder/arbor combination simply did not have the stacked clearances to allow the cylinder to seat all the way down against the hand. This got me thinking that perhaps the arbor itself was not square to the recoil shield? Even though it is a new pistol and has never been fired, the fact the Kirst gated conversion assembly would not drop on is leading me in this direction. I am fairly sure the Kirst is not the issue as it is very well made. A few days ago I took 45 Dragoon’s advice and re-checked the arbor length (it is a Uberti) and sure enough it was too short. Three #6 stainless steel washers dropped into the arbor hole “added” .087” of length and this was exactly what it took to get a correct overall arbor length. The wedge was filed a slight amount on one side and it now locks nicely into the arbor with a screwdriver handle tap, with the spring lip just extending out the right side. And this got me to thinking…. Could the arbor have been bent slightly off-square to the recoil shield when the factory assembled the pistol and then forced the wedge in…which would have moved the arbor upwards a bit? In turn, this slight amount of off-square was more than enough to overcome the tolerances in the Kirst gated converter assembly such that the cylinder could no longer enter the converter ring? Your thoughts are most welcome as the London is a truly beautiful pistol and if the arbor is in fact off-square to the recoil shield I would like to try and fix it. Thanks! Head Tomcat