Frame Stretch Explained

[Smokey Plainsman]

Guys master woodsman and percussion revolver guru Blackie Thomas of Shaman’s Forge Bushcraft has a new and superb video out where he explains the phenomenon commonly known as “frame stretching” on brass framed cap and ball revolvers:



Extremely good stuff. Mr. Thomas has an entire playlist on percussion revolvers and those interested in such guns would be treating themselves to some of the finest information on the subject available anywhere. Just passing this along guys, take care!

-Smokey P.

 

[drobs]

I like Blackie and subscribe to his channel. He reminds me of my good family friend and mentor Ron G. who taught me to hunt and shoot as you kid growing up in a single parent family. Ron was a Navy Corpsman serving with the Marines in Vietnam and grew up hunting to put food on the table in rural Arkansas.

 

[M. De Land]

Yeah, I never believed the cylinder window was actually stretching either but I don't think Blacky has realized yet that the bearing face for the ratchet is not the main bearing for the cylinders rear word movement. It's actually the raised area just out side the ratchet well on the recoil shield. The ratchet will imprint at the bottom of the well when the raised bearing gets peened back from recoil.
On solid frame guns the face of the ratchet, which is flat, is the cylinders rear bearing.

 

[M. De Land]

Yeah, I never believed the cylinder window was actually stretching either but I don't think Blacky has realized yet that the bearing face for the ratchet is not the main bearing for the cylinders rear word movement. It's actually the raised area just out side the ratchet well on the recoil shield. The ratchet will imprint at the bottom of the well when the raised bearing gets peened back from recoil.
On solid frame guns the face of the ratchet, which is flat, is the cylinders rear bearing.

In Blacky's video ,when he had the gun apart and looking back at the recoil shield you will notice two bright spots on the raise portion of the recoil shield on your left (the guns right side). This is probable where the cylinder has peened back the bearing surface to allow the teeth of the ratchet to contact the bottom of the well. Actually when you look at the teeth on the end of the ratchet there is practically no flat surface at all for a bearing, to stop rearward cylinder travel and when they loose support from the recoil shield bearing it's no wonder they cut into the brass bottom of the ratchet well.
I don't think even a steel bushing in the bottom of the well would work for long because it would need to be hardened to resist the ratchet teeth imprint, if the recoil shield bearing surface where not corrected. If the bottom of the ratchet well bushing is made hard then it will likely peen over the ratchet teeth and effect the hands ability to rotate the cylinder.
I'm quite sure the correct fix is to steel bush the raised bearing surface in the recoil shield as this is the original design for handling the cylinder recoil inertia.

 

[M. De Land]

I was thinking on how to dress the new steel bushing added to the recoil shields raised bearing surface and the answer came to me.
I would make a fillister/ end mill type cutter of four teeth that snug slip fits over the arbor just as the cylinder does only a bit taller then thread a flex drive shaft into the center end of it for a drill motor drive. Mount the frame into a padded vice and rotary trim the new steel bushing to proper thickness. Using the revolver own arbor as the cutter axial would insure the bearings perfect squareness to the cylinder rear bearing surface.. It would work just like a case trimmer does for shortening brass cases.

 

[shortstart]

Guys master woodsman and percussion revolver guru Blackie Thomas of Shaman’s Forge Bushcraft has a new and superb video out where he explains the phenomenon commonly known as “frame stretching” on brass framed cap and ball revolvers:



Extremely good stuff. Mr. Thomas has an entire playlist on percussion revolvers and those interested in such guns would be treating themselves to some of the finest information on the subject available anywhere. Just passing this along guys, take care!

-Smokey P.

Yes, Blackie Thomas has some great videos on cap and ball revolvers. Everything from sighting in to antiquing.

 

[curator]

Over the years when I have offered C&B revolver repairs to my gun club members, I have had several brass frame "Colt" replica revolvers brought with cylinder arbors pulled right out of the frame. I have also had a few with arbors that have snapped clean off at the frame. Brass-frame "top-strap" revolvers do suffer from the cylinder slamming into the recoil shield increasing the cylinder gap. The 1858 Remington "Old Armys" made with brass frames also occasionally have the frame crack where the loading ram goes through, an area that is quite weak. The Spiller and Burr replicas appear to be one of the better designs utilizing a brass frame. The open top .36 caliber "Navy" revolvers seem to hold up much better than the .44 "Army" revolvers with brass frames. No surprise here considering the heavier ball and powder charge of the .44s.