Niederlander
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Gentlemen, Will later K-frame .38 Special cylinders fit the pre-War M & P's? I know I've seen a really good post on what parts will interchange, but I can't find it now.
Cylinder Interchange
- Thread starter Niederlander
- Start date
I'm not aware of a thread like you mention except for N frames.
I don't think they address your question. But I believe the 38 cyls do interchange with the usual possible slight variations of all cyls.
I don't think they address your question. But I believe the 38 cyls do interchange with the usual possible slight variations of all cyls.
Green Frog
Member
That was a question I had as well. I am specifically curious about using a post-War K-22 cylinder with a pre-War frame. I know the e-rod threads were reversed in the '50s, but as long as the whole cylinder assembly stays together, I'm thinking it should all work, no? BTW, the LERK being absent might look funny, but there should be no problem with function, if I'm reading the situation correctly.
Froggie
Froggie
Froggie,
It's because I have measured, compared, and confirmed, pre and post war 22 cyls will interchange, that I believe 38 cyls will as well. I have a post war 38 K frame, if anyone has a pre war 38 cyl overall dimension, I can confirm it.
The extractor rods are a little more problematic. But left hand threaded pre war 'barrel' style ext rods do exist. Because the I frames switched to left and threads when reintroduced after WW II.
And apparently Smith had lots of pre war notched (for the barrel knob) barrels in inventory to use up. So they made up left hand ext rods with barrel knobs to fit those notched barrels.
An I frame ext rod with barrel knob for a 3" or 4" barrel will work on a 38 K frame LH post war rod/cyl assembly if it has a 2" barrel with a little fitting to length. They will also work on longer K & N frame barrels by simply inserting a section of another ext rod cut to make up the additional length need.
There are no LH 'mushroom' knob ext rods. However mushroom knobs from before ~ 1920 were a separate piece that threaded on the ext knob so they do exist. By merely threading the end of a post war LH straight ext rod (no Knob) one can have a mushroom knob for LH rod/cyl assembly for a pre war barrel with the two step notched.
It's because I have measured, compared, and confirmed, pre and post war 22 cyls will interchange, that I believe 38 cyls will as well. I have a post war 38 K frame, if anyone has a pre war 38 cyl overall dimension, I can confirm it.
The extractor rods are a little more problematic. But left hand threaded pre war 'barrel' style ext rods do exist. Because the I frames switched to left and threads when reintroduced after WW II.
And apparently Smith had lots of pre war notched (for the barrel knob) barrels in inventory to use up. So they made up left hand ext rods with barrel knobs to fit those notched barrels.
An I frame ext rod with barrel knob for a 3" or 4" barrel will work on a 38 K frame LH post war rod/cyl assembly if it has a 2" barrel with a little fitting to length. They will also work on longer K & N frame barrels by simply inserting a section of another ext rod cut to make up the additional length need.
There are no LH 'mushroom' knob ext rods. However mushroom knobs from before ~ 1920 were a separate piece that threaded on the ext knob so they do exist. By merely threading the end of a post war LH straight ext rod (no Knob) one can have a mushroom knob for LH rod/cyl assembly for a pre war barrel with the two step notched.
Just measured my 1905 4th Target cylinder at 1.558" and 1902 1st Target
at 1.559 and post war C series pre-10 at 1.561
Stu
at 1.559 and post war C series pre-10 at 1.561
Stu
Hi Stu,
My 1981 14-4 cyl is also 1.561". So they will interchange. A slight fitting may be required if the extra .003" length causes the cyl to be too tight, but not likely in a well used pre war gun.
Beware of this if you happen to come up with a 1977 cyl:
1977 changes from gas ring on yoke to cyl and back again on Models 10-7 & 8, 14-4, & 15-4.
Pre war cyls have the gas ring on the cyl.
My 1981 14-4 cyl is also 1.561". So they will interchange. A slight fitting may be required if the extra .003" length causes the cyl to be too tight, but not likely in a well used pre war gun.
Beware of this if you happen to come up with a 1977 cyl:
1977 changes from gas ring on yoke to cyl and back again on Models 10-7 & 8, 14-4, & 15-4.
Pre war cyls have the gas ring on the cyl.
Last edited:
Green Frog
Member
So it looks like if I take a late 1950s or '60s K-22 cylinder complete with its own extractor and e-rod, then thread the end of the e-rod for a pre-War knob, I'll be good to go. Then again, I probably don't have enough time left to finish all the projects I've already dreamed up and started... they'll take another 20-30 years, but just in case... 
Froggie
Froggie
Yes for the mushroom knob.
For the barrel knob (Lerk), just hunt up a pre war and exchange it for the straight rod.
Those never were a separate piece except on the triple lock but they had male threads and the rod
was a larger diameter.
Lots'a projects means good retirement security!
For the barrel knob (Lerk), just hunt up a pre war and exchange it for the straight rod.
Those never were a separate piece except on the triple lock but they had male threads and the rod
was a larger diameter.
Lots'a projects means good retirement security!
Last edited:
Green Frog
Member
Yes for the mushroom knob.
For the barrel knob (Lerk), just hunt up a pre war and exchange it for the straight rod.
Those never were a separate piece except on the triple lock but they had male threads and the rod
was a larger diameter.
Lots'a projects means good retirement security!
Yeah, but at my current pace, I'll have to live to about 108 to complete the ones I'm working on or have planned already!
S&WsRsweet
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Boy Green Frog I hope you make it to get those projects all done and maybe Hondo and the rest including myself will be right here either giving great advice or in my case eying great advice .My wife asked me how old do I want to live to be . My standard answer is I want old folks to ride by and see me on the porch and ask,how old is he? And the reply be I'm not sure but he was an old man when I was a kid lol. Heres to long life good health and being able to remember even half this stuff y'all talk about .
Green Frog
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I don't know how old he is, but the old guys deferentially call him "Sir." 
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