Originally Posted by
Coffeecup
Having handled about 8-9 of the original Gemmer conversions, and built a couple copies, here are some random thoughts.
Before I'd actually handled one, I had the impression that these were serious functional upgrades, much like the Freund conversions of the Sharps. After seeing a few of them, I think they were more of a way to sporterize common surplus rifles. My reason for thinking this is simple: with the exception of one Spencer conversion, they all used the original (round) factory/military barrel rather than the octagonal barrel we see when we think of one of these.
The (5) original Gemmer trapdoors I've seen shared a number of common factors. All were fit with commercial lock (not the original trapdoor lock), and all had double-set triggers. They all had Hawken-style stocks (in maple) and furniture (including a folded, soldered-on, hollow rib), and a silver front sight blade. All used an iron nosecap and separate entry pipe. Three used the original military rear sight, while two used the Hawken-pattern slide-adjusting rear sight.
Best matches for furniture are (not surprisingly) the late pattern buttplate and triggerguard. The closest-to-matching lock is L&R's "Leman" lock, with a modified hammer from an original back-action lock (or with a bit more work, L&R's back-action lock). The hammer will have to be bent and extended to hit the firing pin, but the back-action hammers will have enough clearance to go around/over the latch so you can open it on half-cock.
L&R's lock will also work well with the set triggers; putting a fly in an original trapdoor lock is a pain. The easiest way is to slot the tumbler and set the fly in the slot, pivoting on a pin. DO NOT USE A BLIND PIN, wasted a weekend's work and a good tumbler when I did that. . . .
The easiest way (for me, at least) to do the breech tang was to file off the original so there was a "step" for the new tang. Then have a good welder (not me) weld on a new tang. Shape the tang to match the ones used on a late Hawken, sort of an elongated beavertail.
To get the stock shape correct, you can use any of the drawing sets of a late Hawken, adjusting to match your hardware. Watch the size of your wiping rod pipes; many sets of Hawken parts are set-up for a 7/16" ramrod--too large for a 45-70.
I did one rifle using a trapdoor lock, wouldn't do it again. The lock is slow, and the size of the plate upsets the lines of the rifle. On the other hand, I used an octagon barrel on that one, and despite not being "correct" or "true to the originals", I really liked the look. The other rifle was done using the barreled action from an H&R, with lock etc from L&R.
If I were doing one today, and wanted a "Gemmer" rather than just a sporter of the period, I'd use the L&R parts and round barrel. If just building a sporter, I'd use a trapdoor lock fitted with a fly, double-set triggers, octagonal barrel, and cast pewter nosecap.
Jim