Besides the new production Red Ryder and Model 105 Buck I just bought and modified, I also have an old style Model 104 w/removable shot tube. It’s the same size externally as the new type Model 105 but internally there are differences:
Plunger assembly minus plunger heads
Old model spring wire diameter is 0.82” (2.1mm). The spring OD is ~0.706” (17.5mm), ID is 0.530”. Old spring has 21 coils and is not flat ground on ends. Free length is 7.5” (has many thousands of shots on it during its ~45 years use). The retainer pin is round. Old spring rate is about 30 pounds per inch. Spring travel for old Model 104 is 2-3/8”.
New model spring wire diameter is 0.91” (2.3mm). The spring OD is ~0.720” (17.5mm), ID is 0.530”. New spring has 28 coils and is flat ground on ends. Free length is 7”. The retainer pin has flats but oddly the flat side is not used against the ground spring ends. New spring rate is about 25 pounds per inch (both spring rates are rough estimate for now, will measure again as time permits). Spring travel for new Red Ryder Model 1938B is 1-7/8”.
The old plunger/guide tube is 1/2” OD. The new plunger/guide tube is 15/32” OD. The slightly closer fit between the plunger tube OD and spring ID may well account for there being no spring twang/vibration on the old gun versus the new one (both the new 105 and my new Red Ryder have the same twang- and they share the exact same powerplant). There are some differences in the rear stamped steel cross piece where the trigger (and sear of the new plastic housing trigger) latches. This can be seen in one of the photos.
Air tube details. Circled areas on the air tubes are the outlet port.
Enlarging the air tube ID is at the heart of making the gun shoot harder. Just adding preload to the spring will be largely wasted unless the air tube is opened up. The new model's air tube has the same ID as the old model from the '70s but they're both smaller than a factory air tube from a '60s Model 1894. The 1894 factory air tube ID was said to be a #40 drill bit (0.098"). I'm currently using an ID of 3/32" (0.094) on the factory air tubes. A standard 3/32" bit isn't usually going to be long enough to reach the bottom of the outlet port on the air tube so I use a standard drill bit for as deep as it'll go then a longer "specialty" bit to finish it off so as to not wear out the long bit prematurely.
The new model outlet port is actually larger (this area is circled, two photos up). The air tubes are not the same length and the air outlets are in slightly different places. Because the new model air tube is shorter, it can't be retrofitted into an old model, else double feeds may result.
New vs. old trigger
The triggers are very different and cannot be exchanged between the old and new models. The trigger hole in the receiver is located 3/8” further rearward on the old model, this accounts for (at least some of) the difference in spring guide tube travel. I got rid of the anti-beartrap by removing the spring. Cocking is MUCH smoother and quieter- like it's supposed to be.
The rearmost trigger return spring (not seen in side view) has also been removed to lighten pull. The pull can be lightened even further by using the rear return spring in place of the front sear spring. The factory sear spring is about twice as stiff as the rear return spring. Be careful! Set up like that, the pull will be very light and could be unsafe in some guns. So be sure to unload the gun while safety testing the trigger after any modifications! BTW, this type Daisy BB gun can be dry fired.
It's a shame the almost-all-steel trigger from the "Worlds Most Accurate" Model 499B cannot be used in the regular Daisy lever guns- it's a whole lot better than the plastic/metal trigger now used on the new models.
The new model's rubber plunger head (seal) and washer are the same as the old model (7/8” OD) and can be interchanged. The old model has a staked-in abutment in the receiver. The old style abutment has a threaded ID so the shot tube can be removed and it uses a separate 1/4” thick x 7/8” OD rubber barrel seal/"bumper" on the compression chamber side that can be removed/replaced. The new model does not use a separate abutment and barrel seal like the old model. On the new model, the abutment and the barrel seal is built into the shot tube assembly. The new model shot tube is now being staked in place and is not ordinarily meant to be removed, but it can be if needed by driving it out from the muzzle towards the breech. Got to be careful replacing it to get the right side ‘up’ so BBs will feed right.
Replacement parts sourced directly from Daisy/DAMACO to follow (including how to get individual barrel and plunger seals)…
Model 104 with Red Ryder furniture top, Red Ryder with full size buttstock bottom