I've learned a lot in the 3 years since I built my .25 cal Disco, in particular from bouncing ideas off of Lloyd.... With recent developments, I decided to revist that rifle and see what improvments I can make.... When I finished the gun before, I had it set up for 11 shots at 45 FPE starting from a 2100 psi fill, although the gun saw a high of 58 FPE during development, right at 2000 psi with Baracudas.... The specs were as follows:

.25 cal LW barrel & bolt from Mountain Air, Disco tube, stock hammer and breech, poly transfer port (0.166"), the hammer spring was 1.75" long by 0.045" wire, running in a homemade RVA.... The valve was bored out to 0.60" ID, the threads shortened to 0.30", the throat drilled to 0.228" and the stem thinned to 0.115" (0.197" equivalent).... The front of the valve was opened up and tapered, and the gauge port was milled off-center to 5/16" to eliminate the original 1/8" hole which restricted the valve from drawing freely on the air reservoir during the shot....

Compared to some of the guns I have done since, that is actually pretty tame.... My .25 cal Millenium Pumper I just finished had porting that was 0.204" or the equivalent as a minimum right through, which is 50% more area, plus it has a heavier hammer with a longer stroke, although the valve is otherwise quite similar.... A couple of years ago, I made a two-piece valve for a guy, but never followed up on it.... Here is what it looked like....



I did use the concept successfully on my Hayabusa, however.... It seemed appropriate to bring that back into the fold for this round of mods to the .25 Disco.... I also wanted to experiment with the new hammer I came up with while working on the Millenium Pumper.... It looks like this....



The hammer is threaded 3/8"-24 NF inside and carries an adjuster which can move back and forth from flush to the end to recessed about 1/4".... Recessing the striking surface increases the stroke (travel) of the hammer before it hits the valve stem.... which in turn increases its energy and momentum.... There is a spring guide / cocking indicator threaded and glued into the adjuster, and a slot in the end provides the means to turn the adjuster.... The threaded hole in the top is for a "locker" to add resistance so that it doesn't self adjust.... The hammer is the stock 1.300" length, but the cocking pin is moved back 0.060" to allow a longer stroke before it hits anything....



Anyway, that is the starting point, and a hint at what is to come.... This should be an interesting project....

Bob