Started a working prototype. Figured no sense starting from scratch when I have a pile of 880's and never shoot this one. Stock 2015 880 internals other than trigger mods.I wanted to see how fast it was with the gun stock 1st. Then I'll mod it up, and see how much faster the arrow flies.Tomorrow while working in my wood shop I'll mod up a pair of grips to clear the vanes.Using crossbow arrows, as that is what I have in 2119, which slides right over the .30 od Daisy barrel perfectly I supported the barrel for the test run near receiver end with part of a bent arrow and some tape.I gave it 2 pumps and aimed at a folded up blanket a few feet away.It launches I'm pumped! This stuff is just too much fun! Mixing my 2 favorite projectile forms.
Just a thunk, but as the pressure goes up, you may have to glue the head socket in better, possibly up to and including drilling a cross pin through the shaft and threaded socket to retain it.Possibly not, but it's a thought..Thank you for pursuing this, An AFFORDABLE air bow, I have seen a video using co2 on one also..I am interested in seeing how fast a stock one will do..https://youtube.com/watch?v=EAJNxpItfX0
Dude.Now I know you'll try anything. And how many 880s do you HAVE!?
Since the Daisy valve is a dump valve, I was thinking to get more valve volume with the pumper, the piston face is flat, you could dish it to possibly get a little more overall air volume.I haven't been that far into a 880 valve assembly to know if it dumps the air all the way to the piston, but it stands to reason it would..
Not too terribly bad, a 25 lb bow hits about 125fps. Just needs a little nudge.Shorter arrows, and shorter barrel?Maybe a .22 barrel for more flow?How about this, since it's a target arrow gun for now. On some arrows , the nock end is spun to a point. How about removing the fletching, and use the spun point as the field point, no added weight in the arrow. Just re-fletch the other end of the shaft.To seal it, I would look into a little silicone lube. To retain the arrow, and maybe let it built a little pressure, a piece of heat shrink tubing on the back of the barrel where the rear of the shaft seats.
Long ago I had the .22 version of the 880. I didn't know if there was a difference in the outer diameter of the straw barrel between .177 & .22. If the OD is larger, what about stepping up in arrow diameter?If I recall, the arrow sizes are the inner diameter in 64th of an inch X wall thickness in thousandths. (2112 = 21/64ths of an inch X .012) But I am old and forgetful.