After putting in a boss valve, boss buddy transfer port, aluminum breech, and a 10' barrel it averaged 475 for 18 shots with the Crosman 14.3 pellets. I kept a hand warmer around the tube and waited a little between shots. It was probably about 65 degrees in the shop. I guess that's pretty good.
Are you noticing any hammer bounce?
Has the barrel port been opened up to match the inner diameter of the transfer port? (I'm assuming the boss buddy transfer port I.D. is larger than the stock one)
Looks like a good velocity number to me.
I don't think that there is any hammer bounce but how do I tell if there is and no I haven't made the hole in the barrel any bigger, should I?
The barrel port must be enlarged. All parts of the path, valve, TP, and barrel should be the same size. Ensure no burr is left on the inside of the barrel (the leade) after drilling to size.
Is it as simple as finding a drill bit that will fit inside of the boss buddy and then drill the barrel with it? How would I clean out any burrs on the inside of the barrel?
Quote from: Jimbo on February 18, 2019, 04:12:17 AM
I don't think that there is any hammer bounce but how do I tell if there is and no I haven't made the hole in the barrel any bigger, should I?
This explains it pretty well. https://www.crosman-air-pistol-owners-forum.com/board/index.php/topic,15198.msg198938.html#msg198938
Wow now I don't know what to think, should I try and find one for my gun or not? Apparently Arkmaker doesn't think it's worth it tho.
I cant say for sure but 18 shots seems low, suggesting wasted air some where. That led me to the hammer bounce post. I suggest searching for "the B-stanley mod (I think that is what its called). Involves some o-rings placed over the valve stem, reducing the hammer strike and the resulting bounce effect. The air saved will improve shot count.
I have heard of that when I was doing things to my marauder, I will definitely check it out thank you.
First gently break off any large burr with a pick, then fine grit wet-or-dry sandpaper rolled with a very small taper on a drill bit of the appropriate size - also accomplishes the task of polishing the leade.
look at enlarging your valves volume along with flowing the exhaust port in .22 a tp of around .165" is about max you can port the barrel and not have pellets fall into the port
Quote from: Jimbo on February 18, 2019, 02:23:21 PM
Is it as simple as finding a drill bit that will fit inside of the boss buddy and then drill the barrel with it? How would I clean out any burrs on the inside of the barrel?
I was looking at Alchemy's web site and see that the Boss Buddy transfer port has an I.D. of .160. I can lend you a carbide 4mm end mill (.1575) that has a small radius on the cutting edges, helps cut down on burrs and will stay nicely centered to the chamfer on barrel port. PM me and we can work it out if you'd like. When I just used it on my 2289 project I just chucked it up in my cordless drill and inserted a small wooden dowel (Q-tip handle will work) in barrel to keep it from hitting back side after going through.
With the boss valve you've got the storage area for more air. With the boss transfer port you've got the larger pathway to get the additional air to your barrel. The last step is to make that pathway through the point of entry into the barrel the same as the transfer port to allow all that same air volume to the pellet.
After drilling out the barrel (courtesy of cherokeesteve) I shot it thru the chrony and the numbers are definitely higher but I'm gonna do it again and then I will post the results.
Now I'm getting an average real close to 500fps for 20 shots with the crosman 14.3 grain pellet. I'm fine with that, I'd rather have a few high power shots than a lot of shots at low power. I might get a power adjuster so that if I'm just target shooting I can adjust it down and if the nasty tree rats get annoying I can adjust up to full power. I think I'm where I wanna be :)
Jimbo adjusting the hammer spring on c02 guns is a really nice option to have.
Shooting outside in summer will see even higher velocity numbers. Upped velocity with slight increase in shot count is the perfect combination. :-*
Quote from: cherokeesteve on March 03, 2019, 04:42:42 AM
Shooting outside in summer will see even higher velocity numbers. Upped velocity with slight increase in shot count is the perfect combination. :-*
I was just going to ask what your ambient temp is...
Are you shooting indoors? So... 70F.
I wont even attempt CO2 outdoors right now.
Quote from: Jimbo on March 03, 2019, 02:33:48 AM
Now I'm getting an average real close to 500fps for 20 shots with the crosman 14.3 grain pellet. I'm fine with that, I'd rather have a few high power shots than a lot of shots at low power. I might get a power adjuster so that if I'm just target shooting I can adjust it down and if the nasty tree rats get annoying I can adjust up to full power. I think I'm where I wanna be :)
A quality power adjuster is good value, indeed.
I was shooting in the shop with the heat on at probably around 65 but I also kept a hot hands warmer around the tube with a rubber band.