Barrel Bushings
Made some new bushings today. Old ones were to loose. They measured 1.010″ and new ones are 1.014″. Also made the back one .050″ bigger and put a o ring in it to stop the air from pushing the power wheel towards the breech. Also added a second set screw to it. I noticed the barrel had moved when I removed the old bushings.
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I was measuring my old bushings and noticed they were not the same size. They were .0006″ different. I don’t know how much matters but I made mine both at the same time and then part them. So the inside and out side are the same on both.
RC,
what worked for me was to abrade a few thou off by hand and finish with a fairly coarse grit. i then took a squirt bottle of dupont nonstick teflon lube(cerflon) and rubbed a few coats into the bushings as well as forward frame area.
theory is that the cerflon takes up the tiny gap left by the sanding, gives just enough to not cause another jam, as well as being the slickest commonly available dry lubricant known
I bought a pair of bushings from AF last month. When I put them on I did not measure them or the inside of the frame.
I have to very forcefully push them into the frame, when I remove the barrel I have to put the end of it in a leather padded vice to pull it out of the frame. IT is really a pain in the ass to get in and out.
It is a one holer at 36 yards.
I know a lot of air gun stuff and fire arm stuff do not run on a parrel line, but it seems to me these AF barrels are not stabe in their fit to the frame.
Regards,
Roachcreek
Thanks. It’s hard with all the difference in the frames.
just recieved mine , great work and fit good
cheers
It is Viton size 020. Grove is .060″ deep and .070″ wide.
dayotat100, what size is the o-ring, what material is it made of, how deep is o-ring groove? thanks
Lots of work in these Doug, they look awesome…
Made some more bushings today. I have 2 guns I’m building, a .25 and .308. Amazing how every frame is different. One set is for a gun that measures 1.010″ and my 2 are 1.012″ and 1.013″.
I’ve used high speed cameras to observe that airgun barrels have harmonic vibrations as well. I recommend soft mounts that don’t interfere with natural harmonics at various power levels. I could be full of shit but I do have one hell of an accurate gun that just happens to use soft mounts… Less than half MOA at 100 is nothing to sneeze at even though you know it requires a perfect bench and great shooting day (if it didn’t it would be easy).
I’m no AF expert but what I’ve paid attention to tells me that O-ring mounted bushings might be far more accurate with multiple pellets and powers than very precise but rigid mounts. But, I’ve got no skin in the game, you guys are paying for the mods with dollars or time…
I use the tri rail and a long one piece scope mount to reinforce the frame between the barrel housing and the tank mount. The only thing that touches the frame is the extended bushing.
The shroud is frame mounted and it did take a little extra work to get the barrel centered with it.
The hammer is a solid brass 100 gram barrel guided that does not come close to the frame at any point.
My next step is a 2 piece ball and socket articulated breech so that the angle between the barrel and the top hat would have zero effect on the floating of the barrel.
Floating firearm barrel and floating an airgun barrel are not the same.
For accuracy with the scope, the barrel has to be rigidly fixed to the same structure that holds the scope, in either case.
Regarding more than 2 mounting points, is somewhat a myth, as the barrel of a firearm has a harmonic and IF one can determine where that single point is where both waves cross the zero line, than hard mount there. Harmonics of lower speed airguns (compared to firearms), are reduced by the bull (thickness) of the barrel.
Correct me if I’m wrong but isn’t a floating barrel one that is only mounted in the reciever and is not touching anything the rest of the barrel. I would think that you would want that mount to be as good and firm as possible so that point could never change. I was told before that you don’t want more then 2 places the barrel is mounted. That is why I was thinking of removing the front bushing and letting the shroud become the second one. To have a condor with a floating barrel and a shroud might work but everything would have to be perfect so it doesn’t clip. A nice bigger snug bushing that makes sure barrel is in the center of the frame might work.
With all the talk of free floated barrels here and how the bushing are, it would seem to me that you would defeet the purpose if the LDC slips on the end of the frame and even remotely touches the barrel at all wouldn’t it???
I agree about the floated barrel, as I have a couple of rifles the barrels are floated and they are good shooters, then I got another rifle I have floated the receiver and bedded the barrel in and it shoots just as well if not better than the other two… I have always heard you wanted one or the other floated and the other bedded…
It would be quite interesting in deed to do a test on the AF rifles to see just how the accuracy would be affected by changing up to one larger bushing in the power wheel location, then float the rest of the barrel…
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Triple O rined this bushing to try and stop the hiss sound I get from my .22. Also machined the barrel to .600″ for a barrel guided hammer. Barrel went from .626″ down to .622″ from the bushing to the step. Now it is .6002″