December 27, 2007 at 6:38 pm #1125riffraffParticipant
I have been toying with the notion of using a 3rd barrel bushing to isolate the barrel from the whole PW/spring/hammer assembly as follows.
Basically you would use a third barrel bushing, bored out so the barrel would not be touching it. This bushing would need to be fixed with a second screw, probably threaded and pulled to the frame.
The barrel bushings would be moved foreward, the first one just ahead of the power wheel, the second one closer to the end of the frame.
The idea is to isolate the barrel from the slap and inertia vibration from the hammer and spring during firing. Anybody see why this wouldnt be a good idea?
I was trying out a limbsaver damper on the barrel, and it seemed to help accuracy if you got it in just the right spot. However this didnt allow the use of a shroud. The damper tries to balance out barrel vibration, so I wonder if this idea would be similar?
Opinions?December 29, 2007 at 10:56 pm #30487blackopsParticipant
Interesting idea…we have tried puting o-rings on the bushings both inside and out to isolate the barrel from the frame but I havn’t seen anyone do what your talking about…be cool to see if it makes a difference?
Interesting note on the damper on the barrel effecting harmonics to some extent. If one were so inclined I guess you could put a rubber sleeve and metal sleeve over it that could be moved up and down the barrel and secured some how? I really like the idea of the o-ringed barrel bushings though…
O-ringed problems encountered were none on the 12″ barrel but on the 24″ barrel the muzzle weight exerted enough force to smash the o-rings and the barrel was held off center…I think I solved this partially by using 2 o-rings on the outside and one on the inside and moving the front bushing to the frame. Using small/thin o-rings help too as they have less to flex/smash.
On the 12″ barrel the guy(forgot his name) had GREAT results from them in his testing…
My Dad is trying 2 o-rings on the outside of the bushings and non on the inside…he is also using longer bushings (2″ish)..
Important note…the set screws can’t push on the bushings at all or they will move the barrel out of alignment…you have to change screws to something that will tighten to the frame as well as remove the threads so the screws just go in the holes and don’t touch/force there way in or they will smash the o-rings.
Hope some of that made sense? Jim.December 30, 2007 at 12:21 am #30499blackopsParticipant
Maybe these pics will help explain the bushings…these don’t have the hole(s) drilled for the “set screw” but you can see how the o-rings work.
Another note…you ideally want the barrel bushing set screws 180 degrees apart so the bushing doesn’t get any significant side loads..
Jim.February 24, 2008 at 6:14 am #34791brushy-billParticipant
I have read several of the post in this thread and it seems that you are concerned with the barrel picking up vibrations from the hammer.
Have any of you ever seen a barrel tuner? They have been used on .22 cal. smallbore rifles It is a threaded sleeve fixed on the end of the barrel
with a collar ( weight ) that is screwed froward or back on the barrel you simply pick the ammo you are going to shoot and start shooting. adjusting the weight untill the rifle groups the best, and lock it down. It stays that way untill you shoot all of that lot of ammo. These would work the same on a CA rifle if the barell was not shrouded.February 24, 2008 at 2:24 pm #34801bodhisdadParticipant
1. the barrel bushings are fine for the most part. If i did anything it would be what James has pictured with teh o-rings and the bushings in the same place. A bit longer if anyting like a 1″ long would help stabelize.
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