missing barrel screw
ok, to make a long, frustrating story short, i had to drill out my rear bottom grub screw for the barrel. now there is about a quarter inch hole where the standard threaded hole used to be. nothing has worked up to this point to fill, tap, re-drill, or otherwise repair the frame to accomodate another screw of any size. how much potential does this have to affect long range accuracy or perhaps a poi shifting problem? i havent been able to shoot long range yet, but i have parts for a .25 conversion on the way, and i fear that the forces of this more powerful setup may make the barrel more prone to moving. again, this is the bottom rear screw. do i have a problem?(or leave it go)
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It should work if the 7/64 drill bit is not too small for the hole.
I have toyed with the idea of making a threaded bushing by drilling out a the 1/4×24 set screw and then tapping it to 10×32, then glueing it in.
I have a drill press, but not the skill or the eyes, well I only have one eye so that should be “eye” as in singular, 😆 , to get it lined up, so this is what I came up with.
Now if that does not work, I would try drilling and tapping from the top or other side.
Regards,
Roachcreek
u da man, roach. think this seems to be the sturdiest option, ill give it a go and see what happens. 🙂
The thread is the one just below this. Lots of Ideas.
RC
Well, I started a thread about this fix a while back, myself and RiffRaft have both used the fix I mentioned, we came up with it independantly from one another, it worked well, the helicoil was not recommended at the time by posters who responded, the fix I mentioned can be done with home tools.
But you have to be able to tap a hole to do it and have the correct taps on hand. You have to lube that tap and work it in and out after just a few turns to clear the metal bits that form on it or you will strip the hole again,
Turning down the set screw is easy also, you just buy a 3/8′” long 1/4×24 and chuck the upper half up in a drill, I ground it down with a dremmel while turning the drill at the same time, but you can use a flat bastard file to turn it down to the outside dimensions of the 10/32 screw you had used before.
So again you just drill out your stripped hole, and retap it and then grind down a screw.
Lets face it, you already have a stripped screw hole, why not take advantage of what you have?
Regards,
Roachcreek
The fix works as can be seen by my target, putting on an appratus to hold a screw hole in place just does not do it for me, but to each his own.
I have put a heli coil in a spark plug hole in an aluminum head. You have to use red loctite if I remember right to hold it in. Worked for me. Give it a try. Ben
the thought crossed my mind. however, whether it does make a difference or not, my paranoia will undoubtedly take over and create a placebo effect of sorts, and i wont be able to shoot for shit, though my gun may do so just fine. as of right this moment, i have only co2 to work with, and my conscious mind says that the hpa when back up and running may jar the barrel enough to make a difference.(though as you said, it may not…) 😕
OR …..you could simply shoot the gun and see if it even makes any difference ..before ya go to “fixing it” why not see if it’s “broke” ❓ ❓
YN that bi-pod mount is a great idea. I might just prepare mine in the eventuality I need it.
Otherwise, the rear bushing has to stay put. It anchors the Power Wheel, Hammer Spring and Hammer. A new bushing in front of the rear one would only need to have one set screw installed in the bottom of the frame.
thanx roach and YN…
what happened was that my cheap ass allen key snapped off as i was snugging(not cranking) the grub screw. 👿 through various failed efforts to remove the broken key, unsuccessfully, and no way to loosen the screw, i tried the old dremel, no dice, and after hours of careful(believe it or not) grinding with diamond burrs, the hole stretched beyond the screw. i made a few subsequent efforts to clean and tap the hole, and ended up with an approximately .25 hole. so the size wasnt intentional, it just ended that way. has anybody tried helicoil? YN, the frame is a red one, you think theres still a demand for it? didnt realize new frames were that cheap, but itd kill me to part with the trigger group that ive spent hours on and have just where i like it… 😥
Use some kind of airgun rail base (riser, scope mount with top cut off etc). Drill and tap through that, attach it to them frame and then use a longer grub screw going through that through the frame and into the bushing to secure the barrel.
Could even combine it with a bipod mount or something…. Like this – but with an extra hole drilled and tapped.
On mine I do recall having to drill a hole so I could get access to the barrel mount grub screw that this covered so its already the right place for a bipod.
Just remember that a new frame only costs $100 and the tinkerers here would snap up an old frame with that minimal damage.
Or he can move the old barrel bushing forward 3/4 of an inch and drill and tap two new holes and fill the others in with set screws or JB Weld.
If you have to drill and tap new holes why not use the old bushing and keep it where it is?
Roachcreek
I guess that you could fabricate a wider barrel bushing and drill & tap the frame bottom hole forward of stripped thread and leave frame side screw in same (present) location
It does effect accuracy with the .25 conversion, this rifle has had two screws stripped out and the two diamater 1/4-24 x .18 screws used on the sides of the forward and rear grub screw holes.
Regards,
Roachcreek
If in fact the hole is too big to tap to 1/4-24 then you can drill a hole from the side and while your at it one from the top of the frame, then tap them to 10-32 and you will then have three retaining holes for the bushing.
If you have trouble or are inexperienced with drilling and tapping holes, take it to a machinist to have it done.
But that is your fix.
Regards,
Roachcreek
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evidently, were in a similar situation, having minimal tools to work with. if i had what some of these guys had, i would probably be building custom guns by now 😎