I made a washer today, and can make them any thickness, but I started at close to the stock o-ring thickness. ID was 0.128", OD .312", and thickness is .075". In a really quick test, I'd say it has the potential to add some velocity, but there's yet another variable I hadn't ever tested, which is maximum hammer travel.
I always read that setting the hammer stop adjustment to 4 lines was maximum hammer travel, and going farther would make no difference. I've even read people who said they tried it with the adjuster removed, but those folks must have been shooting closer to stock. One of the things I wanted to look at today was whether there really is a maximum hammer travel. For all practical purposes, there is no physical stop other than the adjuster. There is absolutely a limit though, because at some point, the o-ring on the valve pin will come out of the hole in the valve tube, and it makes a really loud noise
It's very likely that you would be unable to reach this limit without extra hammer weight, and/or some spring pre-load.
I look back now and realize that I haven't been setting the hammer stop at any specific spot. I usually set it right on the 4th line (foolishly thinking that was past some other physical limit), but it's often left just beyond the 4th line a bit. At some point it hits the shroud, so I never tried to go beyond that before today. In very brief testing, I determined that somewhere beyond the 4th line is max hammer travel, and you have to find the point where the valve pin doesn't come out of the valve tube hole. It's kind of like the joke about tightening a screw until it strips, then back off a quarter turn
Now that I've looked into this more, I realize that there's a potential improvement for at least "my" rifle. When I had the valve tube out doing the slotting, I noticed that the machine work inside the tube isn't very good. It's surprisingly rough where the valve seat o-ring has to seal, but somehow it seals. The other thing I noticed is that the hole in the rear of the valve tube is partly chamfered, but not cleanly. It looks like maybe a drill was initially used to cut the inside hole, and they went a little too far. That chamfered front edge reduces my hammer travel slightly, because the o-ring becomes unseated earlier than it should.
Here's a question for anyone who hasn't slipped into a coma by this point in the post- If you look inside your valve tube, is the rear hole square on the front side, or roughly chamfered?
Thanks,
Rusty
I always read that setting the hammer stop adjustment to 4 lines was maximum hammer travel, and going farther would make no difference. I've even read people who said they tried it with the adjuster removed, but those folks must have been shooting closer to stock. One of the things I wanted to look at today was whether there really is a maximum hammer travel. For all practical purposes, there is no physical stop other than the adjuster. There is absolutely a limit though, because at some point, the o-ring on the valve pin will come out of the hole in the valve tube, and it makes a really loud noise
It's very likely that you would be unable to reach this limit without extra hammer weight, and/or some spring pre-load.I look back now and realize that I haven't been setting the hammer stop at any specific spot. I usually set it right on the 4th line (foolishly thinking that was past some other physical limit), but it's often left just beyond the 4th line a bit. At some point it hits the shroud, so I never tried to go beyond that before today. In very brief testing, I determined that somewhere beyond the 4th line is max hammer travel, and you have to find the point where the valve pin doesn't come out of the valve tube hole. It's kind of like the joke about tightening a screw until it strips, then back off a quarter turn
Now that I've looked into this more, I realize that there's a potential improvement for at least "my" rifle. When I had the valve tube out doing the slotting, I noticed that the machine work inside the tube isn't very good. It's surprisingly rough where the valve seat o-ring has to seal, but somehow it seals. The other thing I noticed is that the hole in the rear of the valve tube is partly chamfered, but not cleanly. It looks like maybe a drill was initially used to cut the inside hole, and they went a little too far. That chamfered front edge reduces my hammer travel slightly, because the o-ring becomes unseated earlier than it should.
Here's a question for anyone who hasn't slipped into a coma by this point in the post- If you look inside your valve tube, is the rear hole square on the front side, or roughly chamfered?
Thanks,
Rusty
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