I have tried reading about bolt timing but I am not sure about this aspect. I have a Rem 700 which was trued and rebarrelled by a very reputable barrel maker. I have not been able to get the accuracy out of it I think I should. I have noticed that the bolt handle hits the bottom of the action bolt notch on closing. Upon firing the bolt rotates conterclockwise rather violently about 10-15 degrees. Can someone explain to me what normally controls (stops)the bolt rotation on closing the Rem 700 action and should the bolt handle bottom out on the action when doing so? The rifle feeds and extracts just fine. I am just trying to get the accuracy out of it that it think it should. (It is chambered 260 Rem and I'm only getting .3-.4 inch groups at best. Average groupds are running more like 1-1/2 inches ad 100 yards. [This rifle was rebarrelled and trued then installed in a solidly bedded Bell and Carlson Tactical stock with a Jewel trigger.]
Should bolt handle contact action on closing?
- Thread starter JCummings
- Start date
Butch Lambert
Active member
What would stop the bolt if the handle didn't?
Butch
Butch
C
Cheechako
Guest
JC
What Butch said. It's the contact that keeps the bolt from rotating a complete 360 degrees.
What you have is a timing problem. The bolt is probably closing too much or, less likely, not enough.
Close the bolt on an EMPTY chamber. Now lift the handle up just a teeny bit, hold it there and pull the trigger. If the handle still flys up try it again only lifting the handle a little more. Repeat until you find out how much it is out of time.
There are ways to remedy this. Glue a piece of something into the notch is just one. Use your imagination.
If the timing is off in the other direction, you will have to remove metal from the bottom of the notch to allow the bolt to close further.
Unless you know what you're doing, this is a job for someone who does.
BTW, I'm not sure that bad bolt timing is what is turning that rifle into a shotgun. Most Remington's have bad timing to one degree or another. And some bolt handles just like to fly up. :0)
Ray
What Butch said. It's the contact that keeps the bolt from rotating a complete 360 degrees.
What you have is a timing problem. The bolt is probably closing too much or, less likely, not enough.
Close the bolt on an EMPTY chamber. Now lift the handle up just a teeny bit, hold it there and pull the trigger. If the handle still flys up try it again only lifting the handle a little more. Repeat until you find out how much it is out of time.
There are ways to remedy this. Glue a piece of something into the notch is just one. Use your imagination.
If the timing is off in the other direction, you will have to remove metal from the bottom of the notch to allow the bolt to close further.
Unless you know what you're doing, this is a job for someone who does.
BTW, I'm not sure that bad bolt timing is what is turning that rifle into a shotgun. Most Remington's have bad timing to one degree or another. And some bolt handles just like to fly up. :0)
Ray
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bolt kicking up.
J,
I've seen that, but not on any gun that I've worked on. The worst was a Browning FN Mauser .264 Win, that was in poor shape. I bought the gun for the action, but have never got around to putting a barrel on it. The former owner said it grouped like a shotgun!
Take a look at the cocking ramp on the end of the bolt. The cocking piece is hitting at the bottom on the radius opposite the ramp, so that the bolt kicks "open" a bit. Can't be good for accuracy.
I can think of several ways to fix it. Such as changing the radius on the cocking piece or changing it on the bolt. It shouldn't take much. Or perhaps a bit of bedding would stop the bolt from closing the final 10-15 degrees & stop the bolt from kicking up.
When you get the "bolt kicking" problem worked out, let us know the gun shoots.
Regards, Ron
J,
I've seen that, but not on any gun that I've worked on. The worst was a Browning FN Mauser .264 Win, that was in poor shape. I bought the gun for the action, but have never got around to putting a barrel on it. The former owner said it grouped like a shotgun!
Take a look at the cocking ramp on the end of the bolt. The cocking piece is hitting at the bottom on the radius opposite the ramp, so that the bolt kicks "open" a bit. Can't be good for accuracy.
I can think of several ways to fix it. Such as changing the radius on the cocking piece or changing it on the bolt. It shouldn't take much. Or perhaps a bit of bedding would stop the bolt from closing the final 10-15 degrees & stop the bolt from kicking up.
When you get the "bolt kicking" problem worked out, let us know the gun shoots.
Regards, Ron
I like to remove the trigger and place the bolt in the action and see where all the pertinent bits line up with the bolt open and closed. With the bolt closed the bottom of the cocking notch should be centered in the slot where the trigger housing fits. With the bolt closed the nose of the cocking piece should not be touching the cocking ramp at all.
ETA: Make sure the bolt handle is not touching the stock when the bolt is closed. The bolt handle should be bearing against the action, not the stock.
ETA: Make sure the bolt handle is not touching the stock when the bolt is closed. The bolt handle should be bearing against the action, not the stock.
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Thanks guys. You've told me what I thought.
Butch, I'm sure that you and I could both come up with numerous methods which would be more precise than the method used.
It seems that attaching a bolt handle to stop the rotation is only a "close enough" or "good enough for government work" method to me.
I would suspect that the neutral, unstressed, blanced point of bolt closure would be less likely to disturb things when the trigger is released. As Cheechako said I would think the point with the least bolt movement upon firing would be the way to set things up. I would think that once machining is done to the bolt and action after the bolt handle was set up on the bolt would be likley to change things (and obviously it did). Therefore I do not think this method of bolt timing is really ideal. I guarantee we could come up with other ways to design this which would eliminate this problem. Of course the precision machining done on modern custom actions is one method. Designing an adjustable stop would be another. Adding and removing material from the bolt handle is certainly a suboptimal design in my opinion.
Butch, I'm sure that you and I could both come up with numerous methods which would be more precise than the method used.
It seems that attaching a bolt handle to stop the rotation is only a "close enough" or "good enough for government work" method to me.
I would suspect that the neutral, unstressed, blanced point of bolt closure would be less likely to disturb things when the trigger is released. As Cheechako said I would think the point with the least bolt movement upon firing would be the way to set things up. I would think that once machining is done to the bolt and action after the bolt handle was set up on the bolt would be likley to change things (and obviously it did). Therefore I do not think this method of bolt timing is really ideal. I guarantee we could come up with other ways to design this which would eliminate this problem. Of course the precision machining done on modern custom actions is one method. Designing an adjustable stop would be another. Adding and removing material from the bolt handle is certainly a suboptimal design in my opinion.
Butch Lambert
Active member
JCummings,
I have seen bolt handles drilled and tapped with a nylon tipped set screw in them to allow adjustment.
Butch
I have seen bolt handles drilled and tapped with a nylon tipped set screw in them to allow adjustment.
Butch
J
jonmdavis62
Guest
Trigger
not a gunsmith but a friend had the same thing after a
trigger change,put the old trigger back in everything was
OK.might just try it....
Jon D.
not a gunsmith but a friend had the same thing after a
trigger change,put the old trigger back in everything was
OK.might just try it....
Jon D.
C
Cheechako
Guest
JC
I've used that fix but I drill and tap the notch in the receiver. It doesn't weaken the bolt handle, it can be adjusted for different bolts, and if you want to remove it you can fill the hole with a plug screw.
I've seen some with a leather pad glued in the notch also. I suppose you could argue that a "soft" stop is better. Or you could argue that it is worse.
If you drill the bottom of the bolt plug (both sides of the sear) install two nylon plugs, and fit them to the receiver it helps by taking all of the slop out of the bolt.
Ray
I've used that fix but I drill and tap the notch in the receiver. It doesn't weaken the bolt handle, it can be adjusted for different bolts, and if you want to remove it you can fill the hole with a plug screw.
I've seen some with a leather pad glued in the notch also. I suppose you could argue that a "soft" stop is better. Or you could argue that it is worse.
If you drill the bottom of the bolt plug (both sides of the sear) install two nylon plugs, and fit them to the receiver it helps by taking all of the slop out of the bolt.
Ray
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Ray:
What I've done for now is just glue some moleskin in the notch.
This actually seems to be working well, atl east as far as bolt movement.
I'll try shooting it like this before I decide whether to do more.
The rifle has a 28 inch medium Palma taper berrel on it.
I'm beginnning to think I may actually be better off if I cut it back to 26inches. I have this sense that for some reason there is too much vibration going on for the accuracy I desire.
James
What I've done for now is just glue some moleskin in the notch.
This actually seems to be working well, atl east as far as bolt movement.
I'll try shooting it like this before I decide whether to do more.
The rifle has a 28 inch medium Palma taper berrel on it.
I'm beginnning to think I may actually be better off if I cut it back to 26inches. I have this sense that for some reason there is too much vibration going on for the accuracy I desire.
James
I have been trying to envision what would cause the bolt handle to rotate when dropping the striker. Does it do it when actually firing a cartridge? Does it do it when dry firing ?
I wonder if it could be from too much clearance between the rear receiver ring and the bolt body. With the bolt closed, ready to fire, the action of the trigger will force the bolt body upward. When the striker is released the bolt would fall back down to the bottom of it's bore. This could cause the bolt handle to rotate upward.
I wonder if it could be from too much clearance between the rear receiver ring and the bolt body. With the bolt closed, ready to fire, the action of the trigger will force the bolt body upward. When the striker is released the bolt would fall back down to the bottom of it's bore. This could cause the bolt handle to rotate upward.
R
relodr36
Guest
Roy Dunlap,in his classic book on Gunsmithing,addressed "bolt jump" in military sporters.
I can't get at my copy right now,but you might want to check what he said about it.
You're right,it's not good.
I can't get at my copy right now,but you might want to check what he said about it.
You're right,it's not good.