I will start like this.
All the bolt lift I am talking about below is while cocking the firing pin.
I have an existing long flat back action with a lift ball bearing and works very smooth. Probably average lift.
This action was originally a 300 WM CF action.
New (to me) old long flat back action - stock. Very rough very hard lift and jumpy.
This is a bolt with the BAS that extends into the cocking piece sleeve.
This action was originally a 7mm RM push feed action.
Both bolts and firing pin assemblies are identical except the BAS.
After inspecting the rough lift bolt the cock pin ramp was very rough. Looks like it had been filed or just an extremely bad machine job.
Disassembled the bolt and ground and polished the ramp. Luckily that part worked out fine.
Polished all the other surfaces I thought needed it, cleaned, lubed etc.
Better but still a heavy bolt lift, but now smooth on the ramp.
At this point it is still probably about 1.5X what my other good bolt is with the lift kit.
While cocking the stiff bolt, Listening I hear the spring popping inside like it is binding.
My existing good bolt does not do this.
I tried swapping this and that to no avail, and finally swapped the firing pin assemblies and cocking piece sleeve.
Now my good bolt with the lift kit is stiffer (guessing most likely from the other firing pin assembly) and my new bolt that was originally very stiff and rough has a slightly less lift than the other.
Any help appreciated.
It all depends on where it is stiff or difficult to operate. It sounds like you have a spring preload issue or a bind. Verify the protrusion then adjust the cocking pin to where it is off the base of the cam slot in the bolt body by about .060. Try again. Aso try lubing it up with a good medium weight gun oil. I wonder if someone put it back together without making the proper adjustments.
I guess Primary extraction could be another issue.
There is no telling.
This action was full of grungy black gunk, the cocking ramp was rough and it was full of some sort of grease.
The exterior of the action was spotless - LOL.
I have never taken a firing pin assembly apart, so not really sure how they are supposed to be set up.
LOL - the length of the two firing pin assemblies are about 1/8" difference. That explains it.
What is the correct length/dimension to set the assembly ??
Thank for the help.
Never mind I found it.
Both of my bolts are off, but the bad one had about .1" clearance.
the sleeve has to rotate around the nub on the BAS.
You set them up to for the parts you have, not a set length. I'll do my best to explain it.Originally Posted by tammons
My world famous picture for reference...
First, you set the firing protrusion. I recommend .030"-.040" or as close at the lock washer will allow, but closer to 30 is better than 40.
Second, install the bolt head w/retaining pin then insert it firing pin assembly without the cocking piece sleeve so the firing pin adjustment nut seats on the bolt head shaft.
Third is a try-adjust procedure. With the firing pin nut bottomed out on the bolt head shaft adjust the cocking piece so the cocking piece pin has about 1/16" clearance at the BOTTOM of the cocking ramp.( uncocked position). You may feel or see a bit of play side to side between the pin and the bottom of the ramp. Ignore it.
Resemble the pin assembly with the sleeve installed. you may have to turn the cocking piece to align the cocking piece pin, the lock washed and sleeve. If you do adjust the cocking piece OUT further.
When the bolt is together, in the rifle and in the fired position you should may notice just little free play lifting the bolt. It only the clearance being taken up between the cocking piece pin and cocking ramp as the bolt body is rotated.
Now the pin assembly is adjusted to it's correct length.
Clear a mud ????
Bill
Simple enough.
Got it working correctly now and I learned something new.
Thanks
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