If I read your post properly, the issue is at the top of the bolt open cycle. Frequently this issue is caused by the rear primary extraction ramp trying to move the bolt rearward before the bolt head lugs are clearing the abutments. So it's a timing issue. To isolate this issue, it is best to remove the cocking pin from the firing pin assy. This eliminates the feel of the cocking pin dropping into the cocking pin notch, another possible issue to iron out.Originally Posted by Larrykwebb
To check for this, slowly move the bolt handle upwards until you feel the resistance you describe. Now look at the rear baffle where the bolt handle has a ramp that engages a similar ramp on the rear baffle. If the baffle is tight against the rear of the action well before the bolt handle nears the fully up position, it may be hitting the extraction ramp too soon. Removing some material from the ramp on the bolt handle or the rear baffle can help.
To discover the exact bolt handle position where the bolt head is clear of the abutments, remove the bolt from the action, grab the rear baffle and rotate it so the ball detent is out of its track, rotating towards the cocking ramp opening in the the bolt body. Slide the baffle over the opening and remove. When ready to replace do the opposite.
With the rear baffle off, re-insert the bolt into the action and close the bolt. Now open while exerting a slight rearward pressure. Note the angle of the handle when the bolt slips rearward. There is a small ramp on the bolt abutments inside the action that you can't see without removing the barrel. You'll feel these as you rotate the bolt while pulling backwards. The bolt head lugs should be "on the ramp" as the rear baffle primary extraction ramps engage each other.
Another possible case of hard opening is the cocking pin notch. If in checking the bolt timing per above you find a smooth opening, and that it's not the issue causing hard bolt life, disassemble the bolt to its major components.
Look closely at the cocking ramp where it transitions to a notch. Frequently there is a burr on the inside bore on the point of the transistion. Smoothing this burr off helps the cocking pin round that corner and drop into the notch. Slightly rounding that corner also helps, but don't overdo it.
Once you're this deep into the bolt, you'll begin to understand how the bolt works and where some polishing and lubrication can help. As others have mentioned, polishing the cocking pin ramp is helpful as well as lubrication. Installing a bolt lift kit reduces bolt lift, as well as perfecting the bolt timing as described above, and polishing the firing pin threads and inside of the cocking sleeve. Note: when replacing the sleeve, you'll have to adjust the rear nut to get the hole to align perfectly with the sleeve. Be sure to take note of the star washer that engages the sleeve. There is a flat on that washer that slides along the firing pin, it will will tend to hang up on the firing pin threads unless its properly centered. With a little fussing and you'll get it centered.
Once you've accomplished all these actions, a smooth, single finger bolt lift is obtainable.
Be sure to write back if you encounter any problems performing these repairs/modifications.
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