Bolt timing help please

[jsthntn247]

I started a thread on here two weeks ago and y'all were very helpful in helping me figure out my issues. Seems I had 2 things wrong with my newly chambered 700. The chamber was a little ruff in the back and I now know I am out of time. I polished the chamber and no longer am getting marks on the brass. I am however still getting clicks at the top of bolt lift, but only when my loads start getting up to full pressure. I have .025 gap from the action face to the bolt so how far forward does it need to be moved?
Here is a pice of the cam ramp on action. You can see how far back the handle hits

This is the gap from the action to the bolt

This is a pic of gap behind the bolt

 

[eww1350]

When you state that you are getting a click at the top of your bolt lift...does this also happen with factory loads..???...try a variety of factory loads and if you do not get the click...you need to take a close look at your handloading and components...

 

[jsthntn247]

I haven't bought a factory shell in 5 years. The problem is not pressure, the primers are round and not even getting ejector swipes yet. I'm still running velocities in the upper 30-06 range.

 

[STS]

In your previous thread you said you thought you had .011 clearance. If you truly have .025 clearance, and it looks like that is quite possible from your pictures, that is way too much clearance. If you will have it moved forward to a clearance of .005 and timed correctly it will extract properly. It would seem that your action and bolt were trued resulting in a substantial loss in primary extraction. It's important to remember that the truing process moves the bolt to the rear with every step. Truing the bolt face moves the extraction groove in the case further away from the extractor resulting in less extraction ability. Get in touch with Dan at AccuTig. Edit to say that the clearance behind the bolt handle is meaningless.

 

[jsthntn247]

Thanks Sts, it was your comments that made me take a closer look today at the range and really figure out what was going on. My main concern is getting Dan to move the handle too far forward if my calculations are incorrect, which would cause all sorts of problems.

 

[STS]

He will have you make note of the measurements that we have been talking about and send them along with the bolt. From those measurements the bolt handle can be set in the correct position. It is critical that you get the correct measurements. From looking at your pictures I believe your measurement of .025 is the right one but you need to make absolutely sure. Check it several times between the front of the bolt handle and the rear bridge of the receiver with a feeler gauge. The gap in your second picture is what you are trying to measure not the gap between the rear of the bolt handle and the shroud. From looking at your first picture, you have almost no primary extraction and it's not surprising that you are having issues.

 

[Dans40X]

P.M. sent to OP w/ instructions.

 

[STS]

The man has arrived to save the day. Thanks for jumping in Dan.

 

[Rustystud]

I am sure Dan is going to elaborate on bolt timing in his p.m.
There are are multiple functions going on when a bolt is being closed or opened.
There are relationships of multiple metal surfaces also. Here are several to think about:
1. Where is the cocking piece in relationship with the cocking ramp when the action is in battery.
2. Where is the bolt handle strap located in relationship the primary extraction ramp on the back of the action.
3. Where is the end of the bolt strap in relationship to the left side lower bolt race.
4. Where the bolt handle is in relationship to the action when in battery.

I prefer the back straight edge of the cocking ramp on the bolt body be perfectly parallel with the cut in the action for the sear. I prefer there be .008-.014" of clearance between the front of the bolt handle and action. I prefer the bolt to come out off battery and engage the primary extraction at the same instant. I want the back of the bolt strap to stop the bolt rotation before the bolt handle hits the action. Let me say Dan does a wonderful job of getting this right before Tig welding the handles on.

Looking at the photographs previously posted one can see the contact point of the bolt strap and the primary extraction caming surface is at the very back of the surface. With a little more wear there will be no primary extraction. I would recomend moving the bolt handle forward to regain that primary extraction.
Nat Lambeth

 

[jsthntn247]

Thanks for the reply's fellas. I just packed the bolt up and sent it to Dan. With the firing pin in I got a measurement of .025 with it out .019. Is there a rule of measurement that you get x amount of primary extraction for every .001 the handle is moved forward?

 

[clowdis]

Do you think that .020 more primary extraction is going to solve your "clicking" problem at maximum bolt lift? Often the click is caused by the handle slamming against the receiver after a difficult extraction, mostly caused by sticky brass or less than smooth cocking ramp. While you're having your handle moved forward .020 take another look at the chamber and have Dan polish the cocking ramp while he has the bolt.

 

[STS]

There's more to it than just .020 forward placement of the bolt handle. That .020 has to be timed correctly to take full advantage of the extraction cam. Part of what will happen to this bolt is the timing will be modified by moving the handle to the right rotational position. Those two things combined will increase the total PE.

 

[Dans40X]

Not my first Rodeo!

Issues-
The bolt handle's drafted extraction cam surface is not matched to the receiver surface resulting in a small radius mark to the RH side of the receiver extraction cam surface.(blend it out w/ a needle file)

Also,upon pushing the bolt fwd the LH side of the receiver cam surface puts a ding/divit into the handles extraction cam surface to the extent of pushing up a burr.
Hence the proverbial "CLICK".

OEM Rem handles of "D"prefix serial numbered receivers to present G & RRXXXXXA are not tempered.
OEM Rem 1/2/3 SG bolt handle of current production have cured the proverbial "CLICKING"as the handles extraction cam surface is not drafted & the 35deg angle is steeper not matching the receiver w/in a row of ass-holes.

All,w/ the exception of 2 custom action manufacturers,the bolts/handles are TIMED into battery & NOT primary extraction.

 

[butchlambert]

Listen to Dan! He has been doing this for years. He has fixed several for me.