Primary extraction and bolt timing

M

Mike A

Member
I am about to rebuild my old 708 into a lightweight 6.5 Lapua.
This old 700 has done a fair bit of work and could do with a bit of a tune up.
The gun has basically no primary extraction and I plan on building up the camming surface on the bolt handle with a bit of TIG hardfacing and dressing it back to suit.
Has anyone done this or do you have any ideas on the subject?
See the photos below.
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The abutment on the bolt handle shows considerable deformation, and looks to be only contacting the corresponding area on the receiver with a very limited surface area.
No such deformation is evident in the action.
I would be quite confident to remove the bolt handle and silver solder it a bit further forward, but I feel that this issue would be better solved by building up the surface area of the contact point, what do you think?
It also appears that the steel in the receiver may be a lot harder than that on the bolt abutment as there is no visible wear in this area.


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I guess all you blokes are all out hunting.
Any thoughts on the viability of advancing the angled shoulder on the bolt parallel about 25 thou to get a bit of primary extraction, I am pretty sure the locking lugs would have cleared by then.
 
Well for a very quick fix, and not on anyone's gun but my own, I did once put a dollop of MIG weld on the corner of the bolt handle to increase the engagement of primary extraction. It was one of those where you had to slap the dang bolt handle up in order for it to pop it open, sometimes twice or more... I added the metal, and polished it up a bit to match the angle on the receiver and it did work. I didn't like it much thought and later replaced it with a Holland's replacement handle located properly, maybe .020" forward of the old bolt handle's location.
 
It looks like about typical Remington extraction camming to me. But, with the wear on the bolt handle camming surface, I'd just replace the bolt handle with a new one getting it as close as possible to the front of the bolt handle cutout and still get smooth bolt action. FWIW, when I silver braze on a new bolt handle on a Remington, I use Silvaloy 355 silver solder and Ultralux flux from Brownell's. Whether you can get it in Australia or not, I don't know. I wouldn't hurt to build up the worn surface on the bolt handle cam instead, just don't get the bolt handle hot enough to release the silver braze or you'll be reattaching the handle anyway.
 
Take a clearance measurement w/ feeler/thickness gauge between fwd surface of handle & rear receiver ring w/ firing pin assy removed.
Take measurement from aft end of both bolt lugs to handle for LOCATION(fwd/aft) purposes.
Remove handle by inducing harmonics w/ dead blow hammer.
Remove silver braze by hand from bolt body & handle.
Build up handle extraction cam surface by TIG welding & peening to work harden & blend to match receiver cam surface.

Depending on receiver serial number prefix letter &/or handle vintage-

Grind approximately .060"/1.5mm off the end of the finger strap of the bolt handle to facilitate proper TIMING(CCW rotation).
Grind 45deg fillet weld relief in end of handle finger strap for TIG fillet weld.
LOCATE handle onto bolt body w/ .006-.008" clearance between fwd surface of handle & rear receiver ring.
A modified 1" parallel clamp to clamp handle to body will allow bolt/handle LOCATION/TIMING function check.
Confirm extraction TIMING(radially) of handle cam surface w/ integral lugs in fwd receiver ring.
Tac weld handle to bolt body on aft end by fusion TIG welding.
Confirm that LOCATION & TIMING of handle is correct.
Insert heat sink/purge device into aft end of bolt.
Fillet TIG weld 45degree relief of finger strap & underside of handle.
Remove copper plating from filler prior to TIG welding for proper COLOR match if bluing after task.
Fusion weld aft end to HIDE 2 tac welds.
Blend weld @ finger strap & underside to TIME bolt/handle into BATTERY.

Approximately 10minutes from start to finish
(after you've accomplished the task several thousand times)
 
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Take a clearance measurement w/ feeler/thickness gauge between fwd surface of handle & rear receiver ring w/ firing pin assy removed.
Click to expand...

And BTW, do this all along the receiver ring, esp. just before the cam on the receiver ring, not just where the bolt is fully closed. Voice of experience.
 
Thanks very much for all the replies
The timing on this action. (C series ) is very good and there is only .009 clearance between the forward face of the bolt handle and the corresponding surface on the reciever.
I reshaped the existing handle and am too fond of it to change it out to a Holland, which are a nice handle but too long for a hunting gun.
I will have a go at building it up a bit and see how it goes.
 
I have just had a bit more time to read the replies on the computer, rather than the phone and would like to add a bit more.
Dans40X thank you for that informative and helpful reply to my post
I really appreciate it that you took the time to share your knowledge
I am a total ametur at TIG welding, reattaching a bolt handle would be beyond me, but I reckon I could add on a bit of a lump to the cam surface.
30 years ago when I left school my first job was silver soldering diamond segments on to concrete cutting wheels, I got to be pretty good at it.
 
For a small fee Dan will convert your Remington to a BMW.
Nat Lambeth

Dans40X said:
Take a clearance measurement w/ feeler/thickness gauge between fwd surface of handle & rear receiver ring w/ firing pin assy removed.
Take measurement from aft end of both bolt lugs to handle for LOCATION(fwd/aft) purposes.
Remove handle by inducing harmonics w/ dead blow hammer.
Remove silver braze by hand from bolt body & handle.
Build up handle extraction cam surface by TIG welding & peening to work harden & blend to match receiver cam surface.

Depending on receiver serial number prefix letter &/or handle vintage-

Grind approximately .060"/1.5mm off the end of the finger strap of the bolt handle to facilitate proper TIMING(CCW rotation).
Grind 45deg fillet weld relief in end of handle finger strap for TIG fillet weld.
LOCATE handle onto bolt body w/ .006-.008" clearance between fwd surface of handle & rear receiver ring.
A modified 1" parallel clamp to clamp handle to body will allow bolt/handle LOCATION/TIMING function check.
Confirm extraction TIMING(radially) of handle cam surface w/ integral lugs in fwd receiver ring.
Tac weld handle to bolt body on aft end by fusion TIG welding.
Confirm that LOCATION & TIMING of handle is correct.
Insert heat sink/purge device into aft end of bolt.
Fillet TIG weld 45degree relief of finger strap & underside of handle.
Remove copper plating from filler prior to TIG welding for proper COLOR match if bluing after task.
Fusion weld aft end to HIDE 2 tac welds.
Blend weld @ finger strap & underside to TIME bolt/handle into BATTERY.

Approximately 10minutes from start to finish
(after you've accomplished the task several thousand times)
Click to expand...
 
This is mostly OT but I recently bought a Walther KK200 22lr match rifle and the action has NO primary extraction . Zero. Works just fine.:confused::cool:
 
Mike A said:
Thanks very much for all the replies
The timing on this action. (C series ) is very good and there is only .009 clearance between the forward face of the bolt handle and the corresponding surface on the reciever.
I reshaped the existing handle and am too fond of it to change it out to a Holland, which are a nice handle but too long for a hunting gun.
I will have a go at building it up a bit and see how it goes.
Click to expand...

Mike,
The bolt handle should be removed before welding on the camming surface. You can't do a good job welding it on the bolt, the solder will probably just melt and the bolt will fall off and you'll have to re-solder it anyway.
 
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