Bad Bolt set up 2

We encountered some more problems after machining the bolt handle off and installing the new Kiff bolt we found that the lugs were lapped at a angle and that we were loosing cam as we rotated the bolt. So, we decided to go back in and re-cut the integral lugs and true the bolt lugs.

Category:

Howto & Style

Tags:

• Bolt
• truing
• rifle
• bolt
• problems
• timing

[AkGrayWolf]

Thank you for your videos on printing and timing the receiver.I have a post-64 Mod 70 375 H&H that the rear of the bolt is partially separated (.002 crack) just in front of the bolt handle (I'm guessing it is made in 2 pieces) and I wanted to understand what would be involved in replacing with a new bolt.The old bolt does not close on a Forster Go-Gauge and the new bolt I bought from Numrich closes less than halfway on an empty chamber.I was going to check the new bolt after removing barrel next

[sgr218]

@AkGrayWolf

You have to understand that each bolt would have to be head spaced with the barrel you have. Sometimes one can remove metal from the back side of the bolt lugs and sometimes you can't and have to either set the barrel back and re-chamber to get the correct headspace. My advice is to get the problem corrected before you shoot it.

[sgr218]

Sir,

no welding is done on the lug area ever. These are hardened. What I do is set back the barrel . The thread pitch on a 700 is 1-16 so every complete turn is .0625 thousands. I set it back that amount and open up the chamber to the correct headspace and the sights are back in the correct position.

SGR

[jhunted7667]

@sgr218  that means if you have a fixed front sight you have to rotate the front sight the corrosponding radial distance to keep the front sight center straight , other wise you have to go exactly one turn , thats touch , alot of fitting and refitting to get it perfect

[sgr218]

@jhunted7667

Normally when you print the receiver and bolt you do it b/4 you install a new barrel. If your not going to install a new barrel then you have to set the barrel back one or more rounds and open up the chamber to the correct length.

SGR

[jhunted7667]

@sgr218 what do you do about the head space between the round and the bolt face don't you end up with a space between the bolt face the barrel

[sgr218]

@jhunted7667

No Welding is done on the lugs......I only remove .001 to .002 off the bolt lugs...... this sets the bolt back that amount and you have to re-move the bolt handle and re-time it so you do not loose all your cam.... nothing more to it. Plain and simple.

[jhunted7667]

@sgr218 did you build up the bolt with weld then machine it down , with all the machining down without building up the loss would not the bolt play between the bolt lug and the reciever hand the round have dangerous play , but if you bulit up the bolt with weld and machined it down , welding weakens the steel around the weld that would be dangerous too right , what do you do to take up the play is what I'm trying to say and stilll have the gun safe to shoot

[sgr218]

@jhunted7667

The bolt was put into a jig and when both ends of the bolt body ran true I cleaned up the back side of the lugs, the bolt face and the front side of the lugs.  Removing as little metal as possible.

[sgr218]

@jhunted7667

The bolt was put into a jig and when both ends of the bolt body ran true I cleaned up the back side of the lugs, the bolt face and the front side of the lugs. Removing as little metal as possible.