Gunsmithing truing bolt

[skog]

when truing a bolt is the labounty fixture worth the money? I tried searching but didnt find much. I see some people using a modified gre tan action jig. I see some using a spud in the back and a steady rest. Dont have steady rest so that is out. Just curious.

thanks
skog

 

[wnroscoe]

Re: truing bolt

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: skog</div><div class="ubbcode-body">when truing a bolt is the labounty fixture worth the money? I tried searching but didnt find much. I see some people using a modified gre tan action jig. I see some using a spud in the back and a steady rest. Dont have steady rest so that is out. Just curious.

thanks
skog </div></div>

There's really no way to dial in a bolt using the Labounty Fixture. A stud in the rear with a cat head in the front and steady rest is one way, there's also a fixture that is a modified receiver truing fixture that can be used to hold the bolt. The idea is to have the bolt body running true prior to making any cuts.

 

[skog]

Re: truing bolt

is there enough distance between the front of a action jig holding a bolt to the front of the bolt to make sure you eliminate run out. That is worded weird, does that make sense? Are the tolerences bad on the labounty fixture as in it does not hold the bolt true or is it usually the bolt tolerances that make the need for more adjustment by using a action fixture? both? Or is it why make/buy a additional piece of tooling when what you have works? Are the bolt bodies usually true enough to indicate off the body and the firing pin hole when using the action jig?

thanks for helping out the new guy
skog

 

[300sniper]

Re: truing bolt

this is what i came up with to true the bolt in a single setup. i modified my action truing jig with a slot for the bolt handle to fit though. a stub screws into the rear of the bolt and the rear set of adjusting screws hold there. the front set of screws holds the bolt body.

 

[Jkob60]

Re: truing bolt

So...how do you line up the rear of the bolt? Surely you don't believe the 1/2" threads in the back of the bolt are concentric with the OD.

 

[eddybo]

Re: truing bolt

I am guessing he indicates them in as far forward and as far to the rear on the bolt body as he can. Seems like if it is indicated in in the front and as far back as he can go that unless the bolt is bent it should be close enough.

 

[300sniper]

Re: truing bolt

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: eddybo</div><div class="ubbcode-body">I am guessing he indicates them in as far forward and as far to the rear on the bolt body as he can. Seems like if it is indicated in in the front and as far back as he can go that unless the bolt is bent it should be close enough. </div></div>

exactly. getting it to within a tenth in a couple spots is close enough for me. especially when you consider there is a few thousandts clearance between the bolt body and the receiver raceway. if the bolt is bent, you are going to have problems no matter how you choose to hold it.


screwing the stud into the back of the bolt just gave my existing receiver truing jig screws something to hold onto. it could have a bunch of runout and wouldn't make a bit of difference on how i indicate the bolt body.

 

[skog]

Re: truing bolt

cool, that is what I wanted to know. so would it be safe to say that indicating where the indicator is in the pic and the the firing pin hole would be the belt place to measure to eliminate wobble?

skog

 

[300sniper]

Re: truing bolt

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: skog</div><div class="ubbcode-body">cool, that is what I wanted to know. so would it be safe to say that indicating where the indicator is in the pic and the the firing pin hole would be the belt place to measure to eliminate wobble?

skog </div></div>

i wouldn't rely on the firing pin hole being concentric with the bolt body. i indicated the bolt body as far back as i could and just behind the bolt head connection. the spots i indicated were probably only an inch to an inch and a half apart but i got it to better than a tenth at each spot.