Getting ready to cut my first Remington 700 breech. Check numbers please...

[Sniperhandle]

I feel there's an error with this statement.

You must not know Dave Tooley?

 

[Taylorbok]

Making the tenon 0.010" shorter than the HS does several things. One- the HS gage protrudes from the tenon allowing one measurement with a depth mic to measure HS. Second- It makes machining the counterbore much easier. As I said , touch, set travel indicator, using the number for the bolt fact to the nose, cut the CB. I open the diameter up some and take one measurement in the whole operation of machining the CB.

I think my confusion is I'm thinking of the cartridge HS and you are (maybe) referring to the action HS, (lugs to action face+ lug). Check my work?

You must not know Dave Tooley?

I don't, and I'm new here but I've learned he's very knowledgeable and helpful...
unlike your comment.

I wasn't meaning to call him out or wrong, I'm trying to understand. I may have not articulated that well

 

[DaveTooley]

No problem here. I'm still learning stuff. The first 10 years I complicated the hell out of everything. The next 10 figuring out what was important and the last 20 making money.
No the action HS is the same number as the barrel. I am not concerned in the least about the clearance between the bolt lugs and the tenon just as long as they don't touch. You can remove the CB and it would function just fine. Oh the last thing you want is the bolt nose to touch anywhere. I like 10 thou end play and at least 10 thou a side on the CB diameter. 20+ with magnum M16 or Sako extractors.

 

[ELR LVR]

I am not concerned in the least about the clearance between the bolt lugs and the tenon just as long as they don't touch. You can remove the CB and it would function just fine.

Exactly

 

[Greg Y]

We're all fortunate to have as much knowledge at our fingertips as we do today. It wasn't that long ago that much of what we do was holed up in the shops of very few and to get them to share was a balance of luck and timing.

 

[DaveTooley]

I think my confusion is I'm thinking of the cartridge HS and you are (maybe) referring to the action HS, (lugs to action face+ lug). Check my work?
View attachment 1736960


I don't, and I'm new here but I've learned he's very knowledgeable and helpful...
unlike your comment.

I wasn't meaning to call him out or wrong, I'm trying to understand. I may have not articulated that well

Going by your numbers
HS is .956"
Bolt nose depth .145"

I would make the tenon .946" gage would protrude 0.010"
To cut the barrel CB touch and go .145" deep X .725" diameter
And those numbers don't have to be exact. +/- 0.002" works just fine
Make the tread fit on the loose side so the shoulders square up
Ream chamber to depth .956". I have never had to allow anything for crush.
A light polish and you're done

 

[Taylorbok]

Going by your numbers
HS is .956"
Bolt nose depth .145"

I would make the tenon .946" gage would protrude 0.010"
To cut the barrel CB touch and go .145" deep X .725" diameter
And those numbers don't have to be exact. +/- 0.002" works just fine
Make the tread fit on the loose side so the shoulders square up
Ream chamber to depth .956". I have never had to allow anything for crush.
A light polish and you're done

.716 lug depth + .250 lug = .966 - .010 (clearance)= .956
but based on the rest of my math that leaves the gauge only .001 out, which is a bit tough to measure.

If I knock it back another 10 thou, to 946 that would leave the gauge .010" out then only cut the recess .144

Or maybe I missed something?

Or make it flat faced at .802 the the gauge sticks out .155?

 

[linebaugh]

I don't see why those numbers would work. When I did things on a manual machine I developed this process which eliminates some of the mental math.
HS minus 0.010" = tenon length I like the HS gage extending beyond the tenon if using a depth mic.
Counterbore depth equaled the distance from the bolt face to the end of the bolt nose. With the tenon being 0.010" short all I had to do is touch the barrel with my boring bar, set the travel indicator to the my bolt face depth number and go to zero. That automatically gave 0.010" end clearance. In my barrel log books there are only 4 numbers; HS, tenon length, CB depth and thread specs if not standard.

I still work similarly. Manual with no DRO. Hitting numbers is not a big deal

 

[DaveTooley]

.716 lug depth + .250 lug = .966 - .010 (clearance)= .956
but based on the rest of my math that leaves the gauge only .001 out, which is a bit tough to measure.

If I knock it back another 10 thou, to 946 that would leave the gauge .010" out then only cut the recess .144

Or maybe I missed something?

Or make it flat faced at .802 the the gauge sticks out .155?

.716 lug depth + .250 lug = .966 - .010 (clearance)= .956
but based on the rest of my math that leaves the gauge only .001 out, which is a bit tough to measure.

If I knock it back another 10 thou, to 946 that would leave the gauge .010" out then only cut the recess .144

Or maybe I missed something?

Or make it flat faced at .802 the the gauge sticks out .155?

The lug depth means nothing. I have never seen the lugs extend beyond the bolt face.
Don't delete the CB
.250( recoil lug)+ .707 ( action face to bolt face) = HS .957" I used your number of .956" before as the HS number. That's the trouble with too many meaningless numbers.
tenon length would be .947"
CB depth would be .145"

Turn your tenon diameter 0.010" under. That leaves a small flat on top of the tread that you can use as a visual indicator to know when to measure/check the thread fit.

 

[WSnyder]

but based on the rest of my math that leaves the gauge only .001 out, which is a bit tough to measure.

Measure to the shoulder not to the end of the tenon when the gage is proud of the end of tenon. You gain stability with the side of the spindle resting on/next to the threads. That or build yourself a headspace measuring gizzie. There are many threads devoted to the various styles.

A few examples here and many more if you search:

Thread 'Chambering Benchrest Barrels'

Sep 20, 2024

I shoot short range benchrest and do my own work. One thing that’s new to me, is doing prefit barrels based off of a barrel that was originally fit to the action. One of the things I struggle with is getting the cone depth correct. I made a little cone shaped tool, but it rocks around too much in the cone.

How do you guys measure the cone?

Also, how do you guys measure the headspace? I plan to make a tool that shoulders on the barrel, and has either a micrometer head on it, or a digital plunge indicator so I can zero it out on the old barrel to match headspace.

I’m sure I’ll think of...

• Jud96
• Replies: 21
• Forum: Advanced Gunsmithing & Engineering

• 

 

[Taylorbok]

The lug depth means nothing. I have never seen the lugs extend beyond the bolt face.
Don't delete the CB
.250( recoil lug)+ .707 ( action face to bolt face) = HS .957" I used your number of .956" before as the HS number. That's the trouble with too many meaningless numbers.
tenon length would be .947"
CB depth would be .145"

Turn your tenon diameter 0.010" under. That leaves a small flat on top of the tread that you can use as a visual indicator to know when to measure/check the thread fit.

OK got it now.

Ya the lugs are back from the BF .009, you are correct that number has no bearing on the HS, just need clearance from there so you don't run the lugs into the barrel, I was getting caught up on that for some reason

Thanks for taking the time.

 

[Carl S]

Cutting counter bores and threads on the tight side,does nothing for accuracy.a build up of crud.bronze brush brisels and anything else that can get in there and a little stretch on the tennon thread's tightens the clearance up more.bad cleaning practices and the bolt nose can be touching.action-recoil lug faces will lock up square if the thread's are not tight.Dave Tooleys method works and it's simple.

.

 

[ELR LVR]

and the bolt nose can be touching.action-recoil lug faces will lock up square

.

This is the reason why i give a little extra tolerance in those areas
if anything gets in between a .005 -.010" clearance - you get resistane on closing
which could be also falsley identified as tight headspace, which its not

 

[tobnpr]

Started with this from Brownells 10 years ago and still do it the same way.
I'm sure there's an easier way, but it works for me.



A mike that measures gage protrusion from the shoulder makes it easy-peasy as WSnyder said.

 

[LVLAaron]

Dave's math works. When I got started I looked up all of these worksheets and tried to use them. They're too complicated. It's basic machine work and is only a couple of measurements to hit, that frankly aren't that critical, considering we commonly talk in tenths.

Don't overcomplicate it.

Think through how everything works together. Eventually it'll "click" and you'll never fill out a worksheet again, and just get to work.

 

[Taylorbok]

Dave's math works. When I got started I looked up all of these worksheets and tried to use them. They're too complicated. It's basic machine work and is only a couple of measurements to hit, that frankly aren't that critical, considering we commonly talk in tenths.

Don't overcomplicate it.

Think through how everything works together. Eventually it'll "click" and you'll never fill out a worksheet again, and just get to work.

Ya I’m not sure why I was stuck on the distance to the lugs. I’ve got it figured out now.

Right now I like the idea of the work sheet just so a guy doesn’t make a stupid mistake but maybe that will change as I gain experience.

 

[WSnyder]

Ya I’m not sure why I was stuck on the distance to the lugs. I’ve got it figured out now.

Right now I like the idea of the work sheet just so a guy doesn’t make a stupid mistake but maybe that will change as I gain experience.

A plus for some sort of worksheet is you now have the dimensions for that action and will never have to measure it for a barrel ever again.

If you buy or make tools like these you can document the barrel or muzzle tenon and you can index and or engrave a barrel without the action or muzzle device in hand. I've bugged him for an 18TPI and a .010" over 16TPI but he hasn't got around to it.

Products - Gunsmithing Tools - Piercision Rifles

www.piercisionrifles.com

 

[Taylorbok]

A plus for some sort of worksheet is you now have the dimensions for that action and will never have to measure it for a barrel ever again.

If you buy or make tools like these you can document the barrel or muzzle tenon and you can index and or engrave a barrel without the action or muzzle device in hand. I've bugged him for an 18TPI and a .010" over 16TPI but he hasn't got around to it.

Products - Gunsmithing Tools - Piercision Rifles

www.piercisionrifles.com

That's a super good point. I did see some of those excel files which would make it easy to save on a computer for future reference. I'm getting a bit ahead of my self there I think, walk before I run.

That Timing tool wouldn't be hard to make your own, I'd have to hand stamp it so wouldn't be as nice but functional none the less.

apologies to @tonyben for completely hi-jacking the thread.

 

[tonyben]

After reviewing all the input from everyone, how about this for some final numbers:

Headspace location from shoulder: 0.957"
Tenon length: 0.947"
Headspace gauge protrusion past tenon: 0.010"
Bolt nose to counterbore clearance: 0.018"

Tony.

 

[tonyben]

That's a super good point. I did see some of those excel files which would make it easy to save on a computer for future reference. I'm getting a bit ahead of my self there I think, walk before I run.

That Timing tool wouldn't be hard to make your own, I'd have to hand stamp it so wouldn't be as nice but functional none the less.

apologies to @tonyben for completely hi-jacking the thread.

No worries! We're here to learn. Thanks for participating!

Tony.