I am about to rebarrel a REM 700 action, I will be shooting long range varmints with it.
Is it worth blueprinting the action, or should I have the action face squared and the lugs lapped?
I am about to rebarrel a REM 700 action, I will be shooting long range varmints with it.
Is it worth blueprinting the action,
Not IMHO..
or should I have the action face squared and the lugs lapped?
The receiver should always have a new face cut on an unmodified factory unit and I've found that about 90% of the time the bolt lugs should indeed be lapped.
FWIW.. YMMV..
Lee,
How do you set up in the lathe to cut the action face?
Not to outdo Redneck, but I mount the receiver on a mandrel.
Not to outdo Redneck, but I mount the receiver on a mandrel.
Do you lock it onto the mandrel or use a dog to drive it?
Not to outdo Redneck, but I mount the receiver on a mandrel.
How is the mandrel "centered up" in the receiver? Split bushings or the like?
A SPIDER is a better option for single point truing a receiver.
Lapping is to burnish & not for material removal.
If your 'smith insists on lapping lugs,seek another 'smith.
Lapping is to burnish & not for material removal.
??
Lapping and burnishing are two different things. Lapping removes a small amount of material with abrasive to fit parts together, in this case to provide even bolt contact. Material removal has to happen to achieve that if contact is uneven. Burnishing is just an action of smoothing off the high spots in the surface finish with no abrasive involved.
Against my better judgement I’ll share what I do. The front ring is held in a fixture and I use straight mandrels in .0005” increments to indicate the centerline of the action that the bolt sees. I have used the Gretan mandrel and bushing methods but could never get repeatable indicating results that I was satisfied with, meaning I need to be able to strip it down and reindicate with the same result. I don’t like to remove metal unless I know it’s as perfect as I can get. I have never had an original thought and I give credit to Alex Wheeler for this method. Others might also do this, not sure. I have never tried the hand tools that are available. I get a very nice finish, lapping actually makes it look worse and is not something I do unless specifically directed to. When done the rear of the bolt needs to float with the lugs in contact.
Shooter71, that sounds like a really good method. Do you mind describing your fixture to hold the receiver? Is it something like a cat head mounted in the lathe chuck, or ?
Shooter71,
'Smiths have been indicating receivers before A.Wheeler came into this world.
And have forgotten more than he'll ever know!
If lapping lugs is required,that tells me the 'smith wasn't quite sure of his set-up.
Here's a Remington I just tore down next to one I just cut. You can see there is a lot of room for improvement.
For me, the time is in getting squared up in the lathe. Once it's dialed....it's an extra 15 minute to single point recut the threads....seems like a no brainer.
Here's a Remington I just tore down next to one I just cut. You can see there is a lot of room for improvement.
Like night vs. day. Thanks for the visual.
Here's a Remington I just tore down next to one I just cut. You can see there is a lot of room for improvement.
For me, the time is in getting squared up in the lathe. Once it's dialed....it's an extra 15 minute to single point recut the threads....seems like a no brainer.
Not really.
I’ve yet to see or have explained to me how a small axial misalignment or being slightly nonconcentric for that matter makes a nickels worth of difference in a radial cut such as truing an action face or bolt face. Unless there’s something wrong with the lathe, the result is going to be perpendicular to the axis. If one is going to after the threads, then yes by all means a spider is a nice way to go as long as it’s not some garbage piece of aluminum sticking a foot out of a four jaw. I’ve machined a collar to fit the outside of the action, trued between centers on a precision mandrel passing through the action and then transferred to the chuck, indicated on the mandrel, removed mandrel, and cut the threads. Don’t like doing it that way, tedious and generally a waste of time. If you go after the lugs chances are your action will be making a trip to Dan to put the bolt handle back where it belongs or it won’t extract right😄.
Money is better spent on a custom action, and a good barrel, the latter being the most important part of the puzzle. If a gunsmith actually charged the amount of time it takes to fully blueprint one at a rate a machine shop charges, it would cost $$$$.
Feel free to straighten me out😄
I’ve yet to see or have explained to me how a small axial misalignment or being slightly nonconcentric for that matter makes a nickels worth of difference in a radial cut such as truing an action face or bolt face. Unless there’s something wrong with the lathe, the result is going to be perpendicular to the axis. If one is going to after the threads, then yes by all means a spider is a nice way to go as long as it’s not some garbage piece of aluminum sticking a foot out of a four jaw. I’ve machined a collar to fit the outside of the action, trued between centers on a precision mandrel passing through the action and then transferred to the chuck, indicated on the mandrel, removed mandrel, and cut the threads. Don’t like doing it that way, tedious and generally a waste of time. If you go after the lugs chances are your action will be making a trip to Dan to put the bolt handle back where it belongs or it won’t extract right😄.
Money is better spent on a custom action, and a good barrel, the latter being the most important part of the puzzle. If a gunsmith actually charged the amount of time it takes to fully blueprint one at a rate a machine shop charges, it would cost $$$$.
Feel free to straighten me out😄
Are you assuming your chuck jaws hold the outside of an action so that the bore is true to the spindle axis? LOL. Do you have much machining experience?
I’ve yet to see or have explained to me how a small axial misalignment or being slightly nonconcentric for that matter makes a nickels worth of difference in a radial cut such as truing an action face or bolt face. Unless there’s something wrong with the lathe, the result is going to be perpendicular to the axis. If one is going to after the threads, then yes by all means a spider is a nice way to go as long as it’s not some garbage piece of aluminum sticking a foot out of a four jaw. I’ve machined a collar to fit the outside of the action, trued between centers on a precision mandrel passing through the action and then transferred to the chuck, indicated on the mandrel, removed mandrel, and cut the threads. Don’t like doing it that way, tedious and generally a waste of time. If you go after the lugs chances are your action will be making a trip to Dan to put the bolt handle back where it belongs or it won’t extract right😄.
Money is better spent on a custom action, and a good barrel, the latter being the most important part of the puzzle. If a gunsmith actually charged the amount of time it takes to fully blueprint one at a rate a machine shop charges, it would cost $$$$.
Feel free to straighten me out😄
Are you assuming your chuck jaws hold the outside of an action so that the bore is true to the spindle axis? LOL. Do you have much machining experience?
My question exactly!
More than some and a lot less than others, LOL.
No I am not assuming that. Any time I assume anything with machining I’m quickly proven wrong, haha. I’ve outlined how I do it. Seems to work well enough I guess, but I don’t compete for fake wood these days.
Gun mechanics are a bit like surgeons. The only thing 2 agree on is that the 3rd one probably doesn’t know what he’s doing. 😄
An assumption I would make though, and probably a pretty safe one, is that Manson’s or Kiff’s action truing kit is likely a money maker for a real gunsmith in terms of time saved while producing a very quality product.
Not to outdo Redneck, but I mount the receiver on a mandrel.
Ditto...... A very LONG mandrel -
If your 'smith insists on lapping lugs,seek another 'smith.
So you never find the need for lapping bolt lugs? Just curious here..
FWIW, I only lap lugs when I see it's necessary - otherwise I do not..
If your 'smith insists on lapping lugs,seek another 'smith.
So you never find the need for lapping bolt lugs? Just curious here..
FWIW, I only lap lugs when I see it's necessary - otherwise I do not..
Lee, on a Remington 7-700 family, I think it is a waste of time if the bolt body is not bushed to fit the receiver bore.
If your 'smith insists on lapping lugs,seek another 'smith.
So you never find the need for lapping bolt lugs? Just curious here..
FWIW, I only lap lugs when I see it's necessary - otherwise I do not..
The need/requirement to LAP lugs signifies the set-up/operation needed to be verified.
I've seen lugs that are galled. I've seen lugs that only contact on one lug and not the other.. As long as contact is a relatively even percentage of contact and are not galled, they're left alone..
I've had a couple of bolts with lugs off enough that they had to be recut in order to get them right..(not just Rem.) We're talkin' .001-.005 here usually.. I remember reading of a rifle-builder that found one bolt off by .014!!
It does happen..
An assumption I would make though, and probably a pretty safe one, is that Manson’s or Kiff’s action truing kit is likely a money maker for a real gunsmith in terms of time saved while producing a very quality product.
Those systems save time for the gunsmith and therefore are a money maker. The only problem the "very quality product" isn't actually true when they get finished. A tap will follow the hole (you know the hole that's not on center and radially out as well) no matter how many bushings are guiding it. There's only one way to get it right and it's not with a tap.
I may be off base, but to me it reads like sometimes Lee and Dan aren't addressing quite the same thing. My impression:
Dan: After fully machining the bolt and action, if the set up was correct then the bolt lugs should evenly contact the lug seats in the receiver. No lapping required.
Lee: On a basic rebarrel job where squaring the face of the receiver is to be the extent of the machining as long as nothing else is way out, a bit of lapping can improve the mating of bolt lugs and lug seats in the receiver.
When I first started truing Remington actions (and others), around 1978, I mounted the receiver on a close fitting mandrel and installed a sacrificial sleeve which would run in the steady. The sleeve was glued on with five minute epoxy and trued with the mandrel held between centers. While this seemed to work fine, it was a bit of a hassle so I made up spiders which would serve the same purpose. These were mounted on the receiver ring then trued just as the glueed on sleeves were. The next move was to build a jig of heavy-walled steel tubing which would allow the receiver to be set up so the jig was co-axial tothe receiver bore. The jig was then set up in the four jaw and steady and the truing cuts were made on the receiver. I still use this method, with some variations according to whim.
At the time I was using the sleeve on the receiver ring, I also messed with a cast iron lap with a floating pilot which I would use to finish the locking lug seats but I soon gave up on that.
I started out bushing bolts but soon switched to retro-fitting bumps which I accomplished by using inserts dove-tailed into the bolt body and trued to the centerline.
Prior to all of this, I simply faced the receiver while it was held on a mandrel, then lapped the bolt lugs in. I used shim stock wrapped around the rear of the bolt to tighten it up in the receiver while lapping. I did not bush the bolt early on. I found that tightening of the rear of the bolt in the receiver did reduce the vertical in my groups (by about .050") and think that any scheme to tighten up this fit is worthwhile in a match rifle. I recall seeing one action where the owner/ 'smith had installed four setscrews in the receiver to center the bolt. This approaches the problem from a different direction but I have no reason to think it wouldn't work except that it seemed a little finicky to set up, to me. After forty years and an uncounted number of Remington, Winchester, Ruger, Sako, Howa, Enfield, and Shilen actions being trued, I still have never been able to quantify what improvement there may be, if any. The exception is with the tightening of the bolt which, in that one 40X-based rifle, was good for about .050" inch of vertcal at 100 yd. GD
I may be off base, but to me it reads like sometimes Lee and Dan aren't addressing quite the same thing. My impression:
Dan: After fully machining the bolt and action, if the set up was correct then the bolt lugs should evenly contact the lug seats in the receiver. No lapping required.
Lee: On a basic rebarrel job where squaring the face of the receiver is to be the extent of the machining as long as nothing else is way out, a bit of lapping can improve the mating of bolt lugs and lug seats in the receiver.
Pretty much....
An assumption I would make though, and probably a pretty safe one, is that Manson’s or Kiff’s action truing kit is likely a money maker for a real gunsmith in terms of time saved while producing a very quality product.
Those systems save time for the gunsmith and therefore are a money maker. The only problem the "very quality product" isn't actually true when they get finished. A tap will follow the hole (you know the hole that's not on center and radially out as well) no matter how many bushings are guiding it. There's only one way to get it right and it's not with a tap.
I’ve read that argument also. Have you ever used one and measured the results?
greydog, very good bit of knowledge passed along there and in a professional way. Thank you. I by no means have your level of experience but what you have relayed is very much in line with what I have seen.
People expect an action blueprint job on their factory rig with a new barrel, so the gunsmith provides it. How it’s done can vary greatly and the results are often times not easy to quantify. And somewhere in there the gunsmith has to pay the bills, and that’s not easily done spending all day on one $125 action job. These things are learned with experience, much in the same way that accuracy guarantees are not extremely valuable.
An assumption I would make though, and probably a pretty safe one, is that Manson’s or Kiff’s action truing kit is likely a money maker for a real gunsmith in terms of time saved while producing a very quality product.
Those systems save time for the gunsmith and therefore are a money maker. The only problem the "very quality product" isn't actually true when they get finished. A tap will follow the hole (you know the hole that's not on center and radially out as well) no matter how many bushings are guiding it. There's only one way to get it right and it's not with a tap.
I’ve read that argument also. Have you ever used one and measured the results?
I have checked the results of the guided tap method. It's not difficult to check the quality of the work by chucking up a cutoff stub and cutting a shoulder and threading it. Put a good mandrel in the bolt way of the receiver and snug it up on the stub that is still in the lathe. Put a indicator on the mandrel and check the runout. The piloted tap method move the centerline closer to correct and take out some of the radial problems as well, but it will not true the action. The only way to get it right is single point trueing in a lathe with good setup practices and good work holding capabilities. The take home message to those considering action trueing services is BUYER BEWARE. Know what it takes to get the job done right.
Nice. Thanks for sharing your technique.