Are there any gunsmiths that have had experience in blueprinting the M1999 action?

Please let me know. Thanks in advance.

It sounds like it isn't necessary with this action.

chuck

30 caliber---

Just measure a M-99 and fill in the blanks on your blueprint.

I found nothing to straighten, nothing to change, and no improvements to make.

I am honored by your reply Mr. Belk, thank you.

Let me make sure that I understand your answer. In barrelling a M1999 action, is there a need to "face off" or "true-up" the front of the receiver ring?

So, in barrelling a M1999, it sounds as if all you need to do is, cut the chamber, cut the threads and lap the lugs. Is that correct?

I would appreciate your thoughts.

I would imagine that Jack checked the lugs for bearing.He likely measured to be sure the receiver face, inner collar, and bolt face were parallel with each other. He may have checked to see that they were perpendicular to the bore. In other words a basic inspection by a thoroughly competent and knowledgable man.
Now, I'm one of those BR guys who has wasted way too much time figuring out ways of checking and, if necessary, improving alignment. I'm a fairly accomplished machinist but am not an engineer so I'm not bogged down by the need to justify everything with the appropriate formulae. I'll explain how I check thread alignment and bore straightness etc. in those cases where I want to do so. Now, I don't have my MRC actions yet but I'll pretend I do and pretend I want to waste a day checking one.
The first thing I need is a gauge to check the threads. To make this I just grab a piece of whatever (cast iron is really pretty nice so is brass but a barrel stub is ok)and put it in the three jaw chuck. This is trued on the outside to give me a reference surface and bored to .750 to give me clearance on the inside. This hole can just be drilled but I like to bore it just in case I want to use it as a further reference. I cut a thread with a special form to ride on the pitch diameter of the receiver thread. I do this by first turning my test piece to a diameter of about .005 less than the major diameter of the thread. I then thread with a 30 degree cutter to a depth about .010 past what is necessary to clear the minor diameter of the thread. I then put in the mormal 60 degree cutter and carefully cut the thread so it screws on by hand with some difficulty. In doing this the cutter is fed straight in rather than on a 30 degree angle. Once this is done the piece can be parted of and there it is. There is no reason not to go ahead and measure the PD of the piece and mark it for future use. What you have now is a piece that, when it is screwed in, rides on the angled face of the thread and is uninfluenced by anything else.
Next you need to make a couple of mandrels. The first mandrel will be a snug fit in the bore of the action but relieved at one end for a distance of about 3 inches. So the mandrel will have a diameter of maybe .702 for most of it's length and be turned down to about .600 at one end for a distance of three inches. This mandrel has to be perfectly straight and the centers have to be perfectly concentric. If you have access to a cylindrical grinder it makes life a lot easier!
The second mandrel will be turned to a snug fit in the receiver at two points. One to locate in the bridge and the other just behind the locking lug seats. It is relieved everywhere else and these contact points are short .If the feed ramp takes awqay any of the lower locking lug seat then you'll have to be sure the mandrel is held against the top of the receiver at this point.
So, you screw in the thread checker then insert the second mandrel through the action and through the checker (that's why you made the 3/4 inch hole). Set the whole works up between centers on the lathe, or in a test fixture, or between two centers set up on your milling table. Whatever. Now run the dial guage on the checker. This will tell you to what extent the threads are either eccentric or misaligned angularly (is that a word?)in relation to what I call the bore average. In other words we have drawn a line directly from the rear of the receiver bore to the front and checked the relationship of the threads to this line. By now indicating the front of the thread guage (or checker, if you wish)we can tell if the threads are misaligned at an angle Or if they are misaligned radially or both. Keep in mind this in relation to our line. If the runout is significant you can take a light cut on the circumference of the guage for a short distance to give you a reference that is applicable only for this setup and only if you don't disturb the checker.
Now remove this mandrel and put in the first one you made. The one with the step down at one end. This one is inserted from the rear so that the action is supported only at the receiver bridge. The action is set up as before and the dial run on the trued portion of the checker. From this we can get an idea of how much the receiver warped in heat treating or how much the bridge is misaligned with the ring. The misalignment is most likely angular since the receiver warped at the mag well/ loading port cut outs. If it did.
If the dial shows no misalignment then we know the previous misaligment reading was strictly in the threads. If the dial shows a lot of mis alignment well, we've got a bit of a problem (not in surmountable)Let's assume to bore ended up to be straight (yahoo!).
Now the action is set up in the jig we've made for the purpose. This jig is simply a piece of DOM tubing trued to be perfectly straight and uniform from end to end. It features 5/8" walls and has four holes at three or four locations with set screws in the holes. Only 8 holes are used at any one time. The different locations are so we can accomodate actions of different lengths. The action is put into the jig and again set between centers. Using the set screws the jig is dialed in 'til it runs true at both ends. Now the jig is set in the four jaw chuck at on end and run in the steady at the other. I made my jig with a bulge at the chuck end so the chuck just grabs a small area. Makes it easier to align. Oh, I forgot to mention, the mandrel has been removed. So has our thread guage. Now you can dial on the face of the receiver, the inner collar, and even the locking lug seats.
My impression, from looking at the actions and figuring how they must be machined, is that the threads, receiver face, inner collar and locking lug seats are quite true in relation to one another. Whether the bore is straight is another matter and it is possible it could be out a little. If seen some remingtons that were out horrible in this respect and some of the post 64 M70s are laughable (the newest ones are remarkably good. At least those I have checked.
There are quicker and easier ways to check the threads. It can be done by making the guage as described, leaving it in place in the chuck, and indicating a mandrel at the tang. Runout here probably indicates angular threads but not necessarily. It could be the bent bore syndrome or eccentric threads or a combo.
The matter of the crooked bore is something that may exist in many actions. Borden's system where the bolt is supported at the front and rear on lockup (the "Borden Bumps")means the bolt follows the "average bore" and the alignment of everything else can be related to this.
Remedial reaming of the receiver bore can do some good but is not a cure all due to deflection of the reamer and the receiver (in the case of a 700. There's not a lot of metal connecting the ring and bridge in a Remington.
One thing I have to say is that all of this, within reason, means squat on a hunting rifle! The difference between a totally reworked 40X action and one that is bone stock is probably about 1/8 inch. Now in the world of BR this is 50% but in the world of the sporter it's the difference between a 1/2 inch gun and a 5/8 inch gun. Not that big a deal.
So there you have it. You can understand why some of the BR 'smiths that do a thorough job of reworking actions charge so darn much for doing so and why the one's that don't charge much probably aren't doing much.
The whole concept of "blueprinting" is something that has kind of gotten out of hand. The term is thrown about with wild abandon and may mean quite a bit or nothing at all. Some who "blueprint" may do more harm than good. The guys who are good though can do an incredible job of fixing an ugly action.
When you think about it some of the work, while it may improve alignment, makes permanent dimensional changes that are the antithesis of "blueprinting". The striker travel may be shortened. The relationship of the extractor cam is changed. There's more to this stuff than meets the eye and don't be surprised if I left something out! Regards, Bill.

The reason that I brought this up was due to the fact that MRC is manufacturing their actions in the same fashion that Remington, Winchester, and Ruger are making theirs. If they are obtaining this good of results with the same processes that we've all seen fail with other manufacturers, it would be interesting for them to shed some light on why it's working the way it is. It wuld also be worth noting what the hard numbers really are, rather than it's good enough.

I think that Mag Fan brought up some interesting points that should be answered by the person that's got the first-hand experience with the Montana action, namely Jack.

The action I worked on was oil quenched which has since been discontinued because there were some heat-treat stability problems. Even so I saw nothing to re-face, re-surface, lap or grind.

I tested that action the same way I do any interior collard action....

I set up a piece of 1.375 stock in the lathe and threaded about .750 of it to fit the action tightly...still part of the thread showing, but not yet bottomed out on the inner ring.
The action is screwed onto those threads two grunts hand tight and a mandrel turned to fit the bolt hole is inserted into the action from the rear.

The spindle is slowly rotated and the amount of wobble on the end of the mandrel is measured. That tells me how the threads are made in relation to the centerline of the action. It's common to see Rem M-700s out by .125 TIR. The M-99 was .005, which is effectively the error of unground threads.

I then re-cut the threads until they're quite loose in the action but the face of the threaded mandrel is faced plumb square. That face butts up to the inner ring flush all the way around because of the loose threads....it becomes "self centering". Again the mandrel is inserted in the back of the action and measured. That tells me how squared the inner ring is with the center-line. Sometimes the loose threads give a false reading.....I got about .010 but that was all parrallel to the bore...in other words the action was "offset" on the spud, not off at an angle which would mean the inner ring was not square.

Then I face off the threaded piece until the shoulder mates against the face of the action. If the mandrel is still running true (with the test threaded part that's had all the machining done on it without removal from the machine.) it means the action has the surfaces that makes a difference square with the centerline of the bore. All that's left is to make sure the lugs contact evenly. They did on that action.

When measured from the face of the action, the bolt face was a consistent distance over all it's surface. It still was when the firing pin spring was pushing the bolt upwards against the bridge, too. That means the bolt is square when it counts.....when the rifle is cocked, loaded and about to fire.

Now you know how I do it.....it's different from how Bill Leeper does it but it does the same thing.

Interesting thread.

mr. belk:

you mentioned in one of your contributions to this thread the degree to which remington receivers are out of whack. could you give us a quick rundown on other name brands? winchester? cz? ruger 77? savage 110 series?

i'm no engineer or machinist, but i do appreciate your explanation of how you checked the 1999. i reckon other non-smiths here would appreciate the info, too.

many thanks.

and you, too, mr. leepers. nice treatise. i could understand a great deal of it, but must admit i'd have to see the rest in order to wrap my brain around it. same question for you: among the normal joe blow hunting rifle actions, are there one or two that seem a little truer than the others? you mentioned that the later winchesters are pretty good, while recent remmies are, uh, not so good. how about the savage and its floating bolt head and unique barrel nut attachment method? howa 1500? many thanks.

We are not magicians. The M70 architecture happens to be a very stiff design. Heat treat does not seem to affect it (in a casting). Ruger engineering said this shape was extremely well behaved, much better than the M77. There are a number of heat treat processes that the castings go through before machining, but the final austempering by S&W takes the hardness from about Rc22 to Rc42 (48 in the case of the bolts.) We're seeing no movement.

Jack got one of six that we oil-quenched. Three showed no movement. Two demonstrated a very slight bow toward the magazine well. One was pronounced and that scared the c*^p out us. Pronouced means you can slide .025 feeler stock under a straight edge laid along the previously flat machined bottom surface. We went all over the place for consultation and austemping (salt bath) was the unanimous recommendation. Our spec's aligned well with S&W's automated line and so we jumped on.

The big problem with the M70 is, as Matt mentioned, tooling. Same with all the big makers. They have major dollars invested in aging tooling and face dwindling margins in a stagnent market. Tolerances get loosened to allow for sustainable scrap rates.

We contract with non-firearms industry suppliers, meaning our vendors have great margins and good cash flow. They buy the latest tooling and when a CNC machining center won't cut the mustard, they sell it to some major firearms manufacturer (Just kidding). They dump it on the used market.

Where the M70 is +/- .005 or +/- .003 in critical areas, we are True Position +/- .001. (7 tenths). This really stacks up across the action when all the interelated parts come together.

Frankly, when we sent that action to Jack, we were very concerned. It was not our best effort, but it was all that was available at the time. Since then, we upgraded the safety to shroud fit. the cocking-piece to shroud fit, and improved our polishing (by outsourcing).

It's still not perfect, but it's pretty darn good.

[ 03-07-2003, 07:51: Message edited by: Rod@MRC ]

What an interesting, informative and educational discussion by Rod and those that work with bolt guns good and bad.

I ahve checked a number of older actions, both military and commercial, and I have found those same rough locking lugs and collars. Most have threads concentric to the bore within the kind of limits that allow accuracy for the purpose, but with measureable deviations. In my experience, the old military and factory bolt guns were not machined to the kind of tolerances current benchrest 'smiths obtain.

I am most impressed by Mr Leepers statement

"One thing I have to say is that all of this, within reason, means squat on a hunting rifle! The difference between a totally reworked 40X action and one that is bone stock is probably about 1/8 inch. Now in the world of BR this is 50% but in the world of the sporter it's the difference between a 1/2 inch gun and a 5/8 inch gun. Not that big a deal."

That being said, if an individual is not trying to make a living doing this, it costs only time for someone with a machinist background to check an action and, if needed, square it up. Since this is not a 1000 yd bench gun action, It makes little sense to pay someone to do this.

In response to the question as to how various actions stack up I can only attest to those that I have checked.
First the very worst action I ever checked was, believe it or not, a Shilen DGA. This was so crooked you could practically have measured it with a ruler! With the barrel screwed in there was room for a .006 feeler guage on one side of the receiver face. I used to use a mandrel made from an old piece of barrel which had been turned between centers. This gave me a mandrel that was pretty straight and concentric. I could insert this mandrel and screw a barrel blank into the receiver and any gross misalignment was obvious just by looking through the mandrel and barrel. On this particular action I couldn't see daylight!
The post 64 M70s up until about 1978 are pretty bad. Every one I've checked the barrel threads point downhill. Sometimes a lot. The bore is not bad.
Remington 700s are consistently mediocre. They are frequently bent at the mag cutout so the bore is crooked. The crooked bore is the reason I cooked up some of the more involved testing procedures. The action would bow the mandrel and at the same time be deflected by the mandrel making simple checks meaningless.
I've only checked one P14 but it is amazingly straight and concentric. Not much cause to check these! This one is for my own 303 match rifle.
The British RPA actions are absolutely perfect! Even the outside of the receiver is perfectly concentric and straight with the bore.
The newest M70s I have checked have been great as far as thread alignment goes but that was about it. Locking lug seats are ugly and the lugs on the bolt match them in finish. The boltfaces look like they were nibbled out by a minature metal eating beaver. They need work.
A ruger 77 I just worked on was real straight and concentric as far as the threads were concerned but the receiver face was crooked. Regards, Bill.

this is real good stuff. keep it coming. thanks.

I want to thank everyone for their participation in this thread to date.

It has been very informative reading all of the posts. I especially want to thank Jack Belk, Bill Leeper, Ron with MRC and all the rest for their learned opinions and observations.

I did not realize that this topic would mushroom like it did but, I like it.

Please keep it up, it has been an education for me.