As you all know, I'm a beginner. So in my beginning to barrel all these actions and being on the cheap, I get REM 700 barrels off fleaBay. Unfortunately, most of them have been fitted with iron sights, thus holes, which leads to my lack of ability to make them clock. Even though I've studied the start of the thread I've failed rather miserably. Any tricks?

Take the number 1, as in one complete revolution of the barrel, and divide by the number of threads per inch. 1 divided by 16 threads per inch = o.o625". That is how far the barrel will advance toward the bolt face if turned in one revolution. Divide that 0.0625 by 2 for half a turn. Remember, every time you screw the barrel in toward the bolt face, the chamber gets shorter and the counter bore in the barrel gets closer to contacting the end of the bolt, and the end of the barrel tenon gets closer to contacting the front of the locking lugs on the bolt. It is simple measurement (with a depth mic) and math...

quote:

Originally posted by copperlake:
As you all know, I'm a beginner. So in my beginning to barrel all these actions and being on the cheap, I get REM 700 barrels off fleaBay. Unfortunately, most of them have been fitted with iron sights, thus holes, which leads to my lack of ability to make them clock. Even though I've studied the start of the thread I've failed rather miserably. Any tricks?

Start by turning the barrel all the way in, with the recoil lug in place, and checking to see how far it moves from contact to fully tight. You need to allow for this.
Now, loosen the barrel off and back it out until the sights are on top. Next back it out the additional amount to allow for the tightening up movement. Now, measure the gap with a feeler gauge. Subtract this measurement from .0625 and you will get the amount you will have to remove to have the barrel index correctly. Cutting a little less does not display cowardice; only caution! After the barrel is indexed, you may then take measurements to determine how much you have to deepen the chamber and counterbore and how much to cut from the face. Clearances on factory Remingtons are fairly generous so you can tighten them up a bit if you want. Regards, Bill

The way I do it may not be correct but it works for me. I put an index mark on the top dead bottom of the action. I then figure out a way to do the same for the barrel. I usually screw a flat top Unertl block to a screw hole so I can get an index on the barrel. Once that is done I screw the barrel to the action and see how far I have to go to line up the marks. If they are within .625 you can usually tighten the barrel until they line up. If they are much further apart material will have to be removed from the shoulder of the barrel. I'll admit many times it is a cut and try proposition, the crush factor adds excitement so be careful.

COA 3: weld up the holes, and then it won't matter where they end up.
However, there are no tricks to do what you want; just straightforward measurement and machining techniques.

OK so a barrel is not a car part. You can't just take it off one chassis and screw it onto another. Any takeoff will have to have the headspace checked and it probably will not pass. so sop is to take material off the shoulder to get the barrel to fit and clock, and then recut chamber and if necessary the breech and even, in some cases, the extractor cutout. The only "trick" is sometimes it's preferable to put the screw holes and logo, if any, on the underside below the wood line, avoids having to weld them and you don't have to get them exactly bottom dead center. (Front sight holes another story, if the front sight is screwed on and not sweated on, you either have to weld, shorten barrel and recrown, or get them correctly clocked).

If you do weld up holes, chances are they will be visible after blueing unless you use the same filler rod as the barrel metal (chrome moly most times).

Bottom line, there is no economy in starting with a takeoff.

Thanks for the replies. My apologies, I should have stated that I'm turning these barrels down to thread into small ring mauser actions. Stupid on my part. This includes in every case the tenon being shortened, too, and then re-chambering. In some cases a lot! Like 7mm Rem to 7x57. Sounds like welding is the way to go. Use a plug screw a little proud as filler? However, on the next one I'll give the maths a shot. The big problem I see is there isn't much leeway with the mauser; if off, you're way off.

Thanks again. I'll work on clarity.

Actually, I would not weld up the holes. It is too easy to make them end up on the top or bottom. Now that I see you are threading them anew. With 12 TPI you have .083 length per turn. Here is how to do it; thread it .050 shorter than the spec; then when you turn it in, you will usually be able to index the top where you want it. Then cut the chamber. Cut and try.
You might consider plugging the screw holes, grinding smooth, and use Duracoat or equivalent; that will cover up the screws.
There is not much barrel left after turning off the 7mm mag chamber. Done that too.
As for fitting a take off barrel onto another receiver; they very often headspace up to spec; just they end up at random places because most modern barrels are not timed. Winchesters are.
How many Swedes do you have?

Love doing 12 tpi barrels, as you can use the quick and dirty method. I'm not a machinist, more of a gun grinder.

As dpcd said, 12 tpi is .083 per turn. I do a lot of octagon barrels, so I think in terms of an octagon, that's .010 per octagon, or .010 per 1/8 turn. Not exact, but close enough for gun work.

I'd start on a takeoff barrel by marking the tdc where the screw holes are. Thread in the barrel till it hits the receiver firmly and decide if you're going to make the holes come out on the bottom so they're hidden, or use them and have them come out on top.

Mark TDC of the receiver on the barrel.

Now, it's time to decide how much to face off the barrel shoulder to make it time.

I would start at your drilled hole TDC and mark out half diameter, 1/4 dia, and 1/8 dia. marks. Your receiver TDC mark on the barrel will fall between two of the marks.

Estimate in 1/10 increment where the TDC mark falls between two of the 1/8 marks.

The amount you have to face off is the difference between your hole TDC and your receiver TDC mark, measured clockwise rotation, minus .002" to .003" to allow for a crush fit tightening.

So, count the number of 1/8 diameter marks, and multiply those by .010". Add in your estimated amount of the last 1/8" mark to your index mark. Subtract .003". That is the amount your face off.

To illustrate: Your holes are 2 1/8 turn marks off from the TDC mark, plus about 40% of the next 1/8 mark. 2x.010 + .004 - .003 crush = .021" faced off to make the barrel index.

As someone else said, nothing cowardly about trial and error; take off .019", thread it in and tighten it 2 or 3 times, and see how far off you are. You should now be within the estimated last mark, and you can re-estimate what portion of the last .010" you're off by and make the final cut.

Now, use your depth gage to get the bolt to receiver distance, and cut the barrel tenon off to that minus the face clearance you want. Now, you can rechamber to proper headspace, and verify with gages.

A real machinist would measure the rotation the barrel is off between receiver TDC and barrel TDC in degrees, divide by 360 and multiply by .083 to determine the exact cut. You can do it that way also, instead of my quick and dirty estimation way.

Thanks for the refinements all! I'll give it a go on the next one.

Let's see if I can get this picture thing right:

https://lh3.googleusercontent....8-h757-no?authuser=0

I have twelve actions in the queue right now: six 96's, four 94's, and two Chilean 95's. As I've stated before, many of them are rescue dogs that I've collected over many years on the cheap. after fitting bolts, I'm swapping between doing scope mounts and barrels. I made a grand discovery in using cheap Redfield M99 mauser bases that can be tweaked to work. The front base needs to be pruned in the mill to fit right and the rear is clumsy enough to be ground on and just sneaks onto the bridge. I've experimented with 'style' on that! I got them each for 10 bucks new (they were made in 1986). Some of the actions are extant and I'm waiting on a backorder for Leupold #51263 mounts for them. Two years ago I had no work to speak of because of Covid. I spent my free time doing ten actions to the point of range time. Some of them actually shot, others not so hot.

I only wish to become a reasonably competent 'gun grinder' for me and me only. My 'for pay' days are over and I'm old enough to realize I haven't the time left on the clock to master this craft. Having said that, I'm having a blast that is equally (?) divided between frustration and something that resembles satisfaction. That goes one way then the other the deeper I dive. I have on hand thirty-five actions and lots of parts collected over the last forty years with which to bang on.

Thanks again, much appreciated.

Sounds like a plan. However, you are a no go at the picture station.
Get a Imgur account. Put your pictures there. Click on Large Thumbnail. And BBC code. Paste that here; it will work.

So when you click on the link it doesn't open a new tab with the picture? It does for me. I'll try Imgur...

Edit to try Imgur:

That worked!
When you click in the Google link, you don't get a picture unless you have a google account. Which I don't.

I've gone to using imgbb.com for picture hosting, of just one use pictures. You don't have to do an account, and the pictures aren't saved to your file or account, they're just good for the link you use them on.

Once you upload (you can do more than one photo) select BBcode fully linked in the embed codes pulldown box, and then hit copy to copy the URL's. Paste the URLs directly into your post, and it brings up a picture.

I'm imbedding a picture below, you can click on the picture and it will take you to the ibb site. From there, you can click upload and upload a picture as I described above.

Thanks again for everything.

I just got sticker shock ... the Leupold 2 piece base for the small ring Mausers is well north of $30 DEALER PRICE!

But then I just had some bases custom made for Talley rings on the small ring actions, with integral pop-up ghost ring on the rear base. Cost north of $200 per set. Ditto for the large ring.

Interesting re Redfield 99 rings. Is the hole spacing standard (.300 rear, .860 front)? When you say "grind" you mean to accommodate the hump? Have you checked that the bases level up with the centerline of the bore?

Once piece bases are $40. I just got some from Brownells. You must not have bought bases lately.

If you mean .5 rear and .860 rear, yes. As far as getting them parallel to the bore, you have to understand what I'm dealing with in MANY cases. All I do is take calipers and do whatever I can to make the tops of them the same height from the bottom of the receiver; welding grinding, filing, or shims. I have like 15 actions that more or less look like this:





But on some that are extant like this '94 Brazilian next to a '95, I mill a flat back enough from the front of the hump to allow clearance aft and do a little 'treatment' to the horns for a better look.

Nice; the 95 Chilean actions are one of my favorites. Smooth and no thumb cut.

I agree. The '93-'95 guide rib is much superior to the '96-'98's IMO; smoother (but not with grit in them) and less bolt wobble. Not to mention what happens when a bridge like I'm dealing with gets ground poorly. One of the 96's I'm dealing with tapers from .050 in the front over the guide race to .070 aft. Just about every one of these is bowed, bent, twisted, and or all at once. All of them had to have the tangs massaged with 2 lb. a copper hammer to get a bolt to start. This is nothing but a reclamation project.

Here are a couple more experimental 'treatments' to the bridges on 96's. The top one was fitted with a slice of black pipe then tigged. The bottom was just cleaning the charging slot with a 3/16" ball end mill leaving a little re-curve at the bottom which looks better to me than a square cut (I've done both).

You, sir, are a persistent fellow. Nice work on salvaging these; they're past the point where I would have taken them on.

The older I get, the more I value my time and the less I care to deal with other peoples screw ups.

Nice work.

Looks like the rear hump has to come off to use those bases? And the rear bridge profile is the standard 30 degree comml mauser profile?

If I'm understanding your question - no, the hump gets modified, not removed. This is another '94 Brazilian that I'm pecking away at. I mill a starting flat centered and far enough forward on the aft part of the hump the length of which is enough for the base to be used unmodified. I've seen Weaver bases that have had the aft right corner knocked off for the bolt to clear. Besides, you have to leave a bit of the hump because clearing it all makes for a VERY bad leave on the left side (no thumb notch to disguise how awful it looks to do so). I then continue hump pruning with various files. Next, I'll either de-horn it, slot it, or fill it in.



Here's a pic of the bases. If you hold them to an unmolested SR, the aft mount is approx. .012 proud of the forward mount. On the fwd mount, you can wiggle a .0015 feeler down the middle but both sides touch the ring. They fit 1910 Mexican without having to shorten the aft of the front mount for to look right, especially if the ring has been faced on a '93-6. The hole spacing within the design JUST works not to hit the lug recess face, and I mean just.

OK now I get it. The rear base is cylindrical so it will not go on a comml mauser or a sr with rear ring modified conventionally to remove the hump.

Here's a suggestion to achieve total hump removal. Run the mill cutter along the entire left edge of the action opening and terminate it at the front ring.

Russ, interesting suggestion. I have several actions that are junk on which I may give a try. Unfortunately, a lot the SR's have deep stamps on the port side that the cut would cross. Oviedo's, not so much. I have a couple of those.