Savage 99 restification project

[KeithB]

Actually, I've found that square threads are no more difficult to cut than 60 degree threads, and a whole lot easier to measure. Don't need to use a thread mike or thread wires to measure pitch diameter. Only problem is that you are taking off the whole amount of material each pass, and that may take more power than some small lathes may have. The workaround is (a) do what Ian suggests and use a narrower tool to cut one face of the thread and then use the compound to feed the tool forward/backward the right amount to cut the other face, or (b) make two tools, one narrower to rough out most of the material and a wider one the right width to finish cut both faces at the same time.

On this job I'm sure Ian plans to cut from the shoulder to the end to prevent running the tool into the shoulder. I agree that the threads most likely don't need to go all the way to the shoulder. The only thing to watch out for is that unlike an Acme or V thread, a square thread needs to have quite a bit of clearance on the leading edge of the tool to keep the flank of the tool from rubbing. The trailing edge doesn't need any clearance at all, it can be left square.

If anyone can get a small lathe to "punch above it's weight class" then Ian is probably the person. Watching this with interest.

 

[Ian]

Thanks, Keith, I hope you're right.

The plan is to put the thread form tool upside down and run everything in reverse if I can get the tool on center that way, we'll see.

Whose bright idea was it to put all lathe headstocks on the left end of the bed, anyway?

Bill, that's the standard form of Lyman, original Savage, and Marbles tang sights. They overhang the back end of the tang, about halfway down the wrist, like most leverguns that have bolts that have to be cleared by the sight. The 99 doesn't have the bolt problem, so the sight can be mounted anywhere. I don't want the sight sticking up two inches or being an inch from my eyeball, but that's the only current option. The Lyman 56S is in the right place (and used the mount holes that mine has), as are the Williams sights for later-production rifles with tang safeties (those use the factory, rear scope base holes in the receiver in front of the safety for attachment).

 

[Brad]

A proper tool for Marlin threads can be purchased from Brownells. Would that tool have proper clearances of run upside down with lathe in reverse?

I tend to do all my threading upside down in reverse anymore. Less stress over a crash makes Brad a happy boy.

Ian, I am watching this with much anticipation.

 

[Ian]

I think the clearance offset is to the wrong side. You should be able to grind and polish one pretty easily. Do you have a Lee hardness tester kit? The 20X machinists loupe from the kit is handy for this stuff.

 

[Ian]

I don't know what the threads are, but I do know.

They are 12 TPI and square, if there's any draft at all it's like half a thousandth from root to top. My lathe will barely cut 12, that's the widest the change gears will go, but it will do it.

Major diameter of the barrel thread is .898"
Minor diameter of the barrel thread is .838"
Minor diameter of the receiver thread is .832-3", a little out of round.
"A" thread land width is .041" to .0402".
"A" thread groove width is .0426-.0430", tough to measure exactly. All that adds up to an inch +/- a few thousandths if multiplied by 12 and added together.

I don't have a good way to measure the inside thread major diameter, but I bet it's right on .900". Since the old barrel is an extremely close fit to the receiver, I'll just copy it exactly and not worry too much about it.

Having only a little experience with precise thread measuring (pitch diameter, class of fit, etc.) and cutting so far, the close tolerances of these threads is amazing. I'm starting to catch on to how Savage could make the take-down versions of these rifles actually work.

 

[Missionary]

Good morning
What an epic story ! I think I will rechamber / rebore if my 300 Savage ever goes bonkers.

 

[Ian]

The barrel I got won't work. I knew it would be close with it being chambered in .30-'06 and a sporter taper, and sure enough there's not enough meat for a shoulder and .30-30 chamber at the same time. (I sawed down just to be sure).

So I'm ordering a fresh one. Anyone have experience with the Green Mountain 8-groove .30-caliber blanks?

 

[Brad]

Better get an 18 twist to be sure.

 

[RBHarter]

I'm sorry to hear that won't work .

This is interesting to me most of the machine work is beyond my grasp , I'm a hands on kind of guy . I'm hoping to be on hand when the new barrel gets fitted on the 92' just so I can see how it works .

I know a pretty good smith that's regards them as good and a good value in the raw configuration . The old AB barrels from Midway were from GM if that is any help .

 

[Ian]

That's ok, I'm sure it will get used for something else one day, maybe a .30 Badger insert for my 16-gauge or something fun like that.

Midway has a free shipping sale today, all they have are Shilen and GM. I'd rather have a LW or Douglas, but this isn't a target rifle and I'm not a precision gunsmith. GM has a pretty good reputation for being at least consistent, and for $93 I'm thinking it's worth a shot.

 

[gman]

Can't say I've heard anything bad about them. For that price it's worth a shot. Better than messing up a $390 Bartlein bbl.

 

[Brad]

For 93 bucks it is hard to go wrong. Like you said, it isn’t a target rifle.

 

[Ian]

Better get an 18 twist to be sure.

That would work just great with 90-grain subsonics

 

[fiver]

I know a guy....

Green Mountain used to make barrels for someone else.
digging deep into the recesses here, but it was surprising to me when I found out.
for the price I would go with it.

order it in the right taper [or real close] or octagon you don't want to be tapering it after it has been rifled.
now if you could get it in a tapered octagon with a 10 twist, or a 7 twist.
7 twist and the 30 Herrit would be quite fun with a 18" barrel and silencer.

 

[freebullet]

Wow what a time, glad you got the old one off. Now the real fun starts ehh?

 

[Pistolero]

Papa Rosannadanna was right. It's always something.

Sorry to hear about the first bbl. I have heard only good things about Green Mtn, but no personal
experience. $93 seems like a bargain and free shipping is a cherry on top. Good luck. I think you
will be cutting just a few thousandths per pass as wide as the cutter will be, given the available
torque (I assume) being lower on smaller lathes. Lowest speed for most torque, something like .005 per pass,
should work. Hope, hope, hope.
A little of extra groove width and slightly narrower thread forms on the bbl will ensure that it will fit.
Will pull out slack as you tighten against the shoulder. I believe if it was me, I'd shoot for about .005
narrower thread forms than the original, same OD, maybe a short alignment tang
at the shoulder to center precisely in the receiver, maybe .040 long or so.

Bill

 

[Ian]

It's starting to come together again. Brown truck brought me a beautiful GM blank, it's straight, finished beautifully inside and out, and looks good to go. Postman brought me a proper Williams tang mount peep sight courtesy of member Barn, it's a perfect fit and is exactly what I needed for this, THANK YOU BARN!! I don't know where I would have found one of these obsolete sights in such good condition if you hadn't offered it up.

It's going to be tough to cut down that nice 26" barrel to 18", I may chicken out and just trim the usual inch off each end, we'll see. The rifle would get used a lot more if it had the ability to mount a suppressor, but with 10" of can hanging off the end of a long barrel it will be like holding up a garden rake by the handle end if I don't shorten it significantly.

 

[fiver]

18 or 20 isn't really a handicap with the 30-30.
I would have to double check my model 94 but I'm pretty sure it has a 20".
with the 4831 load a can would lower the sound down to about a whoosh and a crack and you'd still have good ballistics.
the can might even increase the velocity some on that load.
another few ounces on the end of the barrel can be counter weighted in the stock putting the balance back between your hands.
if you do it with an empty magazine, and you decide to take the can off, the ammo will then put the weight back in the center again and you don't have to take the weight out of the stock.

 

[Ian]

That's a good load, I have about 4-5 lots of partial cans/kegs/paper sacks of canister and bulk flavors of 4831 all mixed up in a gallon jug just for that and for "plinking" with the 45/90 (with a kicker of RX-7 and some COW). Yeah, don't tell the safety nannies . I bet a can would bump a case full of to about 2K fps in a 20" .30-30, but I also bet you'd have time after the shot to light a smoke off of the afterburn going on inside.

Not worried about performance when shortening the barrel, the can will indeed make an 18" barrel perform like a 20". I just don't like cutting down a really nice barrel, kind of like I think it's a sin against the Almighty to buy good, straight 16' lumber and whack it into short pieces.

I'm really liking how the 1899's rotary magazine prevents the rifle from shifting balance when loaded, and it feeds really smoothly.

20" is really a lot more barrel than needed for a .30-30, and the rifle ought to be a lot more handy with 18". Generally speaking, loads that have been the quietest when using a suppressor (sub- or super-sonic either one) are the ones that make the least gas volume and muzzle pressure, although my best .30-caliber can employs a baffle design which feeds off of pressure, and the more there is the better it works.

http://www.artfulbullet.com/index.php?threads/suppressed-marlin-30-30.2758/

 

[fiver]

you could always drill out the last 8" of the barrel and cut slots in it then shroud it.
making the barrel itself the silencer internals, if you really wanted to keep the length.

I really like the sighting plane of my 24" barrels, 32 or 34 wouldn't break my heart in a well balanced target rifle.