Looking for mandrels to blueprint a Savage 110 short action. Would like to make it is all square and straight. Any help is appreciated.
Thanks
CH
Printable View
Looking for mandrels to blueprint a Savage 110 short action. Would like to make it is all square and straight. Any help is appreciated.
Thanks
CH
You either need a lathe and or buy some PT&G tools. When using PTG stuff manually it will chatter on the lugs unless you have a way to control feed. As an example the tail stock can control thrust making a lathe the better option if you are single point or truing tools
MHO, Remove minimal stock from the lugs.
I use Manson's- but there's a lot for you to consider here.
Process:
Receiver threads- PT&G makes a threading tap at OEM thread pitch, which will true them to the boltway axis but not cut oversize. I've used it for customers that want to be able to use standard prefits. To fully and completely true/clean up- whether single-pointing or using a tap mandrel- you need to cut them oversize, meaning you will not be able to use the standard spec prefits.
In order to cut the threads 10 thou over, you need to ream the threads first (another mandrel). This will re-cut the lug abutments in the receiver as well.
Then, there's the receiver face, the bolt lugs, and the boltface.
Without getting into a lot more technical crap- it's not going to be close to worth the coin for a full set of tooling unless you're going to do several actions.
Personally, I think the floating bolthead on the Savage goes a long way towards mitigating the need for bolt/lug work, I usually lap the lugs in without recutting the receiver abutments and don't have problems getting needed contact area.
Is this for a new scratch build, and what's the rest of the rifle going to consist of?
This sums up how I feel.Quote:
Without getting into a lot more technical crap- it's not going to be close to worth the coin for a full set of tooling unless you're going to do several actions.
I have a full equipped hobby shop with 2 lathes 12x36” Clausing, plus a new PM13x40 GT, 2hp fully CNC mill, and a manual mill. I’m a retired engineer who likes toys. ;-) The Lathes have Bison set true chucks with less than .0002 repeatability and I took machine shop in engineering school. I did most of the Profs lab machining, while i was an under grad, student way back. While not a Journeyman Machinist, I do have fun.Quote:
Originally Posted by Robinhood
i googled for tools but did not find Savage specific tools Brownells only listed 700 Rem and Tikka iirc. Thanks for your help, ad info.
CH
Hum, I guess, I just wanted to do a good job on my 6.5 CM build. The action is a vintage 1968 short action. I guess I can just DIY build what I need to get the job done. Not exactly sure what “worth it” means from owner/shooter/hobbist perspective. Thanks for your opinions.I’ll ponder this for a while.Quote:
Originally Posted by Robinhood
CH
"Worth it", was meant pure dollars and cents- not necessarily in terms of value added.
It wasn't indicated in your OP whether you had machining equip/experience, so this changes the dynamic.
Anything done with the tooling we're talking about can be done on the lathe. Personally, single-pointing internal receiver threads gives me a pucker factor that results in me using the tap mandrel for that operation.
There are multitudes of ways to perform truing and barrel work. Since you're new to the game, suggest you start with Dan Hinnant's book. It will give you solid background to build on the processes.
https://www.brownells.com/gunsmith-t...-prod6915.aspx
Oh Ok sorry. I thought I filled out a profile with my experience and available tools and tooling. I’ll try to be more clear, next time. Ye internal blind single point gives me an uneasy feeling, too.
I looked at PTG only ting they listed was for Mauser. I have most of the tooling for them, I built several rifles for family and friends. Used old 98 large ring actions. I’ve built some Remingtons on the XB40s and 700’s tat where tack drivers. Especially the 7mm S&H guns.I have ben looking at the 6.5s to reduce recoil. Im getting older and can’t handle the Belted Mag cartridges as much any more. I’ll check Manson.
Thanks
CH
Sorry CH, I have only on few occasions looked at someones profile. Impressive list of tools and experience.
PT&G tools are here. Scroll down.
http://pacifictoolandgauge.com/1258-savage-tools
I found that a lot has to be taken off of the lugs for the action face to be cut parallel with the PT&G tools I used. Not sure why but still not good. The part of the mandrel that inserts into the bolt raceway is .500 and needs alignment bushings that are fitted to the action bore. Tapered bushings could be used to cut out the number you would need on hand to find the right fit.
Ultimately single pointing would be my preferred method but you still need an alignment rod if you use the raceway to line everything up. Some might tell you the "floating bolthead solves the perpendicular lug surfaces issues. Call American Rifle Company, Bighorn or several other of the custom action makers that use a interchangeable floating bolthead if they true the lugs or not.
I cut threads everyday so picking up id threads while takes some practice it is not that hard. Tip. Engage the thread feed nut and put the chuck in neutral, turn the chuck by hand to manage all the things going on and get your tool in there. Work on the far side and feed out to see better if you have a left hand boring bar. You really need to have a lot of experience for chasing the threads single point so the tap method is probably ok
On the 3rd page of the classifieds there is a set for sale. Not sure if it's what your looking for or if it's even still available but might be worth checking it out.
I’m no pro either but I have a fair understanding and I’m not afraid[emoji3]. I’m sure someone will come along and explain all that’s wrong with this. So keep that in mind when you get started.
Dave Manson will make you an arbor with bushings. He’s an awesome guy. I’ve made my own for Remingtons out of .750 stress proof. Takes some time and patience but you can get them nearly perfect. Might have to throw one or two arbors away before you get it right. I did. You can face the action using the arbor, I’ve put screws in the scope base holes to hold the action from turning on to the arbor. Make the arbor long enough to turn on centers. I also had to go after the action threads on a damaged Remington once. I made a sleeve to fit over the action, secured it through the front action screw hole, used the same mandrel mounted on centers and turned the collar. Then I chucked the collar in my 4 jaw and dialed it in using the mandrel to indicate off of both radial and axial. The internal threading is no big deal, just need lots of light and go REAL slow. I was in back gear and had my vfd down to 20 cycles or something. Did I say go slow? Don’t want to crash into lug abutments. I’m sure there’s better ways to do it, but I used what I had and it worked well.
Would I true the threads again like that? Not unless I had to. On the Savage, true the action face and ride on. It’ll shoot great with a good barrel regardless.
You should never treat a Savage like a Remington, the technology is not the same. If you have ever witnessed the process of how they are manufactured, you would know what can possibly go wrong and what can't.
Re-cutting the threads is usually never necessary, unless you have a severely screwed up mess to begin with. If you set it up on a mandrel through the receiver bore and intend on making the receiver threads concentric to the bore, you are doing it BACKWARDS. The biggest reason that the threads are not in line with bore is the fact that they warp during heat treat, especially anything that was made before 2008.
The actions that were made on the old tooling (pre-2008) were known to have warped receivers and out of square receiver faces, because of the primitive process. The receiver faces got knocked out of square right from the get go. After the receiver was broached, it left a huge burr on the face. A quick and dirty method to remove the burr was to grind it off with a v block on a disk sander, subsequently leaving it out of square, depending on operator, the wear on the sanding disc, and if the table on the sander and V block were actually square.
The last operation on the receiver was machining the breech end with an 80's version CNC mill. The receiver was clamped in a V block vertically, and a 3/8" end mill was used to bore to the minor thread dia, and to cut the lug abutments, It also cut the closing ramps in the same operation. Then the tool is changed out to a thread mill and the receiver threads are thread milled in. This is all done in one fixturing, so the lug abutments and the threads are all square with one another. The receiver face however may not be square with the threads, because of the de-burring method.
At this point, the receiver threads are typically within tolerance to the center of the bore, (.003") which is acceptable. Unless the receiver was improperly clamped, or there were chips, debris in the fixture, the norm would be within .003" of dead center. Receivers were checked with a piloted and threaded mandrel for straightness.(but probably not 100%)
The heat treat process consisted of 2 induction coils, one at the front of the receiver, the other around the bridge. Once the temperature was achieved, the machine actually dropped it in a huge oil tank. Most receivers didn't move a big amount but, the single shot solid bottom actions ended up in a banana shape, with the curve going upward because of the lack of mass in the port area.
At the starting point, receiver blanks were gundrilled, reamed and then turned between centers, to insure the i.d was concentric with the o.d. After heat treat the receivers were hand polished on a belt sander, only to the point that the polishing was limited to the area that would show above the stock. On many you can see the original turning marks on the very bottom, that disappear into a smoother finish going towards the top. Depending on how heavy handed the polisher was, concentricity from inside to outside most likely just went out the window. That's why you need to start from the inside out.
The receiver face must be square with the threads. The easiest way to do that is mounting receiver on a threaded mandrel that bottoms out on the lug abutments. A truing cut is made and now the whole front end is square within itself. Now the back end needs to be in alignment with the front end. To determine if or how much distortion is there, you need a raceway gauge, because a round mandrel will tell you nothing about where the kink or curve is. Making it straight is not a machining operation, it's a straightening procedure. If you can get the tang end running within .010" of the front, it's good enough.