Ronnie Maxwell
New member
can anyone tell me what the diameter measurement would be using the 3-wire method (.029 wires) for a 1.120 x 2TPI. i come up with 1.1313.
Thank You,
Ron Maxwell
Thank You,
Ron Maxwell
ODmeasurement over 3-wire
- Thread starter Ronnie Maxwell
- Start date
Ronnie Maxwell
New member
i meant 1.120 x 20 TPI
jackie schmidt
New member
For true pitch diameter calculations, that thread is actually a 1.125. The measurement over .029 wires should be 1.237.
Last edited:
Ronnie Maxwell
New member
Thanks Jackie, appreciate the reply. what i am thinking of doing is making a thread gage for truing the Savage large shank receiver. most of the prethreaded barrels seem to be posted as 1.120. so would the prethreaded barrels be based on a true 1.125 for pitch diameter measurement but have the nominal OD cut to 1.120.
Ron
Ron
jackie schmidt
New member
Ronnie, I would be lying if I said I knew. In most worlds, with threads in the 12 to 20 tpi range, we will make the major diameter about .005 under the nominol size, for instance, if I was machining a 1.250 12 tpi bolt, I would machine the major diameter it to 1.245. I was assuming that if you measure a Savage, it will be 1.120, but by actual definition it is a 1.125
Since most threads are valued in even sizes, I assume that the Savage is in reality based on a industry standard 1 1/8 diameter, or 1.125. Sort of like saying a Remington is a "1 1/16 16tpi.
Of course, since wires measure the pitch diameter, this is all really a moot point.
I may be all wet on this, though...........jackie
Since most threads are valued in even sizes, I assume that the Savage is in reality based on a industry standard 1 1/8 diameter, or 1.125. Sort of like saying a Remington is a "1 1/16 16tpi.
Of course, since wires measure the pitch diameter, this is all really a moot point.
I may be all wet on this, though...........jackie
Last edited:
Ronnie Maxwell
New member
Jackie,
being still new to rebarreling and calculting threads I for the most part understand what you are saying and i usually reduce the OD by .005 myself so not to get binding. as i dont have the barrel yet and this is my first large shanks savage I was trying to get ahead of the game and make a stub gage.
you wouldnt to happen to have a large shank Savage barrel around that you might be able to provide me the OD over wires do you.
Ron
being still new to rebarreling and calculting threads I for the most part understand what you are saying and i usually reduce the OD by .005 myself so not to get binding. as i dont have the barrel yet and this is my first large shanks savage I was trying to get ahead of the game and make a stub gage.
you wouldnt to happen to have a large shank Savage barrel around that you might be able to provide me the OD over wires do you.
Ron
4
4Mesh
Guest
I should probably avoid this discussion... but...
Even if Jackie has a stub, I'm not sure the numbers off of it would be of much help. Well, not for making an example (gage) anyhow.
I have a spreadsheet that I use for doing thread calculations when the thread is a bastard. I'll include the data for your 1.125-20 thread. These values are all calculated, so, if they differ a little from what you see in a manual somewhere, it's because they use the forumlas from the machinerys handbook and not a table of values.
Sorry, but some of the bold type for headings isn't there, but, you get the idea. Your wire measurements are shown for .0289 wires (mean best size)
FYI, it looks like your measurement of 1.131 is right on the money for a class 2 thread.
Even if Jackie has a stub, I'm not sure the numbers off of it would be of much help. Well, not for making an example (gage) anyhow.
I have a spreadsheet that I use for doing thread calculations when the thread is a bastard. I'll include the data for your 1.125-20 thread. These values are all calculated, so, if they differ a little from what you see in a manual somewhere, it's because they use the forumlas from the machinerys handbook and not a table of values.
Sorry, but some of the bold type for headings isn't there, but, you get the idea. Your wire measurements are shown for .0289 wires (mean best size)
FYI, it looks like your measurement of 1.131 is right on the money for a class 2 thread.
1.1315 on a factory large shank here.
Measurement over wires minus constant equals pitch diameter. Constant for .029" wires in a 20tpi thread is .04370.
1.1315 - .04370 = 1.0878
1 1/8" pitch diameter for class 2A is 1.0911 to 1.0866
If you make your gauge 1.092 in pitch diameter all factory barrels should fit and the slop is certainly fine.
About truing the Savage, are you using oversized bolts? Since the bolt head floats and the bolt body has play inside the reciever raceway, you do not need to true the threads to the raceway. At the factory, the lugs and threads are milled in the same set up so the threads are true to the lugs. On the new actions that have the digitized number under the tang, the face is also machined in the same setup so no truing is needed at all.
If you have an older action, thread a stub in your lathe chuck so that your action will screw on. Square up the face of this stub and turn the front 1/2" down to .990" so when you screw on the action, it stops on its lugs against the stub face. This stub is running as perfect as your lathe is capable. If you skim a thou at a time off the action face until it is cleaned up, normally around .003", you will have all three surfaces true to each other. Make sure the lugs action threads are spotless before threading it onto the stub. You can reuse this stub several times by picking up the threads and skim enough off to true them again then reface it.
Cheers,
Rob
Measurement over wires minus constant equals pitch diameter. Constant for .029" wires in a 20tpi thread is .04370.
1.1315 - .04370 = 1.0878
1 1/8" pitch diameter for class 2A is 1.0911 to 1.0866
If you make your gauge 1.092 in pitch diameter all factory barrels should fit and the slop is certainly fine.
About truing the Savage, are you using oversized bolts? Since the bolt head floats and the bolt body has play inside the reciever raceway, you do not need to true the threads to the raceway. At the factory, the lugs and threads are milled in the same set up so the threads are true to the lugs. On the new actions that have the digitized number under the tang, the face is also machined in the same setup so no truing is needed at all.
If you have an older action, thread a stub in your lathe chuck so that your action will screw on. Square up the face of this stub and turn the front 1/2" down to .990" so when you screw on the action, it stops on its lugs against the stub face. This stub is running as perfect as your lathe is capable. If you skim a thou at a time off the action face until it is cleaned up, normally around .003", you will have all three surfaces true to each other. Make sure the lugs action threads are spotless before threading it onto the stub. You can reuse this stub several times by picking up the threads and skim enough off to true them again then reface it.
Cheers,
Rob
Ronnie Maxwell
New member
4MESH,
thanks for the calculations and file. i came up with the 1.1313 by using the formulas in the book as well.
Ron
thanks for the calculations and file. i came up with the 1.1313 by using the formulas in the book as well.
Ron
Ronnie Maxwell
New member
PEI Rob,
Thanks for details, I did not figure in a constant. need to read some more as still new to a lot of this. if making the stub gage to 1.092 will that make a lot of slot?
I usually have a barrel blank and true my Rem's and chamber/thread barrel to fit which is my perferred method. same with my 30BR build on a BAT. but for this Savage (have a couple) rebarrel my issue is i may have to be moving and want to get my receiver trued before hand and have ready to set barrel.
this one is the old Mod 112 in .223, varmint contour (.800 muzzle), small shank, heavy laminant stock, adjustable cheek, by-pod rail system which i piked up used for a little less than $200. so i figured i couldnt go wrong even if bore was shoot out. which it it. group about 4" at 100 yards.
after pulling barrel and checking things out I found the barrel nut was split and most likey caused by the rocking on receiver face, which had half of the face going in one direction and the other part going in the other drection. kind of like a high point almost in center and caused a rocking motion. firgure the barrel just torqued up and down the entire time and eventually split the nut. this alway caused the tenon and receiver threads to get all out of shape. i made a stub gage for the factory small shank thread to check the fit and it is just as slopy as the barrel tenion that you can move it up and down at the tenon a good 1/8" inch. to me this is way to much slop in the threads.
so my plan is to open the threads to the large shank (1.120) (in a .223) and while at it just true to the bolt raceway. this is why i am looking into making the stub gage so i can use that to open the threads up to fit large shank tenons. on this I come up with a minor diameter for the receiver of 1.070, based on my calculations of a 1.1313 stub. any suggestions.
Ron
But here is my/the real issue and the need to cut a stub gage (my thinking anyway, for the above move) is
Thanks for details, I did not figure in a constant. need to read some more as still new to a lot of this. if making the stub gage to 1.092 will that make a lot of slot?
I usually have a barrel blank and true my Rem's and chamber/thread barrel to fit which is my perferred method. same with my 30BR build on a BAT. but for this Savage (have a couple) rebarrel my issue is i may have to be moving and want to get my receiver trued before hand and have ready to set barrel.
this one is the old Mod 112 in .223, varmint contour (.800 muzzle), small shank, heavy laminant stock, adjustable cheek, by-pod rail system which i piked up used for a little less than $200. so i figured i couldnt go wrong even if bore was shoot out. which it it. group about 4" at 100 yards.
after pulling barrel and checking things out I found the barrel nut was split and most likey caused by the rocking on receiver face, which had half of the face going in one direction and the other part going in the other drection. kind of like a high point almost in center and caused a rocking motion. firgure the barrel just torqued up and down the entire time and eventually split the nut. this alway caused the tenon and receiver threads to get all out of shape. i made a stub gage for the factory small shank thread to check the fit and it is just as slopy as the barrel tenion that you can move it up and down at the tenon a good 1/8" inch. to me this is way to much slop in the threads.
so my plan is to open the threads to the large shank (1.120) (in a .223) and while at it just true to the bolt raceway. this is why i am looking into making the stub gage so i can use that to open the threads up to fit large shank tenons. on this I come up with a minor diameter for the receiver of 1.070, based on my calculations of a 1.1313 stub. any suggestions.
Ron
But here is my/the real issue and the need to cut a stub gage (my thinking anyway, for the above move) is
jackie schmidt
New member
Darn, Im sorry about that. I just flat did the math wrong.
Sure am glad you wern't making a 10,000 piece production run off that.
I have a question. What is the class of fit on most actions. I ask this because I have 1.0625 18 tpi barrels that fit one action perfect but will not screw into another, there is obviously some minor pitch diameter differences in what each calls "right"............jackie
Sure am glad you wern't making a 10,000 piece production run off that.
I have a question. What is the class of fit on most actions. I ask this because I have 1.0625 18 tpi barrels that fit one action perfect but will not screw into another, there is obviously some minor pitch diameter differences in what each calls "right"............jackie
Ronnie Maxwell
New member
Jackie,
no problem on the math, that is the reason I posted as I wasnt sure I did the math right myself and as you, now looking for the "best" size to make the stub gage and receiver cut.
hopefully someone else will chime in on our questions.
Ron
no problem on the math, that is the reason I posted as I wasnt sure I did the math right myself and as you, now looking for the "best" size to make the stub gage and receiver cut.
hopefully someone else will chime in on our questions.
Ron
Wayne Shaw
Active member
Jackie, I can't speak to the class of thread fit, but i have found without a doubt one needs to reduce the major diameter of a tenon at least .005, .008 wouldn't hurt. The pitch using wires is the real thing. It seems some actions were threaded with not so sharp tooling.
Just my thoughts.....
Just my thoughts.....
jackie schmidt
New member
Ronnie, That is the big question. Every Gunsmith probably has a different opinion as to just how "loose" or "tight" the barrel to action fit should be on the pitch diameter. When I get a new action, I fit a stub and declare that that is the way I want it, and make them all like that from here on out.
I am watching the end of the Daytona 500 at the moment, 5 to go, and the lead pack just crashed. Get back later.........jackie
I am watching the end of the Daytona 500 at the moment, 5 to go, and the lead pack just crashed. Get back later.........jackie
Ron, the slop I was referring to comes from your max sized gauge VS a min spec sized barrel that may be used in the future. 6 thou is fine. That barrel I checked is 1.1115" major btw.
Making a 338 Lapua out of a Stevens 200 involved rethreading it to a large shank. I just used a barrel instead of making a gauge.
Those dangerous jig screws were replaced.
Making a 338 Lapua out of a Stevens 200 involved rethreading it to a large shank. I just used a barrel instead of making a gauge.
Those dangerous jig screws were replaced.
Last edited:
Ronnie Maxwell
New member
PEI Rob,
yes i understood what you were speaking of and hope my discussion on my receiver excess play wasnt take wrong as i was only pointing out that this one receiver has way to much slope and having the crests (believe that is right for internal for the bore side) of the threads have been rounded way off by the barrel torquing around.
thanks for the photos and it looks great. yea i replaced my dangerous screws as well.
probably best to wait on getting a barrel before cutting receiver for best fit, but would be nice to have a universal gage to go by for a fit all type thing.
Ron
yes i understood what you were speaking of and hope my discussion on my receiver excess play wasnt take wrong as i was only pointing out that this one receiver has way to much slope and having the crests (believe that is right for internal for the bore side) of the threads have been rounded way off by the barrel torquing around.
thanks for the photos and it looks great. yea i replaced my dangerous screws as well.
probably best to wait on getting a barrel before cutting receiver for best fit, but would be nice to have a universal gage to go by for a fit all type thing.
Ron