Sako tenon

C

Chuck W

Guest
I've been lurking here for some time and have learned quite a lot. I have modified some of my barrel and general machining approaches from the info gathered here. Thanks to all.

I have a Sako L61R magnum action and am getting ready to chamber a barrel for it. I got the action without a barrel or stock so I can't measure the tenon. Does anyone know what the tenon for this action measures? Also, how do you measure the major diameter of internal threads?

Thanks in advance for any help.

Chuck
 
Wow, Don't mean to sound flippant here but I think you need to see a qualified smith for this job. The simplicity of the jobs you mention would leave me to believe you are gonna be over your head with this.
 
Jkob

"The simplicity of the jobs you mention would leave me to believe you are gonna be over your head with this."

Not to sound more flippant than your reply, however, this isn't my first rodeo. Even though I'm not a qualified Machinist or a Benchrest gunsmith, I've chambered several barrels for my varmint rifles (.243AI & .250 sav AI), elk rifles ('06 AI & .35 Whelen AI) and a couple deer rifles( '06 and '06 AI). On one of my varmint rifles I trued the action and sleeved the bolt. I'm not sure but those don't sound like "simple" jobs. I have pillar bedded all my rifles, made the pillars myself. (that was "simple) I've done trigger and spring work on all my revolvers and slicked up a few.45 ACP's. I could go on, but I don't type very well, so I'll hope I have made my point.

As far as the Sako goes I found a factory Remington 700 barrel will screw in but it feels a little loose. I asked for the tenon measurements to make sure there is proper fit. I already know the threads are 16 TPI, just don't know the exact major diameter. Not a difficult question. If someone knows the answer I would greatly appreciate it.

Chuck
 

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16 tip? it could be metric?

sako have used both metric and unified threads , so check with a pitch gauge frist !

as for finding the major size measure the inside across the tops the add (2x the thread depth which is 0.03834'') i alway and a extra .005 then work till the action fit nice

next the tenon as small a parelle section the same diameter as the bolt ( the lenght of this is 1/8 '' )

my sako l579 was metric

hope this is help full !
 

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Chuck

I always believe it's better safe than sorry. If it was me I'd take all the measurements and info I could get my hands on and then make a barrel stub out of brass or bronze until I got the fit I wanted. That stub can stay with the rifle for the next guy who owns it. Who knows, someone may have trued that action before you got it and the existing dimensions don't match the factory specs.

JMHO

Ray
 
Enfield,

It's unified, the first thing I checked. 16 TPI drops right in and the Rem barrels screw all the way in, just a little sloppy. Thanks for the math. Is your Sako a magnum? I was wondering what purpose the parallel served. The threads in my action go in to the level of the extractor.

Ray,

I have a piece of brass that'll work great for a stub. Good idea.

Thank you both. Now I need to finish another .250 AI that's in the lathe and get measuring and make that stub. So many projects, so little time!
 
it was .308 min

mine was .308 but you be able see to if you need the paralle bit ( sounds like your dont) it gose in passed the threads and locatas in the same bore as the locking ing lugs, the bolt nose clearance is important ot the extrcar dose not work! try to get hold of metric thread guages as the defrance in pitch is only .003'' so a verey slak 16 tpi well fit but i would have dout it was safe just please check it and make shoure

buy the way the thread data comes a paocket ref refance book form zeus precision chats
 
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Chuck, Just looked at my chamber job note book. I have done 12 L-61 barrel jobs of various calibers. All were 1.050 x 16. It does not take a rocket scientist to figure out what the tenon should look like. The pictures of your work show that you can easily figure this out.

Don
 
Chuck W, The Sako L579 has a thread O.D. of 1" dia with 16TPI. The Sako L-57 had an O.D. of 25MM and 1.5 MM thread. The Sako L-46 O.D. is .855 and 16 ...I picked this up someplace and can't verify. All but the one you need. Kenny
 
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If a 1.050 -16 thread is what the action is supposed to have, then the action that he has must have been opened up at some time or another. An 1 1/16 -16 thread shouldn't screw into a 1.050 -16 thread much less be loose. I go with Ray's suggestion and make a trial barrel stub before you thread the barrel. At least that way, you'd know what you have before you work on the barrel.
 
So, what happened to good old machine shop practice of measuring the internal thread and machining the male threads to fit. Did you miss that lesson in trade school?
 
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