Sako A111 threads and?

[Cloudrepair]

The reciever threads Have any of you guys chased/trued the threads on one.
Have you threaded it at 1.062-16 and have good results or did you need to do it at 1.5 mm pitch?

 

[Dusty Stevens]

Ive heard of cats threading them to 16p. Either theyre already 16 or close enough by the time they clean up they are 16. Bout like a ruger or browning you wont get many opinions on truing a sako either

 

[GenePoole]

Hmmm. 1.5mm is about 16.9 TPI. People are really threading 16 TPI and it works? I find this hard to believe.

 

[Dusty Stevens]

Yep. Been lots of talk on this for years. Started out with somebody with no metric change gears or somebody ran a manson tap into one trying to true it not knowing it was 1.5

 

[Cloudrepair]

Thanks Dusty
What would you do
Say you already have one the barrels pitted and worn with some rust spots inside and out (how I got it )
But the action is in great shape with a good trigger in it?

 

[Dusty Stevens]

Id put a new barrel on it- with the correct threads.
Or if youre an experimenter change it to 16. If it was my personal action with no sentimental ties id make it a 16- ive had to trash more than one action in my days but most times things work out

 

[Cloudrepair]

I chambered up a Wilson barrel in 280Ai and threaded it 16tpi and made a custom barrel nut for it.

The reason I brought this all up is because I wanted to know from someone that may have done it already (changed it to 16tpi).

On another thread the issue (if you can call it one) of a few threads taking most of the load came up and I thought the 16tpi would be a good one to try an idea on.
A double barrel nut, the first one that locks it to reciever would have a positive angle cut in it and a matching negative angle in second one to lock the first one down like a jam nut increasing the load on the last threads of the first nut.
You wouldn't need as much torque for a secure fit.

 

[Dusty Stevens]

Nah dont worry about a nut just set it up and true it with 16tpi threads and put a barrel on normally.

 

[GenePoole]

Looks like the 1.5 mm figure is wrong. A search shows them to be 1.6mm. This would be 15.875 pitch which makes it a bit more believable that this would work when punched out to 16 TPI.

 

[Alex Wheeler]

Not related to your question, but when you set out to test a new idea like your double nut idea how are you going to prove it made an improvement? Either you need some equipment capable of measuring movement in the thread joint or you need to be able to shoot smaller aggs than it shot with a shoulder. To rely on the shooting to be the proof, you need to have a rifle capable or world record accuracy and the shooter to match. When I want to try an idea I get with the best shooter I can find and will watch trends. Usually trading labor for feedback. It takes multiple barrels to see trends before you can start to make conclusions on whether the idea is better than the old way. We are at the point where there are no obvious or big accuracy gains to be found IMO.

 

[Cloudrepair]

Not related to your question, but when you set out to test a new idea like your double nut idea how are you going to prove it made an improvement? Either you need some equipment capable of measuring movement in the thread joint or you need to be able to shoot smaller aggs than it shot with a shoulder. To rely on the shooting to be the proof, you need to have a rifle capable or world record accuracy and the shooter to match. When I want to try an idea I get with the best shooter I can find and will watch trends. Usually trading labor for feedback. It takes multiple barrels to see trends before you can start to make conclusions on whether the idea is better than the old way. We are at the point where there are no obvious or big accuracy gains to be found IMO.

Thanks Alex
The idea was to improve the nut design.
Can it make the nut design more accurate maybe not make the system work better maybe. Maybe a answer looking for a question?
Will it do what it't purpose is?
I think so.

 

[Danny1788]

Ive heard of people doing this to Howa 1500 actions as well. Ive never tried it but id like to hear from people that have changed them to 16tpi as well.

 

[Stan Taylor]

Thanks Dusty
What would you do
Say you already have one the barrels pitted and worn with some rust spots inside and out (how I got it )
But the action is in great shape with a good trigger in it?

Have you remove that barrel yet.

 

[Cloudrepair]

Have you remove that barrel yet.

Yes I have a aluminum action wrench I made for a mauser that fit it good and worked great with the barrel vise I made also

 

[SBS]

Looks like the 1.5 mm figure is wrong. A search shows them to be 1.6mm. This would be 15.875 pitch which makes it a bit more believable that this would work when punched out to 16 TPI.

1.6 is correct. Same as for the medium Sako action which has a 25mm OD thread. This makes the threads .063 apart compared to .0625 for the 1-16. Not much, but when fully threaded (about 8 threads), there is a .004 difference at the end.

 

[Cloudrepair]

1.6 is correct. Same as for the medium Sako action which has a 25mm OD thread. This makes the threads .063 apart compared to .0625 for the 1-16. Not much, but when fully threaded (about 8 threads), there is a .040 difference at the end.

Do you mean .004 difference in 8 threads?

 

[Stan Taylor]

Yes I have a aluminium action wrench I made for a mauser that fit it good and worked great with the barrel vise I made also

What did you come up with as far as od of the threads.

 

[Cloudrepair]

What did you come up with as far as od of the threads.

I think It was 1. 057 i pulled it a while ago
I'l check tonight when I get home I'll measure the pitch again to.

 

[Dusty Stevens]

I think youll see 16tpi when you get it measured. 1.040 something i think. Too many sakos out there

 

[Stan Taylor]

I think It was 1. 057 i pulled it a while ago
I'l check tonight when I get home I'll measure the pitch again to.

The reason I am asking is my book at work says it is a shank diameter is 1.040 x 16 tpi. PS that is for l61 A111 AvSako action.