Sako / tikka barrel tennon?

[X Count]

Rito. . .. a friend has a barrel threaded for a Sako 85 and I'd like to screw it into either a Sako 75 or a tikka T3.

From what I've read there seems to be a lot of debate as to if the threads are metric or imperial and if or when they changed from imperial to metric or vice versa in the earlier and later models. Some say that the threads are actually metric 1.6mm pitch but it's close enough to 16tpi that they just force it on anyway.

I'd like to know what the ACTUAL thread pitch of the actions are and if the 75, 85 and T3 are interchangeable in both thread pitch, diameter and head space (good enough for a wildcat 6 dasher).

 

[Will Henry]

The Tikka barrel I checked is absolutely 16 tpi. An L579 barrel I checked is absolutely 1,60mm. I don't have a 75 or 85 barrel here to check. WH

 

[X Count]

Thanks Will. Was that a tikka T3 or an earlier model? How did you go about checking the pitches?

The difference is about .00075"/ turn so not a huge amount to measure but its probably going to be .008" over a tennon length

 

[Will Henry]

It is a T3. I used thread pitch gauges. As you said. there isn't much difference , but there is enough that it is obvious with the gauge, WH

 

[X Count]

I wasn't sure how feasible it would be to pick .004 over the length of a gauge so that good to know!

 

[Bat Rastard]

Slightly off topic, but I think you are the guys who will know the answer:

I have heard it is tough getting the factory Tikka barrels off the first time.
After the initial removal, do they go off and on easily?

 

[Will Henry]

The last one I removed was pretty damn tight, but fine once it broke loose. It took a couple of solid smacks with the three pound hammer to break it loose. The thread fit was unremarkable, but it was torqued right up. WH

 

[CCM]

Slightly off topic, but I think you are the guys who will know the answer:

I have heard it is tough getting the factory Tikka barrels off the first time.
After the initial removal, do they go off and on easily?

I've only had a couple that I've really had to work at. Most pop loose fairly easily with some hammer work. Trying to do it without the shock of the hammer sucks.

 

[Doug Beach]

The Tikkas are 16 tpi, for sure. Cut to standard pitch diameter, thread right on. No forcing required.

 

[JMA]

I wasn't sure how feasible it would be to pick .004 over the length of a gauge so that good to know!

Hold with light coming for behind .004 is very easy to see

 

[Will Henry]

With the wrong pitch, the gauge rocks. If the pitch matches, it will not. WH

 

[LVLAaron]

never had a tikka in the shop... but I have a brand new take off barrel for some reason.


16TPI - .9934 major diameter

 

[Carl S]

Tikkas -Sako 1"-16tpi

 

[joshb]

never had a tikka in the shop... but I have a brand new take off barrel for some reason.


16TPI - .9934 major diameter

What is it? I may want it!!

 

[jackieschmidt]

There is around .0004 difference in the pitch of a 16 tpi and a 1.60 mm thread.

just my opinion, but that’s a little too much over the length of the tenon.

If you had access to a suitable lathe, you could Chuck the barrel up, set your thread to 1.60mm, engage the half nut on the lathe and catch the thread exactly in the middle of the tenon. It will then cut a little off one side on one end, a little off the other on the other.

in other words, you will be splitting the difference. The thread might end up a little loose, but it will closer to the correct pitch.