Chuck, thanks for the answer to my question. Not knowing how the action was fixtures during manufacturing. What I understand you saying is the action was fixtures action face up and the receiver face was milled flat in the x, & y axis and then the receiver was bored and threaded in the z axis. 
Cheers Richard

Richard, That would work if you have threading capability on the mill.
Generally use the lathe as shown in the pictures.
If the action is pretty well complete, might look at Greg's (GT) fixture to hold the action.
Chuck

calledflyer wrote on Nov 30^th, 2021 at 8:52am:

Why is that? Extensive testing of 22RF ammo has shown that anything over 18" is primarily for looks and longer sight-picture as it has no relation to accuracy. If using a scope there is no reason for a longer barrel. 
That said, my shortest 22RF barrel is 23". I like the looks of the longer barrels. 

Even if I lost velocity, or had a scope, I'd still not own a .22RF single shot with a barrel less than 24", and most of mine have 28"-30" barrels. Beyond the better looks, and sight radius, I like the balance also.
I have a full size Rolling block that came with a new 22" half octagon barrel, and shot very well. But looked hideous with 11" of octagon, and 11" of round on the full sized action. We turned down the round portion, and used a 19" piece of old .45 barrel to press over it, and but to the octagon. It now looks and balances wonderful, and still shoots like it did before. 
If I ever built another .22 single shot I'd use a 22" barrel and the bloop tube extension to do this same thing again.

I’m going to open a can of worms here about the length of a 22rf barrel longer than 18” benefiting more than just aesthetics and sight radius.  I have built 14 rifles now for this little cartridge – in single shots, a few more in gate latch and semi-autos and nearly twice that many more in the works, (it’s a disease) all but a couple have barrels that exceed 28”.  Several have 30” RKS barrels, most of these are gaintwist, and several are left hand… a personal preference…  I shoot mostly open sights but that isn’t the sole reason for the extra length.  Once the barrel has been either seasoned, (about 2K rounds fired through it to smooth the bore) or it has had approximately one round for every inch of barrel fired through it before data is collected, I’m not seeing validity to the rumor of a longer barrel slowing down the projectile… My average velocities have increased as a rule -due to the consistent distribution of lube?  I did experiment with pre-lubing the barrel but trying to match the Mfg.’s lube is challenging.   I've had some intense objections about the velocity comparisons I've done because the barrels all differ, but the longer barrels have averaged higher velocities than the shorter barrels using the same ammo when these procedures are followed.   

The other real interesting note with the longer barrel – the velocity Standard Deviation dropped in almost every case.  This is using a LabRadar for data collection.  Several of these rifles have produced consistent single digit SD’s and the vertical string at further distances (250 - 400-yard experiments) has coincided with these results.  Head and tailwind contribute to vertical but in my case, I have a severe obstruction at my range that creates a consistent variance from the 3 o'clock position so my horizontal is generally frustrating at these distances.    
   
There are a few of us locally building/built with these features, there’s more experimenting happening with different chamber configurations and most recently, some changes in twist rates.

I picked up a Pope-Ballard that has a 28” barrel that may have instigated this pursuit, not that I wasn’t already on this path, but the ODG’s had an idea I think.   This rifle gave me some data that made me pursue the subject further, several different brands of ammo gave impressive groups and most gave very low single digit SD’s.   It may be just a Pope thing – but interesting to say the least. 
My 2¢
Greg

All I will say here is that Merkava has little understanding of fishing equipment. Or .22 shooters. 
I don't get involved with the competitive rimfire guys because the 'serious' centerfire crowd is pretty intense itself, and the double-deuce contingent is about rabid. Carry on fellows. I'm done here.

No understanding of fishing equipment or 22 shooters.
Send me your resume.
If you were sitting in a restaurant, with a bunch of fellows discussing 
.22 rifles or fishing equipment, would you talk to them the same way 
You do here??
I think not.
Hide behind the computer screen.
You are a legend in your own mind.

I don't take bait- how's that for fishing expertise?