Project Sowa - Converting a Howa to Savage thread pattern.

BallisticsGuy

Well-Known Member
Joined
May 8, 2016
Messages
1,377
Location
Heck
I'm building a match rifle based on a Howa action and last night while I was at the gunsmith we both realized about at the same time that since the Savage thread major and minor dimensions are fatter than for the Howa that I could just have the Howa receiver re-cut for Savage threads since the major and minor dimensions on the Howa are all smaller, meaning that there's more meat left in the receiver than in a Savage. Both guns have a 1.350" receiver OD so there's plenty of material to support a Savage small shank spec thread being cut into the Howa. This will allow me to use drop-in pre-fit Savage small shank barrels and makes it so my gunsmith doesn't have to set up his lathe for metric which is apparently a PITA.

There's already a Howage barrel nut system offered by McGowan which really bugs me because now I have to come up with a different portmanteau of Savage and Howa so as to not collide. Maybe Sowa? Definitely not Sowage, that's a poopy name. I'm down for some ideas. Perhaps we just go ahead and make up something.

I wonder if this mod might get more popular. It seems to me that there's no reason for it to not.

So, obligatory cruddy pic of what we're dealing with. Here's the base rifle which was a tapered barrel .308 sitting in a Postman Precision Howa chassis which is undergoing a paint job now. I have a 6mm barrel from Columbia River Arms that I put 1800 rounds of .243AI through with 115's at ~3200fps. It eroded the throat enough that ammo got longer than the mag but we gauged the barrel and it's the same internal diameter as it was when I first got it so we're cutting 2" off the back end and rechambering it in 6XC. CRA barrels don't have conventional rifling and I'm trying to find out exactly how far one can take one when pushing it hard.
fullsizerender-2.jpg


I really dig on this chassis. I can't get enough of it. The familiar features of adjustable LOP/cheek rest height/butt pad height are all there and it's got an embedded bubble level that I actually don't have to break my cheek weld to see but the really cool one is that the pistol grip can be slid forward or back to give you just the right reach to the trigger. Handy if you suffer from stubby-ness like I do or if you've got particularly large meat hooks.
 
Don't use savage threads, use standard Remington threads. The Howa threads are closer to 17tpi, using remage barrels because they have the counter bore already, savages barrels don't.
 
Is the counterbore really necessary? It's an extra margin of safety in theory but I question the utility. I also don't do much with Remingtons but I have a ton of Savages.
 
Technically you can run without a bolt nose recess but if you look at the extra support and thickness of a flat bolt nose vs a recessed you can see what ends up in your face if the worst happens, the bolt noses tend to stay in place in the counter bore when they blow from what I've seen.
The Howa is also a cast action, I don't know how I would feel about opening one up, over the years the consensus has been to leave them and thread them metric which is no issue.
 
Well, it looks like my gunsmiths have kiboshed the notion of converting to a savage thread. I don't know why, they just said, "Nope, won't do it." and left it at that. So the barrel is being cut for the metric thread now and I've ordered a McGowan Howage barrel nut. Sigh. Just once I'd like something to go to plan.
 
In the meantime, I've gone ahead with experimenting with the paint job. For those that don't know me that well, I have a tendency to paint my rifles in unconventional themes. I did one of my rifles up in a Deadpool (comic book character, not the Dirty Harry movie) theme. Since Deadpool seems to share a lot of inspiration with (if not being an actual ripoff of) Deathstroke I'm doing up this rifle in a Deathstroke theme. Both rifles are 6XC's that I use in matches though I think I'm going to take one to South Africa with me next year to hunt with.

Deadpool:
deadpool_photo.jpg
deadpool_gun.jpg


And now Deathstroke:
10-26-deathstroke-arrow.jpg
img_41431.jpg


Still gotta get around to painting "Chimichanga!" on Deadpool and "Sweet Christmas!" on Deathstroke.
 
They are but that's almost meaningless in the context of the rest of the thread. Metric units of measure can be converted to non-metric units of measure, just usually not super cleanly. The normal Howa thread is M26x1.5mm which would convert roughly to 1.03"x16.7TPI which isn't far off of Femington or Savage threads (certainly it's not interchangeable though). My gunsmith is very unexcited about having to cut metric threads because it requires him to do some things with the toolhead to reset after each pass that he normally doesn't have to do.
 
They are but that's almost meaningless in the context of the rest of the thread. Metric units of measure can be converted to non-metric units of measure, just usually not super cleanly. The normal Howa thread is M26x1.5mm which would convert roughly to 1.03"x16.7TPI which isn't far off of Femington or Savage threads (certainly it's not interchangeable though). My gunsmith is very unexcited about having to cut metric threads because it requires him to do some things with the toolhead to reset after each pass that he normally doesn't have to do.

You can't disengage the half nut when threading metric. I've done it but I'm no pro at it. Why not just due a shoulder less prefit with a nut? I know a few places offer them now for Howas
 
That would entirely negate the whole reason for using the barrel that I'm using. I'm trying to find the maximum bore life of a Columbia River Arms/Black Hole Weaponry 3-land polygonally rifled barrel. The one I'm using already had 1800 rounds of very fast moving .243AI's through it. I'm going to follow that up with as many 6XC's as I can push down it while occasionally measuring minimum bore diameter and keeping an eye on grouping and velocities.
 
The simple method of working with metric threads is to use a CNC lathe where you program the thread form and cut away. No gear changing, no headstock manipulations, no leaving the lathe in gear, etc. Write the program, set X and Z then run. I can thread just as many metric barrels as I can Unified Thread Standard threads. I have the Accuracy International metric threads programmed into my machine and simply select the action thread for the barrel. I don't need their action at all. :D
 
You can't disengage the half nut when threading metric. I've done it but I'm no pro at it. Why not just due a shoulder less prefit with a nut? I know a few places offer them now for Howas
I watched my gunsmith do it. He disengaged the half nut, then ran the lathe backwards and re-engaged on the same number he started with.

He just backed it out for every pass.
 
Warning! This thread is more than 5 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.
Top