Gunsmithing Howa mini rebarreled w/ M24 contour?

[BurnOut]

So, one of my more recent brainfarts is to take a Howa mini action that I already own (currently chambered in .223) and have it rebarreled with a 26" M24-contour barrel chambered in .223AI. The question that I have at this point is in regard to the action. The body of the action is 1.18" in diameter, while the breech end of M24 contours are 1.20". So, turn down the first few inches of the barrel to match the OD of the action and Bob's your uncle, right?

Alas, it is not quite that simple. There is a radius on the front of the action that is perhaps .030" or so that would require further diameter reduction of the barrel to not look goofy. My question is, if I have a 'smith turn this radius off the front of the action (effectively truing/squaring the face of the action), would there be any reason why the plan mentioned above wouldn't work? The end goal is a bench-rested prairie dog gun. Would the weight of the M24 barrel be too much for the breech threads of the mini action and/or the open-top design of the Howa? The below pic illustrates the area that I'm talking about:

 

[LRI]

So long as the setup is qualified properly, facing the flange surface back to flush with the recoil lug won't have any problems down the road. Just know it'll alter your overall thread shank length when fitting up the new stick.

Pretty easy stuff. You should be fine.

 

[rookie7]

I had a person in the industry who works with a great variety of actions tell me that Howa is about the strongest action out there. I believe they were referring to the regular 1500 though.

Regardless, I really like the mini and think it is perfect for the 223. I wish there were more stock, chassis, and mag options though.

 

[Supersubes]

That’s a petite receiver for such a heavy barrel. If it concerns you, bedding the first inch of shank would probably take away some stress.

 

[RTH1800]

Bed the barrel, glue it to the stock and let the receiver float. Only way to avoid stress

 

[BurnOut]

All- I appreciate the feedback. This is my first time playing with a Howa of any sort. I'm REALLY impressed with the results when playing with the stock trigger; cutting around 1.5 coils off of the tension adjustment spring, I have mine under 1.5 pounds with a really clean break and drop safe... there's no reason to spend money on the Timney or Rifle Basix triggers for these things unless you just can't deal with a two-stage trigger (IMO).

The execution of this project is at least a few months off, but I want to have all my ducks in a row when it's time to move forward.

 

[Supersubes]

Have you considered just going lighter on the barrel? I don’t think you’d give up anything going with a heavy sporter-ish taper, maybe a number #5 or so.

When my shop is up and running again, my own mini is getting something in the #4 or thereabouts and will be a .20 cal(20-221fb). Seems appropriate given the dimensions of the action.

 

[BurnOut]

Have you considered just going lighter on the barrel? I don’t think you’d give up anything going with a heavy sporter-ish taper, maybe a number #5 or so.

That's a possibility; looking at the numbers from Bartlein (https://bartleinbarrels.com/contours/), though, it looks like there's only a few ounces of difference between a #5 and an M24, though I suppose there could be a difference in the distribution of that weight such that it didn't stress the receiver quite as much...

 

[Supersubes]

The m24 weight is most definitely out front. I would have guessed it was more than .2 lbs. between the two frankly. My Krieger #5 at 20” was something like 3 lbs. Unless I’m building a specialized rig, I stay well away from the bigger straight rapers. Palmas are my go-to. Looking at bartlein’s chart, a med palma, even at 30 inches, saves .85 lbs. from the m24. More still if you chop it shorter of course.


Cool little actions for sure, gonna be a nice project.

 

[flatland1]

I put a Bartlein light Palma 5R 1-8tw in 6RAT with the shank turned down to 1.090", finished at 24" on the first Mini I built. It started out as a 6.5 Grendel w/std wt sporter bbl, and since the RAT is based on the Grendel case, it worked just fine. Turning the light Palma blank's 1.250" shank down to 1.090" resulted in a longer shank, so I shortened it so that there's 1.15" of shank from the receiver face to the first taper of the Palma blank. That's the bbl channel inlet I spec'd when McMillan did a Game Scout stock in desert ambush for it, and the channel they cut is a nice match for the actual bbl contour. Mine weighs right at 10lbs in that stock, with a Warne 20 MOA scope rail/30mm TPS TSR rings on an Athlon Ares 4.5-27x50 scope, DIP aluminum DBM, empty OEM 5rd mag, and a TBAC flash suppressor/mount for the Ultra 7 I use on this rifle. Going with a Krieger #4 sptr would have saved a little weight, but it shot a nice group with about 2.5" of vertical at 600yds a couple of evenings ago, so I guess I can live with a Mini that's not really that light.

I never considered turning off that extension on the receiver face - didn't see the need, and didn't mind turning the bbl shank down instead. Did the same thing on a CZ527 a few years ago, but went with a Krieger #4 sporter at 24". I think that 1.090" dia shank is a good match for these smaller dia actions. I also shortened the actuator spring on my Mini's HACT trigger, and got very similar results to those you mentioned. It's a very crisp trigger, and saved over $100 compared to buying a Timney. Sure gotta watch those tiny little E-clips when you finally get them to slip off the trigger & actuator pins - I had to rob one off an older Howa pre-HACT trigger to replace the first one I flipped off my Mini's trigger.

 

[flatland1]

I've also got a Mini with std sporter contour bbl in 222 Rem that I'm going to re-barrel in 223. I'm after a rifle as light as the Sako Vixen 223 sporter I bought new in 1971. There's a Krieger #3 sporter blank with 1-7tw (would prefer one with 1-8tw) in the shop, and I've got a good 223 Match reamer that's produced some pretty accurate bbls over the past several years. I was hoping that Manners would model the Mini inlet from a Mini in 6.5 Grendel I sold Tom a couple of years ago, so I could maybe get an EH-2 stock for this build. But it seems they've got too many irons in the fire to have time to spare for the Howa Mini stock. Boyds does the inlet on several of their sporter stocks, as well as the ProVarmint, but laminated wood will wind up weighing a bit more than I wanted for this walking varmint rifle.

 

[flatland1]

There's quite a bit of difference between a Krieger #5 (which is a sporter contour) & Bartlein's #5, which is a hvy straight taper target contour. The Krieger #5 is .700" at the muzzle when finished at 26"; the Bartlein is .820" at the same length. Krieger #5 weighs 4lbs, while the Bartlein runs 6lbs.