Howa Mini actions, custom chamberings, max OAL?

[Justin Utherdude]

Howdy guys.

I'm mostly a long action guy, but a nifty howa mini build caught my eye and got me wondering. Does anyone know what the max OAL length is for the mini magazines, and maybe the max cartridge size/diameter? Could you get a barrel chambered in 223 wssm to fit, or something similar?

 

[Steel Mover]

Howa Min action:

• Mini Action Calibers: .223 REM, 6.5 GRENDEL, 7.62×39 & 350 Legend

So if you bought a mimi Action w bolt the AR-15 cartridges based on the 223 or 7.62x39 could be used with a rebarrel, like the 6mm TCU, 6mm Mongoose, 6.5 Grendel, etc.

 

[memilanuk]

So if you bought a mimi Action w bolt the AR-15 cartridges based on the 223 or 7.62x39 could be used with a rebarrel, like the 6mm TCU, 6mm Mongoose, 6.5 Grendel, etc.

...or .22 ARC or 6 ARC.

 

[ShaunBrady]

^^^^^^^^^^^

22mm, 0.866" barrel tenon, 0.616" bolt body, so 7.62X39 case heads are a good upper limit on diameter.

The Howa 7.62X39 magazine has an internal length of 2.35".

 

[Justin Utherdude]

Well the 7.62x39 is an 11.35mm/.447in case head... and the 223 wssm is 14.1/.555 . So that kind of squashes that plan. I guess that's why one of the chamberings was 22 ARC. I figured that it might be fun to build one of these with a 14in 224 barrel with a 1/7 twist. I thought bumping up from a 223 to something bigger would help regain some of the velocity lost by both shortening the barrel and going with heavy pills.

I may need to reconsider. I'm wondering how useful it would be to have a mini over just getting a normal action where I wouldn't be quite as limited. Still, I see the howa actions on sale every now and then, so they are tempting.

 

[ShaunBrady]

I bought a Howa Mini 7.62x39 barreled action several years ago when Brownell's was clearancing them for $125. Mostly because it amused me to buy something like that for such an absurd price.

A couple years later, I bought an MDT Oryx chassis for it during a Black Friday special.

The original idea was it'd become a 6.5 Grendel that wasn't constrained by bolt thrust or gas system timing.

 

[Justin Utherdude]

I mean, they're stupidly affordable. Maybe I'll just do 223 AI. I was looking at the jtac elf owl or something similar.

 

[ShaunBrady]

I may need to reconsider. I'm wondering how useful it would be to have a mini over just getting a normal action where I wouldn't be quite as limited. Still, I see the howa actions on sale every now and then, so they are tempting.

The largest attraction for me is the cleaner feeding and extraction of the mini actions that the smaller diameters give with the shorter cartridges.

The magazine isn't long enough to max out the 223 with 75+ grain bullets, but it is long enough to get more from the 7.62x39 variants than the AR15 magazines they were designed for.

The Howa's are a simple design, but it's well thought out and cleanly executed. They don't have the aftermarket support of the R700 pattern but everything I need is available.

On the cost side, a rant by a colleague about the economic realities of his wife's free horses comes to mind.

 

[TrapperBR549]

I have a 6mmARC heavy barreled action from Brownells. I like the gun but the bottom "metal" did not suit me. There are a few options, I like the "ADL" bottom metal, but none are super cheap so take that into consideration.

 

[jackieschmidt]

A good friend wanted to re barrel his Mini, but his lathe does not cut metric.
So I got him to send me the action, and I set it up and converted it to a 24 TPI. I also made him a barrel tenon gage.
A question. Are these little actions made by some type of investment steel casting. The steel was fairly hard, but shavings came off in flakes similar to some powdered metal pieces I have machined. That, and there doesn’t seem to be a machine mark anywhere aside from the tapped holes.

Anyway, it came out good, and the threads snd action face are now dead true with the bolt way.

 

[17cal Fan]

I rebarreled a mini 223 into a 221 FB and it's a blast. Had some feeding issues with the plastic mag but think I got that resolved. Put mine in a Boyds Spike Camp stock and it's handy as a pocket on a shirt.

 

[Jon Leary]

A good friend wanted to re barrel his Mini, but his lathe does not cut metric.
So I got him to send me the action, and I set it up and converted it to a 24 TPI. I also made him a barrel tenon gage.
A question. Are these little actions made by some type of investment steel casting. The steel was fairly hard, but shavings came off in flakes similar to some powdered metal pieces I have machined. That, and there doesn’t seem to be a machine mark anywhere aside from the tapped holes.

Anyway, it came out good, and the threads snd action face are now dead true with the bolt way.View attachment 1709102View attachment 1709103

Are they originally 1 mm thread ?

 

[jackieschmidt]

Are they originally 1 mm thread ?

Yes, the pitch is 1mm, really close to 24 tpi.

 

[D-mon]

I would not put a 223 wssm case in there, but I have a couple in 450 bushmaster ( 308 bolt head). I rebarreled one in 338br. And that works pretty well.i was going to rebarrel the other one in 458 socom, but I realised that this would involve milling out or removing some material of the rear bridge just above the right race way to be able to have the case eject properly. I left that project aside. I know someone who rebarreled his in 20 br.

 

[JPB3]

And the factory barrel is TIGHT, at least it was on this one..

Jackie was very kind and generous with his time to thread this action to 24tpi. I then was able to barrel it and put the barreled action in a Stockys carbon fiber stock. These stocks weigh in at 21-21 oz and seem very well done, I have a couple of them. I used Jefferson Outdoors BDL type bottom metal. The mag box allows 2.450'' OAL plus a little.. This one is a fast twist .223. Makes for a very nice little rig!