Gunsmithing Howa Mini 1500 stock fitting.

[LRI]

The word I get is that the more popular aftermarket composite stock companies have elected to avoid the Howa Mini 1500 action. My suspicion is that doing so would require some significant costs with retooling molds as the tang geometry is a fairly large departure from what is typical these days.

So, smelling fertile soil, we dove in headfirst to see what it takes to make it run. Our little FB LRI "Clip of the Day" vid covers the cliff notes on what we have going on and how we got there. As mentioned, the tang took a little work to get right. Fortunately working with composite materials is a low-risk thing for us.

The stock hasn't gone to finishing yet, but the heavy lifting is all done now. Kinda cool. We'll be adding this to our lineup from here out.

Thanks for looking.

C.





Step one: Getting everything modeled up so that we have some idea of how the toolpaths need to be applied.



Two: Test pieces. New jobs like this are always vetted with lumber. We kill quite a few trees here... Top and bottom



2.1: Test fitting and killing more trees.



Four: Inlet and make a "skin graft" to cover up the scab on the tang.

 

[LRI]

Five: Post machine work mockup. Its all pointless if it doesn't function to standard. When feeding issue topics with DBM's pop up here I like to try and help by describing the methods we use. The whittled down rule I try to follow is the "figure 8". An "8" is basically a pair of tangent arcs sitting on top of one another. When a center-fed magazine works properly it almost always presents the cartridge to the bolt face in this manner. The primer will lie tangent to the receiver bore, thus exposing the proper amount of case rim to the bolt nose for peeling it off the magazine. So long as feed lips of the magazine don't drag on the bottom of the bolt, you really can't have too much of this overlap. More is always better because one must be respectful of the change in pitch as the cartridge travels up the feed ramp. That angle becomes even more aggressive with short/fat cartridges featuring a steep shoulder angle. (BR's, Dashers, etc)

The general theme I've come to follow is that in a center feed magazine, the magazine should hang onto the case a bit longer in the feed stroke than with a control round feed. Doing so gets the bullet up the ramp and into the breech ring. This is why the overlap with the bolt nose/case rim is so important.

The trick here is maintaining that height which is controlled by the floor metal. Very, very few floor metals have the ability to tailor the installed magazine height while also presenting the floormetal flush to the belly of the stock. Here is where a wood stock is much easier to work with. You simply file it down and blend with sandpaper. Composites don't allow for this convenience. It's not always possible to get it 1:1. What compounds this further is that the draft angles vary from manufacturer and with different stock models. 2.5 to 3 degrees is the norm. A half-degree difference may not sound like much, but over a 6.5 to 7-7/16 span it pencils out to a difference of as much as .07" of an inch. Good carpenters work inside that...



Six: These actions require some unconventional thinking with regards to pillar construction. As always, we use stainless instead of aluminum.

 

[rookie7]

What cartridge and barrel profile is the mini?

 

[rookie7]

Nice job and video.

 

[Elnicko]

It’s a 17 fireball with a pac nor #4. Looking good Chad!

 

[BurnOut]

Very nice! As a Howa mini action fan, I commend you for pursuing this!

 

[BadAccountant]

Five: Post machine work mockup. Its all pointless if it doesn't function to standard. When feeding issue topics with DBM's pop up here I like to try and help by describing the methods we use. The whittled down rule I try to follow is the "figure 8". An "8" is basically a pair of tangent arcs sitting on top of one another. When a center-fed magazine works properly it almost always presents the cartridge to the bolt face in this manner. The primer will lie tangent to the receiver bore, thus exposing the proper amount of case rim to the bolt nose for peeling it off the magazine. So long as feed lips of the magazine don't drag on the bottom of the bolt, you really can't have too much of this overlap. More is always better because one must be respectful of the change in pitch as the cartridge travels up the feed ramp. That angle becomes even more aggressive with short/fat cartridges featuring a steep shoulder angle. (BR's, Dashers, etc)

The general theme I've come to follow is that in a center feed magazine, the magazine should hang onto the case a bit longer in the feed stroke than with a control round feed. Doing so gets the bullet up the ramp and into the breech ring. This is why the overlap with the bolt nose/case rim is so important.

The trick here is maintaining that height which is controlled by the floor metal. Very, very few floor metals have the ability to tailor the installed magazine height while also presenting the floormetal flush to the belly of the stock. Here is where a wood stock is much easier to work with. You simply file it down and blend with sandpaper. Composites don't allow for this convenience. It's not always possible to get it 1:1. What compounds this further is that the draft angles vary from manufacturer and with different stock models. 2.5 to 3 degrees is the norm. A half-degree difference may not sound like much, but over a 6.5 to 7-7/16 span it pencils out to a difference of as much as .07" of an inch. Good carpenters work inside that...

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Six: These actions require some unconventional thinking with regards to pillar construction. As always, we use stainless instead of aluminum.

View attachment 7325884View attachment 7325885View attachment 7325886View attachment 7325887View attachment 7325888

Chad, you beautiful bastard. My wife just got a Howa mini Grendel build.

 

[sjg]

Final assembly on this girl today, she didn't turn out too bad.

 

[Elnicko]

Beautiful! Came out great

 

[rookie7]

That's the best looking Howa mini I have ever seen! Perfect!

 

[DedicatedShooter]

Great to see someone else getting behind the Mini Action!

 

[BadAccountant]

6 ARC...

 

[Supersubes]

$64,000 question. When will you take my money for one of these Chad?

 

[LRI]

$64,000 question. When will you take my money for one of these Chad?

For $64,000 you get to move to the front of the line, lol.

Hand it over.

 

[Bache Kermooni]

You guys did the bolt work on my Mini last year. Love it. I wish you had this stock then. I ended up with a Boyd's cuda inletted by my GS. PacNor is awesome. Are they open yet?

 

[Gregor.Samsa]

Final assembly on this girl today, she didn't turn out too bad.

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That paint scheme kicks ass!

 

[sjg]

That paint scheme kicks ass!

"Ripzilla", in-house stencil. Here are a couple more..

 

[Bache Kermooni]

 

[flatland1]

I missed seeing this thread from a couple of years ago - if it hadn't appeared below your new thread on modeling the Sako 85 inlet in the "Similar threads" box, I'd probably never have found it. Very cool work, always like seeing Howa Mini builds & innovation. I'd been looking for a 'petite' action for 6 RAT builds, thinking along the lines of the Sako 6PPC actions for several years. But even if I could've found a few reasonably priced Sako PPCs, I didn't want to part them out just for the action.

So when Howa brought out the Mini in Grendel, I jumped all over it, even though - by that time - I'd done a 6 RAT on a CZ527 carbine in 7.62x39. Never did get the CZ magazine to feed with 100% reliability, but the one I did the RAT on was an attractive, well-proportioned little rifle, with a Krieger #4 sporter bbl finished at 24". At last count, there were 5 Mini-based custom rifles here in the office - in chamberings from 20 Tactical, 223AI, 22 Grendel (soon to be punched out to 22 GRINCH), 6 RAT, and 6.5 Grendel. To be honest, I never considered asking you guys to spiral flute a Mini bolt, but it looks very cool in your photos. McMillan did a Sako Varmint stock for the RAT rifle, but I was not that happy with it, only because I didn't like it in prone. I sold that stock to another online Mini owner, and asked McMillan to do a Game Scout for that rifle, which I like very much. The 20 Tactical is in a Boyds Varmint Pro w/adjustable cheekpiece, and it's a good fit for the Mini. The last three rifles used B&C M40 & sporter style stocks, one of which is the 22 Grendel, and it's the only one that's ever given me more than minor feeding issues. I milled the bottom inlet .020" or .030" deeper for the DIP aluminum DBM in an attempt to get it to feed better - and it helped. But it's still not close to 100% reliable, and I'm reluctant to go any deeper. I hardly think that turning this rifle into a 22 GRINCH is going to help the feeding, but what have I got to lose at this point?

Would really like to hear & see any further developments you've come up with for the Mini actions...