Howa Mini Rifles, Builds, and Upgrades

[Ferrulewax]

There are quite a few howa mini build threads and questions scattered around the forum but I thought it would be nice to have one thread to compile and discuss builds on this particular platform. Here are some of the threads and discussions that inspired me:

6mm ARC Lightweight Backpacking Rifle Build

Thought others might be interested in this build. I have had an interested in adding a lightweight deer and goat rifle to the quiver for some time. As I have two other rifles that cover most of my Elk/Deer hunting I wanted to take a budget friendly approach as this rifle would only be used on...

rokslide.com

Mini Howa Build: open bolt face for 6 BRA

This is for @Jbuck but figured I'd start a thread on it. Richard Luna of Bring the Edge, a small shop in NM did the work. He has done lots of barrels for me and they all shoot. I wanted a little backpack rifle in a small caliber, but with some ooomph. I have a bunch of 6mm bullets and 6 BRA...

rokslide.com

Lightweight Howa Mini Builds - .223 Rem & 6.5 Grendel

I recently decided to buy or build myself a lightweight .223 after moving to AZ and realizing that any game I could hunt with any regularity in the state could be handled just fine with a .223. After soaking in all @PNWGATOR's thread ".223 for bear, deer, elk and moose" had to offer, and...

rokslide.com

Although most of these builds are for western style hunting and ranges, the primary focus for my rifle was for shots inside of 100 yards for bear, deer and Hogs. Because of that I went ahread and chopped down the factory barrel, and topped it with a leupold fx2.5.

My rifle build last year from the "what's your rifle weigh" thread:

Here’s my latest entry.

Howa Mini 6.5 grendel cut to 16”: 3lbs 10.4 to 3lbs 4.6oz
Bottom plastic: 1.9oz
Magazine: 1.5oz
Leupold fx-ii fixed 2.5x: 6.5oz
Talley LW lows: 2.2oz
Stocky CF stock, some holes drilled (not worth it) buttpad replaced with foam, sling studs removed: 18.9oz modified to 15.8

Total weight is 5lbs 1.7oz give or take
——— not including ammo ———

Plan to replace magazine with a blind mag bottom metal -0.5oz
Actions screws swap to titanium -0.25?
Flute Bolt -1oz?
Possibly flute barrel and mill down the action but these probably aren’t worth fooling with -5oz?
Wish I could find a super skeletonized bolt handle
If anyone else has ideas I’m all ears.

I have absolutely loved hunting with this rifle so far, hunting thick woods and brush here, It's light enough to hand carry all day- so I totally removed both sling studs. First day out with it, after sighting in the evening prior, I was able to get this buck at about 20 yards.

Skipping forward to this season, the only changes I have made have been to switch to a blind mag, add a supressor, and a camo paint job when I got bored last week.

Here's the rifle as of a few weeks ago (pre-paintjob)

the rifle's lighterpack: (yes, I am a nerd)

https://lighterpack.com/r/zcukrp

Although the rifle is still the handiest thing I own and is comparatively a joy to carry compared to a traditional hunting rifle, It was honestly so much nicer without the suppressor. Wanting the best of both worlds: short/lightweight package and suppressed shooting, has me to my next plan: SBR.

Here's some backstory and though analysis on that:

SBR Howa mini vs ULUL- 7.62/6.5/300blk

I am currently thinking about making a change to my howa mini for mountain hunting, shots within a 100-150 yard max range, with most around 20-75 yards. Rifle is currently 5.5lbs scoped and supressed. Build is: 6.5 Howa mini, 16.25” barrel Stocky CF sporter Stock Talley LW mounts Leupold FX2.5...

rokslide.com

I am still looking to lighten it further, so if there is an UL bolt shroud or bolt handle out there somewhere, let me know.



Anyway, I would love to see some builds and information from the other Howa mini owners here.

 

[9.3koolaid]

I've been inspired by all the minis too! Got the Jefferson hinged BM, swfa ultralight, and leupold backcountry rings ready. Stockys vg arrives today and the 22" sporter contour 6 arc is at the gunsmith getting chopped to 16". I'll update once it's done!

 

[Ferrulewax]

I've been inspired by all the minis too! Got the Jefferson hinged BM, swfa ultralight, and leupold backcountry rings ready. Stockys vg arrives today and the 22" sporter contour 6 arc is at the gunsmith getting chopped to 16". I'll update once it's done!

Any guesses at 6arc speed from that barrel length?

 

[9.3koolaid]

Any guesses at 6arc speed from that barrel length?

If I can get 2600 from 95 nbts or tmks, I'll be happy.

 

[KyleR1985]

If I can get 2600 from 95 nbts or tmks, I'll be happy.

 

[9.3koolaid]

View attachment 801803

Nice! Lever was what I was thinking

 

[Tanner]

That’s a sweet little setup. Nicely executed.

 

[turbobrick]

I have a bunch of data on this, been playing with 6arc and the Minis for a good while. My first arc was a 12" SBR AR upper. That was right when the cartridge came out, and the only factory ammo I could get was Hornady 105 bthp, it was 2298fps.

I really liked the performance potential of the cartridge, but I knew it needed a little more barrel to get what I wanted, so I got 2 of the Minis and had them cut back to 16". I did chrono them with factory ammo for a baseline though. The same 105bthp was 2631 in the 20" and 2495 in the 16", as a wild card it was 2640 in the 19" Carbon6 barrel I had put on one of them later on. For additional factory ammo info, the 108 ELDM was 2470 in a 16" and 2598 in a 20". I only ever tested the 103ELDX in one 20" and it was 2631.

I did a huge amount of reloading, trying to find the best combo for a monolithic hunting projectile. I was able to get the 105bthp to 2682 in 16" but that was pushing it I think, on the edge of pressure.

Ultimately, I did get my goal, the 87AH 3005fps 7.8sd, 18.6es out of the 19" Carbon6, and the whole gun with can is right at 7lbs ready to hunt.

Like I said in the other thread, I prefer projectile weight when we're talking short barrels. The projectiles for 6 and 6.5 mm will have a expansion threshold well above what you're going to get to with a sub 12" barrel. I'd much rather a 190gn in .30, or 280gn in .338 at 1050fps that I know is going to open up every time, than 6 or 6.5 100gn at 2300 that probably won't open.

I did a bunch of reloading for 8.6blk, I was originally stoked on it being a super/sub double threat. With the 12" barrel I was getting 2200 with the 185cx, and didn't see a route to much more than that. That velocity is right at the expansion threshold for that projectile, so it really limits range IMO. So, I decided to cut the barrel back to 8" and dedicate it to subs. Now, I have the 280 Discreet, the 350 Maker, and 345 Cutting Edge all right at the subsonic limit, shooting good, and sounding amazing.

I have done the same with 300blk, the 188 Discreet is going to open out of a 8" barrel at 1050 muzzle. So thinking about your project, I'd probably get a .223 Mini, send it to Carbon6, have them install a 8" CF barrel in 300blk (If they'll make one that short), and shoot one of the expanding projectiles in the 180-220gn class. If you really wanted to get even lighter, you could get a can like the Q Erector 9, and play with the length to find your best balance of suppression, length, and weight. Many of the 9mm cans out there will be rated for 300blk subsonic use, will be stupid light, and often fully modular. I have a SiCo Sprectre 9 that weighs 5oz and would be perfect for this.

 

[KyleR1985]

 

[Schmo]

@KyleR1985 ,
How temp sensitive have you found that Lever to be?

 

[Ferrulewax]

I have a bunch of data on this, been playing with 6arc and the Minis for a good while. My first arc was a 12" SBR AR upper. That was right when the cartridge came out, and the only factory ammo I could get was Hornady 105 bthp, it was 2298fps.

I really liked the performance potential of the cartridge, but I knew it needed a little more barrel to get what I wanted, so I got 2 of the Minis and had them cut back to 16". I did chrono them with factory ammo for a baseline though. The same 105bthp was 2631 in the 20" and 2495 in the 16", as a wild card it was 2640 in the 19" Carbon6 barrel I had put on one of them later on. For additional factory ammo info, the 108 ELDM was 2470 in a 16" and 2598 in a 20". I only ever tested the 103ELDX in one 20" and it was 2631.

I did a huge amount of reloading, trying to find the best combo for a monolithic hunting projectile. I was able to get the 105bthp to 2682 in 16" but that was pushing it I think, on the edge of pressure.

Ultimately, I did get my goal, the 87AH 3005fps 7.8sd, 18.6es out of the 19" Carbon6, and the whole gun with can is right at 7lbs ready to hunt.

Like I said in the other thread, I prefer projectile weight when we're talking short barrels. The projectiles for 6 and 6.5 mm will have a expansion threshold well above what you're going to get to with a sub 12" barrel. I'd much rather a 190gn in .30, or 280gn in .338 at 1050fps that I know is going to open up every time, than 6 or 6.5 100gn at 2300 that probably won't open.

I did a bunch of reloading for 8.6blk, I was originally stoked on it being a super/sub double threat. With the 12" barrel I was getting 2200 with the 185cx, and didn't see a route to much more than that. That velocity is right at the expansion threshold for that projectile, so it really limits range IMO. So, I decided to cut the barrel back to 8" and dedicate it to subs. Now, I have the 280 Discreet, the 350 Maker, and 345 Cutting Edge all right at the subsonic limit, shooting good, and sounding amazing.

I have done the same with 300blk, the 188 Discreet is going to open out of a 8" barrel at 1050 muzzle. So thinking about your project, I'd probably get a .223 Mini, send it to Carbon6, have them install a 8" CF barrel in 300blk (If they'll make one that short), and shoot one of the expanding projectiles in the 180-220gn class. If you really wanted to get even lighter, you could get a can like the Q Erector 9, and play with the length to find your best balance of suppression, length, and weight. Many of the 9mm cans out there will be rated for 300blk subsonic use, will be stupid light, and often fully modular. I have a SiCo Sprectre 9 that weighs 5oz and would be perfect for this.

I believe that ELDM, ELDX, and SST should have an expansion velocity of around 1800fps, which is well above both 6.5grendel and 6arc exit velocities- even with a 12" barrel. Admittedly, I have no firsthand experience with lower velocity upset of those bullets, but that is what I have heard here on the forum numerous times. I think there are quite a few examples of these bullets upsetting well at low velocities in the 6.5 and 6mm threads. If an 1800fps threshold is true for reliable upset, even granting a 50fps buffer of 1850 I should be good to 300 yards even at sea level from a 11.5" barrel @ 2300fps (very conservative based on graph above) with the 6ARC.

I do think if I was looking for a western rifle, these extremely short barrels would not be the way to go, but for my needs the velocity should be more than enough. If anyone thinks my upset velocities are incorrect then please let me know.

Any shorter than 11.5" and the barrel won't make it to the end of the stock, but an 8" 300BLK or 338arc would be a blast to build at some point. I think for something super compact in 300blk I would probably end up building a straight pull ULUL ar. However, I really just like the "feel" and balance of a bolt action, hence my current fascination with the howa mini. Thanks for all of your insight, some very cool ideas to keep in mind.

edit: saw you mentioned shooting monos, which probably changes minimum velocity needs significantly.

 

[KyleR1985]

@KyleR1985 ,
How temp sensitive have you found that Lever to be?

I load it at 65 in my house. And it’s been shot between 30 and 45 at the range.

I’ll probably run it all again once the temps swing opposite direction next summer. I’ll be loading at 70 in the house and temps 80-95. I’m sure I’ll need to back off a little. Maybe not.


I’m new to reloading, so don’t take any advice from me. Just data.

 

[turbobrick]

I believe that ELDM, ELDX, and SST should have an expansion velocity of around 1800fps, which is well above both 6.5grendel and 6arc exit velocities- even with a 12" barrel. Admittedly, I have no firsthand experience with lower velocity upset of those bullets, but that is what I have heard here on the forum numerous times. I think there are quite a few examples of these bullets upsetting well at low velocities in the 6.5 and 6mm threads. If an 1800fps threshold is true for reliable upset, even granting a 50fps buffer of 1850 I should be good to 300 yards even at sea level from a 11.5" barrel @ 2300fps (very conservative based on graph above) with the 6ARC.

I do think if I was looking for a western rifle, these extremely short barrels would not be the way to go, but for my needs the velocity should be more than enough. If anyone thinks my upset velocities are incorrect then please let me know.

Any shorter than 11.5" and the barrel won't make it to the end of the stock, but an 8" 300BLK or 338arc would be a blast to build at some point. I think for something super compact in 300blk I would probably end up building a straight pull ULUL ar. However, I really just like the "feel" and balance of a bolt action, hence my current fascination with the howa mini. Thanks for all of your insight, some very cool ideas to keep in mind.

edit: saw you mentioned shooting monos, which probably changes minimum velocity needs significantly.

Personally, even a 2300 muzzle is too slow for me to risk a 6mm pencil through a game animal, but that is just me. You could very well get expansion at those velocities, but it's not for me personally. Close range, short barrel, hunting, that all adds up to mass as the equalizer.

I have a 7.5" Mini Fix in 300 blk that is perfect for what you want, but its a little heavy. I also built a straight pull 300blk AR, and it sucked out loud. I tried it with standard upper, Kali key, and two different side chargers, and two different lowers standard and Fightlite SCR, through all that the form factor blows. The new Bear Creek Arsenal bolt action upper shows some real promise, that might truly change my mind on the viability.

 

[Ferrulewax]

Does anyone have photos of a howa mini action that they have had “slabbed” or machined to remove weight?

 

[hereinaz]

Does anyone have photos of a howa mini action that they have had “slabbed” or machined to remove weight?

Curious as well. I am going to work on my mini when I get my mill up and running.

 

[Ferrulewax]

Curious as well. I am going to work on my mini when I get my mill up and running.

Here are a few pictures that @Te Hopo sent me a year or so ago. Hope he doesn’t mind me posting them up.

I wish Brownells would get some stainless 6ARC actions and I would be calling the gunsmith right now!

 

[hereinaz]

Thanks, I like the direction he took. I have been toying with a few different things. Probably will do similar to the action body, without creating a gap between the action and stock. Ending the cut at the stock line would be slick.

Hopefully I can get to it before my bolt gets back from the smith.

 

[Ferrulewax]

Thanks, I like the direction he took. I have been toying with a few different things. Probably will do similar to the action body, without creating a gap between the action and stock. Ending the cut at the stock line would be slick.

Hopefully I can get to it before my bolt gets back from the smith.

What are you having done to your bolt? I considered having mine fluted but I seem to always have crap that would be prone to get into the action.

 

[hereinaz]

What are you having done to your bolt? I considered having mine fluted but I seem to always have crap that would be prone to get into the action.

I am having the firing pin bushed for small rifle primers and the bolt face opened up to run 22 BR. Its a lot to put into the Mini, but its the only platform available to keep it in a small platform. I had it don for the 6 BRA I built, and then decided to sell it and build again for the 22 BR. I can run the 80s and 88s in the factory mags. Preferred did a prefit for me with the barrel nut.

It really is a nice little rifle platform, and I feel like the 22 BR squeezes everything out of it, so it's worth it to me. This will be a forever rifle... I am done with the merrygo round and something new all the time.

I will probably do some fluting on the bolt, but I don't end up with a lot of crap in my actions where/when I hunt. And, when I am not carrying it, I keep it in my Scoped Action Armor.

I have been planning on doing interrupted fluting. Maybe I will do it so that none of the flutes run into the action, if that make sense. I will leave a full ring where the ejection port is, and not put any flutes that line up with the sides. At least then, it won't allow anything to fall and work its way in. If it has crap on it, I can tip the action before cycling the bolt.

 

[Ferrulewax]

Does anyone have real world velocity numbers on short barreled 6.5 grendel? I’m leaning towards cutting down a 6.5 grendel barrel to 11.5” because that’s what I have on hand instead of tracking down a 6arc barrel.