Howa Mini Rifles, Builds, and Upgrades

[hereinaz]

Design decisions... do I go for a complete redesign?

To change OAL effectively, I think that I would need to change the whole system, bottom metal and magazine. I can use the area where the current release is to fit a longer magazine, if the release moves to the back. When redesigning the magazines, I can also work out flush fit mags as an option.

But, that could entail changing the inlet, which could be done with a dremel by the DIY types.

 

[jeremy.b]

What is the max COAL that would be helpful? Seems like the factory 6 arc chamber supports 2.3-2.45ish coal depending on bullet profile. How much more COAL would other cartridges need?

Measuring my action, I don't think it can support much past 2.5" COAL without modifying the action itself.

 

[The Guide]

Design decisions... do I go for a complete redesign?

To change OAL effectively, I think that I would need to change the whole system, bottom metal and magazine. I can use the area where the current release is to fit a longer magazine, if the release moves to the back. When redesigning the magazines, I can also work out flush fit mags as an option.

But, that could entail changing the inlet, which could be done with a dremel by the DIY types.

The potential for 2 designs is good. A easy direct replacement that replaces the plastic and full redesign with custom magazines. I think the basic replacement made from metal would be a hot commodity while the new design would be valuable for a much smaller percentage of the total ownership.

Jay

 

[KyleR1985]

What is the max COAL that would be helpful? Seems like the factory 6 arc chamber supports 2.3-2.45ish coal depending on bullet profile. How much more COAL would other cartridges need?

Measuring my action, I don't think it can support much past 2.5" COAL without modifying the action itself.

2.5" is the magic number to maximize action efficiency - as you noted.

.223 mini factory barrels will allow loading long out to something like 2.45"(mine does anyway). Significant velo gain with the extra case capacity. Plus the ability to dial in seating depth for accuracy.

The 6ARC probably won't need as much room - the chamber will lead to most bullets being loaded under 2.4" OAL. But same principle applies.

Having the Mag, inlet, and stock all maximized to 2.5" opens lots of options for rechambers, maximizing current chamberings.

If you want to go past 2.45-2.5" you're probably going to a different rifle. But there's a world of difference between 2.3" and 2.45"

 

[270quest]

Its probably already on here, but typically, what is the COAL that is afforded for the 6 arc in the JO bdl bottom metal? I thought it was a touch more than the factory mag option?

 

[KyleR1985]

Its probably already on here, but typically, what is the COAL that is afforded for the 6 arc in the JO bdl bottom metal? I thought it was a touch more than the factory mag option?

Almost certainly More than the chamber will allow.

6ARC with 95tmk loaded optimally is .011” short of max OAL in a saami chamber. And right around 2.3”. I don’t have the 108eldm at hand, but it’s similar.

But 2.4-2.45” is what all of the aftermarket metals will allow. The action inlet is 2.5” if I recall correctly. And you have to fit a mag box in there.

 

[Qholum37]

I will probably just go with the JO replacement bottom metal that utilizes factory mags for now. The factory mags have functioned perfectly for me. It would be nice to have a touch more room but there are still plenty of good bullet choices that will fit fine at 2.33-ish inches.

 

[KyleR1985]

I will probably just go with the JO replacement bottom metal that utilizes factory mags for now. The factory mags have functioned perfectly for me. It would be nice to have a touch more room but there are still plenty of good bullet choices that will fit fine at 2.33-ish inches.

Windowing factory mag allows 2.39” for 5 .223 cartridges. Just have to stop the hole above the mag catch

 

[270quest]

Sidetracking here, but has anyone on here had Karl at Kampfelds cut down, thread, and install one of his campfire or other aftermarket bolt knobs? I want nothing to do with a clamp on unit. Seems a lot of people comment that the regular bolt handle can be an issue due to its smaller size....