Howa Mini 6 Arc problems?

[Haysulli22]

Simple, the load is too hot. Try and find tougher brass to work with, ditch the hornady, if possible

Question: are you reloading for this or only using factory ammo? The primer pockets maybe loosening up on the brass.

In pictures in post 6, there appears to be a tad bit more pressure on the suppressed case, look at the marks on the shoulder and the color of the brass in the web, probably normal, but the load is hot for the rifle.

Also, the load may not be hot, but the brass maybe too large for the chamber. Using a micrometer, measure the unfired round in the web and the web of a fired case. This measurment is going to tell you volumes, and you can not use a caliper for this kind of work.

No doubt that the brass is building up on the bolt face, making the problem worse.

I am only shooting factory for now but do plan on hand loading in the future. I understand that the factory options are pretty limited in 6 arc so I feel like I don't really have much of a choice other than to reload to get the best performance out of the rifle.

 

[Austinbintx]

What load is shooting the best for you?

I don't have my files in front of me right now, but I ended somewhere like 75% of the max book load for 95gr SSTs and AA2520.

I had plenty of room to go up, but the lighter load ended up being perfect recoil and noise wise for my daughter.

 

[Roughrice]

In case anyone is curious…
For my Howa Mini, I loaded a few 22 ARC cases with 77 TMK and CFE223 for velo/pressure tests and hit 3200 fps and tight bolt of course.
This was at max charge on one data site and .6 grains above max on another for 75-77 grain bullets.

I dropped 1 grain and will tune from there, which is still 3000+fos.
Factory Hornady 75 ELDM run 2970-3000..

 

[VinceMule]

While out of stock, this is the first fix of a lot of problems;

https://alphamunitions.com/product/6mm-arc/
6mm bore dimensions come in two sizes of barrels made in the USA, .236 and .237. No telling what the bore dimension is of your barrel.

Start with fresh, new brass reloading, your issue maybe solved quickly. I would chronograph that factory load.

You learn to hate crappy brass in a hurry.

A butt load of carbon from back pressure and/or copper fouling can not do your pressure issues any good at all.

I am sure you will get the issues iorned out.

 

[wilkup]

While out of stock, this is the first fix of a lot of problems;

https://alphamunitions.com/product/6mm-arc/
6mm bore dimensions come in two sizes of barrels made in the USA, .236 and .237. No telling what the bore dimension is of your barrel.

Start with fresh, new brass reloading, your issue maybe solved quickly. I would chronograph that factory load.

You learn to hate crappy brass in a hurry.

A butt load of carbon from back pressure and/or copper fouling can not do your pressure issues any good at all.

I am sure you will get the issues iorned out.

Good to know Aloha is on board as a brass option for the ARC!
To OP
Hornady factory loads seemed hot in my rifle as well. I use the Hornady brass for my reloads and have not had any issues since. Something else to consider is that the Howa action is a cock on opening and fairly steep. Compared to my Defiance actions it feels "over pressure" just to open the bolt with nothing in it. It's breaking in but still WAY stiff by comparison to my other rifles.

 

[Roughrice]

Look out 22 Creedmoor!
This Howa Mini 22 ARC is all business!
Loaded and shot these today!
22" sporter barrel with Scythe.
I think I'm done for now!

Apologies on my target sheet data…These are 77 TMK.

 

[Tonopah]

"Simple, the load is too hot." This seems unlikely as factory 6mm ARC cartridges are loaded to the lower pressure required by gas guns (52,000 psi, I think). Bolt guns like the Howa Mini can easily handle much higher pressures than factory ammo produces. My Howa Mini in 6mm ARC now has a total of five rounds downrange as I just got the rifle scoped and in a new stock (B&C) today. I started zeroing at 25 yards. The first three shots went into one hole but the bolt was very difficult to lift after each of those shots. The next two shots also went into one hole and the bolt handle was much easier to lift. Gotta finish the zero tomorrow at 100 yards and get more rounds through it before I worry too much about the bolt lift.

 

[ATH]

My buddy has a gas 6ARC and shoots the Hornady ammo and does not reload. Since I have a Howa Mini in 6ARC, he let me pick up his brass. When I went to process it I realized about 20% were missing their primers as they'd blown out.

My reloads run fine in mine.

 

[Roughrice]

"Simple, the load is too hot." This seems unlikely as factory 6mm ARC cartridges are loaded to the lower pressure required by gas guns (52,000 psi, I think). Bolt guns like the Howa Mini can easily handle much higher pressures than factory ammo produces. My Howa Mini in 6mm ARC now has a total of five rounds downrange as I just got the rifle scoped and in a new stock (B&C) today. I started zeroing at 25 yards. The first three shots went into one hole but the bolt was very difficult to lift after each of those shots. The next two shots also went into one hole and the bolt handle was much easier to lift. Gotta finish the zero tomorrow at 100 yards and get more rounds through it before I worry too much about the bolt lift.

My Howa Mini 22 ARC has a snug bolt lift as well. It has 47 rounds thru it and may be getting a slight bit smoother and lighter.
My Howa Mini 6.5 Grendel has 400 or so rounds through it and the bolt is now smooth and normal.
I hope the 22 ARC does the same. It makes me feel like I'm over pressure but there are no other signs.

I thinking it's just a Howa Mini bolt cocking break-in period. They are hard to lift on an empty chamber after dry firing.

 

[Tonopah]

I zeroed at 100 yards today and the Howa Mini is shooting 3/4 to 1 inch groups. The bolt is getting easier to lift. I may put a tiny bit of grease on the rear bolt lugs and see if that helps. From what I have read, the stiff bolt lift does get better as one shoots more. As Roughrice said, it's probably a break in period.

 

[ruby76]

Didn't experience any of that with mine. It shot the factory 108's extremely good, under 1/2". Quickly changed to starline brass as soon as it was available and have 5 reloads on those so far.

 

[FEENIX]

While out of stock, this is the first fix of a lot of problems;

https://alphamunitions.com/product/6mm-arc/
6mm bore dimensions come in two sizes of barrels made in the USA, .236 and .237. No telling what the bore dimension is of your barrel.

Start with fresh, new brass reloading, your issue maybe solved quickly. I would chronograph that factory load.

You learn to hate crappy brass in a hurry.

A butt load of carbon from back pressure and/or copper fouling can not do your pressure issues any good at all.

I am sure you will get the issues iorned out.

OCD, very nice play on the acronym.

 

[Bravo 4]

Maybe it isn't short chambered/headspaced (as the bolt closes fine with multiple types of new factory ammo) but maybe it is short throated and you are actually jamming the bullet somewhat into the lands. This could cause the pressure to spike. If this is a common issue with Howa ARC/Grendal chamberings, then maybe it's something they need to remedy in future rifles.

 

[Roughrice]

Maybe it isn't short chambered/headspaced (as the bolt closes fine with multiple types of new factory ammo) but maybe it is short throated and you are actually jamming the bullet somewhat into the lands. This could cause the pressure to spike. If this is a common issue with Howa ARC/Grendal chamberings, then maybe it's something they need to remedy in future rifles.

No headspace issues with my Minis.
Not jamming bullets either as I measured my chambers.
However, bolt lift was stiff on both of my Howa Mini rifles but the Grendel lightened up and smoothed out nicely over time but my newer low round count 22 ARC is still tight to lift.
It is tight when lifting after dry firing an empty chamber as well.
Hopefully it frees up as nice as my Grendel did.

*NOTE*
The Mini bolt handles are short… so the feel of bolt lift is exaggerated somewhat.