6mmARC wonky oncefired brass

[MThuntr]

I have a Howa Mini 6mmARC that seems to mess up brass. It seems that maybe my chamber is out of spec? Once fired brass looks correct and measured doesn't seem to be an issue until I try to size it. 2 different presses tried will require major cam over to get the brass to fit in the rifle. Then the brass has a little ring on part of the brass down on the case web. I've talked to Hornady and they sent me a new die body but the issue remains. Brass is starline but I have tried Hornady Black 105s ammo. FWIW the factory ammo is very hot in this rifle (cratered primer, swipes and heavy bolt)

also all loads I've tried seem hot. I'll work up to about middle of the road for Hornady's bolt gun data.

Do I have a wonky chamber? Possibly too much headspace? Any thoughts because Hornady doesn't have any ideas.

 

[Muledeerfanatic]

Mine is pretty much the same other than the brass sizing problem
Pretty sure mine is a bit tight on the headspacing
Shoots great though with middle upper handloads for me

 

[Hummerdawg]

Not unheard of in the Grendel family of cartridges. Usually more prevalent with Lapua brass

 

[General RE LEE]

I have a Howa Mini 6mmARC that seems to mess up brass. It seems that maybe my chamber is out of spec? Once fired brass looks correct and measured doesn't seem to be an issue until I try to size it. 2 different presses tried will require major cam over to get the brass to fit in the rifle. Then the brass has a little ring on part of the brass down on the case web. I've talked to Hornady and they sent me a new die body but the issue remains. Brass is starline but I have tried Hornady Black 105s ammo. FWIW the factory ammo is very hot in this rifle (cratered primer, swipes and heavy bolt)

also all loads I've tried seem hot. I'll work up to about middle of the road for Hornady's bolt gun data.

Do I have a wonky chamber? Possibly too much headspace? Any thoughts because Hornady doesn't have any ideas.View attachment 713208View attachment 713209View attachment 713210View attachment 713211

Grendel Belt. Look it up. Sargent of Arms makes a Belt Buster die to alleviate the issue. How much are you bumping the shoulder?

 

[MThuntr]

Grendel Belt. Look it up. Sargent of Arms makes a Belt Buster die to alleviate the issue. How much are you bumping the shoulder?

It makes the belt before I even touch the shoulder. I'm thinking 20 thou would be nice. It takes way more to make the case fit which basically moves the belt down.

I've not had issue with my 6.5 Grendel in AR15 so the 6ARC threw me for a loop.

 

[Hummerdawg]

I changed brass and die brand same loads never saw issue again

 

[MThuntr]

I changed brass and die brand same loads never saw issue again

Currently using hornady dies and starline brass. What did you end up with?

 

[TimberHunter]

Tagged… was just about to buy a how’s mini in 6ARC. Maybe this is the sign to go with a tikka 243 instead… good luck!


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[Hummerdawg]

Started with hornady dies and lapua brass. Ended up with Redding bushing die and hornady brass.

 

[MThuntr]

I have a 6.5 Grendel and my buddy has the same 6mmArc Howa and a 6.5grendel without issue. Personally a 6mm Creedmoor would be my next choice

 

[TimberHunter]

I have a 6.5 Grendel and my buddy has the same 6mmArc Howa and a 6.5grendel without issue. Personally a 6mm Creedmoor would be my next choice

But the 6ARC has a lot going for it with 1800fps retained 108 velocity out to +- 600 yards and low recoil with only using 27/28 ish grains of powder


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[General RE LEE]

But the 6ARC has a lot going for it with 1800fps retained 108 velocity out to +- 600 yards and low recoil with only using 27/28 ish grains of powder


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100%. 6 ARC is an excellent cartridge. Here’s a 3 shot group at 600 yards with 108 ELDM handloads. 1800 FPS at 600 yards in such a light kicker with excellent barrel life (4000 + rounds) is a win in my book.

 

[TimberHunter]

100%. 6 ARC is an excellent cartridge. Here’s a 3 shot group at 600 yards with 108 ELDM handloads. 1800 FPS at 600 yards in such a light kicker with excellent barrel life (4000 + rounds) is a win in my book.


View attachment 714960

In your research, is this 6ARC brass issue something that is common?


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[General RE LEE]

In your research, is this 6ARC brass issue something that is common?


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I had issues with a Grendel Hunter upper but since I went to the Howa Mini-zero issues.