6mm ARC

[kmw1954]

I too have been having an internal discussion as to which why I should go with my next build. Fast twist Match 223, or one form or another of 6MM. Quality match 223 brass is mostly available. 6mm ARC, BR, Dasher, GT not so much. Reason for my indecision is all my shooting will be at 300yds or less.

 

[12Bravo20]

I too have been having an internal discussion as to which why I should go with my next build. Fast twist Match 223, or one form or another of 6MM. Quality match 223 brass is mostly available. 6mm ARC, BR, Dasher, GT not so much. Reason for my indecision is all my shooting will be at 300yds or less.

If that is all the farther you will be shooting then 223 will work just fine. But if you want something different than 223, then 6 ARC is a good choice.

 

[kmw1954]

If that is all the farther you will be shooting then 223 will work just fine. But if you want something different than 223, then 6 ARC is a good choice.

Something different would still be a heavy barrel 223 with a 1:7 twist using 80/85gr bullets. Already have a 6ARC Savage bolt head and a 243 bolt heat so no excuse there. Still thinking and believing the 223 would be much more economical. Also seems there is a greater variety of powders available suitable to the 223.

 

[Varminterror]

seems there is a greater variety of powders available suitable to the 223.

I don’t believe this is true.

I believe it is true that more people own 223’s and have tried and proven more powders (which doesn’t really mean all of those “recommended” powders by every Tom, Dick, and Harry are actually good choices), but there’s really nothing about the 223/5.56 which makes it more versatile for accepting more powders than any of these other cartridges being discussed. Simply, more people own 223/5.56’s, so more people have tried more things, and such, more people will claim more things worked. This isn’t a set of “these powders all work with 223, vs. these powders do not work with 6 BR,” it’s a comparison of the sets of “these powders all work with 223, vs. I’ve never touched a 6ARC, BR, Dasher, or GT so have no idea what works or doesn’t.” But I’d be very confident that the same broad spectra of powders will apply - within the equally broad spectrum of “acceptable efficacy” for any of these cartridges with respective spectra of bullet weights.

 

[kmw1954]

Part of my comment is the experience I have with the 223 and then talking with the shooters in our league group of which many are shooting some form of 6mm.. I have tried 6 powders and all put one I was able to find some very consistent loads. The shooters on the league all seen to flock around 3 powders with the by far favorite being Varget.

 

[Varminterror]

the by far favorite being Varget.

There’s good reason for that.

 

[kmw1954]

There’s good reason for that.

Yes because it works that well in those loading. Which again goes to my belief in more limited available powders that work very well, otherwise they would be using many different offerings..

 

[Varminterror]

Yes because it works that well in those loading. Which again goes to my belief in more limited available powders that work very well, otherwise they would be using many different offerings..

Get on a competitive firing line with 223 and note how many powders are out there. You won’t see very many options being used there either. It is one of, if not THE most temperature stable powders on the market, and has the one of the most consistently forgiving velocity reliabilities on the maker for it.

You’re swallowing someone else’s experimental bias fallacy as gospel here. Guys aren’t using cheap ball powders in 6ppc’s because guys shooting 6ppc’s aren’t blasting in their backyards, just to make noise. Huge spectra of powders can be used successfully in most cartridges - at least within this capacity range, as we simply run out of slow powders when we get up in the supermagnums, as an example - but the definition of “successful” has to be pretty loose, just the same as the definition of success measured by every dude telling you how great 35 different powders work for them in 223/5.56.

 

[Walkalong]

Yes because it works that well in those loading. Which again goes to my belief in more limited available powders that work very well, otherwise they would be using many different offerings..

It would be the same way at a serious match shooting.223, there would be one powder most people used with one or two more in the mix. Those standards are much higher than most folks looking for "great" loads. Top end matches with top end competitors cull a lot of things.

Plus, they are copycats sometimes, person A beats everybody a couple of times and guess what, folks start trying what they used.

 

[kmw1954]

Plus, they are copycats sometimes, person A beats everybody a couple of times and guess what, folks start trying what they used.

I am not doubting either of you as I know you both have more than twice the experience as I have. I actually consider my experience as very limited but with my position working at the range I get to interact with many shooters and do ask what components they are using. Like here most are eager to chat it up.

Again my experience has been very limited to just the 223 at this point and again with the mainstream powders I have tried I was able to find very workable loads. Yes of the powders I have tried I have found that Hodgdon Benchmark produces the best and most consistent, with 2460 right behind. Had tried and used a whole lb. of Varget and never did find a load as good as the Benchmark. Yet I still have not tried any VV powder, though two of the powders I do use are very readily available and relatively inexpensive, selling for under $35.00 per lb.

 

[Varminterror]

with the mainstream powders I have tried I was able to find very workable loads.

How many powders in 6 ARC have you tried which did not also produce very workable loads?

 

[high country]

I talked to Starline briefly at SHOT. They do not have plans for 6 ARC at this time.

Really only three options at this point:

Factory ammo and then reload.

Grendel brass sized and trimmed. Works well.

Forming brass from something else. I've made probably 750 pieces of ARC from 7.62x39. Works well but is time consuming. Also some brass is harder to form than others. Norma comes to mind. Lapua is another that doesn't form as easily as some others. I've also made ARC from .220 Russian but the cost of these probably doesn't warrant using them over 7.62x39.

That is a bummer that starline isn't picking it up (yet, anyway). If I can get some hornady brass from commercial ammo, and find some lapua cases in 6.5 Grendel to resize to 6 ARC that should keep me busy for a while anyway.

Of the 6mm cartridges that use the same bolt face as 7.62x39, 6 ARC seems the likeliest to have commercial brass availability since it is SAAMI spec, even though it is lacking for now. I am specifically looking at 6mm cartridges that use that bolt face, which knocks out any .223 and .308 bolt face diameter cartridges.

For what it is worth, the project is slowly taking some shape. Brownells said the barreled actions were expected in April, but I decided I wanted to build the action I have for several reasons. I ordered a McGowen barrel in their #5 heavy sporter profile, and am going to order a boyd pro varmint with adjustable comb to set it in. Excited to get that together, seems like it has a high likelihood of performing well.

 

[kmw1954]

How many powders in 6 ARC have you tried which did not also produce very workable loads?

What kind of question is that? I have already stated I do not have a 6mm of any kind. So how would I be able to attempt this?

 

[gotboostvr]

Of the 6mm cartridges that use the same bolt face as 7.62x39, 6 ARC seems the likeliest to have commercial brass availability since it is SAAMI spec, even though it is lacking for now. I am specifically looking at 6mm cartridges that use that bolt face, which knocks out any .223 and .308 bolt face diameter cartridges.

I'll agree with that, the 6ARC is probably going to be around for awhile and factory support will catch up eventually.

Are you wanting to use a x39 sized action/ bolt face you already have?

If not, have you considered 6 BR/Dasher/et al?

 

[Varminterror]

What kind of question is that? I have already stated I do not have a 6mm of any kind. So how would I be able to attempt this?

That was my point.

 

[high country]

Are you wanting to use a x39 sized action/ bolt face you already have?

If not, have you considered 6 BR/Dasher/et al?

Yes, I am building on a Howa Mini Action, and already have the action in 7.62x39. In a full size action, 6 Dasher or 6 BR would a solid choice, but for this particular project I am limited (by choice) to 6 ARC, 6 PPC, 6 Rat, etc based on the 7.62x39/.220 Russian/6.5 Grendel case. Of those I settled on 6 ARC, primarily due to likelihood of finding brass instead of having to form it from something else.

I already shoot and load for 6.5 Creedmoor and .223 and wanted something that fills the gap between the two. Using less powder and generating less recoil than the Creedmoor, but legal on deer in CO and able to stabilize longer/heavier bullets than my .223 1-9 twist.

I also like the downsized actions (CZ 527 and Howa). Not for any particular reason, I just think they are neat despite their respective shortcomings.

 

[gotboostvr]

Yes, I am building on a Howa Mini Action, and already have the action in 7.62x39. In a full size action, 6 Dasher or 6 BR would a solid choice, but for this particular project I am limited (by choice) to 6 ARC, 6 PPC, 6 Rat, etc based on the 7.62x39/.220 Russian/6.5 Grendel case. Of those I settled on 6 ARC, primarily due to likelihood of finding brass instead of having to form it from something else.

I already shoot and load for 6.5 Creedmoor and .223 and wanted something that fills the gap between the two. Using less powder and generating less recoil than the Creedmoor, but legal on deer in CO and able to stabilize longer/heavier bullets than my .223 1-9 twist.

I also like the downsized actions (CZ 527 and Howa). Not for any particular reason, I just think they are neat despite their respective shortcomings.

Oh yeah, that all absolutely makes sense. I would have gone the same direction most likely in that scenario myself.

 

[horsemen61]

Yes, I am building on a Howa Mini Action, and already have the action in 7.62x39. In a full size action, 6 Dasher or 6 BR would a solid choice, but for this particular project I am limited (by choice) to 6 ARC, 6 PPC, 6 Rat, etc based on the 7.62x39/.220 Russian/6.5 Grendel case. Of those I settled on 6 ARC, primarily due to likelihood of finding brass instead of having to form it from something else.

I already shoot and load for 6.5 Creedmoor and .223 and wanted something that fills the gap between the two. Using less powder and generating less recoil than the Creedmoor, but legal on deer in CO and able to stabilize longer/heavier bullets than my .223 1-9 twist.

I also like the downsized actions (CZ 527 and Howa). Not for any particular reason, I just think they are neat despite their respective shortcomings.

Heck yeah keep us updated I can’t wait to see how this thing turns out!

 

[troy fairweather]

Yes, I am building on a Howa Mini Action, and already have the action in 7.62x39. In a full size action, 6 Dasher or 6 BR would a solid choice, but for this particular project I am limited (by choice) to 6 ARC, 6 PPC, 6 Rat, etc based on the 7.62x39/.220 Russian/6.5 Grendel case. Of those I settled on 6 ARC, primarily due to likelihood of finding brass instead of having to form it from something else.

I already shoot and load for 6.5 Creedmoor and .223 and wanted something that fills the gap between the two. Using less powder and generating less recoil than the Creedmoor, but legal on deer in CO and able to stabilize longer/heavier bullets than my .223 1-9 twist.

I also like the downsized actions (CZ 527 and Howa). Not for any particular reason, I just think they are neat despite their respective shortcomings.

selling your factory barrel should give you enough for a aftermarket bottom metal, it's really the only think that needs to be replaced on the howa mini.

 

[high country]

Heck yeah keep us updated I can’t wait to see how this thing turns out!

Will do. It is going to take a little while to get the pieces together, the McGowan barrel I ordered has a ~6 week lead time. As soon as I can stop flip-flopping on laminate color I will get the stock coming. I am pretty sure I am going to go with the orange blaze, for a little flash. But, I keep hesitating because might be too much flash. I have a little more time to waffle before I really need to decide.

selling your factory barrel should give you enough for a aftermarket bottom metal, it's really the only think that needs to be replaced on the howa mini.

I will probably sell that barrel, and will definitely be ordering a different bottom metal. Leaning towards using the DIP bottom metal with a shortened magazine, although the BDM style bottom metal from Jefferson Outdoors looks tempting too. The bottom metal using the CZ magazine is of no interest, the magazine is my least favorite thing about the CZ 527.

I really like 7.62x39, but the cartridge lost some of its appeal when the steel case ammo that shot well in the rifle dried up. To reload, a 123 gr .311 SST costs about as much as a 108gr ELD-M or 140 gr. Matchking.

 

[Howa 9700]

Back to the issue of brass........if things work out as planned, I may be taking possession of a 6mm CM sometime in the near future..........and have been looking for brass. As recent as a few weeks ago, it was widely available. Now most sources have dried up. Nosler brass at over $1 per piece may still be out there. Then noticed the Hornady Black loaded ammo can be had for around $25 for a 2o round box. Normal hunting ammo is $40 plus.

For a new gun, does it not make sense to buy 5 boxes or so.....use it to break in the barrel and fire form the bass at the same time? At $25 a box, you get the brass, bullet, primer and powder for less than components can be purchased individually. The Black appears to be downloaded a bit, so a mild load, and Hornady claims they use the same brass for it as any other load. So basically, blammo that yields decent brass to reload. Not seeing the downside. Buy the Black for now and buy Hornady brass alone when it shows up again.

 

[kmw1954]

For a new gun, does it not make sense to buy 5 boxes or so.....use it to break in the barrel and fire form the bass at the same time? .

As I mentioned , my friend and coworker has been buying 6ARC factor stuff like you suggest and shooting it just so he can get the brass to load for his Savage 110 bolt rifle. So far seems to be working pretty well.

 

[12Bravo20]

As I mentioned , my friend and coworker has been buying 6ARC factor stuff like you suggest and shooting it just so he can get the brass to load for his Savage 110 bolt rifle. So far seems to be working pretty well.

That is what I am doing until 6 ARC brand becomes available. I know I could always reform 6.5 Grendel brass but right now I don't want to mess with that.

 

[Varminterror]

For a new gun, does it not make sense to buy 5 boxes or so.....use it to break in the barrel and fire form the bass at the same time?

Then you’re only left with 100pc of brass which was only worth ~60¢/pc, and had to burn 8% of your barrel life to get it, AND don’t yet have any info in hand for load development.

A shooter has to do what they have to do, so if your trigger finger is itchy and you can’t wait for brass to come available, then factory ammo is a viable option for some shooters.

 

[Tinker-S]

That is a bummer that starline isn't picking it up (yet, anyway). If I can get some hornady brass from commercial ammo, and find some lapua cases in 6.5 Grendel to resize to 6 ARC that should keep me busy for a while anyway.

Of the 6mm cartridges that use the same bolt face as 7.62x39, 6 ARC seems the likeliest to have commercial brass availability since it is SAAMI spec, even though it is lacking for now. I am specifically looking at 6mm cartridges that use that bolt face, which knocks out any .223 and .308 bolt face diameter cartridges.

For what it is worth, the project is slowly taking some shape. Brownells said the barreled actions were expected in April, but I decided I wanted to build the action I have for several reasons. I ordered a McGowen barrel in their #5 heavy sporter profile, and am going to order a boyd pro varmint with adjustable comb to set it in. Excited to get that together, seems like it has a high likelihood of performing well.

I do not know if you are still going forward with your 6MM ARC.
I recently put together a 6MM ARC upper, and since there is no factory ammo readily available, I converted some of my new Starline 6.5 Grendel brass to 6MM ARC. One of my first batches is on their 3 firing, and doing well so far.
Also, since I am using my 6.5 Grendel brass, I went ahead and purchased some Starline 7.62 x 39 brass, and tested out to convert it to 6.5 Grendel. I tried 10 shells, and only 7 fit the gauge, so I put the 3 non-conforming casings aside, as I continued to prepare another batch of 6.5 Grendel to 6MM ARC.
Then, out of curiosity, I ran 2 of the brass pieces in the 6MM ARC FL, and voila', they are good to go! From 7.62 x 39, to 6.5 Grendel, to 6MM ARC!
There is more to the secret sauce, but I would leave it at that, unless anybody wants the details.
I plan to fire the 2 this week.
I am waiting on a set of headspace gauges to measure the shells at the shoulder, but if they fit the headspace/case length the rounds will chamber.