6mm ARC bolt gun for competition?

[SMTGWKD]

Yeah a lot of people call it a budget action and in the world of customs it is on the low side for price but not at all for the features. Has features that make it a great choice over even more expensive actions.

I have 100 rounds though my rifle and they feed like butter. Same with extraction and ejection when I run it like in a match. If you slow extract you can get some pops back into the action but it's not an issue when actually "running" the rifle. The MDT mags work great also. When I got them I loaded them with 12 rounds and let them sit for a few days and then loading after that was easy.

I was going to buy some N140 to try with the 110 ATip but seeing the Varget recommendations and also the CFE223, both of which I have, I might try some of them first.

For what it's worth, my gas gun pet loads are primarily with Varget. I'll be very interested to see how fast these same loads run in a bolt with a longer barrel as these are from an 18" Proof:

26.7 gn Varget with 108 ELDM 2545 fps
26.8 gn Varget with 105 Hybrids 2551 fps
29.7 gn Lever with 108 ELDM 2671 fps
30.7 gn xbr8208 with 58 Vmax 3205 fps

 

[Rob01]

Yeah I don't want to mess with Lever even though people say it does great because it's not temp stable. N140 and Varget are. CFE223 not as much but better than Lever. If I get in the 2750fps area I will be totally happy.

 

[Force_Multiplier]

Yeah I don't want to mess with Lever even though people say it does great because it's not temp stable. N140 and Varget are. CFE223 not as much but better than Lever. If I get in the 2750fps area I will be totally happy.

2750 should be doable with Varget and a 28”… 2775 should be

 

[CK1.0]

Yeah I don't want to mess with Lever even though people say it does great because it's not temp stable. N140 and Varget are. CFE223 not as much but better than Lever. If I get in the 2750fps area I will be totally happy.

I think I read you or someone else mentioning VV N140/N540 a little while back... and after looking into it, whether for 6ARC or any other 6, I'm going to try some. The way all the data out there that I've found shakes out, it looks like those are Vihtavuori's Varget-alikes...

That said, another one to try is Shooter's World Precision Rifle (AKA Lovex-Varget), especially now that the prices have come back to earth. It's been great in my 6GT, the largest SD number I've seen so far was a 6, and that was the first firing on virgin brass. Since then, and while trying a couple of different charges I pulled out of the air (no ladder/OCW stuff at all), my SDs have been no higher than a 4... the other day I got an SD of 2 over 10 shots and nearly shit lol! Same temp stability as Varget, whether it's cold or hot out, it almost doesn't change. I honestly should just stockpile it while we can.

 

[danr]

Gentlemen, can I get a Hell Ya!!
6mm ARC
Zermatt TL3
PROOF 26”
XLR Envy Pro
Trigger Tech Primary
Dead Air Brake
MDT 10 rd mag
I have some CFE 223/Varget loads ready 1/2 grain short of max to try her out tomorrow. We’ll see how she does.

 

[Ronws]

Gentlemen, can I get a Hell Ya!!
6mm ARC
Zermatt TL3
PROOF 26”
XLR Envy Pro
Trigger Tech Primary
Dead Air Brake
MDT 10 rd mag
I have some CFE 223/Varget loads ready 1/2 grain short of max to try her out tomorrow. We’ll see how she does.
View attachment 8263693

Cool beans. I can make out Arken Optics but I cannot determine the model.

 

[danr]

Cool beans. I can make out Arken Optics but I cannot determine the model.

Yes it’s a EP5

 

[SMTGWKD]

Gentlemen, can I get a Hell Ya!!
6mm ARC
Zermatt TL3
PROOF 26”
XLR Envy Pro
Trigger Tech Primary
Dead Air Brake
MDT 10 rd mag
I have some CFE 223/Varget loads ready 1/2 grain short of max to try her out tomorrow. We’ll see how she does.
View attachment 8263693

That is a sick build! Are you running bolt pressure loads? Please post results (load data, velocity, accuracy) as I'm considering a near identical build for PRS for an efficient, low recoil 6. Very cool!

 

[danr]

That is a sick build! Are you running bolt pressure loads? Please post results (load data, velocity, accuracy) as I'm considering a near identical build for PRS for an efficient, low recoil 6. Very cool!

 

[danr]

That is a sick build! Are you running bolt pressure loads? Please post results (load data, velocity, accuracy) as I'm considering a near identical build for PRS for an efficient, low recoil 6. Very cool!

Here’s some results from the first 100ish rounds down the Proof barrel. Very promising. All rounds were loaded on brass fired thru my AR ARCs so I did have a few rounds chamber tight but that was to be expected. Other than that every round fed well from the MDT magazine. This is my first chasis and I’m loving it

 

[Hunter280]

I'm really enjoying the 6ARC for PRS. Granted this is my first season and I'm a shitty enough shooter that it's more about learning than being competitive.

Tried reloading it with 103 eldx's, 107 SMK's, 108 eldm's and 112 match burners. In a stock Savage bbl I haven't been able to get anywhere near Hornady's advertised speeds without hitting pressure signs. I've spent the most time shooting 107 SMK's at 2615 with 27.9gr of LVR and 112 match burners at 2525 with 27gr of LVR.

I have a Rock Creek bbl from PVA on order that I'm really excited to try for both a better rifle balance and hoping something will be different about the chamber and I'll be able to get another 200fps out of it.

All told I'm having fun with it, and the throat is holding up amazingly well for having 1300 rounds through it.

I'm really enjoying the 6ARC for PRS. Granted this is my first season and I'm a shitty enough shooter that it's more about learning than being competitive.

Tried reloading it with 103 eldx's, 107 SMK's, 108 eldm's and 112 match burners. In a stock Savage bbl I haven't been able to get anywhere near Hornady's advertised speeds without hitting pressure signs. I've spent the most time shooting 107 SMK's at 2615 with 27.9gr of LVR and 112 match burners at 2525 with 27gr of LVR.

I have a Rock Creek bbl from PVA on order that I'm really excited to try for both a better rifle balance and hoping something will be different about the chamber and I'll be able to get another 200fps out of it.

All told I'm having fun with it, and the throat is holding up amazingly well for having 1300 rounds through it.

I'm really enjoying the 6ARC for PRS. Granted this is my first season and I'm a shitty enough shooter that it's more about learning than being competitive.

Tried reloading it with 103 eldx's, 107 SMK's, 108 eldm's and 112 match burners. In a stock Savage bbl I haven't been able to get anywhere near Hornady's advertised speeds without hitting pressure signs. I've spent the most time shooting 107 SMK's at 2615 with 27.9gr of LVR and 112 match burners at 2525 with 27gr of LVR.

I have a Rock Creek bbl from PVA on order that I'm really excited to try for both a better rifle balance and hoping something will be different about the chamber and I'll be able to get another 200fps out of it.

All told I'm having fun with it, and the throat is holding up amazingly well for having 1300 rounds through it.

Hello AKM, been playing with the 6ARC on a savage with a PVA Osprey 26" bbl attached is the velocity data with LVR from the Garmin with Barnes match burners 105's. Is just an idea on velocity versus powder charge with LVR on this particular bbl. None of the primers were flattened just a little cratering on the last 2 high loads.

 

[memilanuk]

Any more updates on these? Still lovin' it, @Rob01 ?

I've got a Bighorn Origin SA, McMillan carbon-fiber A6, Seekins bottom metal with a Proof CF 6.5CM thats getting a little long in the tooth. Definitely more of a 'field' gun than a 'gamer' gun - just heavy enough to be steady, still light enough to be not-miserable to carry around. I see Proof makes a 22" 6 ARC pre-fit barrel, and that's got me... intrigued. What else would I need? Bolt head and... mags, from MDT?

Honestly, I'd kinda like to build a 'heavier' gun on an Aero Solus and go with a Proof CF 20" .308 bbl on this gun, but until/unless they come out with a PPC/Grendel/ARC bolt head for the Solus like the Origin, guess I'll be building with what I have. I figure the 22" barrel will pair with my 9" Sandstorm Ti can a lot better than the 26" tube I have now!

 

[Rob01]

Any more updates on these? Still lovin' it, @Rob01 ?

I've got a Bighorn Origin SA, McMillan carbon-fiber A6, Seekins bottom metal with a Proof CF 6.5CM thats getting a little long in the tooth. Definitely more of a 'field' gun than a 'gamer' gun - just heavy enough to be steady, still light enough to be not-miserable to carry around. I see Proof makes a 22" 6 ARC pre-fit barrel, and that's got me... intrigued. What else would I need? Bolt head and... mags, from MDT?

Honestly, I'd kinda like to build a 'heavier' gun on an Aero Solus and go with a Proof CF 20" .308 bbl on this gun, but until/unless they come out with a PPC/Grendel/ARC bolt head for the Solus like the Origin, guess I'll be building with what I have. I figure the 22" barrel will pair with my 9" Sandstorm Ti can a lot better than the 26" tube I have now!

Yup. It's a fun cartridge. I been trying to find a VV that works with the heavies but not sure I can find one so I am just going to use CFE223 which I have a couple 8 pound jugs of now. It gives me good velocities with the 110 ATips. Getting around 2780fps with the 26" Osprey barrel.

Bolt head and mags is all you will need besides the barrel. The MDT mags work great and allow longer than factory OAL.

 

[memilanuk]

been trying to find a VV that works with the heavies

No luck with N140/540/150? Usually they fill the same niche as Varget

 

[Rob01]

No luck with N140/540/150? Usually they fill the same niche as Varget

Nope. N150 is too slow and N140 I couldn’t get enough in the case to get me near 2700fps. Never tried N540. I tried N135 also and the first outing was the same as N140. I am going to work up some and see what happens.

 

[Force_Multiplier]

No luck with N140/540/150? Usually they fill the same niche as Varget

I’m shooting CFE223 in both of mine, but have a buddy that’s been playing with n540 and getting good results… he got a 108eld going 2850 from his 28” TL3

 

[mark5pt56]

Do you all have any feed issues with the MDT magazines? I'm contemplating a bolt in this caliber.

 

[Rob01]

Do you all have any feed issues with the MDT magazines? I'm contemplating a bolt in this caliber.

Nope. I have 4, two 10 and two 12 rounders, and they all feed great.

 

[Ronws]

Do you all have any feed issues with the MDT magazines? I'm contemplating a bolt in this caliber.

Depends. If using the metal AICS mags, you will need a feed lip tool to bend in and out until you get the right aperture to feed but to also load singles.

KI Precision Mag Lip Tool — KI Precision

This is a mag lip adjustment tool. Stop using plyers and ruining your mag. Small Slit in the front always you to adjust your mag lips without destroying them. Mag Lip tool also allows you to fine tune your magazines and fix feeding issues with your AICS Mag. Made from Aluminum, Cerakoted, Black,

www.kiprecision.com

 

[Rob01]

Didn’t need any tool with my 4 mags. All Fed great out of the box. From the mag or single feed.

 

[Ledzep]

Same here. MDT magazines have been great.

 

[Force_Multiplier]

Do you all have any feed issues with the MDT magazines? I'm contemplating a bolt in this caliber.

12 rounders have fed great

 

[Ronws]

My mileage may have varied. The reason I benefited, IMHO, from having a mag lip tool is because when I put my 7 PRC in an Oryx chassis, the recommended magazine was the ACIS metal mag for .300 WM. So, a very slight adjustment made it feed perfectly, as well as just throwing in singles.

 

[Rob01]

My mileage may have varied. The reason I benefited, IMHO, from having a mag lip tool is because when I put my 7 PRC in an Oryx chassis, the recommended magazine was the ACIS metal mag for .300 WM. So, a very slight adjustment made it feed perfectly, as well as just throwing in singles.

He is asking a specific question about 6mm ARC mags from MDT.

 

[Ronws]

He is asking a specific question about 6mm ARC mags from MDT.

True and so my answer is probably not germain to this thread.

Sorry.

 

[mark5pt56]

Rob, May have missed it, what velocity are you getting from the bolt with the factory Hornady? I believe you have a 26"?

Mark

 

[Rob01]

Rob, May have missed it, what velocity are you getting from the bolt with the factory Hornady? I believe you have a 26"?

Mark

The 108 ELD-M factory ammo is around 2720fps. With CFE223 and the 110 ATips I am getting about 2780fps.

 

[mark5pt56]

The 108 ELD-M factory ammo is around 2720fps. With CFE223 and the 110 ATips I am getting about 2780fps.

That's pretty good with factory, 26" barrel? How is the CFE working out?

 

[Ledzep]

If you load CFE223 or LVR with bolt-gun data (we publish both bolt gun and gas gun data) you can push 105-110gr class bullets to around 2900fps in a 28" barrel. With 27.5gr Varget I'm in the 2750-2780fps range depending on the barrel.

 

[Rob01]

That's pretty good with factory, 26" barrel? How is the CFE working out?

Yup a 26" barrel. The CFE is doing ok so far but dirtier than other powders I usually use and why I was trying to get a VV powder to work but can't get the velocity with N140 and still playing with N135.

 

[mark5pt56]

Awesome, ever try the PP MR 2000? Although I used it with success in a heavy .308, it is listed as one for the 6ARC.

 

[Rob01]

No never messed with it. Just used some of what I had on hand.

 

[mark5pt56]

Rob01, Checking to see how the build is going?

 

[Rob01]

Rob01, Checking to see how the build is going?

Looks like it will be CFE223 for my rifle. Does what I need. I pulled the barrel though and put my 6 Creed barrel on as I got some N160 to work up a load for the 110 ATips.

 

[mark5pt56]

Awesome, did you get a chance to shoot it much at distance?

 

[Rob01]

Yup I have gotten it out to 1000 with both the factory 108 load and my 110 load and it shot great. Nice low recoil. After I get this 6 Creed load I will be putting the barrel back on and using it some more in matches.

 

[Lazyfaire]

I hope we can read about updates from the field. I did not think of it in this vein. I know of a guy who has a CMMG 6 ARC (semi-auto) and he built it up as a truck gun good for varmints and up to whitetail deer.

So, this would be interesting to follow, as well.

What barrel length did he build off of? 12 1/2" ?

 

[mark5pt56]

Excellent! While I don't need it, I'm probably going to do one this year, of course I work at two speeds-1-I'll have it by tmrw or 3 years from now, still trying to figure it out! Like the pull wagon that comes in today-4 years!

 

[TheOE800]

Meh. Mine in the PX.

 

[Ronws]

What barrel length did he build off of? 12 1/2" ?

I don't remember. It's the Social Regressive on YT. He has a whole series on it, using a CMMG in 6 ARC.

Here is the playlist.

 

[CollarChoke]

What freebore are y'all running on your bolt action 6ARCs?

I've been loving my 6ARC and it's shooting great (Zermatt Origin with a 20" 1:7.5 Benchmark barrel) but today I noticed some lands mark on a round I ejected unfired.

That got me scratching my head because I load to factory Hornady dimensions with (zero'd on ogive gauge) seats CBTO at ~1.699" ... so I busted out the OAL gauge and sure enough my lands are touching at 1.666" so I'm negative into the lands 0.033" and in full on jam territory even with factory COAL.

Digging up the paperwork on my barrel order, sure enough the freebore on my barrel is 0.090" which seems awfully short for a 6mm and I reckon not ideal to have even factory ammo jam into the lands. It shoots fine, and holds 0.3-0.5moa groups pretty consistently but it was running pretty high velocities for a 20" barrel (2850fps with 30.7gr LeverEvolution), which I chalked up to good fortune but now I'm guessing I'm spiking pressure a bit due to the jam into the lands.

I was seeing a little bit of extractor shine on the caseheads as well today, which I think was because I had some carbon ring, which combined with the jam put me over into early pressure sign territory. No other signs on the brass or primers though.

Normally I try to stay around 0.020" off of the lands, so I guess I'll have to order a new barrel, which I'll probably go to a 24" and hopefully regain some velocity that I'm giving up on getting away from the jam.

Seating off of the lands with my current freebore would get me into powder crunch territory I think.

Lesson learned: always measure everything and don't assume.

 

[46caliber]

What freebore are y'all running on your bolt action 6ARCs?

I've been loving my 6ARC and it's shooting great (Zermatt Origin with a 20" 1:7.5 Benchmark barrel) but today I noticed some lands mark on a round I ejected unfired.

That got me scratching my head because I load to factory Hornady dimensions with (zero'd on ogive gauge) seats CBTO at ~1.699" ... so I busted out the OAL gauge and sure enough my lands are touching at 1.666" so I'm negative into the lands 0.033" and in full on jam territory even with factory COAL.

Digging up the paperwork on my barrel order, sure enough the freebore on my barrel is 0.090" which seems awfully short for a 6mm and I reckon not ideal to have even factory ammo jam into the lands. It shoots fine, and holds 0.3-0.5moa groups pretty consistently but it was running pretty high velocities for a 20" barrel (2850fps with 30.7gr LeverEvolution), which I chalked up to good fortune but now I'm guessing I'm spiking pressure a bit due to the jam into the lands.

I was seeing a little bit of extractor shine on the caseheads as well today, which I think was because I had some carbon ring, which combined with the jam put me over into early pressure sign territory. No other signs on the brass or primers though.

Normally I try to stay around 0.020" off of the lands, so I guess I'll have to order a new barrel, which I'll probably go to a 24" and hopefully regain some velocity that I'm giving up on getting away from the jam.

Seating off of the lands with my current freebore would get me into powder crunch territory I think.

Lesson learned: always measure everything and don't assume.

.090" Freebore is short for most 6mm cartridges because most of them are designed as bolt action cartridges. .090" is SAAMI spec for 6MM ARC and it's not really that unreasonable when you remember it was designed to be used in small frame AR magazine with a max COL of 2.245-2.260".

With CBTO of 1.699", I assume you're referring to the Hornady 105 BTHP. It's ogive is such that you have to load real short to fit in the chamber. I was touching lands at 1.715" with my Origin and Crown Ridge barrel and the Hornady 105. The guys that I know that have been running 6ARC in bolt guns for awhile typically have their smith throat the barrel a bit more for their loads.

If you want to run the Hornady 105 BTHP, you'll want to make sure you stay on top of any potential carbon ring. 2850 out of a 20" barrel is hot. I'm running Hornady 105 BTHP currently at 2750 out of a 25"

 

[CollarChoke]

.090" Freebore is short for most 6mm cartridges because most of them are designed as bolt action cartridges. .090" is SAAMI spec for 6MM ARC and it's not really that unreasonable when you remember it was designed to be used in small frame AR magazine with a max COL of 2.245-2.260".

With CBTO of 1.699", I assume you're referring to the Hornady 105 BTHP. It's ogive is such that you have to load real short to fit in the chamber. I was touching lands at 1.715" with my Origin and Crown Ridge barrel and the Hornady 105. The guys that I know that have been running 6ARC in bolt guns for awhile typically have their smith throat the barrel a bit more for their loads.

If you want to run the Hornady 105 BTHP, you'll want to make sure you stay on top of any potential carbon ring. 2850 out of a 20" barrel is hot. I'm running Hornady 105 BTHP currently at 2750 out of a 25"

Ah yeah if you follow my adventure in this thread @padom helped me get to the same conclusion. I have a 24" on order that I'm going to ask them to throat out an additional 0.090" ... 2850 was over pressure, 2750 was my safe max out of the 20".