My 6arc build

[Dino11]

I like that upper, hopefully your barrel will be interference fit and match your lower.

Here is a picture of my billet 6 ARC upper, still waiting on the matching lower, should get it this week it was in stock.

[ATTACH=CONFIG]17630[/ATTACH]

[mel]

I like that upper, hopefully your barrel will be interference fit and match your lower.

Here is a picture of my billet 6 ARC upper, still waiting on the matching lower, should get it this week it was in stock.

[ATTACH=CONFIG]17630[/ATTACH]

I wanted one of those tried to contact those guys when i built my 28" gren and they never got back to me

[mel]

barrel is sitting at the post office , my damn arc mags i bought from midway have been in transit/arriving late since the 20th starting to get a bit mad about that but atleast i can just use my gren mags for the time being

[mel]

be shooting it tommorow , friend is lending my dies tonight so ill load ammo up tonight to shoot tom going to break in the barrel with some 90g gamekings and 6.5 staball , hunting load is going to be 70g nosler balistic tip varminters with ar-compas long as i can get that combo to group well

[mel]

[mel]

got 5 rounds to test loaded up with 70g nosler balistic top varmints over 31g of ppv

70g 6 arc nexto a 90g nosler 6.5g

[StoneHendge]

Very interested in what sort of velocity you get. I had them going 3050+ in my 18" LBC with XBR and they were starting to group nicely albeit the load was getting warm. I stopped to conserve my stash 6 months ago (my 6x45 loves them, prairie dogs hate 'em) because I wasn't seeing any on the market (and haven't seen any NBTVs since). FWIW, the 70 gr Varmageddons should be completely interchangeable from a powder charge and zero standpoint - they just start getting a little more dispersion around 250 yds and have a lower BC.

[mel]

Very interested in what sort of velocity you get. I had them going 3050+ in my 18" LBC with XBR and they were starting to group nicely albeit the load was getting warm. I stopped to conserve my stash 6 months ago (my 6x45 loves them, prairie dogs hate 'em) because I wasn't seeing any on the market (and haven't seen any NBTVs since). FWIW, the 70 gr Varmageddons should be completely interchangeable from a powder charge and zero standpoint - they just start getting a little more dispersion around 250 yds and have a lower BC.

ill let ya know tommorow i only have my friends dies till sunday night so ima run a ladeer and try to work up a load so i can get 50 rds loaded up for the time being though grabagun shipped my dies already so those should be here soon enough

[mel]

noticed some funky stuff on the shoulder of the brass my friend converted for me so im scraping those rounds , they need to be run back threw the arc die now that i know what the issue is

to start after running the gren brass into the arc die , it needed to be trimmed a good bit then run back into the arc die hard to move the shoulder back and size the neck properly.

my friend had only run the gren brass into the arc die as far as it would go which was not enough without being trimmed a second time , the brass my friend ran for me was trimed back to normal grendel trim lenght , what i noticed was after that first step the brass needed to be trimmed back to 1.490 ish and then hit int he arc die hard a second time , and then finally a small trim back to 1.475 , without the second step threw the arc die the necks are seriously way to tight


from left to right

left 3
nosler 70g balistic tip varminters over 30.5g of ppv should be around 3200 fps out of the 20 inch barrel oal 2.150

next 3 are 80g sierra spbt varminters over 31g of power pro 2000mr expected mv should be around 2750-2800fps oal 2.125 power pro varmint would get theese going a bunch faster but im conserving that powder for the lightwieght arc and heavy grendel bullets

last 4 are sierra 90g fmj gamekings over 30g expected mv in the 27/2750 fps range loaded ot an oal of 2.215 but theese wont chamber so ill have to seat theese deeper and that oal is tbdsame here power pro varmint would get theese going faster but saving that powder for other uses

edit knocked the 90's back to 2.150 and they now chamber

[mel]

Have it on my 28" grens lower atm

[StoneHendge]

noticed some funky stuff on the shoulder of the brass my friend converted for me so im scraping those rounds , they need to be run back threw the arc die now that i know what the issue is

to start after running the gren brass into the arc die , it needed to be trimmed a good bit then run back into the arc die hard to move the shoulder back and size the neck properly.

my friend had only run the gren brass into the arc die as far as it would go which was not enough without being trimmed a second time , the brass my friend ran for me was trimed back to normal grendel trim lenght , what i noticed was after that first step the brass needed to be trimmed back to 1.490 ish and then hit int he arc die hard a second time , and then finally a small trim back to 1.475 , without the second step threw the arc die the necks are seriously way to tight


from left to right

left 3
nosler 70g balistic tip varminters over 30.5g of ppv should be around 3200 fps out of the 20 inch barrel oal 2.150

next 3 are 80g sierra spbt varminters over 31g of power pro 2000mr expected mv should be around 2750-2800fps oal 2.125 power pro varmint would get theese going a bunch faster but im conserving that powder for the lightwieght arc and heavy grendel bullets

last 4 are sierra 90g fmj gamekings over 30g expected mv in the 27/2750 fps range loaded ot an oal of 2.215 but theese wont chamber so ill have to seat theese deeper and that oal is tbdsame here power pro varmint would get theese going faster but saving that powder for other uses

edit knocked the 90's back to 2.150 and they now chamber

You've got A LOT of room to move the 70 gr NBTVs out. In my 6x45 they are at a max COAL of 2.31" and the base to Hornady datum line is 1.82"
For the Sierra 90s, I was 0.03" off the lands at a 2.27" COAL and a 1.865" base to datum line

[mel]

You've got A LOT of room to move the 70 gr NBTVs out. In my 6x45 they are at a max COAL of 2.31" and the base to Hornady datum line is 1.82"
For the Sierra 90s, I was 0.03" off the lands at a 2.27" COAL and a 1.865" base to datum line

hornady data says 2.095 for 75g bullets so i just went someplace close to there to start knowing they could be loaded longer ill adjust as i test more powder charges

[mel]

my magneto speed doesnt fit on this rifle theres not enough barrel sticking out for it to mount to the barrel without sitting up on the flashhider , ill have to either take the flash hider/qd mount off or build myself a keymod hg mount for it, or just use my older caldwell chrono for this rifle, however i do have some titan mini brakes on the way for this and my other rifles so maybe it will fit witht hat on it instead

[mel]

first up the winner of first round of testing

70 noslers over 30.5g of ppv oal of 2.150


not bad for arbitrarily picking a charge weight and seating depth im not changing a thing with this bullet now i just need solid chrono numbers i think i saw a 3315 flash on my chrono before it errored ( had chrono issues for all 10 shots this am )

and the other testing

top is the 70 noslers . mid is the 90 sierra fmj gk's theese flattened every primer so way to hot aparently and bottom is the 80g sierra spbt varminters , lil work and those should tighten right up

[TOU]

Amazing build and I am following with great interest...well done.

I do have a question, not meant to troll, but I keep reading that these are barrel/throat burners. I am curious what your thoughts are on it's the life expectancy of it with full loads? Comparatively to a 6.5G? Thanks in advance.

[Lemonaid]

This thread has firsthand data about Grendel barrel life. I would guess the 6mm ARC would be less than the Grendel, more than the Creed. 6K to 8K? https://www.65grendel.com/forum/showthre...light=king

[StoneHendge]

Amazing build and I am following with great interest...well done.

I do have a question, not meant to troll, but I keep reading that these are barrel/throat burners. I am curious what your thoughts are on it's the life expectancy of it with full loads? Comparatively to a 6.5G? Thanks in advance.

6 arc is certainly going to have a shorter case life than 6.5 Grendel. Basically the same case capacity and more overbore. This is my experience with my 243 LBC (aka 6 Grendel aka 6m ARC + 0.03") thus far - just had it borescoped. https://6mmarc.com/showthread.php?tid=218

[TOU]

Thank you, that was excellent info and just what I was looking for. Basically, I will never likely shoot out my 6.5 G CZ 527 or my 24" AA AR barrels in my lifetime...especially unless it becomes available in bulk surplus.

On another note, I have a CZ 527 16.5" threaded in 19 Badger (30 Carbine parent case) that I acquired along the way that I had intended to suppress and try my hand at coyote calling. Life hasn't really allowed much of that yet...just targets of opportunity. (Still, no can yet either.) That said I'm starting to think a similar rifle in 6mm ARC would also likely never be shot-out being used for sporting purposes. Sorry for the topic deviations but I appreciated it.

Again, awesome build, I will be following the thread.

[mel]

newest addition to the 6 arc build , though this will see also see time on my 12 inch build as well

7.8", full Ti, progressive baffles stack, form1 can , soon as my paperwork comes back ill finish the can , send it off for engraving and cerakote


i almost did a modular can with a 5inch base + 3 inch extension but it was going to be way to costly to do

[mel]

converted some lrp x39 geco brass loaded up 3 rounds of the 90g fmj with 28.5g of 2000-mr oal of 2.140

and loaded up some more of the nosler 70's identical to earlier for one more test group and chrono data