Help decide 6mm ARC barrel length

[troy fairweather]

Btw, X-Caliber has one of their frequent 20% sales going on now, you could order exactly what you want for $275 + shipping if you can wait a little while to get it.

I went RLGS on my 18", and it was doing well with an SA bleed off about 8.5 turns out, which is about where I run my Grendel and .223s. +1 would probably be good, but wasn't an option, I'd go +2 for longer barrels (my +2 21" is very smooth shooting and hasn't bobbled).

I haven't noticed the Hornady black being particularly hot, the first batch or two were loaded a bit long and were in the lands on some rifles, but they fixed that a while ago.

That's a nice deal for those barrels, if I had the money I'd really like I try one. I know the 105 problem early on but still read some guys getting hot lots of 105 ammo. There saying there only getting about 3 reloads and about 7+ from ammo that's normal pressure. Maybe just guys in hot temps and the powder is heat sensitive.

be cool if hornady came out with a crossover load, 75-90 grain that would work for varmint and large game to. Even the lighter 6mms have pretty good bc so will reach out fine.

 

[12Bravo20]

Tagged for results.

I have been thinking about getting rid of my 1 and only 6.8 SPC A4 upper and going a different route. The 6mm ARC is one f the choices I have been looking at.

 

[stillquietvoice]

I can't decide what barrel length to go with for my 6arc build, have a idea on the barrel brand thanks to loonwulf and its a great deal. But length I can't decide on, my mind wants me to get a 22" to get the most from the round out of the ad-15. But a 18" may look better and handle better even tho both barrels are hbars.

Real world the 22" maybe 100-125 fps faster then the 18" I only have 600 yards to shoot thanks to the new range opened near by, but most days will be under 300 yards. I plan to try some loads for varmints and deer.

Here's what I've got so far for the build.

Aero m4e1 lower.
View attachment 1100092

San tan tactical pillar sst-15 upper.
View attachment 1100097

Diamondhead bed-T 5.56 handguard 15" measures 16.5" at the bottom.
View attachment 1100098

Vg6 gamma 65 break.
View attachment 1100099

no butt stock yet, I'm thinking an A1 or A2

I'd go 20 in as well it's probably the best compromise on length, weight, velocity and portability.

Would you be able to cut, machine. Rethread and recrown the 22" to 20 so you could still use your vg6.

 

[LoonWulf]

Good question, the is why I'd like to try this scope out, sightron is one of them scopes I know basically nothing about and I can't place it in my head. I've never heard much anything bad about them other then normal nit picking like any other scope. These seem to be well liked for the money and camrealand is running a really nice deal on the 2nd focal plane scopes now. I believe these are made in the Philippines, some maybe better then the average China scope.

Ill have that scope out soon so you can poke at it a bit. I finally looked for rings last night and only came up with a set of 34s that are the right height.

 

[troy fairweather]

Ill have that scope out soon so you can poke at it a bit. I finally looked for rings last night and only came up with a set of 34s that are the right height.

No worries, I'll look for a ar mount I should get on to have anyways. Did Shaw have discounts when you looked they have 15% off now and wonder if you get that on top of your savings.

 

[LoonWulf]

No worries, I'll look for a ar mount I should get on to have anyways. Did Shaw have discounts when you looked they have 15% off now and wonder if you get that on top of your savings.

No, but the 15% off is the same as what we get. If your looking to keep cost down, ive had good luck with those monstrum mounts so far.

 

[IALoder]

The 18" will do great out to 600yds(pretty good to 1000) the 22" will push that a couple hundred yards further. I have a 24" X-Caliber barrel in 6mm ARC, and it does great out to 1100, where I ran out of scope dial with the scope I was using. So either barrel length will do great, it depends on if you want a longer rifle or not!

 

[ECVMatt]

Definitely following this one with interest.

The 6mm ARC is the first "other than 5.56" AR rifle cartridge that has caught my attention.

I could see building a light version for hunting.

Thanks for all the info that has been posted.

 

[BigBlue 94]

Im running a 24" hbar from Satern on my 6.5G to get every bit of velocity i can. So i vote 22"

Just for reference, A2 length handguard and a couple extra inches of flash hider

 

[rdnktrkr]

I vote 22" or 24" for velocity.
Something else to think about is when looking for rings to get a +20moa set to help if you ever want to shoot around 1000yrds, I just changed out mine on a 24" Grendel and had to site it in again. I also installed a muzzle brake that makes it a VERY easy shooting target gun.

 

[Gtscotty]

Finished my load work with the 100gr TGK in the 18" yesterday, the barrel does well with 108gr factory ELDs, so next step is to work out a handload that's similar.



I had a spread of 108gr and LVR (28.7, 28.9, 29.1, 29.3 and 29.5) loaded and ready for yesterday, but I was working with three rifles and managed to fumble the cartridge box and spill most of the cases together after shooting the 28.7gr load . Still had two of each I was sure about, that I put on target and it looks like 29.3gr - 29.5 gr is where I'll focus with those next time. After truing my drops out at 600 and 750 yds with some the remaining rounds (that I think were 29.3 gr or 29.5 gr), it seems they are running ~2,630 fps.

Edited to add Strelok drop charts for an 18" w/108gr ELD @ 2,630 fps.


And an estimated 23-24" w/108gr @ 2,750 fps.


20" & 22" should, on average, be somewhere between those two. The environmental conditions in those calcs, are what I was shooting in yesterday in Chapel Hill, TN.

The longer barrel would get you more comfortably to 1k before getting transonic. I've taken my 21" out to 1,250 yds, but it's sucking wind, 1k is a lot more convincing and those little 108gr hit with some authority at 750. Of course this would all look pretty different at higher elevations.

 

[horsemen61]

@troy fairweather I went with a 24 inch Shilen barrel I did the 1~7 twist with a heavy contour this is a bench rifle for me it is wearing a Luepold VX®-3i 6.5-20x40mm EFR with the fine target crosshair I love shooting it it is a Rifle length gas system she is a heavy girl though also I did the A2 stock and one of my favorite features is the CMC FLAT Competition trigger it’s 2.5lbs on the pull single stage and I love it for this rifle!





If I were you I’d do the 18 inch sounds like you may have more than one use for it so I’d do the shorter 18 inch length for the maneuverability

 

[Bcwitt]

I think i might go with the longer barrel for something like that. You can always cut & crown if it proves difficult or awkward to handle.

 

[12Bravo20]

Well I bit the bullet and ordered an 18" Odin barrel and bolt. We'll see how it goes once I have everything to finish the build.

 

[troy fairweather]

I'm hoping my Shaw barrel will be here this week, think I said I ordered it. 22" so should gain a few fps . I'd still like to maybe build a 16-18 inch upper for just hunting after this build and the heavy 5.56 I'd like. I'm hoping I'll have enough money to order the rest to finish this arc build on the black Friday sale. Still over $400 of stuff I believe.

 

[12Bravo20]

I have everything to complete the upper coming from Primary arms except for a muzzle device. I haven't decided what I want to go with yet. I'm debating between a good compensator or a muzzle brake.

 

[troy fairweather]

I have everything to complete the upper coming from Primary arms except for a muzzle device. I haven't decided what I want to go with yet. I'm debating between a good compensator or a muzzle brake.

I'm going to try the vg6 gamma 65 break I have, hoping it works out. I still need the stock,bcg,trigger,charging handle,scope mount. Hard finding a mount for about $100 that I feel is ridged enuff.

 

[gotboostvr]

I'm going to try the vg6 gamma 65 break I have, hoping it works out. I still need the stock,bcg,trigger,charging handle,scope mount. Hard finding a mount for about $100 that I feel is ridged enuff.

I "accidentally" ended up with one of those. Bought a used Bergara HMR-14 in 6.5CM and it came with one of those. Almost feel bad that I'm not going to use it much since I'll be mostly putting a can on it.

 

[12Bravo20]

Well everything came in for my build. I ended up going with the VG6 Gamma 65 BBSS brake.

A word of caution on the Expo Arms 15" handguards that Primary Arms sells. They will not work with the Odin Works adjustable gas block. The gas block was hitting the inside of the handguard. I will save it for a 22lr build instead. I ended up ordering a GunTec 15" M-LOK handguard which works fine with the Odin Works. I know another cheap handguard, but I have had great luck with GunTec handguards in the past.

Now to decide on what scope to use. I have a spare Primary Arms 4-14 FFP MIL DOT I could use for now (until I decide what scope I want).

 

[kje54]

Be wild, get a 32" barrel...........

 

[troy fairweather]

Barrel came today, looks great. I think I'll do a thread on the barrel since there isn't much good info out there about the shaw barrels.

 

[troy fairweather]

Well everything came in for my build. I ended up going with the VG6 Gamma 65 BBSS brake.

A word of caution on the Expo Arms 15" handguards that Primary Arms sells. They will not work with the Odin Works adjustable gas block. The gas block was hitting the inside of the handguard. I will save it for a 22lr build instead. I ended up ordering a GunTec 15" M-LOK handguard which works fine with the Odin Works. I know another cheap handguard, but I have had great luck with GunTec handguards in the past.

Now to decide on what scope to use. I have a spare Primary Arms 4-14 FFP MIL DOT I could use for now (until I decide what scope I want).

I just got a expo arms upper parts kit and didn't think a parts kit cloud be cheaper then a normal mil spec kit. They cut a bunch of corners and is cheap as possible on everything, save up $2 and get the aero kit.

How you like that 4-14, a member on another forum has one for $140

 

[12Bravo20]

I like the Primer Arms 4-14 MIL DOT. The glass is clear and the reticle is crisp. I just don't think it will work for shots over 650 yards without dialing the scope in. I like to be able to dial the scope in or use hold overs (depending not the situation/target)

 

[gotboostvr]

How you like that 4-14, a member on another forum has one for $140

I had one of those for a few years, and it gave very good service on a 308win bolt gun until I upgraded to something nicer about a year ago.

Sold it to a buddy for a song and it's reportedly continuing to give good service on a 22lr bolt gun apparently.

 

[12Bravo20]

Well I decided on a scope. I went with an Arken SH4 Gen 2 6-24 scope. It was about $20 less with a coupon code than the Swampfox Patriot 6-24 with military discount. I can do a good side by side comparison of the two scopes once I receive the Arken.

And if the Arken doesn't work out on the 6mm ARC, I'll use it on one of my 22lr rifles.