6 Arc

W

William Suter

Well-known member
I been on and off the fence on buying/building a 6 Arc. Went to a small gun show today, just looking and ran across a PSA lower with a Bear Creek upper in 6 Arc. It has a great trigger, and I'm sure its not factory (flat blade and light) and a Magpul PRS Lite stock. For what I paid, I'm not expecting a lot but figure it may help me decide it I want to go this route and I have plenty of re-usable parts to work with. This was the "pros".

Now the "Cons". First reviews I read weren't the greatest on the BCA upper. Some got decent accuracy and some not so great. But the worst was when I took it apart. The previous owner must have shot it suppressed or just never cleaned it. It was the nastiest filthy rifle I have ever had to clean. Everywhere I touched it I got black carbon fouling off it. I spent the better part of two hours just cleaning the upper. I still need to take the trigger out of the lower and give it a good scrubbing. Really makes me wonder if I really want a suppressor that bad. The barrel is an 8 twist and 18" long. I have not idea what ammo to try first but I haven't got it scoped yet so I guess there is no hurry. ( Can't believe for someone that doesn't like AR's I now have two.)

Gun sales were slow slow slow. Not much of anything moving. Prices were still high as expected. Sunday morning the place was like a ghost town. I did snag two box's of 50 grain HP bullets in 222 for $20. I didn't need it but couldn't pass up 222 ammo.
 
William Suter said:
Now the "Cons". First reviews I read weren't the greatest on the BCA upper. Some got decent accuracy and some not so great. But the worst was when I took it apart. The previous owner must have shot it suppressed or just never cleaned it. It was the nastiest filthy rifle I have ever had to clean. Everywhere I touched it I got black carbon fouling off it. I spent the better part of two hours just cleaning the upper. I still need to take the trigger out of the lower and give it a good scrubbing. Really makes me wonder if I really want a suppressor that bad. The barrel is an 8 twist and 18" long. I have not idea what ammo to try first but I haven't got it scoped yet so I guess there is no hurry. ( Can't believe for someone that doesn't like AR's I now have two.)
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Probably a combination of both suppressed and non-cleaning practices.
In my opinion as a "AR" owner using suppressors, one really should use adjustable gas block to control the carbon / gas sent back to the action. The other answer that there was a lot of hype about was piston driven gas systems on the AR. Did it work for use with suppressor? Yes, but it also introduced a different harmonic to the barrel vs the gas impingement as originally designed.

Second this with actually maintaining by cleaning after each and every shooting event. Would you drive your car without changing or adding oil to it?? If one does that they are soon walking. That comment is not directed at you Bill, but it seems to me that many refuse to understand that simple concept. And shoot until accuracy degrades just like a rimfire, then wonder why?? The results is now they are cleaning harder to get the caked on carbon down to a acceptable degree than if they simply used a simple proper cleaning regiment.

I do have a suspicion of BCA barrel quality, but it is based on what others have wrote or stated, not on actual hands on experience. That suspicion is not favorable.
I suspect solely based on what others have stated the very first steps would be trash or donate the barrel and handguards. Select a known good barrel and handguard with a adjustable gas block, for tuning extraction angle and cycling. The Armalite series in it's original format is over gassed on purpose for reliability (even when properly tuned for ejection angle).
Powder choice will also affect the amount of carbon introduced into the action, IMR 4895/4064, Varget is way dirtier than say H322, H335 or even CFE223. Does that mean the "dirtier" are bad no, just means one needs to clean more often. I've seen some great accurate load with the "dirtier" powders. To be honest it just amazes me how many people refuse to clean a rifle properly.

Best of luck with the ARC while I don't own one I suspect it will be a highly effective caliber when done right.


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The Arc is just an itch that needed scratched. I'm usually not pessimistic but I'm also logical (most of the time), used rifle...gun show. LOL its here for a reason. And the way it looked internally, I'm sure there was a reason. The barrel cleaned up pretty good and not a bunch of copper fouling or carbon, but the bolt, what a mess!! While I'm not expecting bench rest accuracy, I do hope it shoots good enough that I might tune a load that shoots reasonably good. I did watch a couple of videos and when they found a bullet the barrel likes it shot very good. Sub one inch. I'll be thrilled with anything close to that. Maybe I'll get lucky. Used guns are like gambling, you can't win all the time and it does give me something to do besides setting on a lawn mower at the gun club.
 
I definitely understand that itch LOL been bitten by it in the past...... numerous times.

Hoppe's #9 and Breakfree CLP has always been a friend in that series, although there have been many claims of "better". My experience is the two just work and work well.
In tuning heck one can tune faster with a inexpensive adjustable gas block faster than weighing buffers or changing adding buffer weights to the buffer etc etc.

Looks like you got a good start on a fun project though again Best of Luck. ( I think you'll have a blast with it )

Mike
 
I love the 6mm ARC and I've piled up a good bit of hogs, deer, and coyotes with it. I built mine using a 18" barrel from Ballistic Advantage. I've had really bad luck with Ballistic Advantage barrels in .223, having returned three and almost destroying an AEM5 suppressor, but every thing else (.308, 6.5G, 22 ARC, 6mm ARC, .300 BO) have lived up to their MOA accuracy guarantee. I have two Ballistic Advantage barrels in .223 that are good shooters but it took a while.

I've seen good and bad reviews on Bear Creek... you have a 50.50 chance of it shooting MOA... it sounds like it was shot a good bit so maybe it is a good shooter and you will be pleased. If not, a barrel swap isn't hard to do.

The only Bear Creek barrel I've personally seen was when I use to give Precision Rifle Classes and a guy brought a Bear Creek 6.5 Grendel build... I will admit that barrel shot well under MOA and I was quite shocked being prejudice already due to many bad reports.

I'm still burning through my factory ammo stash to acquire brass, even though brass is now available, so I've not played with the cartridge at the reloading bench... thus I have no load recommendations.

Good luck... keep up posted after your first range trip.
 
I've already looked at barrels. LOL, I haven't even fired a round and looking at barrels. But the Ballistic Advantage will probably be the one I go with if I need a barrel. One video a guy shot some 105's and 103's in Hornady factory fodder and results were not to good. Then he shot a lighter bullet maybe 88 or 90grain (brain fart?) and it stacked them on top of each other. Another video was similar but the 105's shot really good in his barrel. I have a bunch of 6mm bullets from real light to pretty heavy so I have some to try. Just no brass or dies yet. May run the gambit on factory stuff until I get some brass accumulated.


Bowhntr6pt, what power scope are you using on your 6 Arc? I have a 3.5x10 Leupold and a 1-6 Bushnell. Main use will be hunting deer, hogs and coyotes. I like them both but the Leupold does offer a little more power if needed.
 
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When the ARC first came out, I bought an upper from Brownells with a BA barrel.

Put 600 rounds down it, and sent it back & got a replacement.

600 rounds later I sold it, & bought a Shilen in 6 ARC from Ranier Arms and my troubles were over.

Good luck.....
 
So I own multiple ARs and own/owned a few arcs, build them pretty regularly. 22 arc x2, 6 arc x2, 6.5 grendel, 22 grendrl, 6x6.8, 6 dti, 25-45sharps x2, 6x45x 2... 22 creedmoor..... end of the day I believe a small frame AR is way more reliable when the cartridge is 223/556 based. These bigger cases dont generate enough velocity with lighter bullets to warrant sacrificing reliability. The ARCs are a great example.... super efficient in a bolt gun. My 70gr load with no pressure signs in a bolt gun cannot be shot in an AR. These bigger cases cause unlocking issues that are impossible to solve completely. In my opinion. There is a reason they list gas gun data and bolt gun data. With 556/223 parent case cartridges this does not seem to be an issue. 25-45 sharps for example: 20in barrel getting 3100+fps 70gr pill. Expendable brass (consideration for an AR) . Reliable, hit hard.

Just another opinion based on experience.

Good luck.
 
William Suter said:
Bowhntr6pt, what power scope are you using on your 6 Arc? I have a 3.5x10 Leupold and a 1-6 Bushnell. Main use will be hunting deer, hogs and coyotes. I like them both but the Leupold does offer a little more power if needed.
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Right now the rifle has a Trijicon Hunter IR TWS, but when I was testing for accuracy I was using a 1st generation Vortex Viper PST 4-16x50.
 
alf said:
When the ARC first came out, I bought an upper from Brownells with a BA barrel.

Put 600 rounds down it, and sent it back & got a replacement.

600 rounds later I sold it, & bought a Shilen in 6 ARC from Ranier Arms and my troubles were over.

Good luck.....
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Sounds familiar... seems twenty years ago BA put out some nice barrels... now days, they seem to be hit or miss with not much in between... at least they have a MOA guarantee that makes it easy to replace the barrel if it's a turd. While I've never had a problem with their customer service, some guys have posted about having trouble getting responses to questions concerning problems. Seems the best way to deal with BA is through their on-line Service Ticket program.
 
If you spent 2 hours cleaning, it wasn't very dirty. I've taken in many that took me days of soaking and scrubbing and picking to get throughly clean.
 
Both of my 6 arc's are bolt actions...

With that said, it seems to me that the 6 arc is a dirty little cartridge. I've also read where others have the same opinion.
 
1stpitch said:
If you spent 2 hours cleaning, it wasn't very dirty. I've taken in many that took me days of soaking and scrubbing and picking to get throughly clean.
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I guess I've just been spoiled when cleaning my bolt rifles. It just seemed really dirty compared to my rifles. But I don't run suppressors either.
 
Suppressors really make a mess of ARs. Adjustable gas blocks help a bit, but not as much as you'd think. A lot of the filth is coming back down the barrel due to the backpressure.
A flow-through type suppressor helps a lot. I have a Huxworx can that I run on my ARs now, and it seems to knock the filth level back to the unsuppressed range.
Also, for the 6 ARC, if you're running Hornady factory ammo, odds are it's LeverEvolution (or similar) powder, which is known to be extra dirty.
 
Well, I got to the range with the 6 Arc this morning. After reading the comments here and the videos I watched all I thought about while driving out there is which barrel should I buy. I bought a cheap Chinese scope mount yesterday and a box of Hornady Black 105 BTHP ammo. Even though the mount was cheap, it works and got my eye really close to where I like my eye. And the Hornady was the cheapest in the store. Why spend good money on a rifle with low expectations of function and accuracy? Boy was I wrong!! After a quick bore sight, I broke paper at 50yds. A little adjustments and shot 2 more rounds. Pretty close to the bull and they were touching. Hmmm, made me take a double take. Then to 100yds. A 5 shot group was a few inches low but maybe 3/4". WOW!! Loaded 5 more after a little more scope adjustments and 5 rounds in a nice tight group that almost covers up with a nickle. I'm stoked! Looks like I got lucky and got a BCA upper that actually shoots. Now I wish I had bought more ammo but I can make a trip if need be.

Now one Con. The rifle feeds fine and ejects fine but on the last shot it doesn't hold the bolt back. It will on an empty mag, just not after the last shot. Not being an AR guy I'm not sure what the issue is. Care to educate me??? I have two more mags to try but seeing how I can lock it back on an empty mag I don't think that's the problem.
 
William Suter said:
Now one Con. The rifle feeds fine and ejects fine but on the last shot it doesn't hold the bolt back. It will on an empty mag, just not after the last shot. Not being an AR guy I'm not sure what the issue is. Care to educate me??? I have two more mags to try but seeing how I can lock it back on an empty mag I don't think that's the problem.
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Sounds like it's short-stroking, meaning that it's not pushing the bolt far enough to the rear. Once it gets dirty, it may start failing to pick up the next round.
There can be a number of causes for this, mostly dealing with not enough gas being directed to where it needs to go, for example:
- Gas block misaligned
- Gas port too small or partially blocked
- Blockage in the gas block or tube. -- Is it an adjustable gas block? If so, is it wide open?
- Gas tube too short or gas block set out too far -- either way, it's not sitting in gas key far enough.
- Leaky gas key
- Leaky / worn gas rings on the bolt
- Buffer too heavy
- Buffer spring too stout
- Too much drag on the BCG - trusting you cleaned it well, not likely, but...

There may be some others, but I would start by looking at the gas block and tube.
 
That's great news... do you happen to know if it has an adjustable gas block? If so, perhaps it was dialed in for suppressor use and you can open it up a click or two.
 
My fix is simple
a. Of course a good cleaning focusing on the bolt carrier and bolt assembly ensure the gas rings are not lined up (look at the gaps in the rings offset them.). slight resistance when putting the bolt into the carrier. Change the load.
OR ,
b. find a proper sized adjustable gas block i.e. .750" dia or .625" dia etc . Doesn't have to be a expensive one. Shut the gas off completely then open a few clicks or so.
Load 1 round into the mag, fire.. did the bolt lock to rear? No? repeat process opening ever so slightly until Bolt is locked to the rear. Yes? Fire one more the same way to confirm once confirmed your done.
This is my preferred method.
Fast,, allows the cyclic action and loads to be tuned to each other whether suppressed or not. Keeping the rifle from battering itself.

To the list that @SupressYourself has posted the most least likely culprit can be a set that has developed on the BHO spring, or dirty as in caked on carbon on the bolt catch mating surfaces in the lower.
Very doubtful on that but can be a cause many don't look at. CLP and toothbrush usually fixes it.

Added:
give the gas block a good look over it might be adjustable...
 
I just took the fore-end off and removed the block (non-adjustable) and tube. I flushed it out with wd-40 and made sure it was clear. Then checked the port in the barrel. One thing I didn't do when I cleaned it last night was check the bolt but I kinda doubt it had a blockage. It cycled perfectly until the last shot. That's when it didn't hold the bolt back. Gas blocks are fairly cheap if you don't need best of the best. I'll replace it with an adjustable one.

Added: It will hold the bolt back on an empty mag, just not after the last round fired.

I was laughing at myself. If I miss the coyote/deer or pig 5 times having to pull the charging handle back to load another mag probably won't matter. The critter will be beyond my range anyway. LOL (But I still need it fixed)
 
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