BCA 6MM ARC Rifle

[m&p45acp10+1]

I now have a new Bear Creek Arsenal AR15 chambered in 6MM ARC. I was planning on doing a build. The price of the complete rifle offered was less than the entire budget for the build. (Parts were going to cost considerably more.) So I decided to go ahead and buy the rifle.

Specs are as follows:

Standard MilSpec lower. The upper is the 15 inch MLOCK hand guard. Semiautomatic action. The barrel is the standard stainless heavy profile nonfluted barrel with spiral flash hider. 1 in 8 twist rate. 24 inch length The barrel is 416R stainless steel, with a brushed stainless finish.


Price of the whole thing was $519 plus tax/transfer fee. Shipping was free. Turnaround from order to shipping Was less than 2 days. I ordered on a Friday night. The order was confirmed on Monday. Was on the truck Thursday. FedEx had it here on the following Tuesday. The store is closed on Tuesday and Wednesday. So I was able to complete the transfer today.

While waiting on delivery I ordered 2 CMMG 10 round magazines. Brass, bullets, dies, powder, primers. I also picked up a box of Hornady Match ammo. (108 ELD-M). All of the components are now in my reloading room, awaiting me to start a load development.(Will post about that in the reloading section.)

I mounted a scope I already have for the initial fire testing. 6-24 x 44 ffp scope. I wanted lots of magnification for the initial accuracy test. Before heading to the range I cleaned, and degreased the rifle. I ran an oiled patch down the cleaned out barrel followed by a few dry patches. I then headed to the range.

Range report.

100 yard indoor range. I used a Caldwell Rock Jr front rest, and sandbag rear rest. After a 3 shot sight in group at 25 yards the target was sent out to 100 yards. I then fired 3 groups of 5 shots. After allowing the rifle to cool to room temperature I used a single shot to confirm zero. (It was dead on.)

Group average was sub half MOA. One 5 shot group was under .36 inches from outside edge to outside edge total.

I did bring along my Garmin Xero chronograph. Factory ammo: Hornady ELD-M
108 grain. Average velocity was 2630 with a standard deviation of 11.7 FPS ES was 39.2 for 19 shots. Barrel length is 24 inch.

[tangolima]

That's excellent.

I also buy BCA's products. They work if you don't mind tinkering. My 6mm ARC upper happens to shoot well too. I bought the barrel from somewhere else before BCA started carrying the caliber.

Your ammo sounds on warm side. Beware that there are two sorts of 6mm ARC ammo. The one for AR has lower pressure. Make sure that's what you shoot with.

-TL

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[m&p45acp10+1]

The ammo is factory Hornady. The higher than seemingly normal velocity numbers are most likely due to the 24 inch barrel. Most are running a far shorter barrel.

If I do any upgrades to this rifle. The first 2 are going to be the trigger, and the buttt stock. The trigger while it is a clean trigger. There is no slop, or creep at all.It is heavy. The butt stock works fine. I just do not like the 60 grit sandpaper feel of it.

I. also want to note the accuracy test was done at an indoor range. I highly doubt getting any results for groups that small anytime in the near future as the hourly rate for that range is too high for me to pay very often. While it is a fine range. That is well lit, and very well maintained. $35 per hour adds up quickly.

[tangolima]

Factory ammo could be for bolt gun or AR.

100yd indoor is uncommon. I have been to one that was a conversion from quarry tunnel. I didn't like it there either. Rather pricey and ventilation was questionable.

The best group I got is 1.2moa at 150yd, 10 shots starting from cold bore. Ammo was handload. Optics was no-name LPVO. Wind was mild and consistent.

-TL

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[rickyrick]

I shied away from BCA for a long time, but I wish I hadn’t. They seem especially good for trying out different calibers without breaking the bank.

[tangolima]

Originally Posted by rickyrick

I shied away from BCA for a long time, but I wish I hadn’t. They seem especially good for trying out different calibers without breaking the bank.

Like buying cheap tools, it usually requires some tinkering.

-TL

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[georgehwbush]

Originally Posted by tangolima

That's excellent.

I also buy BCA's products. They work if you don't mind tinkering. My 6mm ARC upper happens to shoot well too. I bought the barrel from somewhere else before BCA started carrying the caliber.

Your ammo sounds on warm side. Beware that there are two sorts of 6mm ARC ammo. The one for AR has lower pressure. Make sure that's what you shoot with.

-TL

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on the warm side? advertized 2750 from a 24" pipe, and so i kinda doubt that is "too warm" but what do i know. just watch for pressure signs, right.

[tangolima]

Originally Posted by georgehwbush

on the warm side? advertized 2750 from a 24" pipe, and so i kinda doubt that is "too warm" but what do i know. just watch for pressure signs, right.

Does it say 2750fps from a 24" pipe on AR? Ammo for AR is 5kpsi lower than for bolt gun, probably because of the thinned out lock lugs. Pressure signs on brass could be too late.

Hornady publishes two different sets of load data; bolt gun and AR.

-TL

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[bamaranger]

An acquaintance just bought a 6mmARC from BCA as well. He's had trouble with his "short stroking" , failing to eject resulting in stove pipe jams now and then with Hornady eLD-match.

I looked seriously at the BCA 6ARC rifles, but ended up wheeling and dealing with bamaboy for one of his.

[tangolima]

Originally Posted by bamaranger

An acquaintance just bought a 6mmARC from BCA as well. He's had trouble with his "short stroking" , failing to eject resulting in stove pipe jams now and then with Hornady eLD-match.



I looked seriously at the BCA 6ARC rifles, but ended up wheeling and dealing with bamaboy for one of his.

Their CS is not bad. I have barrel extension came loose. They replaced the whole barrel. The bolt's firing pin hole was over sized. I had hard time making them understand the issue, so they just sent me couple of firing pins. None worked, but it was ok. A forum member donated an old firing pin with over sized tip that he had use of.

-TL

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[m&p45acp10+1]

I bought the complete rifle. With the 19 rounds of ELD Match factory ammo I have fired out of it. Not a single hiccup. I used 2 CMMG (6.5 Grendel.) The barrel is a 24 inch with a full length gas tube.

I am thinking that since it was a factory build rifle. It is set up to run reliably. If one uses their own lower then they May have to tinker to resolve problems.

On the box it says velocity figures were for a 20 inch barrel. The 24 inch I used showed an increase that is on par with the chart they have on the load page for the 108 ELD-D that list powder choices, and charge weights. Below that it list The average increase is around 150fps. None of the brass showed no pressure signs. The rifle ran fine. I got a little bit of the extra smoke in the chamber from the machine oil in the gas tube burning off.

Overall I am impressed with the rifle. The quality is there. I will probably change the buttstock. it is the only part on the rifle that seems cheap to me. It is a basic entry level MilSpec plastic adjustable AR butt stock with the aggressive 40 grit sandpaper feel. I will be changing it out with something for an upgraded The trigger is heavy though there is no slop, wobble or creep in it. It breaks clean, and the reset is short. I will find one to replace it with to lighten it up.

I was originally going to build a lower, and add the upper piece by piece. The upper I wanted was not in stock, and the entire rifle had the upper, and barrel combo I wanted. The entire thing was well below the budget I set. Even after I replace the stock, and trigger I will be far under the budget. That leaves more for the glass budget. The scope is likely to cost more than the rifle.

[stagpanther]

Just my personal opinion (I jumped on the ARC bandwagon soon after it was rolled out)--the typical twist rates get dicey once you're up in the 107+ gr bullets; I'd go 1:7 or 1:7.25 if that's where you want to be much of the time.

[tangolima]

Originally Posted by tangolima

Does it say 2750fps from a 24" pipe on AR? Ammo for AR is 5kpsi lower than for bolt gun, probably because of the thinned out lock lugs. Pressure signs on brass could be too late.

Hornady publishes two different sets of load data; bolt gun and AR.

-TL

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Looked into the matter more.

Saami spec is 52kpsi, good for both gas and bolt guns. So factory ammo must be good as it may not exceed saami. I stand corrected.

Hornady's load data for bolt gun is 62kpsi, which is above saami. There is no such factory ammo. But if I handload, I will be careful which load data I go by. Not sure when pressure signs would show though.

My own load has 85gr bullet, going around 2600fps with 18" barrel. It is not quite at max pressure yet. That's why I thought OP's load might be on the warm side.

-TL



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[stagpanther]

The ghosts of grendel type1/type 2 bolts will never go away!

[tangolima]

The Grendel lineage could indeed cause unique issues. One is the "Grendel belt", which took quite a bit of doing to resolve.

-TL

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[m&p45acp10+1]

I had to edit my previous post. The brass showed no signs of over pressure. It cycled fine. I used a Garmin Xero chronograph. It has proven to be accurate. I tested it against an old school shoot trough chronograph.

Note the. numbers are high due to a longer barrel. That is a huge reason I picked the one I did. If they had offered a 26 inch barrel I would have bought it. I like the longer barrels, and prefer them for the extra velocity gains. I shoot as often as I can get out to. The range I have been going to is a 45 minute drive each way. Though it has steel targets out to 600 yards. I like to hit the 600 yard targets.


I was having issues with the scope I had on it. So in the interim of finding a better scope. I have an SFP Simmons on it. The scope works, the turrets track true. Though I will not lie it is a cheap scope. Turning the turrets takes strength in the fingers.

[seanc]

A month ago I got my BCA 6mm ARC complete upper with 20" straight flute 416R stainless barrel, 1-in-8 twist. I should have done some more homework on the twist and got a 1-in-7, but the price was phenomenal. I ordered the full suite of Hornady loaded ammo in 6mm ARC (80, 103, 105 and 108 grain) to see how they shot and to get some brass to work with. All shot well except the 103 gr ELD-X, which hung up on my brass catcher and I'd get a double-feed and crushed, scarred, brass. When I finally figured out what was happening, I took my brass catcher off and it cycled just fine.

Best accuracy was from the 108gr ELD match. For reloading, I ordered some Hornady 105gr BTHP (cheapest bullets I could find) and 2 boxes of the 108gr ELD match loaded ammo for more brass and to make up for some of the crushed 103gr cases.

I loaded up the 105gr BTHP's with what I had on hand (Win748 & CCI SRP). The 1st 3 rounds clover-leafed at 100 yards, but the 5 shot group was just over an inch. I only loaded up 2 different, but close, powder charges and they both grouped well and to the same POI. I'll be sticking with the lower powder charge going forward. The factory 108gr rounds continued to group well, between 1-1.5" at 100 yards. 2 old goofballs jumped the line and got to the 200 yard lanes before I did, so no long range shooting this past weekend, but from 3 weeks ago at 200 yards, the 105 & 108's were consistent between 1-1.5 MOA groups. The 103 and 80gr factory loads opened up to 3 MOA at that distance.

My Caldwell chrony stopped working, so I don't have any fps to share. I'm kind of curious though, since I couldn't find Win748 load data for 105gr bullets, I extrapolated from the 103 and 107gr load tables for AR loadings, splitting the difference and being a a little bit cautious. I have a decent quantity of CFE223, but I'm saving that for 223.

The upper has gotten compliments each time I've been to the range, even after I tell them it's a BCA upper. I've shot it on a cheap blem PSA lower and a Savage MSR lower which didn't make a difference at all in accuracy that I could tell. Both fit tight. I did have 1 ftf with a light strike on 1 of my reloads. That could have been from poor seating, but I thoroughly cleaned the bolt and carrier and after re-assembly the round fired to POA, so I put that on me.

[m&p45acp10+1]

I have 250 pieces of Starline new brass. 500 108 ELD-M (factory seconds.) I have CCI Small Rifle Bench rest primers. For powder I have LeverEvolution. I have a few others I may try at some point. I also Have 200 75 grain v-Max I may work up loads with eventually.

I did a small scale load work up at the range. As far as a run for from start to max charge checking for pressure signs. The wind was not being nice to my target so no group info. The target was like shooting a flapping piece of loose sail in wind that went from high to knock you over speed. Chrono numbers nearly matched the numbers given for a 24 inch barrel. My loads came in 15 FPS over that. I am going to be working lower than the max charges. As the higher charged did not show pressure signs. They had feeding issues that caused some mangled brass.

I do not have my notes handy at this time. I will be posting a thread in the hand loading section at a later time.


Now to clean the rifle, and break out the bore scope.

[tangolima]

My brass are conversion from 6.5mm Grendel. W748 powder works quite well. Best bullet is Sierra MK. More affordable Speer is a bit behind, but still good enough for my purpose.

My barrel has shorter than expected throat. The round ended up headspaced on bullet ogive, causing inconsistent ignitions and even hang fires. I would suggest measuring bullet jump to determine bullet seating depth.

-TL

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[Shadow9mm]

I have a 20in build with a ballistic advantage barrel. Shoots about moa with eldx, and 1/2 moa with hornady match. Still in the process of a load workup with the 103eldx and 107 smk. Have AR stoner(midwayusa) 25rnd mags, and a 10rnd duramg ss, both feed flawlessly. Bullets make a much more significant berm impact compared to 223. Need to finish a 223 and 6mm arc workup so I can get back to my 6arc.