ARC Coup de Grace: The Good, The Bad, The Almost Ugly 

Also ran into the same issue with the MDT 12 round 6BR mag in my Matrix Pro chassis with the adjustable mag catch. I had to remove the mag catch and take it to the grinding wheel. Now it locks in and feeds with zero issues. The only other issue I’ve seen with this action, is the mechanical ejector. With the shorter BR style cases if you run the bolt slow it will or rather it can drop the case back into the receiver and cause a malfunction. Secondly because the mechanical ejector is located at the farthest rearward area of the receiver it’s not optimized for the BR variant of cases. Other receivers with a plunger style ejector can be ran with a shorter bolt throw and there for a little faster all other things equal. Having said all that I own two and have no thoughts of selling them at all. These things mentioned are just stuff that you have to be aware of, train and prepare accordingly. Great video and thank you for sharing your experiences with the action. I’ll be running one this PRS season for the first time.

I have one in the long action with lapua bolt head. It’s at the gunsmith now. Having it chambered in 300 Norma improved. Really looking forward to getting it back and seeing how it functions.

I run mine in an mpa ba chassis with aw mags. Ive never had to touch a thing. Super smooth on feeding. I did have to put a polishing compound on the extractor to clear up a slight binding. My action was shipped before they changed extractors. On that though. I opened my mailbox one day and had new extractors in it for my actions. I never reached out, never knew it was a problem, they just sent them to make things right. I haven't put them in yet as ive had no issues after i polished mine.

I'm not sure how the action manufacturers intended it to be pronounced but the French phrase is pronounced phonetically coo de graw.

So, if I were to sum it up, once the extractor was replaced, the issues were with having to adjust the mag release in the chassis for AICS mags and possibly having empty cartridges ejected forward of the firing line. Otherwise the thing shot like a laser. I don't know how this action can be beat for the price.

Any issues with the extractor getting over the case rim when single feeding? Didnt look like you were having an issue, but I figured Id ask. Only reason I ask is because I own a couple of Nucleus's, a short and a long action. The short action with 6 CM has zero issues single feeding, bolt closes easily on it, and can literally slap the bolt closed. The long action is a 300 PRC, and when I go to close the bolt on that one, it sometimes takes a pretty good nudge to get brass to slip past the extractor. I suspect it has something to do with the massive Mauser style extractor the Nucleus uses, and the magnum bolt face has that much bigger of an extractor than the 308 size bolt face. In both cases the guns feed great from a mag as they are controlled round feed, ARC for the short action, Accurate 300 RUM mags for the long action. Ive been considering building a 223 gun with this action, and setting it up to just only run as a single fed gun and use a sled instead of a mag, and dont really want to have issues with the extractor causing potential issues with single feeding like my 300 PRC does.

Great video, what barrel vice and action wrench is that?

Ha! Same disclosed issue here concerning the AICS magazines. I am using AccurateMag WSM magazines for a 6.5 PRC. I got tired of trying to sand the mag latch. I don't own a belt sander. Ignorantly, I sanded a notch on the magazine itself. It works flawlessly now. But, any upward pressure on the magazine binds the bolt. It's not a deal breaker since I don't compete.

Much appreciation for your video. My rifle experience comes from 40+ years of sporter weight hunting rifles.....now getting enthused about target range time shared with my son. He's a math lover and geeking out over the dope calculations and corrections....having fun. I'm setting up a pair of lgs off-the-rack rifles for .308 (2) & 6.5CM (2) (HMR, RPR, TAC A1) in addition to a B14R. that we both really enjoy Each have 5-25x50/56mm glass with MIL/MIL turrets/reticles. Gonna have big fun together dueling it out. Also wanted something more "custom" and ordered a CDG. Picking it up today from my FFL. I have that same Viper vise and am also using Inline Fab mount.....love their gear. Using a TT Diamond 2-stage. Scored 4 AIAW mags from backorders. My 6GT barrel is "in production" and should be here next week. Topping it with Razor G3 6-36x56mm MIL / MIL in a M-Brace. Xylo chassis (my first chassis gun). Appreciated your points to consider...hopefully the mag-related stuff will be avoided here. Old dog learning new tricks. Going to be super fun. I haven't told my son about this particular rifle.......was gonna break it out on a range session after he was done whupping me on our head-to-head "matches" using the 4 similar .308 & 6.5cm's..........He'll go nuts.

what is still a little bit annoying is that removing and inserting the bolt in the receiver is sometimes not easy as it should because of the ejector...any clue on how to mitigate this?

Does the rifle Come with a 2 or 3 position safety?

Are you using 100 ft/lb on the barrel?

So for a hunting rifle do you think this vs a lone peak action?

anti seize on the barrel threads :D

I can see where the barrel was marred because it slipped in the vice. ALWAYS use drywall tape around the barrel! It'll never scratch or get marred! And I'm an amateur.

It's surprised me...I felt my tikka action was much smoother than this one.

Coo duh grahh

Now I'm hesitant to buy one...

I think that’s the typical ARC MO. It never quite works. They sell a cool engineering story with their actions, and everyone eats it up, but then when the action gets out to people - there are always teething issues. I’m not trying to be elitist, but that’s why I got a 737r. There is nothing really “cool” about it but it just works.

What's with the 80's porn music.