I picked up an AR in 6.5 grendel in trade and it doesn't shoot well at all. 4 inch groups at 50yds with Hornady ELDM loads. I had a Howa mini in 6.5 grendel that would shoot well one day and not good another day. I want to like the grendel, but now have had two that don't shoot well. I'm intrigued by the ARC. I can pick up a new 6.5 grendel AR or just dump the caliber and get the ARC upper for about the same price. Use would be deer and pig hunting. Not looking for a long range shooter really, but want something that will shoot 1.5 moa or better. This is a budget gun so looking at a Radical Firearms grendel or a Bear Creek upper in the ARC. Suggestions?

I just kinda question the thought process that leads to you considering a boutique, accuracy-centric cartridge like 6.5g or 6mm ARC and then shooting it through the cheapest possible upper.

Not a lot of mystery here about why your guns aren't shooting well.

Valid. If it was a gun for competition or something like that it would be different. Don't see the need to spend more for a gun that will only be used for hunting within 200yds. Would rather save the money for the guns that need it.

Grendel hits harder than arc

What are the specs of the one you have? I’ve owned a few ARs and none shot that bad.

The problem is not with the cartridge it is the gun or the shooter. I've built 2 of them both sub MOA. Rebarrel what you have with good barrel and decent optics. Grendel has no problem with pigs or deer. Prefer it over the 6mm

I agree there is something wrong with the one I got. Pretty sure it was a home build. Got it in a trade, so didn't expect much from it. Same optic, mount, and a PSA 223 wylde upper average .75 to 1 moa. I am going to pull it apart and check everything as well as try new ammo. I was shooting the same 3 boxes of ammo in the Howa. It would shoot .75 one day, then the next shoot 1.5. Again, not looking for a quarter moa gun, just a good beater that shoots well enough to hunt with.

Ruger American gen 1 instead of the Howa

Tried to pull the barrel and whoever built it over torqued the hell out of stuff. Broke off a wrench trying to unscrew the set screws on the gas block. Will get that barrel off and use the upper for another build in the future.

An AR15 is like a sausage... there is a bunch of things stuffed in there that can impact the final product. A cheap AR is assembled with mixed parts sourced in bulk. If you are lucky it might shoot MOA. The fact that someone rockset everything is a red flag.

The Howa Mini is surprisingly good for the price. My guess is that your gun is in the flimsy factory stock. Check the action screw to make certain it is properly secured. Next check to see if the barrel is free floated (doesn't touch the stock. Now test the fit while you are set up like you shoot supported on bag or tripod and have it under load/pressure. Most likely the stock is touching the barrel when you are pressing into the rifle when shooting. This is common problem with most factory stocks. The plastic rubber gradually weakens over time resulting in contact. This is why you see a lot of people immediately replace the factory tupperware stocks.

6ARC and 6,5 Grendel are both great. I chose the 6.5 Grendel for hunting (little bigger hole and heavier bullet options). If it were primarily a range toy for shooting distance then the higher BC of the 6ARC would be worth considering.

The heart of a rifle, be it a bolt action or an AR, is the quality of the barrel and the quality of the machining of that barrel. By machining I mean the fit of the barrel to the action (or upper) and the chamber cutting. 6.5 Grendel is an inherently precise shooting cartridge. I have spotted for several ARs chambered in 6.5 Grendel and we got them all the way to 800 yards, with no problems. I like running bullets heavy for cartridge. To hunt 200 yards with and to shoot distance with, I would stick with the 6.5 Grendel.

I would agree with a quality barrel being key in an AR. You don’t have to spend a fortune to get a really accurate barrel. I have two ARP 223 Wylde barrels and a Bison 6.8 SPC that shoot like fine bolt actions. The barrels were only around $200 a piece.

I have two Grendel’s, my 8 year old daughter has only shot hers 9 times from 50 to 175 yards. She has always been within a 1 1/4”. So I bought another one for my son to start using in a year or so and figured I’d play around with it in the mean time. It shoots great. .75 grouping at 100 yards.

The 6 ARC and Grendel use the same bolt carrier/bolt. You could just buy a decent 6 ARC barrel and put it in your AR. The 6 ARC is plenty at 200 yards. I have never shot a Grendel but I have three 6 ARCs - two ARs and one bolt. I think the ARC is one of the best calibers there is for the AR-15 platform.

My PSA Grendel is easily 1.5moa at 50, but usually better, shooting factory hornady 123gr SST ammo and better with my hand loads.

I chose the 6mm ARC due to a member here who sold me a very nicely put together premium upper. I matched the upper with a comparable lower and it shoots like a dream. Even at the reasonable cost he asked for the upper, I still have well over $2k in the rifle. I also ran across a Gen 2 Ruger American in the same cartridge here not long ago.

So as an update, picked up the Radical 18 inch 6.5 grendel. Same ammo, scope, mount, mag, and lower it shoots right at or just above moa at 100. Going to trash the barrel in the old upper and maybe build a 6ARC just for fun.

In my experience, 6.5 Grendel does really well with a longer barrel. I had one many years ago with a 22 inch fluted ER Shaw barrel, Noveske upper/lower, and an Alexander arms full BCG. It is to this day was one of the most accurate ARs I’ve ever owned. Ended up selling it to a member of this forum. I shot the 123 grain Hornady customs which I believe were the AMAX bullets. I killed many deer with it and the furthest being out to 300 yards. All DRT kills. That thing was an absolute tack driver. Have no experience with the 6mm ARC, but I am still a huge fan of the 6.5 Grendel. Good luck on your 6 arc build.

I'll put another vote for the grendel. Especially based on your primary usage of short-ish (< 200yds) hunting then I'd like to shoot the larger bore.

While never having shot the 6mm arc, seems like it would be hard to tell that one or either cartridge is more accurate at this range. Had a grendel that I home built on Wilson Combat and Odin Works parts. Shot lights out, easily 1.5moa with hornady black ammo. Shot closer to 2" @ 300 yards with 123 eldm handloads. I regret selling this rifle. Still have a 6.5 grendel in a bolt action now. Love the caliber.

Having bought several Grendel uppers, one a Bear creek upper all have shot very well. Functioned perfectly also.

I have 4 different grendel guns. Absolutely love them. Cheap ones, expensive ones. I shoot them, my wife shoots them. It's my buddy gun too. That being said, I have a 20" Ballistic Advantage barrel that probably has 200 rounds through it I'd make you a deal on. I'm in springtown.

6mm ARC for a range toy and 6.5 Grendel for hunting, both calibers are capable of excellent accuracy