The Ultimate 3 Gun Rifle – Part 4

in AR-15, AR-15, Authors, Build an AR, Building an AR-15, Competition, GA Guides, Gear Reviews, Gun Reviews, Gunsmithing, Rifles

Updated: March 7, 2021 BY Matt Kartozian

The Ultimate 3 Gun Rifle – Part 1

The Ultimate 3 Gun Rifle – Part 2

The Ultimate 3 Gun Rifle – Part 3

With the rifle assembled it was time to break it in, test it and then beat on it. According to Craddock, barrels with cut rifling don’t need a break in, shoot 10 rounds to check function then a good cleaning. I did my long normal break in anyway. During the break in I also tuned the gas block. Start with the gas closed. Load a mag with 1 round and shoot. If the bolt does not lock back, open the gas port 1 click and repeat until it locks open.

Once the gas block is tuned for the buffer and BCG I like to fire a few rounds with free recoil. In short, you barely hold the rifle and watch how much it recoils and moves. It gives you an idea of how well everything is tuned to work together.

I finished assembling the rifle at the end of May, right in the middle of the The Rona, and the massive surge in gun and ammo purchasing. Unfortunately several factory loads I was going to test were no longer available. But I did have enough other ammo to make it worthwhile.

The following loads were tested for accuracy. For accuracy testing I used a Nightforce NX8 2.5-20 with the Mil-XT reticle. I can shoot much better groups at 20 power than I can with 8 power so I borrowed the NX8 from another rifle. All ammo was shot over a Magnetospeed V3 Chronograph to get the 10 shot average velocity and Standard Deviation (SD). All were grouped at 97 yards. (My home range calls it the 100 yard line but it measures at 97. Have you ever checked the actual distance to target on your known distance range?) The heavy loads were also shot for groups at 500 yards. Group sizes measured with the Ballistic-X app. All groups were 5 rounds each. I shot several groups at 97 and 500 with each load using the Atlas bipod and a Wiebad WCMFC rear bag. 97 yard groups were sitting at a bench; 500 yard groups were prone.

Black Hills 77gr OTM 5.56

Hornady 75gr ELD Match .223

Hornady 73gr ELD Match .223

Hornady 75gr Steel Match .223

Fioccchi 55gr 223A .223

IMI 77gr Razorcore 5.56

Sig 77gr Elite Match OTM .223

Ammo	Velocity	SD	100y Group Size	500y Group Size
Black Hills 77	2768	38	.66 in/.65moa	2.57 in/.49 moa
IMI 77	2698	22.4	1.06 in/1.04moa	4.54 in/.87 moa
Sig 77	2417	17.2	.44 in/.44moa	3.16 in/.60 moa
Hornady 75 ELD	2755	26.5	.95 in/.93moa	4.81 in/.92 moa
Hornady 73 ELD	2672	20.9	1.46 in/1.44moa	4.65 in/.89 moa
Hornady 75 Steel	2649	37.5	.98 in/.96moa	6.61 in/1.07 moa
Fioccchi 55	3063 fps	29	1.72 in/1.7moa	N/A

As you can see, the Sig 77s edged out the Black Hills 77 at 97 yards but the BH 77 was the winner at 500 yards. All loads except the Hornady Steel Match were sub–moa at 500 yards which is more than enough accuracy for multigun. But the Steel Match turned in a respectable 1.07 moa group at 500, especially when you consider this ammo used to be about 40 cents a round; the others are all about $1 per round give or take a nickel or two (Pre Rona pricing).

I thought the Sig ammo would fall off a bit at 500 due to it being over 300 fps slower than Black Hills but that just isn’t the case. The Sig ammo had the best SD and the second best group at 500 by a small margin. Though it should be mentioned that my 500 yard dope with Black hills was 3.0 Mils and with Sig it was 4.2 Mils. That is a difference of over 21 inches of drop at 500 yards and it’s due to the velocity difference between the two brands.

The fact is all of these loads are overkill for multigun accuracy and good enough for much more precise shooting sports. My goal before I started selecting parts for the build was a sub-moa rifle. I never thought it would be possible to have a multi gun rifle shoot sub half moa groups at 500 yards. I would not hesitate to use any of these past 500 yards in a match.

The Black Hills, IMI and Sig 77 all use the same Sierra 77gr projectile. OTM stands for Open Tip Match but it is also known as the SMK – Sierra Match King and the 77gr BTHP. Black Hills and IMI use a 5.56 case while Sig chose the .223 Rem case. Each company uses their own powder recipe.

In multi-gun matches, I normally use whatever 55gr ammo I can get cheap out to 200 yards. For the last couple of years, it has been the Fioccchi 223, as I found a good deal on it and bought a bunch. For 200+ yards I am still working on a supply of Hornady Steel Match 75gr. This load uses the same 75gr BTHP Match Hornady projectile as the 75gr Match but it uses a steel case. Yes, I built this fancy rifle and almost immediately shot steel-cased ammo through it. Sadly, Hornady ceased production of the Steel Match line of ammo a couple of years ago. Rumors said they had trouble with the steel case supplier. Like all rumors, there is a good chance it’s bullshit. It was great ammo at a great price in any caliber. I have some 155gr Steel Match 308 that shot sub-moa 5 round groups at 500 yards out of Scar 17 which was about 70 cents a round.

The Hornady Steel Match, IMI Razorcore, and Fioccchi came from my own stash. I requested 50-100 rounds of each load from Sig, Hornady, and Black Hills, and all were happy to oblige. Black Hills deserves special mention though. Instead of sending me a few boxes of ammo, Black Hills sent a full 460 round ammo can! One really cool thing is that the can includes the test sheet from Sierra showing the results of two 10 round groups shot with that lot of ammo. The ammo comes in the same 20 round brown cardboard boxes as the ammo Black Hills makes for the military, Mk 262 mod 1. The only difference is the boxes are stamped Mk 262 Mod 1 C, the C is for Civilian. Otherwise, this is the same ammo that is shipped to military units all over the world. For ammo nerds like me, there are some interesting articles about how the Mk 262 Mod 1 became the military’s choice for short-barreled rifles after assaulters stole some from the snipers and saw how well it worked in short-barreled rifles.

All this data was interesting but real world competition testing was needed as well. I have now shot 25+ matches with the new rifle to shake things out and see how it performed. They were a mix of multi gun matches, rifle only style match out to 450 yards (Rio Black Rifle) and precision style matches out to 700 yards (Cowtown Accurized AR). My second stage of the first match I had a feeding failure. Examination proved the failure was the result of a D60 drum mag that had been loaded for months and banging around in the back of my truck. I have noticed that you have to be a bit gentle with the drums or it will come back to bite you. Aside from that one failure, the rifle has run 100% through many matches and over 3000 rounds using both mags and drums.

As I expected, the accuracy of the rifle is outstanding. When I did my part the bullets hit where they were supposed to at any range. On up close stages it is fast to throw around and in and out of ports and has minimal recoil. The Hiperfire trigger is fast and reliable and the JP comp keeps it all under control.

The extra ammo sent by Black Hills allowed me to do a lot more long range testing with the rifle. Screwing around one day after the Cowtown match I wanted to stretch the legs of the rifle to see what it had. Cowtown range has many pieces of steel at known ranges out to 1000 yards and beyond. After two missed shots for wind (I really suck at wind calls) I had no trouble repeatedly ringing a 20 inch or so tall coke bottle target at 850 yards with the Black Hills 77gr.

After all the testing and matches I still had 100 rounds of Black Hills 77 gr. left. Accuracy was better than I had hoped and I decided to really push the accuracy and use it in a PRS match. If you don’t know about PRS you can read my article PRS for Dummies here. PRS is the home of custom built hyper accurate bolt action rifles. There is a Gas Gun division for autoloaders but it’s mostly purpose built rifles chambered in long range calibers like 6.5 Creedmoor, .224 Valkyrie and various 6mm cartridges. I planned to shoot it with a 3 gun rifle and 5.56mm commercial ammo. I did swap out the Nightforce ATACR 1-8 I use for multigun for the Nightforce NX8 2.5-20.

In the match, the rifle preformed great and hit everything when the shooter (me) didn’t screw something up. Not having to manually run the bolt between shots actually helped me by letting me just concentrate on the shot. Stages I would have normally timed out on with my bolt gun I finished with the 3 gun rifle. The low recoil let me easily see misses and how much correction was needed. I had my highest score yet in a PRS match and cleaned my first stage, and won the Gas Gun division. All misses were shooter error, not the rifle or ammo. The match was at Cowtown so again I wanted to stretch its legs after the match even farther. I found a full size IPSC target at 1035 yards. Again I needed two rounds to figure out my wind, it was ¾ Mil right. I sent three rounds in about 9 seconds and was rewarded with 3 hits.

I had always thought a 1000 yard AR was pretty much impossible but thanks to Craddock Precision, Bartlein, Nightforce and Black Hills I know it is very doable. I set out to build the Ultimate 3 Gun Rifle, and I did. But I also accidentally built a rifle capable of PRS competition and hitting targets past 1000 yards.

I want to thank all the companies that assisted with this dream rifle build. Below you can find links to each part used in this rifle.

SPECS:
Caliber	223 Rem/5.56x45mm
Chamber	223 Wylde
Barrel	18 inch single point cut rifling
Twist	1 in 7.7 inches
Gas System	Rifle length gas system with adjustable gas block
Trigger	2.5 lbs – Single Stage
Length – Stock Collapsed	36.75 inches
Length – Stock Extended	40.75 inches
Rifle – No Mag, No Optics, No Bipod	6.79 lbs
Rifle – No mag, With Optics	8.68 lbs
Rifle – With Optics and Bipod, No Mag	9.56 lbs
Nightforce ATACR 1-8 and Scalarworks Mount	1.66 lbs/26.6 oz
FTP Alpha 3 and Arisaka Mount	0.23 lbs/3.6 oz
Atlas Bipod with Spiked Feet	0.88lbs/14.2 oz