Predator AR build barrel questions for the hunters

G

goose_boy

New member
I have been researching over on ARF but I want to get some input from people that actually hunt dogs. After quite a bit of research trying to find a barrel for a flattop AR that I want to shoot at least 1moa, I decided that an Olympic Arms standard match barrel would fit the bill at a decent price, which is supposed to get 1/2 moa. Now here's my dilemma...

The Oly barrel is offered in 16" and 20" lengths, and I was originally thinking an 18". What are the ballistic differences between the 16 and 20s as far as a .223 is concerned, particularly with factory loads? Are there any other concerns with the 16" vs 20" barrel, such as gas system length? IIRC, the 16" would need a carbine length system (maybe a mid), and the 20" should be able to use the rifle length.

Second, what do you guys recommend? Should I go with the 20" or the 16"? The 16 would be handier to carry and lighter, but would any ballistic, gas system, or balance issues make the 20" a better choice?

For the record this build will be a free float, so the FSB on either of these barrels will be removed and replaced with a low profile. Also still open to suggestions on a barrel that fits my requirements, I always like options. Thanks guys!
 
I had D-Tech flute me a 20" Oly SUM (stainless Ultramatch). That got the weight down to very close to the unfluted 16" and I didn't sacrifice any velocity.
After 3 years, I'm still convinced that was the best way to go. I had a 20" Oly unfluted stainless upper before that, and the weight was bothering me after carrying it all day.

Supposedly, Oly offers barrel fluting at the factory, maybe you could call and ask about that.

16" barrels are much louder. Velocity drop probably varies with powder and bellet weight, but most people estimate around 40-50 fps loss for every inch shorter.

The Oly SUM is a 1:10 twist stock, but they also offer alternate twist rates of 1:8.5 and 1:14.
The 1:10 will stabilize anything lighter than about 69 gr. , if you want to shoot the long VLDs, get the 1:8.5
Mine shoots pretty much any ammo right around 1 MOA, but it shoots Hornady 55 gr. V-Max factory loads into a cloverleaf at 100 yards. It's just a matter of working up the correct load, because those barrels are excellent.
Even the button-cut stainless I had was sub-MOA, it was just a load to pack all day.
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I have a 16" bull barrel, a 20" fluted bull barrel, and a 22" non-fluted bull barrel on my ARs. The longer ones are 'match' grade..The shorter one is not free floated..

As E L stated, you may lose a few fps with the shorter barrel. Your long range accuracy may suffer a little, but for shooting out to 250ys, I don't think you will notice any difference relative to accuracy using the ammo that the barrel prefers. I have two custom uppers and the 16" is a DPMS factory rifle...For short to medium range they are equally accurate, as long as I match the ammo to the rifles.

You will find a definite quality difference in barrels and that is where you don't want to skimp on an AR...If it came down to functional difference, I would skip the free floating and apply the money to a match grade barrel, it can always be free floated later, but free floating will not usually make up for the poorer quality barrel..

The same goes for the trigger group...a good trigger will make a world of difference in the accuracy of any AR..Almost all of them, I'm aware of, have benefited from an aftermarket upgrade...Rock River Match and JP Industries are two that don't cost an arm and a leg, but produce good reliable results.. Timney and Chip McCormick produce drop in units that are pretty trouble free..
 
I built my LW AR just for predator hunting. I went with the lightest barrel possible and that eliminates any fluting. The barrel is a 16" LW match grade barrel that measures .625 at the muzzle and w/o the flash supressor attached. I also installed a float tube on it to aid in accuracy. I've got other ARs, but this is the best possible rifle for my predator hunting. MI VHNTR
 
Quote: The barrel is a 16" LW match grade barrel that measures .625 at the muzzle and w/o the flash supressor attached.

Which barrel is it, and where did you buy it?
I'm in the process of building a carbine (lower is complete) and that would work well, from the sound of it.

Thanks
 
Originally Posted By: Evil_Lurker Quote: The barrel is a 16" LW match grade barrel that measures .625 at the muzzle and w/o the flash supressor attached.

Which barrel is it, and where did you buy it?
I'm in the process of building a carbine (lower is complete) and that would work well, from the sound of it.

Thanks

It is a 16" LW Shaw match grade barrel from J&T. I built this upper well over a year ago. You can use the link for the 16" barreled upper and select the lightweight barrel under the "Barrel" selector. The folks at J&T will build you whatever you want. Just ask them. MI VHNTR

http://jtdistributing.net/store/more_bu_16bu.html
 
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