[spoonxman]

Does anyone know the difference between RRAs Predator Pursuit and their 20" Varmit uppers? The only thing I can find is one has a bull stainless barrel and the other one a Heavy match stanless barrel. Does anyone own either of these, if so how does it shoot? When looking at the specs for the rifles instead of the uppers both said 3/4 moa accuracy.

I am looking to add a 556 varmit rifle to the collection.

 

[paulosantos]

The Varmint uppers have a Bull Barrel, which is heavier.

 

[zoomie]

The only difference I know is just the barrel diameter (and the option for other barrel lengths in the Varmint). The PP is a slightly thinner barrel.

I had an 18" Varmint upper. For one, it was HEAVY! It shot well. I used mostly bulk FMJ and SP ammo, but it shot that right around a MOA. I'm sure it would do under a MOA with quality ammo.

Unless it'll be a blind/truck bed gun, I'd skip the heavy barrel and get something lighter. I had mine turned down by ADCO - it shoots just as well, but it's MUCH nicer to carry now.

 

[spoonxman]

Thanks for the info. However, it brings more questions. Rather than a bull or heavy match barrel how thin of a profile can you go and still maintain accuracy? Is an SPR barrel a profile or a length? How does it compare to a bull barrel?

What I am looking for approximately, is a rifle longer barrel than a carbine, fairly accurate, threaded for a muzzle device, 1 in 8 rate of twist, preferable stainless, free floated. Used for some hunting mostly target shooting. Needs to be an assembled upper as I don't have tools (mind is ok, but no vise, barrel wrench, upper receiver block, etc) to assemble it myself.

Prefer to stay in the price range of under $700 if possible. I know many will suggest 6.8 but I already have one in 18" length. Does barrel length between 18" and 20" in 556 make a big difference in bullet speed and accuracy?

Thanks

 

[ron169]

http://68forums.com/forums/showthread.php?t=5919

Check that upper that Jamesb is selling, sorta close to what you are looking for

 

[zoomie]

Is an SPR barrel a profile or a length? How does it compare to a bull barrel?

It's a profile. It's thinner with step-downs vs a bull with a constant diameter for its entire length.

What I am looking for approximately, is a rifle longer barrel than a carbine, fairly accurate, threaded for a muzzle device, 1 in 8 rate of twist, preferable stainless, free floated. Used for some hunting mostly target shooting. Needs to be an assembled upper as I don't have tools (mind is ok, but no vise, barrel wrench, upper receiver block, etc) to assemble it myself.

There are lots of places that will build a custom upper for you. White Oak (http://www.whiteoakarmament.com/complete_uppers.htm, http://www.whiteoakarmament.com/contact_us.htm) will build what you want. I think AR-15 Performance (http://www.ar15performance.com/home) will build custom uppers in 5.56, too.

Prefer to stay in the price range of under $700 if possible. I know many will suggest 6.8 but I already have one in 18" length.

$700 for an upper can get you a very nice setup from the above two or elsewhere.

Does barrel length between 18" and 20" in 556 make a big difference in bullet speed and accuracy?

Accuracy is independent of length, and the velocity loss will be minimal.

 

[spoonxman]

Another question, does the 556 need a mid or rifle length gas system? How accurate can an 18" barrel be? Personally I have never shot past 200 yards, but if I go hunting with my brother some shots out to 400 would be possible would an 18" barrel be long enough for shots that far? I am reconsidering about the heavy barrels and may go with an SPR.

I looked at WOA website most of their uppers seem to feature 1-7 rate of rifling. Most of the ammo I shoot is 55gr fmj. I realize I would need hunting ammo in that environment but even in 556 it is getting expensive.

I will have to email constructor, I thought he put his customs on hold for a little while.

The upper Jamesb is selling is longer than what I was looking for. But thanks for the link. Does WOA build custom or do they modify the uppers they already have?

 

[lunchb0x]

The 5.56/.223 rifle length gas system operates under less pressure and is therefore 'gentler' on the internals, especially when paired with a heavier buffer assembly. Now I've got an RRA predator pursuit upper in 20" that I had turned down to a medium profile and threaded for a Smith Vortex. It does shoot 1 MOA with factory PMC 55gr FMJBT ammo, but of course when the barrel starts heating up the groups begin to open up a little.

If your looking into hiking around all day the NM upper (which is simply a heavy barrel profile) is ok, but to take it down to a medium profile (contoured down from ~.950" at the chamber to about 17" of .750" diameter to the muzzle) took a little over 12 ounces of material off. Making it quite a bit more comfortable to carry.