DPMS GII .308

[kattman]

Anyone know the brand of the fixed stock shown on the vertical picture of the GII on page 82 of the January 2015 issue of AMERICAN RIFLEMAN???

Thanks

Kattman from michigan

[1slow01Z71]

If V7 makes a barrel nut to put the KMR on the G2 I will be getting one. Any reliability issues lately? A short, lightweight, fast twist 308 sounds like fun.

[andy_ita]

Hi im andy in italy.
Im ordering from a local retailer a g2 recon rifle in.308
I saw by the pics that the rail monted is a middle lenght floated. And the front gas block is visible. Other rifles as the sass ormthe Repr have the rail that seem to be 11 or 12" long.
Its possible to buy this rail and change the one mounted on the recon?

[Tokarev]

http://www.precisionreflex.com/Detail.aspx?PROD=1103874

This is the first aftermarket charging handle I'm aware of for the G2. I'm glad to see PRI getting onboard!

[mr.robbdee]

OK New to the .308/7.62 x51. I have 3 AR's two that are in 5.56 x45 and the other in 6.8 x43 which I love. So now it's time to move up to the next level and the GEN II RECON is what I want so far? But, I have question, would the 16" 1 in 10 twist barrel of the DPMS be able to fire Federal/ATK MK319 130gr Mod 0 SOST ammo out to at least past 300m or farther? As I understand the round was designed for the SCAR-H with a 1 in 12 twist short barrel.

[LRRPF52]

OK New to the .308/7.62 x51. I have 3 AR's two that are in 5.56 x45 and the other in 6.8 x43 which I love. So now it's time to move up to the next level and the GEN II RECON is what I want so far? But, I have question, would the 16" 1 in 10 twist barrel of the DPMS be able to fire Federal/ATK MK319 130gr Mod 0 SOST ammo out to at least past 300m or farther? As I understand the round was designed for the SCAR-H with a 1 in 12 twist short barrel.

It will be fine. A tighter twist on a .308 isn't going to hurt a thing. 1/10 is generally sought by those shooting longer pills that have more bullet shank engagement with the rifling, but there are no ill effects in .308-velocity guns.

[Lian]

my G2 Recon absolutely despises norinco steel cased rounds.
like clock work, after ~200rounds, the chamber gets so fouled up that cases get stuck in the chamber with rims ripped off by the extractor.

am getting 0.75 MOA with handloads. cheapy 155gr CMJ's @ 2700fps. a good shooter would do 0.5MOA and less, easily.

[MistWolf]

1/10 is generally sought by those shooting longer pills that have more bullet shank engagement with the rifling, but there are no ill effects in .308-velocity guns.

The RPM needed (which is twist AND velocity) to stabilize a bullet has nothing to do with bearing surface. What matters is the bullet's center of pressure in flight. Bullets with lower drag numbers tend to have a radically different center of pressure than long, blunt nosed bullets and thus need more RPM to stabilize in flight. Bullets with better ballistic co-effecients also tend to have less bearing surface

[LRRPF52]

If you take two bullets of the same length, one a flat-based, and the other a boat tail, then yes, the boat tail bullet will usually have less bearing surface. However, there are scores of examples of high BC projectiles with more bearing surface. The end goal is still the same as you point out, to spin them faster so the pressure balance between the Mach wave shape and CoG are optimal. A VLD nose profile will have a different Mach cone pressure profile at the meplat, as well as how the pressure normalizes as the bullet flies through the air medium, which is why we like boat tail bullets for the streamlined tail-end depressurization from what is built at the nose. A flat base will of course have a more inefficient negative pressure value, with more errant vortices off the projectile tail.

Roger on the speed and twist, which is why I pointed out ".308-velocity guns". I think many people just getting into internal and external ballistics hear something about tight twist causing problems, when it just doesn't.

Legacy projectiles in certain bores had really tight twists, with blunt-nose, flat base pills.

The short story again is that these 130gr SOST flat base pills will exit fine from a 1/10 twist.

[MistWolf]

A round nosed flat based bullet of the same length as a VLD boat tail generally needs less RPM to stabilize because the center of pressure is different.

Take two bullets of the same weight and material, one a standard boat tailed spitzer, the other a VLD, the spitzer will generally have a longer bearing surface because it's nose shape is shorter. The same is especially true when comparing a flat based round nosed bullet.

The truth about boat tails is they play only a minor role in external ballistics until velocities reach the trans-sonic range.

In any case, my point was that bearing surface has nothing to do with twist rate (other than too little bearing surface can result in skidding)