[gmd3006]

If I uploaded properly, you'll see a scan I made of a Remington ad that I've seen in several different gun mags. It seems that Remington came out with a new round that's tailored for their new AR, and has ballistics similar to the .308 win.

The curious thing is, the bullets for both are shown as having rising trajectories vs. distance! Huh?

Nobody in any of the editorial staffs noticed this?

( or maybe I should have posted this in the Humor forum )

 

[nimrod375]

The way I interpret that graph, the line represents the amount of holdover vs distance, not the actual trajectory, which is why it goes up. Looks like you need about a foot of holdover at 300 yards with both cartridges.

 

[mattsbox99]

Nimrod is right, that is the holdover, not the trajectory. Why they decided to shot that is beyond me, because different bullet weights and velocities will have dramatically different holdover/trajectory.

 

[gmd3006]

Doh! Of course, you're right.

I guess I was misled into thinking it's trajectory because the graph is titled, "Short Range Trajectory".

And I was misled into thinking the rifle was held on target because the Y-axis is labeled "Inches Above or Below Target Hold".

But, your interpretation is the only thing that makes sense. Thanx!

In that case, it's a feat that the .30 Rem AR can get by with less holdover than the .308 from a case that's smaller!

.

 

[shane256]

Is that graph using bullets of the same design/weight? Looking at the Remington site, the 30 Remington AR using 125gr bullets is similar in muzzle velocity to the .308 using 150gr bullets (and less energy) with the AR having 2880fps and the .308 having 2820 fps. And because the 125gr bullet has a worse BC, it slows down faster, being slower at 100yds.

30 Rem AR, 125gr, Muzzle: 2880fps, 100yds: 2465fps
.308, 150gr, Muzzle: 2820fps, 100yds: 2533fps

The 30 Rem AR looks more comparable to the .30-30 than the .308... and with that small case, heavier bullets will probably take up powder space.

 

[osprey572ci]

I'm still trying to figure out the necessity for a new caliber, especially in one so close to the .308, in an AR for that matter?

 

[MZ5]

There are a number of cartridges that are _very_ similar to the WSSM case, necked up to whatever bullet diameter. The reason for these kinds of cartridges is this: You can get what amounts to a 308 Win. in a std. AR-15 lower, instead of having to buy an AR-10 lower. AR-15 lowers are dirt cheap and completely ubiquitous by comparison, and the WSSM cartridge fits std. AR mag length & width. Burns very slightly less powder than a 308, too.

Olympic has a 300 OSSM, too. At least I think that's what they decided to call it. Again, more or less a WSSM case necked up to 30-cal. Oly claims ballistics exceeding the 308 and 30-06, and Remington seems to claim both better and worse than 308 for theirs, depending upon which of their pages your read, and how you interpret their apparently-conflicting statements/graphs.

 

[Cavitation]

The 30 RAR would be good for 300 yards or so do to bullet weight Remington will screw it up just like they did with the 6.8 SPC. If you want an AR with power jump to the 300 OSM. Claimed velocity of this osm is said to be close to 300WM. WITH EQUAL BULLET WEIGHT! Ill wait to see some proof first. Or the larger heavier framed 308 class AR10 or DPMS style.

AL

 

[mattsbox99]

I have no desire to get pounded on the shoulder or wallet with the various wildcats available. To me, the most interesting and useful round is the 6.8 SPC.

 

[Huntdaddy1]

Beware of on-paper ballistics !!!!!!!! HD1

 

[gmd3006]

The .30 RAR has the same rim diameter as the .308 - .473", but a larger case head diameter of 0.5" (http://accurateshooter.wordpress.com/2008/10/15/remington-introduces-new-30-remington-ar-cartridge/)

That's bigger than the 6.8SPC's head diameter of 0.421" (http://stevespages.com/jpg/cd68spc.jpg),
and smaller than the WSSM's diameter of .555". (http://wssmzone.com/main/default.aspx?c=wssm_overview&n=cartridges)

.

 

[Huntdaddy1]

Check out the 6.5 Grendal round !!! It looks great to me, may build one for my son after I finish my 375 Win project. HD1

 

[broom_jm]

"The face of said bolt (AR-10) is commonly sized for the .473-inch rim diameter of the .308 Winchester, but Remington went one step further by opening it up a bit and increasing the rim diameter of the .30 AR case to .492 inch."

So, basically this is a .284 Winchester case, shortened to 1.530" and with an odd-ball rim diameter of .492"...I'm not feelin' it. If you want 308 power, get the AR-10. If you want a smaller caliber deer round, go with the 6.8SPC. This looks like another example of Remington coming up with a solution to a problem that does not exist, while simultaneously NOT providing factory support for their own, existing cartridge!

Would have made a great deal more sense to neck up a WSSM to 30 caliber in the AR-10 platform and offer a product that will not compete with the 6.8SPC round, which they seem to have abandoned, despite how useful it is.

 

[mattsbox99]

A .30 cal WSSM exists, and it fits in the AR15 platform, but I'm not sure Remington would have fooled anyone by chambering something based off the WSSM case.

 

[broom_jm]

A .30 cal WSSM exists, and it fits in the AR15 platform, but I'm not sure Remington would have fooled anyone by chambering something based off the WSSM case.

I knew about the 358WSSM, but not a 30WSSM. Makes sense, though and it's no surprise Remington is missing the boat by building this odd-ball cartridge when a more obvious solution was readily available.

 

[nimrod375]

+1 on the 6.8

I have no desire to get pounded on the shoulder or wallet with the various wildcats available. To me, the most interesting and useful round is the 6.8 SPC.

A friend of mine bought a 6.8 in a tactical styled Remington 700. I reckon its a sweet cartridge, it was an absolute tack driver and mild to shoot.

 

[shane256]

Check out the 6.5 Grendal round !!! It looks great to me, may build one for my son after I finish my 375 Win project. HD1

At least on paper, I like the 6.5 Grendel better than the 6.8SPC. Much more versitile in terms of bullet weight selection. It can load up 120gr and 140gr, which are great deer bullets. The 6.8SPC seems to top out at 115gr, which is fairly light for a .274 (low SD), before the longer bullets start hurting performance, I guess.

 

[mattsbox99]

You can go up to 130 grains, but the Barnes all copper .270 bullets are long enough that they offer pretty decent BC's if you intend to shoot long range.

 

[shane256]

I typically prefer higher SD to insure two holes. 130gr in .270 is pretty good, though. I use 140gr in my .260 (similar SD to a 150gr .270).

 

[Combat Diver]

I think another area that Remington missed was that they use a new different bolt carrier and upper reciever, barrel extension. The pluses for an AR15 rifle is that it is modular and can swap components, not so with the .30 RAR rifles (yes, lowers are same but not uppers) Seems Ruger just came out with a new M77 Hawkeye Compact in 6.8 SPC that would make a perfect youth gun.

CD