12.5 6 ARC vs 12.5 300 Blackout for the do all ar15?

The comparison bowlers should really be asking themselves.

Is a 12.5 6 ARC or a 12.5 300 Blackout the best option for a do-all SBR? This is a question Walter has been wrestling with for months. Before we get too far down the rabbit hole, Walter would like to establish a few foundations as the basics for this conversation. First, in addition to basic potential Second Amendment thwarting tyranny responsibilities, Walter's qualifications for a do-all SBR require it to be able to be used for hunting four-legged animals up to 300 pounds. This immediately disqualifies 556/223 rifles.

For the record, as of late October 2024, Walter has shot less than a hundred rounds off 556, excluding some mags through buddies machineguns, in the last two years, instead focusing on the added performance of the 6-arc 300 Blackout. Secondly, Walter's ailling ears cannot afford to shoot without a suppressor, and until Costco relinquishes his hearing aids (they are holding them due to a customer service dispute over excessive "consumption" of Bagel Bites at a sample stand while waiting for his hearing aids to be finished), he will continue to avoid shooting unsuppressed at all costs and thinks you should too. Thirdly, Walter thinks bowlers need to be realistic about their intended ranges and uses. Just because a rifle can make hits out 1200 yards doesn't mean that's its best use case. Lastly, this discussion is based on the performance of Walter's Pissing Hot, Warranty Voiding, 300 Blackout Super Loads, not whatever, 147 grain FMJ bullshit most bowlers are pumping through their PSA's. For 6 ARC, Walter is using 103 and 108 grain offerings from Hornady as a basis of comparison, with an emphasis on the 103's ELDX's for hunting. Walter has written about this at length and encourages curious bowlers to dive into those posts before asking deadbeat Donny'esq questions. 

For an apples-to-apples comparison, Walter has been testing a factory 12.5 Noveske 6 Arc Upper and a 12.5 Noveske Barrel he bought on sale. Both of these uppers are set up to suit their strong suits, with the 6 arc being more optimized for long range with a NX8 2.5-20 and the 300 blackout being set up with a lightweight suppressor from Silencer Co. and a PLXC 1-8. 

Ringing reduced c zone out 930 yards with 12.5 6 ARC.

Walter has focused his gaze on two projectiles for 300 blackout supers, the Barnes 120 and the Hornady 110 CX, with these matching the performance of 6.5 Grendel. Both of these projectiles require around 1600+ FPS for expansion. Some say the Barnes bullet expands down to 1400 FPS, but Walter believes in being conservative when it comes to taking ethical shots on animals. Leaving the barrel at around 2400 and 2500 FPS, respectively, these projectiles slow down beyond this threshold at a little past 400 yards. Well, that's pretty damn impressive, Walter, but 6 ARC is a good damn laser beam and can kill moose. How's that thing doing at 400 yards? Funny you ask, but the difference between the 110 Walter's Hot Load at 400 yards and the 103 ELDX, doing 2379 FPS, is.3 inches in elevation with 100 FT/LBS of energy more on the 6 ARC. Sure, the 103 ELDX with its higher BC maintains its needed velocity to expand out to almost 600 yards, but we're talking about a 61% increase in frontal surface area from the 300 blackout as well as the benefits of a solid copper expanding bullet vs. bonded. Furthermore, Walter would like to ask bowlers for realistic access if they have ever shot an animal past 400 yards. Inside of 400 yards, Walter would take the 300 blackout all day, with the ballistic advantages of 6 ARC only showing up past 450 yards, at which range Walter would rather be throwing a 212 ELDX out of hybrid brass. 

Walter is a massive fan of ringing the steel out to as far as possible and has shot the 300 blackout out to 930 yards and the 12.5 6 arc out to 1250 yards. On paper, the 300 blackout shooting Walter's Hot Loads runs out of steam at 750 yards, while the 6 ARC stays supersonic past 1000. This is insanely cool, with both 6 ARC and Walter's Hotloads outperforming 77 grainers out of their respective barrel lengths and 12.5 6 ARC dominating any length 556 rifle. As a target rifle, the 6 ARC is the clear winner with a better BC and an additional 250 yards of supersonic flight, but having shot thousands of rounds of 6 ARC over the last two years, ranging from 12.5 to 16 inch barrels, Walter has made noticeably more hits with 14.5 and would deal with the added 2 inches of length any day. This extra 70 FPS gets you to 1100 yards of supersonic travel and, from Walter's experience, has proven to be far more consistent at making hits at ranged passed 800 yards.

All of the performance of the 300 Blackout Hot Loads is a magchange away from nail gun quiet and lethal subsonic performance, a feature that 6 ARC could never dream of. But Walter, Subsonic doesn't kill shit; I shot a pig once with 220 SMK's, and I never even saw blood!! Shut the fuck up, Donny! Have you seen what the Discreet Ballistics 188's do? It's like shooting an expanding broadhead out of a gun at 1050 FPS. As time marches on, more and more bowlers will see the benefit of subsonic bowling and hunting, and this will become a bigger deal. Most hunting in North America is inside of 200 yards, ranges where subsonic 300 blackout excels. 

For Walter's money, he'll save his 6.5 ARC for 14.5 and longer barrels. For general purpose, do all SBR, from hunting to tyranny repelling, Walter feels that a 300 Blackout 12.5 is an overlooked and very relevant solution to a problem that most bowlers have. Now we just need to start getting some ammo manufacturers to keep up with the times and make some modern supersonic offerings that are relevant today. If You Will It, It Is NO DREAM!