June 17, 2020
By Neal S. Shera
Recently Hornady made big news in what seems to be a proverbial drought of new products with the new 6mm Advanced Rifle Cartridge. If you are interested in a detailed history of the 6mm ARC, Senior Field Editor David Fortier provided a great rundown in this article. As the industry continues to find more variations for AR-15 platforms, one has to wonder how much life this cartridge will have, as so many have landed in niche followings? Well, regardless of how commercially accepted this new entry becomes, if one were to acquire a rifle or build one of their own, reloading your own 6mm ARC ammo will guarantee it remains in your collection.
6mm ARC Brass
If you are interested in reloading the 6mm ARC, the obvious place to start is with suitable cartridge cases. So, considering brass your best option is to grab a few boxes of Hornady ammo. They currently have 4 choices, 3 commercial offerings and one for LE use. Start with factory ammunition and get a baseline on your rifle and see what bullets it likes. This will provide you with some Hornady brass to get you started reloading. Hornady 6mm ARC brass looks to be of good quality, is fairly consistent and should give you a number of reloads as long as don’t lose them, or are pushing for maximum velocity.
I doubt it will take long before virgin brass from Hornady becomes available. If you prefer ammunition or brass from other manufacturers, it will only be a matter of time before the rest of the market reacts. It’s a good bet that those companies already loading 6.5mm Grendel will be the quickest onto store shelves.
Some may want to try and reform 6.5mm Grendel cases into 6mm ARC. That’s perfectly fine. Remember though, it’s not as simple as running a case into a 6mm ARC sizing die. I would recommend getting a Body Die to help correctly set the new shoulder, as the 6mm ARC’s is slightly further back. This was done to help prevent 6.5 Grendel from chambering in 6mm ARC rifles. Then, there will be some neck trimming which needs to be done. Plus you will have some turning to do to remove all the extra brass before you can load the new cases.
6mm ARC Bullet Selection
Since no case is complete without its proper toppings, we move to bullet selection. As 6mm (.243-inch) has been a fairly popular all-purpose caliber for decades, there are a lot of good choices. At least, that is what one would initially think. Yet, the 6mm ARC was designed to play in the deeper end of the bullet pool. You will likely run into feeding problems with an AR-15, due to the shorter overall length, if you try loading bullets lighter than 90 grains. Also, there could be neck tension issues if those lighter bullets are seated too far out. Accuracy may also suffer. So, I suggest staying loading bullets 90 grains and heavier.
Hornady is an obvious first choice for selecting 6mm projectiles to load the 6mm ARC with. They have 10 solid options ranging in weight from 90 to 110 grains. Half of these are designed for hunting and the rest for match shooting. There are older veterans, like the SST and Interlock designs up. Plus, there are newer additions to Hornady’s line like the ELD Match, ELD-X and A-TIP.
Berger has long been associated with great bullets and they have the largest selection of offerings. I counted thirteen options in their BT Target, Classic Hunter, VLD, VLD Hunting, VLD Target, Hybrid Target and Long Range Hybrid Target lines. These range from 90 to 115 grains and will fill any list of needs. Remember though, Berger bullets will be the longest you will use, so verify your barrel twist. Some Berger bullets require a very fast one turn in 7 inches twist rate.
Lapua with their Scenar and ScenarL line offer 90- and 105-grain choices. The ScenarL have a longer shape over the regular Scenar, for better exterior ballistics. These would likely be a better fit regarding the cartridge’s overall length. Lapua bullets are well respected for their quality, and should make a good match for the 6mm ARC.
6mm ARC Powder Options
Now, on to what goes beneath the projectile. Due to the relatively small case volume to bore diameter, the 6mm ARC can digest a wide variety of powders. You will want something fairly clean burning and temperature stable. The case volume will easily allow for up to 30 grains of powder, but please wait for qualified load data to be available. As for the selection, the burn rate chart has a listing of 22 powder options, but not all are good for semi-automatic rifles.
If you like Vihtavouri powders, then consider N140 and N540. Alliant's Reloader 15 would be another good option to consider. Hodgdon has perhaps the best variety, including H335, Varget, CFE 223, BL C(2), H4895, and their IMR 4895. From Ramshot Powders you should consider X-Terminator and TAC. So your cabinet may already be full with some, or all of these options. These would have the best results if set off with match grade small rifle primers. I suggest considering CCI BR-4s.
As one last little bit of information before the door is closed on the subject, it would be best to invest in a small-base reloading die set. These sets will not only have the required full-length sizing die to maintain proper case length, but will also completely size the body. This will ensure more reliable chambering of the reloaded casing in an auto-loading rifle. Nobody likes unnecessary stoppages while they are shooting.
That's one great thing about the Hornady 6mm ARC, it’s not trying to remake the wheel. It can reach maximum results with what is already out there, and these components have been thoroughly tested in other cartridges. There is room to produce inexpensive range fodder, and create some home brewed match winners. So, while others wait to see what ammo options will populate their local gun store, a savvy reloader can be well on his way to making the Hornady 6mm ARC a staple on his reloading bench.