6mm Predator/Grendel vs 6mm ARC

AdamT

Well-known member
What are the advantages to the 6mm Predator vs the 6mm ARC. I found a couple ARP 6 Predator barrels I may be able to purchase and was wondering if it would be better than going 6 ARC.

I have access to a couple different reloading setups, but I don’t currently have the equipment to do it at home, so there would be some traveling involved to load for the 6 Predator but nothing major. I’m not very experienced in loading either and data for the 6 Predator seems to be few and far between. I don’t have any newer manuals so not sure if there’s even anything officially published out there.

The 6 ARC has factory support but ideally I’d rather shoot something in the 75-95 range in either so I’d probably end up wanting to load for it also.

I know there’s been discussion about the Grendel bolts being weak and this is part of why white oak armament isn’t doing barrels chambered in 6 ARC. Has anyone experienced any bolt failures with either of these cartridges?

I would use the rifle for coyote hunting and maybe whitetail deer on occasion.
 
Factory ammo and brass, cheaper and common loading dies, are the advantages of the Arc obviously.

The Arp barrels are normally pretty accurate, although I had one that wanted to throw the first shot sometimes. I used bushing dies for my 6 Predator and 243 LBC, which are pretty much identical, maybe completely identical. I would want the upper with me when I made brass with the bushing die just to be sure the brass chambered easily.

For load data I'd simply use Arc data now and maybe bump it up half grain or so.

I have broken 2 Grendel bolts, they were both cheap brands and had around 1500 rounds on them. But it's not like a catastrophic, blow up in your face type of thing. Change bolt and carry on.

Today, I'd go with the factory round all day every day. The factory ammo shoots well, judging from my hunting partner who's all in with 3 uppers in the caliber. I can't think of any reason to go with the wildcat at this point. You can still make brass from Grendel brass if you want.

Full disclosure I no longer have anything based on that case, just because I moved back to the simpler 243 Win in a light G2 DPMS, but I do miss the lower report, and much better barrel life of the small rounds. Oh and burning 28 grains of powder instead of 42 lol.
 
I appreciate your reply, it was informative and insightful. I knew the factory produced ammo and brass was the big advantage. I guess I was just wondering if there was any significant performance gain. Probably not enough to notice in the grand scheme of typical hunting distances.
 
You will gain about 40fps with the predator. The ARC is shortened .030 so it hold a tad less powder.
There is plenty of data on 68forums for the predator. You can start with any data from the .243 LBC or take a 1/2 grain off the 6mm SPC variants out there to start. I.e the 6dti or 6x6.8spc, They are so close.
 
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With little access to reloading supplies and experience I would pick the ARC. IF your not set up to reload the ability to go buy factory ammo is priceless. Powders are harder to come by these days for someone that doesnt already have a decent stock at home. The 103 precision hunter load from Hornady would be perfect for whitetail. Ive been using the 108 Match on coyotes and its an absolute HAMMER!

Get the ARC, run factory ammo and enjoy while you save your brass and start stocking up on components.
 
I have the 6mm ARC and it's a neat little cartridge that's deadly on hogs and coyote.

Problem is... Hornady does not seem to be supporting this cartridge very much. Ammo is scarce and expensive when you can find it.

I've had brass on back order for almost TWO YEARS now... thanks Hornady. PLENTY of bullets, primers, powder but unfortunately no source for ARC brass, not interested in converting 6.5G brass as some reviews are mixed.

I have about 600 rounds factory ammo and perhaps 200 pieces of once-fired brass.
 
I've converted 200 Lapua, along with several hundred Hornady and Starline brass to ARC with no problem at all. I wish I wouldn't had converted the Lapua but was wanting to keep my Grendel brass separate and have different head stamps.
I ended up using some of the Hornady and Starline brass for hunting ammo or any time I thought I might lose the brass anyway.
 
Well I decided to not pursue the 6mm Predator barrel and dies. I found an older ad on a different site than the current listing that was word for word the same from a different user name and first name on the ad. I asked the user with the active posting about who manufactured the bolt and about being the original owner and never got a response. Can’t say for sure if it was scam or not, but no big deal.

I may reach out to Mike @ DTech about the 6 DTI. I have a 6.8 and a decent amount of old SSA loaded ammo and brass that could be used. I think any cartridge right now for the most part is suffering from component shortages. I know the factory ammo availability of the ARC is a huge advantage, but I would really like to shoot something in that lighter weight range of bullets, 75-95, and preferably somewhere in the middle to low side of that range. It would be rare that I used it for whitetails, mostly coyote hunting and an alternative to my 243 for shooting groundhogs.
 
Another option to consider is a 6 Hagar if you want to stick to lighter bullets.

I had DTI do a 12" twist 6 Hagar barrel for me this year.

I have a great load with 65 Bergers at 3330 in a 20" tube.
 
I sent you a PM.
The 6mm Predator/243 LBC was the OG before Hornady marketed it and coined it the ARC. Absolute hammer on coyotes and rock chucks.
Depending on barrel length your going to see about 50 fps more speed and shoulder is bumped .030 further with the ARC.

It's also fairly straightforward to load for if your just getting going.
Use Hornady 6.5G brass for the 243/pred, the shoulder neck junction is more rounded and wont give you a line (where the old neck/shoulder junction was).Lapua brass will do this,and is better suited for the ARC.
 
I’m beginning to build a new upper for 6 ARC for coyote hunting. Should go with 22 in or18? I won’t be using suppressor. Also, thoughts/experience with Shaw barrels?
 
Not a fan of the ARC for light bullets, ESPECIALLY if its a regular barrel, they are optimized for long heavy bullets having fast twist and long throats.

IMO there are way better options, one being the 6x6.8. Better bolt, more speed and more brass.

If you haven't spent any money, I'll make this really really easy, jump on Xcaliber barrels website, order your 6x6.8spc to YOUR specs and have it in about 8 weeks. No waiting forever from Mike and no screw ups from Ritch!

I have two 6x6.8s and it easily outruns the ARC and no broken bolts. I have an 18" and 22", two different hunting buddies that have them as well, absolute hammers on coyotes.
 
Thanks for the info. I haven’t purchased anything, yet. I wasn’t aware of Xcaliber offering the 6x6.8. Does CH4D still do the FL die set for that cartridge? I believe I remember there was a group buy for a run of Hornady dies here once also.

I’ve been leaning real heavy towards the 6 DTI. DTECH is currently out of the Hornady dies, but should have them soon according to email exchange. Doing some searching and reading, seems like most folks really like the 65-70 grain bullets in the 6DTI, which is really where I’d like to be at. The +’s to that cartridge for me is the 6.8 bolt head, increased case capacity, and the chamber being designed around the lighter bullets.

About the only + for me to the ARC is factory ammo and brass availability. I have zero desire to shoot long heavy bullets. I’ve read mixed reports on lighter bullets, and people having to use temp sensitive powders to get the lighter bullets to work.

Either way I plan to go with a 22” barrel since I don’t run a muffler. Also planning to buy my own reloading equipment and would prefer to have a FL die set for whatever I go with considering being relatively inexperienced at that on my own.

Off topic but, does it bother you all to have brass with a head stamp that doesn’t reflect the actual cartridge you are using it for, especially if you have another rifle with a chamber that matches the head stamp. Example, having a 6.8SPC and also a 6 DTI/6x6.8.
 
So yes, CH4D stocks the FL dies. They list it as 6mmspc or 6spc. The full length sizer is all I recommend. One pull with regular 6.8spc brass and its ready to go, no screwing around with multiple bushings or sizing it multiple times.

After initial sizing I run a redding bushing die with appropriate bushing to maximize case life but its not mandatory. I use a regular 6arc seater die.

Having 6.8spc on my cases is meaningless to me, I never think about it!

I get everybody wants to be a modern day sniper that shoots 5 miles every day on the internet with their ar15 so for that application the ARC and Valkyrie are perfect as they are PURPOSE BUILT for that but if you want a purpose built AR15 coyote slayer, get the 6x6.8 and don't look back. Even though its a wildcat its stupid easy to load for, no fireform, super fast and accurate, more brass options, no broken bolts and optimized fir 55-80 grain bullets.

For 22" get the rifle length, 1/10 twist, SPR contour from Xcaliber, you'll have it in about 8 weeks, maybe sooner. It will have a properly chambered freebore to allow lots of options accurately. 55-58s will get you about 3500fps and shoot dime sized 5 shot groups with 31gr of 8208xbr, cci450s, starline brass with either 55NBTs or 58vmax.

If you have trouble or questions feel free to pm me and we can have a phone conversation.
 
Originally Posted By: Kino MSo yes, CH4D stocks the FL dies. They list it as 6mmspc or 6spc. The full length sizer is all I recommend. One pull with regular 6.8spc brass and its ready to go, no screwing around with multiple bushings or sizing it multiple times.

After initial sizing I run a redding bushing die with appropriate bushing to maximize case life but its not mandatory. I use a regular 6arc seater die.

Having 6.8spc on my cases is meaningless to me, I never think about it!

I get everybody wants to be a modern day sniper that shoots 5 miles every day on the internet with their ar15 so for that application the ARC and Valkyrie are perfect as they are PURPOSE BUILT for that but if you want a purpose built AR15 coyote slayer, get the 6x6.8 and don't look back. Even though its a wildcat its stupid easy to load for, no fireform, super fast and accurate, more brass options, no broken bolts and optimized fir 55-80 grain bullets.

For 22" get the rifle length, 1/10 twist, SPR contour from Xcaliber, you'll have it in about 8 weeks, maybe sooner. It will have a properly chambered freebore to allow lots of options accurately. 55-58s will get you about 3500fps and shoot dime sized 5 shot groups with 31gr of 8208xbr, cci450s, starline brass with either 55NBTs or 58vmax.

If you have trouble or questions feel free to pm me and we can have a phone conversation. The 6x6.8 variants with light/medium bullets are coyote slayers for sure! 6DTI is working for me, but that Excalibur option looks good too.
 
If I was starting all over again in the AR coyote shooting world and was limited to only a few uppers, I would have an xcaliber 9 or 10 twist 6x45, 10 twist 6x6.8 and or 6 DTI shooting 55 to 80 grain bullets. I would load with aa2200, arcomp, 8208 and h4895. If brass was still available the 6 Hagar would trump those and be a must have.
The advantage to the Grendel based cartridges is simply another brass option if the others happen to not be available. Having the ability to reload is the key to everything.
 
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The 6DTI (or 6x6.8 variants) has over 90% of the performance of the mighty 243 Win with like bullets, but in the AR15 platform.
 
Thanks for all the info. I’ve ruled out the 6mm ARC and will go either 6 DTI or 6x6.8. I guess this discussion on 6 ARC vs the 6mmx6.8SPC variants is similar to the one regarding the 22 Nosler vs 224 Valkyrie. The cartridge designed for lighter faster flatter bullets makes more sense for what most of us are wanting in a varmint/predator round.
 
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