help me pick a unique cartridge for ar upper build

ghilliedup

New member
Hey all im needing some advice from some of you specialty caliber AR guys. I already have a couple 223 Ar's now and after hunting/shooting with the 243 & 204 bolt guns all last year I want something with a little more horsepower than the 223 has go to offer. & something that would be different than the run of the mill 5.56 Ar that everyone has. I just don't know enough about these caliber choices to decide what would be my best bet.

I want something in either 243,25 or 6.5mm caliber. I don't want a 6.8 SPC or the Grendel I want to stay with something that can produce fairly high velocity (3000fps +) with a heavy varmint bullet for coyote hunting & calling & casual range shooting days (my private range goes to 650yds & i would like to be able to get there with this new one) I don't want something that is a huge pain in the neck to handload for cause I shoot 1-3 times a week aand would need a fair amount of brass to load just to get started. The ease of components is a huge deal to me & would rather not have to special order a set of custom dies. I also want to stay on the AR15 frame (otherwise I'd have a 243Win AR10 already !)
Also I would like to do this in an 18" possibly 20" barrel so maybe that makes some difference.

Ive looked at: 6x45mm, 243Wssm, 6mmDTI, 25DTI, 25 Wssm. I know the Wssm's would have enough power & some to spare but they are pricey & I read of a few issues...what about the DTI options? Is there any huge pro or cons to any of these? Is there a cartridge im missing that would fit the bill with less hassle of setup? I like the idea of the 6x45 but it doesnt seem like im gaining enough to justify all the extra effort. I have a fair budget to work with but I really don't want to go too crazy on the upper as I will have to buy glass still. And if im gonna have to spend $1500 just on an upper/dies etc id just as soon buy a higher end bolt gun in a more standard caliber.

Thanks in advance for all your help!
 
I should clarify what was meant when I said "heavy" varmint bullet @ 3000fps+... By heavy what I have in mind is about a 70,75 or 80gr bullet like a NBT at 3000fps or better out of an 18" barrel. Im not sure if that can even be done but that's kind of what I have in mind for this little project. Id like to shoot either the 6mm 80gr Nosler BT, the 85gr Nbt in .25 cal or the 100gr Speer in 6.5mm(yes I know a 100 grainer wont get me 3000+MV with a shorter barrel)
 
The 6X6.8 will do what you after and would be well with in your budget. The 243 LBC would do it as well. Both use easy to find components. Your only draw back will be the 18" barrel. I would go with a 20" standard profile. In that length either cartridge will push an 87 grain bullet well over 3000 FPS.

RPG produces all of the variants based on the 6.8 case as well as the Grendel case. The 6.8 variants include the 20, 22, 24, 25 and the 6.5. The Grendel cased cartridges are the 20, 22, 24. All can be loaded with off the shelf dies and DO NOT have to be fire formed.
 
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Originally Posted By: ghilliedupHey all im needing some advice from some of you specialty caliber AR guys. I already have a couple 223 Ar's now and after hunting/shooting with the 243 & 204 bolt guns all last year I want something with a little more horsepower than the 223 has go to offer. & something that would be different than the run of the mill 5.56 Ar that everyone has. I just don't know enough about these caliber choices to decide what would be my best bet.

I want something in either 243,25 or 6.5mm caliber. I don't want a 6.8 SPC or the Grendel I want to stay with something that can produce fairly high velocity (3000fps +) with a heavy varmint bullet for coyote hunting & calling & casual range shooting days (my private range goes to 650yds & i would like to be able to get there with this new one) I don't want something that is a huge pain in the neck to handload for cause I shoot 1-3 times a week aand would need a fair amount of brass to load just to get started. The ease of components is a huge deal to me & would rather not have to special order a set of custom dies. I also want to stay on the AR15 frame (otherwise I'd have a 243Win AR10 already !)
Also I would like to do this in an 18" possibly 20" barrel so maybe that makes some difference.

Ive looked at: 6x45mm, 243Wssm, 6mmDTI, 25DTI, 25 Wssm. I know the Wssm's would have enough power & some to spare but they are pricey & I read of a few issues...what about the DTI options? Is there any huge pro or cons to any of these? Is there a cartridge im missing that would fit the bill with less hassle of setup? I like the idea of the 6x45 but it doesnt seem like im gaining enough to justify all the extra effort. I have a fair budget to work with but I really don't want to go too crazy on the upper as I will have to buy glass still. And if im gonna have to spend $1500 just on an upper/dies etc id just as soon buy a higher end bolt gun in a more standard caliber.

Thanks in advance for all your help!


Looks to me that you do not need any help. You listed everything you do not want. So buy what's left.
 
Buy/build an upper with an 18" BHW 25x6.8 barrel. 3000fps isn't even pushing it for 70-87gr bullets and is achievable with a variety of powders. Brass is a simple necking down using a Redding Type-S bushing die, or purpose built dies from CH4D. I'm still working on a lot of loads and combinations but this is a rough rundown of what I can get it to do right now.

75gr at 3250fps
87gr at 3100fps
90gr at 3000fps
100gr at 2900fps
110gr at 2650fps
 
Originally Posted By: tucker1203Check out the 25-45 sharps , building one myself

The 25 X 45 is in the same class as the 6 X 45. They are both great cartridges, but not in the same class as the 6.8 based rounds.
Look at the 6.8 and Grendel cases as more of a magnum version when compared to the 5.56 cased rounds.
 
I like the 6.8 case... I have a 6DTI and I love it. I would love to give the 6x6.8 a try but I imagine its gotta be pretty darn close.

I have a 10 twist 22" tube and send 75 hp's out of the muzzle at 3200. 80 bt's at 3150. Whats not to like there...


 
Ballistically identical rounds. Big difference is you can buy the 6.8 bushing dies and have more neck tension control. The dies can be used to load any of the 6.8 variants for the price of a bushing and cases are formed without any need to shoot them for maximum capacity.

Greg
 
I don't have a 25DTI or a 6mmDTI but I have shot them, and seen David kill a lot of hogs, coyotes and bobcats with his.

If I get something I would probably get the 25 DTI for the shorter barrel. Venatic can tell you more than you need to know about the DTI as he has shot and loaded for it more than anyone I know.
 
Originally Posted By: MPFDMight as well buy a bolt gun...

Well I already have a few, but in a bolt gun the caliber its an easy decision for me, the old standby 243 win is about as perfect a coyote/intermed range target round as ive came across..

Im leaning towards something in 25 cal, since I want something different plus the 18" barrel is very appealing...I guess I should ask, what would be the easiest of the 25 cal choices to get/make brass for? the 25x6.8 is just a simple neck down, is that correct?

And ive been reloading for a few years with good success but ive never had a wildcat or semi custom round, so the neck busing thing is also new to me. Does anyone just make a set of dies for these calibers? The convience of buying a set of dies would be nice as well

Thanks again for eveyones hlep
 
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Originally Posted By: ghilliedupOriginally Posted By: MPFDMight as well buy a bolt gun...

Well I already have a few, but in a bolt gun the caliber its an easy decision for me, the old standby 243 win is about as perfect a coyote/intermed range target round as ive came across..

Im leaning towards something in 25 cal, since I want something different plus the 18" barrel is very appealing...I guess I should ask, what would be the easiest of the 25 cal choices to get/make brass for? the 25x6.8 is just a simple neck down, is that correct?

And ive been reloading for a few years with good success but ive never had a wildcat or semi custom round, so the neck busing thing is also new to me. Does anyone just make a set of dies for these calibers? The convience of buying a set of dies would be nice as well

Thanks again for eveyones hlep

The 25 X6.8 is a simple neck down, using a bushing die. I do mine in 2 steps. The best part is you only have to buy one die and you can do all the variants off the 6.8 case. To change calibers all you need is a bushing and a seater die. CH4D also makes a standard die for the 25X6.8 as well.
Another thing to consider is with the 25 X 6.8 you don't have to fire form. It comes out of the size die ready to use.

You could go the other route and do a 25-223. The brass is simple to make with just a single pass through a size die and your in business. The only draw back is the 25-223 is under powered compared to the 25 X 6.8 based round.
 
Hmmm, I like quarter bores and don't currently have one in the arsenal (aside from Mama's Bob). This .25x6.8 of which you speak of is very interesting.
 
Originally Posted By: DesertRamHmmm, I like quarter bores and don't currently have one in the arsenal (aside from Mama's Bob). This .25x6.8 of which you speak of is very interesting.

Think 250 Savage. Easy to make and a real pleasant cat to shoot.

Greg
 
True, but available in an AR? Just as well shoot my evil black rifle, no?
grin.gif
 
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