Help me build an upper please

I wouldn't consider the .204 an effective enough killer past 300 yards, but if you go with .204 imo you should run a 22" barrel or your really defeating the purpose of that blazing fast little round. 6x6.8 sounds good also 6.5 grendel would be a great caliber for 500+ yards.
 
Check out ritchsprecisionguns.com for prices on barrels. You could always go 22x6.8 also or maybe 20practical. But I think if your not saving the fur and doing coyote tournaments I would go 6x6.8. Call and talk to Ritch he is very knowledgeable and will give you a good recommendation. I don't think I would go 204 I have had a lot of people tell me they had more runners with the 204.
 
I would go 20 Practical (my current build) as the 204R case is longer thus your bullet is seated darn deep and usually at the ogive. The 20P is the same case as the .223, bullets can be seated normaly and to mag length VS the 204.
The speed difference will be perhaps 300 fps depending on bbl. I would stick to the 22" bbl also, go 24" and again you will be kicking yourself for such a long beast on an AR15 frame.
In my last 20P, 22" length bbl. build I was spitting a 32g bullet at 3700+ fps.
But still its not a 500 yard gun.
The 6x6.8 VS the 243...you can build it on the AR15 frame VS the much heavier AR10 frame.
 
Looking around some more, the 223 AI has caught my eye. I'm thinking with a 40 gr Nosler BT, I could push this around 3800-3900 fps. This bullet has a decent BC, and with a case capacity of 32 or so grains it should be just what I'm looking for. The 223 AI should also be easy to reload for. I should be able to drop a coyote at 500 yards with this. What do you guys think? I know everyone keeps coming back to the 6x6.8, but if I wanted to go with a 6mm projectile, I'd build a 243 Win or a 243 AI off an AR10 lower. I sent Ritch an email to see what he can do for me, and what his opinion is. Thanks for the info so far guys. Keep it coming.
 
Originally Posted By: PowellSixOWhat about this barrel?




Well, it looks as if you really have your heart set on a 204! Here's my thoughts, keep in mind I just finished a similar build in the last couple weeks. If you're chasing all out velocity go with the 24", that's what I did, although I went with the lightweight profile. The 22" barrel will probably shoot to within 15/30 fps of the 24" and be a little more handier as a calling rifle. Even with the light profile it is a little front heavy. I see you went black cerakote, I would just get the black shot peening as it is cheaper and I belive more durable. I'm shooting 40 grain vmax and it is extremely accurate. I have not shot enough coyotes to figure out if it's the ticket or not, but so far so good. Good luck with your build!
 
That one will be accurte as all get out. It isn't too haevy as i shoot one in 6X45 well. The cerakote as mentioned is not near as durable as the standrd black. It is hard as the hubs of Hades and it would be my choice. I would go 20 Practical personally for a bit more verastility but if factory ammo is in the picture then you have chosen well IMHO.

Greg
 
Thanks guys. I really appreciate the info. I'm really leaning towards a .204 (if you haven't been able to guess, haha), or possibly a 223 AI. I'm thinking the 223 AI might just be the ticket. It has a little bit better BC, and is probably going to be easier to load for. I can just get some 223 rounds (that have good brass) and go plink away, and I'll end up with some fire formed brass to reload. I'm thinking this is going to be my route. So I guess I'm now down to a 223 AI chamber, with a 22 or 24 inch barrel, with the shot peened finish. What barrel profile should I go with? The standard, LTC, LTM, M4, or the Bull? Thanks guys.
 
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Ok. Gosh darn you guys. Lol. I don't know what to do now. Haha. What kind of velocities should I be able to see with a 22-24" barrel chambered in the 6x6.8 with a 55gr Nosler BT? Since I already reload for my 243, it's making more sense to stay with the 6mm bullet. I don't know. Haha.
 
Quote:I don't see what advantage it has over a tried and true 243. Maybe I'm missing something.

You can get it into a AR-15 rifle. Can't do that with a .243 (have to go AR-10).
 
Originally Posted By: Yellowhammer Quote:I don't see what advantage it has over a tried and true 243. Maybe I'm missing something.

You can get it into a AR-15 rifle. Can't do that with a .243 (have to go AR-10).



Yep, I knew that. I guess my deal was with the ballistics. Everything thing I found on the 6x6.8 was with 70+ grain bullets. This round really has me scratching my head now. If I can break the 3500-3600 fps mark with this round and a 55gr nosler bt, I'm sold. Do you guys think I can achieve this? Also how hard is the brass to find and how hard is it to reload? Once again thanks guys.
 
I'm really impressed with my 243 and the 55gr nosler bt. I'm getting roughly 3850 fps with them, and I can push them to 4000 fps if I wanted. But they group great and coyotes don't stand a chance against them. If I can get close to these numbers with the 6x6.8 I'll get one.
 
3550+ with a 58 is easy. 3650+ with the 55 is a piece of cake. Brass is easy to make using either the Redding bushing dies or a standrd type from CH4d.

Reloading data is all over the place and I have more than you can shake a stick at.

Greg
 
It sounds like you're coming around to "NOT a 204," but I'll cast my vote on that side just in case you're still waffling. The 204 just isn't a 500yrd coyote cartridge.

I've been through 6.8 and 6.5's, a 204 bolt gun, and my bread and butter coyote rifles are 223's. I'm currently building a "fur friendly" 204 upper and a "long range thumper" 6.8spc II. I debated the 6x6.8 and another grendel, but ultimately, I have no problem with the 6.8SPC's killing power.

Not casting real dispersions on the light and fast 6x6.8 bullets like that 3550-3650 load mentioned above, but I'm a bit of a momentum-fiend, not just velocity. If you can dope the 55grn to 500yrds with a 6x6.8, you can dope a 120grn in a 6.8 too, but the 120's going to hit a lot harder. Momentum is so important, Newton wrote a law about it. Energy depends primarily on velocity (double velocity = 4x energy, 10% more velocity = 21% more energy), but penetration is really about momentum, and momentum cares as much about bullet weight as it does velocity. I've found that bigger, slower bullets anchor dogs better at long range. Both work, but for my favor, a heavier pill has a distinct advantage. Plus, it's kinda nice having readily available ammo and brass.
 
Thanks again for the advice guys. I really appreciate it. I called and spoke with Ritch at lunch today, and we spoke for 30 minutes about it. He explained all the pros and cons of each of the cartridges I was interested in, as well as the 6x6.8. WOW does he have a ton of knowledge! He really didn't try to push me one direction or the other which I really liked. After speaking with him though, I think I'd be dumb not to go the 6x6.8 route. It really does sound like exactly what I'm after. I'll be honest......... It kinda scared me away when you guys started recommending it. Haha. I had never heard of it, and what I saw from my short research didn't persuade me much. But now that I understand it more I really like it. It will allow me to shoot a higher BC bullet than the .204 or .223, it's got the velocities I'm looking for, and I can go up in bullet weight if for whatever reason I choose to do so. If I can load an accurate round with the 55gr Nosler BT at 3600 fps, I'll be extremely happy. Another great thing, is that he lives less than 2 hours from me. He was kind enough to open his doors to me, and said stop by any time and I'll even show you how to size the brass properly. So I guess I have that part of my build figured out. I have a lot of overtime coming up for work (every year we do 8 weeks of 7 12's for our overhaul), and I'll be putting my order in shortly. In fact I'll probably just have him build the upper for me. That way I know it's done right. You guys have been great. I really appreciate it, and a big thank to Ritch.
 
Good choice from talking with Ritch.

Hornady factory 6.8 SST 120 at 2450 500 yard drop 75.9 drift 28.8

55 Nolser BT at 3550 500 yard drop 40.7 drift 28.8

Take your pick

Greg
 
Ive been running the 55g NBT in my 6x6.8 at about 3500 fps. I can go a tad faster, but in my Ar15 frame this ended up as the most accurate load, 22" barrel 1/10" twist.
I have no issues at 500-600 yards range time.
99% of my coyotes are 150 yards or less though, it flat out drops them w/no giant exit hole & that depends on angle of hit.
On top of that it can as stated above be loaded w/70-95g bullets for bigger game.
It spits the 70g NBT a over 3000 fps as well.
 
Originally Posted By: GLShooterGood choice from talking with Ritch.

Hornady factory 6.8 SST 120 at 2450 500 yard drop 75.9 drift 28.8

55 Nolser BT at 3550 500 yard drop 40.7 drift 28.8

Take your pick

Greg
That's some good info right there. Thanks Greg. Same drift but 35" less drop. I'm sticking with the 55 gr. I know the energy difference is probably huge, but there should still be enough to kill a dog at 500 with the 55. And yes I'm very glad I called Ritch.
 
Originally Posted By: 5spdIve been running the 55g NBT in my 6x6.8 at about 3500 fps. I can go a tad faster, but in my Ar15 frame this ended up as the most accurate load, 22" barrel 1/10" twist.
I have no issues at 500-600 yards range time.
99% of my coyotes are 150 yards or less though, it flat out drops them w/no giant exit hole & that depends on angle of hit.
On top of that it can as stated above be loaded w/70-95g bullets for bigger game.
It spits the 70g NBT a over 3000 fps as well.

Thanks for that. What powder are you using if you don't mind me asking with the 55 gr Nosler BT? Also, what is your COAl with them? I've got a lot of H1000, H4350, and Varget, but I'm sure these are not ideal for this load. My 243 really likes the Varget with the 55gr NBT though. Thanks.
 
COL on all my 6x6.8 loads is 2.250"
I can take them to 2.280" max in my mags, but stay at 2.250" so they run in them all.

31.5g x8208, 55g NBT, 3344 fps .750"
31g benchmark, 55g nbt, 3595 fps & .700"
28g H4198, 55 nbt, 3611 fps & .700"
33g H335, 55nbt, 3678 fps & .270"...col was 2.270" on this load.
30g varget, 55nbt, 3045 & .900", I didn't work much w/ varget.
30g Exterminator, 3349 fps & .680"
Other powders that run the same:
W748, BLC2, Varmint Pro, H335, aa2015,
 
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