Ar-15

I've got the disease!!!! 4 .223's and one play one in 9mm. I really want an AR10 but its hard(exspensive)to get good 7.62.

You should take a look at the ballistics of the 6.5 Grendel vs. the 7.62. And it works in the AR-15 architecture.
 
barrel, magazine and bolt. I believe you can reuse the carrier.

The Grendel shoots flatter than the 7.62 and at 600 yards carries more energy. It's faster so your BD comps are alot easier to calculate. The downside is that brass is expensive. The caliber really favors the handloader, but the results are amazing.
 
Keep this in mind- when you buy an off-the-shelf rifle, it's built to work with all the ammo out there. If you build your own, you can specify alot of different things that will dramatically improve accuracy. The biggest is chamber reaming. Not only can you have a higher-tolerance reamer used, you can get a shorter throat cut. That will allow you to seat your bullets to match your throat depth. Factory chanber are cut deep and the bullet is forced to jump the gap to the throat and the beginning of the rifled bore. With the shorter throat, you can set bullet seating to the throat- so when chambered, the ogive of the bullet is touching the throat. Big increase in accuracy.

The downside- on an autoloading rifle, you may get the occasional failure-to-feed. But on a properly tuned, well cared-for rifle, it would be rare.
 
barrel, magazine and bolt. I believe you can reuse the carrier.

The Grendel shoots flatter than the 7.62 and at 600 yards carries more energy. It's faster so your BD comps are alot easier to calculate. The downside is that brass is expensive. The caliber really favors the handloader, but the results are amazing.

So wouldn't you just buy a complete upper and then have both the 223 and the 6.5

My buddy is in love with the AR-15. He has complete uppers for his guns so in a minute he can go from 22, 9mm, 223. He mentioned something about a 260 or 270 one as well. Now I am wondering if it is the 6.5 you speak about. He just changes uppers, has different mags for the different ammos and goes on about shooting. Seems like a good thing to me. He likes Spikes tatical, but of course they are only a few miles from us.
 
So wouldn't you just buy a complete upper and then have both the 223 and the 6.5

.

Depends on your way of thinking. I personally wouldn't. The cost of a lower, trigger group and a stock wouldn't keep me from owning another rifle. So, me- I'd have both :)
 
Get a Colt if you can afford it, they are very well made and will absolutely not decrease, but increase in value. .223 ballistics are very good for what it is intended for, killing people and varmints. 200-300 yds. is when almost all rounds really start to bleed off velocity. The 6.5 grendel is a .260, or actually, a .264 and is a hell of a cartridge. I personally, wouldn't go above 6-700 for a used Bushmaster.
 
I don't know much about the technical aspects of the different calibers, but I do know that my .270 Browining A-Bolt is very accurate at range. It makes sense that if a 6.5 = .264 it should also be very accurate.
 
There are alot of components that go into how a cartridge performs ballistically. Case design can have a huge effect on how the cartridge performs. In the case of the Grendel, the case diameter and shoulder design balances very well with the burn charachteristics of a couple popular rifle powders.

Another aspect is the performance of the projectile. Some of the factors governing performance are bullet weight, velocity and coefficient of drag. Moving the projectile faster means it drops less in a given distance- flat trajectory. A bullet drops at the same speed whether dropped from your hand or propelled to 4,000 feet per second. It's just that at 4Kfps it doesn't have time to drop as much. A low coefficient of drag means that the drag of the bullet is lessened, allowing it to retain more velocity. And velocity is energy. Mass is also energy. So when you put all this together, the 223 moves very swiftly and has a low coefficient of drag, but since it's only 55 grains in weight, its energy at distance is much less. If you go to the 7.62, the CD is up substantially and speed is down, but energy remains high with a typical bullet weight of 168gr. The 6.5 moves almost as fast as the 223 and at 123gr has substantially more weight. So you get a good, flat trajectory and good energy at long distances.

Another aspect of CD and energy is deflection. Unless you're at an indoor range, you're dealing with wind and thermals. And those two can greatly affect accuracy. In that respect, the 6.5 is a solid performer. While CD is important, bullet profile is the big one here. Big, fat bullets are easy to blow around. So are light one's. The 6.5 is a good balance.

I've been playing with my own 6.5 for a couple years. It's base is the Remington 300 Short Action Ultra Mag (SAUM). I necked the case down to 6.5mm and messed with the shoulder a little bit. I chose this base as I wanted to try it in an autoloading rifle and the AR-10 platform would accommodate the cartridge length. So far I've been astonished with the performance. The ballistics absolutely blow the 7.62 away.
 
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You guys are all saying colt. I have been told that the newer colts aren't what they used to be, and now your really paying for the name. Armalite I hear a good ones. They says bushmasters are a good bang for the buck. Though I'd probably go with the spike's tatical as they are local for me.
 
You guys are all saying colt. I have been told that the newer colts aren't what they used to be, and now your really paying for the name. Armalite I hear a good ones. They says bushmasters are a good bang for the buck. Though I'd probably go with the spike's tatical as they are local for me.

Take a look at Rock River.
 
A locally-built gun may be a flawless piece, but unless you're going to keep it forever, it could be a tough sell. A pro-built gun doesn't present that problem.

My experience has been that DPMS provides the best balance of cost, value and performance. You can also easily resell it. RRA also builds a very high-quality weapon. Armalite as well.
 
buy a Colt.....

I have a couple of AR's...no Colt though... we cant get new Colts in Canada and the used ones are stupid money.
 
You should take a look at the ballistics of the 6.5 Grendel vs. the 7.62. And it works in the AR-15 architecture.

Chris,

Does that mean it would be reasonable to start with a Colt AR-15 LE and eventually modify it to handle the 6.5 Grendel round? Or would the Armalite AR-10 be a better place to start?
 
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