AR questions.

[PinnedAndRecessed]

1) If I buy a DPMS rifle in 223, what's the largest most effective deer caliber I can mount on the gun?

2) If I have a DPMS lower, can I order an upper through the mail sent directly to my home?

3) The DPMS rifles I looked at said they were chambered for 223. What if I fire mil spec 5.56 ammo? What's the detriment?

4) Some RRA rifles I saw advertised were chambered for 223 Wylde. Is this a wildcat cartridge requiring special brass?

5) If I order a stainless barrel, do I still have to order a chrome moly barrel?

thanx.

So far all I know is that I'm supposed to order a 5.56 mil spec. But I don't know if that is going to be an option for the DPMS.

 

[DogBonz]

well, now that depends

What kinda of range are we talking? You have the two choices from Alexander Arms, the 6.5 Grendel with bullet weights from about 90-130gr factory loaded, and the big 50 Beowulf that loads (i think) 325-400gr in factory offerings. The 6.5 Grendel will give you about .260 Rem balistics, with awesome BC's and SD. This would make a great deer rifle. The 50 Beowulf will give you about 45-70 balistics, but in reality it is about a 150yd gun. I have the Grendel mounted on a DPMS lower and it sub MOA.

 

[GunnySkox]

1) If I buy a DPMS rifle in 223, what's the largest most effective deer caliber I can mount on the gun?

There's a pretty good selection, I'll just run down all the ones I know of:
6.5mm Grendel (Alexander Arms)
6.8mm Remington SPC (Barrett has an upper)
.50 Beowulf (Alexander Arms)
7.62x39mm
.458 SOCOM
.45 Bushmaster

Those are all the replacement calibers I can think of at the moment, but I'm pretty sure there are more.

2) If I have a DPMS lower, can I order an upper through the mail sent directly to my home?

Yes, only the Lower Receiver of an AR-style rifle is considered a firearm; you can buy uppers 'till the cows come home, then buy the cows some uppers.

3) The DPMS rifles I looked at said they were chambered for 223. What if I fire mil spec 5.56 ammo? What's the detriment?

My understanding (which may be flawed) is that 5.56mm NATO has a longer leade (I think that has to do with where the rifling starts) than .223, which can lead to increased pressure when firing the former in the latter. You should email DPMS and ask them if it's okay to fire 5.56 in their .223s

4) Some RRA rifles I saw advertised were chambered for 223 Wylde. Is this a wildcat cartridge requiring special brass?

No. Once again, my potentially flawed understanding, but a .223 Wylde chamber is one which is cut roughly halfway between the specifications for .223 and 5.56mm, so that there's less accuracy loss when shooting .223 in the slightly longer 5.56 chamber, and that it's safe to shoot 5.56 in the Wylde.

5) If I order a stainless barrel, do I still have to order a chrome moly barrel?

I can't imagine why. My brother's AR has a chrome-moly barrel and I have a chrome-lined one, and stainless steel barrels are popular all over the place for accuracy.

thanx.

So far all I know is that I'm supposed to order a 5.56 mil spec. But I don't know if that is going to be an option for the DPMS.

Cheers,
~GnSx

 

[DogBonz]

to the best of my knowledge...

which might not be much...

My understanding (which may be flawed) is that 5.56mm NATO has a longer leade (I think that has to do with where the rifling starts) than .223, which can lead to increased pressure when firing the former in the latter. You should email DPMS and ask them if it's okay to fire 5.56 in their .223s

5.56 is higher pressure due to thicker case walls of military brass.

 

[Bartholomew Roberts]

GunnySkox handled all the questions well. Firing 5.56mm in a .223 AR15chamber can cause problems due to the higher pressure. The higher pressure is partly because 5.56mm is designed for a chamber with a longer leade and also because 5.56mm is just loaded hotter than .223.

One of the perpetual problems during the development of the .223 round was that the light 55gr bullet would not reliably penetrate the M1 steel helmet at 500yds (which was a military requirement) because it shed velocity too quickly. Somewhere along the way, SAAMI standardized on a version of .223 that was different from the final version the military chose.

Because part of the extraction cycle requires the brass to shrink away from the chamber walls within a certain period, big increases in pressure cause extraction problems even if they aren't large enough to cause safety problems. A second problem from large pressure increases is that the brass can flow back into the bolt - particularly the area around the ejector. As the gun extracts and cycles, the ejector can bite off tiny pieces of brass that can later bind the ejector and cause failure to eject. I've never personally seen it present a safety issue in a rifle; but no gas-operated firearm likes big spikes in the operating pressure so it can cause functional issues like I described above.

Further confusing the matter, many manufacturers mark their chambers 5.56 but chamber in .223 or mark their chambers .223 but chamber in 5.56. I'd ask DPMS first if that is a concern. If you can get a Wylde chamber, I've had excellent luck firing 5.56mm NATO out of my Wylde chambered SS barrel so far.

 

[MachIVshooter]

1) If I buy a DPMS rifle in 223, what's the largest most effective deer caliber I can mount on the gun?

.243 and .25 Leviathan from Accuracy Systems, inc. Spendy stuff, though.

3) The DPMS rifles I looked at said they were chambered for 223. What if I fire mil spec 5.56 ammo? What's the detriment?

Only DPMS can answer that. I don't know about them but, IIRC, Armalite markets the M-15 as .223, yet the recievers are marked 5.56mm. I know my AR-10 was listed as .308, but the reciever is stamped clearly "Rifle, 7.62mm AR-10". It runs both commercial .308 and 7.62mm NATO just fine.

 

[rangerruck]

or you can get an MGI MILITARY SALES, rifle, totally modular, and get just about any caliber you want.

 

[Reginhild]

For deer and medium game the 6.5 Grendel will do well including use as a beanfield deer gun and mountain hunting of rams due to its long range capability. There isn't any other alternative caliber production round for the AR15 that has the 6.5 Grendel's long range capability.

 

[browningguy]

Even though I don't have one I'd go for the 6.5 Grendel also. I currently have .223, 6x45 and .50 Beowulf uppers that work fine on my DPMS and RRA lowers. The 6x45 is just a little on the weak side to be ideal, but the 6.5 looks like it has excellent ballistics to be an all around hunting round.

I love my .50 Beowulf also, handloading 325 gr. Speers it makes a fine, although short range, deer and pig gun.

 

[mc223]

Always consult the Oracle.


http://www.ammo-oracle.com/body.htm

 

[MisterPX]

1) 50 BMG
5) Stainless is what the barrel is made of, chrome moly is what the barrel is made of. Two different barrels, not found mixed..