My first AR.. and some noob questions

[Skullz]

While I was visiting my in-laws in NH, I decided to purchase my first AR.

I've owned hand guns since the day I turned 21 and dome some competition shooting and I am relatively proficient with a shot gun (I shoot sporting clays every weekend and score consistently in the 90s), but I've never owned a rifle.

For some time I was considering a tricked out model with all the upgrades, even though I honestly don't know enough about the rifles to justify getting anything other than a functional weapon. After reading a number of threads I decided that the best advice I had seen was to buy a decent rifle and become skilled using iron sights, etc. before moving into optics.. so thats what I did.

I bought a DPMS Panther Carbine A2. I've read a number of threads that .223 and 5.56 are basically interchangeable, but now that I have the weapon I'm a little more confused. The lower is stamped "cal .223 - 5.56" and the barrel is stamped "DPMS cal 5.56 1-9". I know the 1-9 is the rifle twist, but what ammo is best to use? Is there any reason I should use a specific 5.56 caliber?

Are there any upgrades or parts I should consider changing in the near future? I'm looking for this rifle to be fun to shoot as well as have some home defense duty... although if it ever came down to it I would choose my XD first, my Mossberg next and then the rifle :-)

Thanks in advance for any advice

Skullz

Oh yeah.. pics..

[tec]

From what I know, which isn't that much, the barrel twist and ammunition coincide with performance. Certain barrel twists work better with grain amounts in the ammunition. Which twists and what grain amount work the best; unfortunately, I do not know. I do know it is posted in a thread somewhere on these forums, I'm not sure where.

[knight0334]

5.56 ammo works at higher pressures than .223 even though they are the same basic cartridge. 1:9" is best suited for 55gr to 69gr bullets at 2600+ fps MV.

You can use .223 ammo in a 5.56mm, but I strongly recommend not using 5.56mm ammo in a .223 gun.

go with 5.56mm ammo if you can.

[RocketFoot]

Thats a nice rifle! I laughed at your first sentence!

While I was visiting my in-laws in NH, I decided to purchase my first AR.

That sometimes makes me wanna buy a gun also! LOL

[Mity2]

While the 5.56 mm and .223 cartridges are very similar, they are not identical. Military cases are made from thicker brass than commercial cases, which reduces the powder capacity (an important consideration for handloaders), and the NATO specification allows a higher chamber pressure. Test barrels made for 5.56 mm NATO measure chamber pressure at a the case mouth, as opposed to the SAAMI location. This difference accounts for upwards of 140 MPa (20,000 psi) difference in pressure measurements. That means that advertised pressure of 400 MPa (58,000 psi) for 5.56 mm NATO, is around 540 MPa (78,000 psi) tested in .223 Rem test barrels. The 5.56 mm chambering, known as a NATO or mil-spec chambers, have a longer leade, which is the distance between the mouth of the cartridge and the point at which the rifling engages the bullet. The .223 chambering, known as SAAMI chamber, is allowed to have a shorter leade, and is only required to be proof tested to the lower SAAMI chamber pressure. To address these issues, various proprietary chambers exist, such as the Wylde chamber (Rock River Arms)or the Armalite chamber, which are designed to handle both 5.56 mm and .223 equally well, and your DPMS is prolly similer chambering

Using commercial .223 cartridges in a 5.56-chambered rifle should work reliably, but generally will not be as accurate as when fired from a .223-chambered gun due to the excessive lead Using 5.56 mil-spec cartridges (such as the M855) in a .223-chambered rifle can lead to excessive wear and stress on the rifle and even be unsafe, and the SAAMI recommends against the practice. Some commercial rifles marked as ".223 Remington" are in fact suited for 5.56 mm, such as many commercial AR-15 variants and the Ruger Mini-14, but the you should always verify that this is acceptable before trying it, and signs of excessive pressure (such as flattening or gas staining of the primers) should be looked for in the initial shooting with 5.56 mm ammunition with gun chambered for .223

I've always wondered about 1/9" twist vs 1/7" twist.

I was told that 1/7" twist shows best grouping at 600yrds with M855 ammo, which is 62grain ball ammo.
But i was told that 1/9" twist shows better grouping at 300yrds with same M855.

But I was always told that tighter twist (smaller the number?) is better for heavier ammo.

Since i shoot mostly 55gr M193(or 55gr .223remington), by designe, will I have best grouping at longer range or shorter range?

[Lycanthrope]

You guys are killing me with these twist rate questions..........

The gun should shoot 5.56 or .223 ammo equally well. The only difference is that 5.56 ammo is loaded to higher pressures.

Faster tiwst (1:7) barrels will prefer longer bullets. Slower twist rates (1:12) will prefer shorter bullets. Sometimes this coincides with weight and sometimes it does not. Steel core military ammo is lighter....and therefore longer, compared to a lead core round of the same weight.......Same deal with tracers.

I've had best luck with 55gr to 69gr bullets in my 1:9 guns. The best bullet tends to be the 69gr SMK for my 1:9. guns. I have shot 77gr Noslers without problem (1.5 moa) in one gun.

1:7 twist guns will shoot anything a 1:9 gun will, but accuracy suffers below 69gr on my guns as compared to the 1:9's I have. Just my experiences. Others may vary.

With any rifle you will need to experiment with several bullet syles and loads to find a sweet spot for your gun.

Lycangoodluckthrope

[Skullz]

Thats a nice rifle! I laughed at your first sentence!

That sometimes makes me wanna buy a gun also! LOL

LOL.. I didn't even notice that. Fortunately, my in-laws are great and we get along very well. I think it was more the fact that the price was better than I could find in PA, there was no FFL charge and no sales tax. So, the price on the weapon was the price out the door (with a couple dollars for ad. magazines and stripper clips).

[Skullz]

You guys are killing me with these twist rate questions..........

The gun should shoot 5.56 or .223 ammo equally well. The only difference is that 5.56 ammo is loaded to higher pressures.

Faster tiwst (1:7) barrels will prefer longer bullets. Slower twist rates (1:12) will prefer shorter bullets. Sometimes this coincides with weight and sometimes it does not. Steel core military ammo is lighter....and therefore longer, compared to a lead core round of the same weight.......Same deal with tracers.

I've had best luck with 55gr to 69gr bullets in my 1:9 guns. The best bullet tends to be the 69gr SMK for my 1:9. guns. I have shot 77gr Noslers without problem (1.5 moa) in one gun.

1:7 twist guns will shoot anything a 1:9 gun will, but accuracy suffers below 69gr on my guns as compared to the 1:9's I have. Just my experiences. Others may vary.

With any rifle you will need to experiment with several bullet syles and loads to find a sweet spot for your gun.

Lycangoodluckthrope

Thanks for the info.

I got a coupon from Cabela's so I went up last night to stock up on some ammo. (They had some decent sales on some calibers / brands too). For .223, I picked up 100 rounds of the 55gr PMC bronze because it was cheap, 100 rounds of Magtech 60gr, 100 rounds of the Remington UMC 55Gr, and then 80 rounds of 60Gr Hornady Tap - I'll probably try out 20 rounds or so and if it's decent, I'll keep it for it's intended purpose.

As a side note I picked up 1000 rounds of the American Eagle 124gr 9mm at $9 a box(I have a Glock, so under 124gr is out for me) and 1000 rounds of WWB 230Gr 45 ACP at $15. I wish they carried the Clays brand shotgun shells as thats my preferred clays round, but I end up ordering that by the pallet and splitting it with some friends - shipping is a killer!

Tracer rounds - do they cause the gun to get dirtier and therefor harder to clean? I always thought they were cool and looked fun, but heard they fouled up the gun faster.

[ssom003]

Looks great...

[ithinkimamedic]

As a side note I picked up 1000 rounds of the American Eagle 124gr 9mm at $9 a box(I have a Glock, so under 124gr is out for me)

WTF!?!?!? Where did you read/hear this? That is 100% totally false! I have (for the last 4 years) shot 115gr 9mm from both a glock 19 and 17 with minimal problems that could be attributed to poor magazines and recoil spring. Like I said I'm not sure what you have heard or read but this is completely false that you can't shoot anything less than 124gr 9mm through a glock. I'm sure there are THOUSANDS of people who shoot their glocks with 115gr 9mm ammunition as that is what one of the cheapest, and most readily available ammunition, Winchester White Box (WWB) from walmart (and other places) is.

Sorry for the detour off your friendly neighborhood thread... back to business men (and women).

Josh