AR-15 noob ammo questions

[AndyWest]

I bought a lovely NIB Colt LE6920SOII, S/N LE106xxx. The manual has some gaps so I'm asking here:

The barrel is labelled "5.56 NATO 1/7" (twist, I assume). What's an appropriate .223/5.56 round for me to start with?

The magazines are labelled "COLT'S MFG; HARTFORD, CT" on the receiver end and "33710; 11-11" near the bottom. They're grey and easily scratched with the minty green followers. What's the proper round count for these?

Thanks AR wizards.

[FrosSsT]

Id go with 5.56 or .223 (it really doesnt matter that much) 62gr. I use the Lake City surplus stuff, its pretty good ammo and you can get it for a decent price if you check around. Unless its a 20" barrel I would stick with brass.

Unless you purchased in a restrictive state your looking at a 30 round magazine.

[AndyWest]

Thanks, FrosSsT.

It is a 20.1" barrel, does that change casing recommendations somehow?

Any other tips appreciated.

[Creeper]

The barrel is labelled "5.56 NATO 1/7" (twist, I assume). What's an appropriate .223/5.56 round for me to start with?
With a 1:7, you can shoot any bullet weight available for .223/5.56... although some thin jacketed, light bullets may over-stabilize and/or shed their jackets. The idea behind the fast twist is to allow use of the heaviest bullets... 80-90 grain.
The magazines are labelled "COLT'S MFG; HARTFORD, CT" on the receiver end and "33710; 11-11" near the bottom. They're grey and easily scratched with the minty green followers. What's the proper round count for these?
The 33701 is the "cage code" for Colt/Okay Industries. Okay has made the mags for Colt for over 40 years, and are considered by some to be the best there is. 33071 can be found on both 20 and 30 round magazines. If the magazine is straight, it's a 20 and if a bit banana'd, it's a 30. There are as many variations of AR mags as there are ARs... take a look (http://www.44mag.com/category/223_ar15_magazines/a).
It is a 20.1" barrel, does that change casing recommendations somehow?Casing... as in what gun case it fits? Maybe... measure twice, buy once. :p

Cheers,
C

[FrosSsT]

Thanks, FrosSsT.

It is a 20.1" barrel, does that change casing recommendations somehow?

Any other tips appreciated.

watch this video and it will explain all you need to know about steel cased ammo for AR's http://www.youtube.com/watch?v=P5ZB3UfG960

[AndyWest]

Excellent technical and practical advice, FrosSsT and Creeper. Exactly what I needed to get started. Thanks and all the best.

[UtopiaTexasG19]

Quote from Creeper...
"The idea behind the fast twist is to allow use of the heaviest bullets...
80-90 grain."

I have been reloading for the .223 two years now any bullet weight over 77 grains has a OAL too long to fit my standard AR15 magazines. Are not weights above 77 grains usually used in bolt action single shot rifles. Am I wrong on this? I'd hate for the OP to go out and buy rounds that won't fit his magazines.

[Creeper]

No, you are not wrong. But I'm thinking of subsonic, hand loads and loads that exceed 2.260" and must be loaded singularly... which, now that I think of it, is probably beyond the scope of this particular thread and OP.

In hindsight, I should have stopped at 80 grains and not mentioned heavier bullets than that. Thanks for pointing out my misstep UTG19.

Cheers,
C

[AndyWest]

I wouldn't use super-heavy rounds, which is sort of why I asked about the 1/7 twist in the first place. Creeper confirmed what I thought, that it was indicative of a fast twist. I don't want stripped light rounds but also don't want heavy rounds to damage the rifling. Surely I'm over-thinking this but it's my first AR and it's a beaut :)

[Creeper]

I don't want stripped light rounds but also don't want heavy rounds to damage the rifling.

You can't damage the rifling with a heavy bullet... it's simply that a conventionally loaded, 80 plus grain bullet round will not fit the magazine OAL, and may not fit within the chamber throat, unless it's modified to do so.

You're good to go with the more popular/common 50 to 75 grain ammo.
You may find that your particular gun has a preference for bullet weight, and not necessarily bullets on the heavier side of the range.

No worries on the first AR thing... we all had the "first AR insanity" at some point or another. Ask all the questions you want.

Cheers,
C

[UtopiaTexasG19]

My 1:7 twist 16" barrel shoots mediocre groups with 55 grain bullets but for some reason is a tack driver with the 64 & 65 grain re-loads I put together. Whether you buy manufacturered or re-load you just have to find out what works for your set up and what you are trying to do. Naturally we would all like to get great accuracy with the cheapest rounds available but sometimes it doesn't work out that way.

[madcratebuilder]

I'm a firm believer in only shooting 5.56 nato in my AR's. .223 can be under powered. You can find true LC/WRA M193 over run surplus for .30 a round. M193 works in my 1-7, 1-8 and 1-9 twist barrels. Now that I have had several outings with my 1-8 barrel, I think they all should be 1-8. M193 and M855 shoots very well in it.

It may be my imagination but I think true M193/M855 shoots better/different than the commercial XM193/XM855 ammo.

[moxie]

Even though it has the NATO cross and circle marking, M193 ammo is not and has never been NATO. It was never adopted by NATO, even though it was the standard issue U.S. round for many years until the 62 gr. M855 was adopted as standard U.S. issue in the late '70s. The M855/SS109 round became the official NATO round in 1977, I think. That's only for 5.56mm. The 7.62mm is a different story.

So there's really not been any "surplus" M193 in any prefix in many years because it hasn't been made for issue. But, it's all good stuff regardless of the prefix to the M. And it's all good stuff, LC or WRA/WCC, even though it hasn't been issued in about 30 years, and has never been NATO. Lake City cranks out good ammo, whether it's run by Winchester or Federal.

[btmj]

My 16" barrel 1:9 twist is slightly more accurate with 62 - 69 grain ammo than it is with 55 grain ammo. I have tried several different 64 - 69 grain soft point 223 loads, and all are about 1 MOA. M855 62 grain from lake city is about 1.5 MOA, but sometimes groups down to 1 MOA.

However, the 55 grain M193 is certainly accurate enough. It is typically 2 MOA, and this is plenty accurate for a battlefield or self defence situation.

If a person was going to use ball ammo for self defense, IMO they would better served by M193 than by M855. The lighter M193 bullet has better yaw / fragmentation performance on soft targets out to 300 yards. The M855 bullet achieves better penetration and better long range (400+ yard) stability, but does less well on soft targets. Penetration performance is King on the modern battlefield where everything is armored, so the military uses M855. But civilians don't need a bullet that was optimised to shoot through steel plate.

Honestly though, expanding bullets such as JSP or open tip make the best choice for self defense.

[customaquatics]

dang ima stock up on the tulammo too since its the same stuff.