AR15 - 55gr or 62gr bullets?

[Mojo-jo-jo]

I recently built an AR15. I'm going to buy a bunch of .223. In order to pay less than about $.50/round I have to mail order, and in large quantity (1k rounds). I am not an experienced AR15 or .223 shooter.

16" 1-9 twist barrel.

Should I buy 55gr or 62gr? 55gr seems to be more available and cheaper.

What are the advantages/disadvantages to each?

Thanks in advance.

 

[schildgen]

All my reloads are 62 grain MC and I feel the 62's are more accurate in 1/7 and 1/9 AR's
I got a flyer in a package from Wideners yesterday that they will have some Prvi Partizan 62 grain SS109 $359/1000rounds. The flyer says available in MARCH.

 

[Onmilo]

I also prefer heavier bullets in 1-9" twist barrels.
I tried some 60 grain flatbase spire points, I believe they were Speer, that were amazingly accurate in my Bushmaster carbine.

I haven't been able to find those bullets since and wish I could.

62 grain lead core is more accurate than the steel core SS109 or M885 offerings.

 

[H2O MAN]

I am going to try 68 and 75 grain Black Hills ammo in my 1-7 ROT 16" barrel.

 

[HorseSoldier]

The heavier stuff should work well in a 1-7 twist barrel. Mk 262 usually produces groups around half the size of M855, though as someone already noted that's not necessarily the bullet weight so much as the complex composition of the round.

 

[MIL-DOT]

From what i understand, the older AR's with a 1 in 12 or 1 in 14 (slower) twist, are best with lighter 55gr. rounds. The newer,faster twist barrels,like yours are more compatible with the heavier projectiles.

 

[possum]

i also have a 1x9" barrel and though i haven't done any real accuracy test with the two. i have had good luck with both military surplus 62gr, and 55gr, which i normally go with the 55gr as like you said it is cheaper, and easier to find.

 

[JWarren]

On the flip side, can anyone comment on using lighter grains in 1x7 barrels?

I am looking at getting an AR in 1x7 twist with M4 feedramps to handle heavier loads. Would I experience any negative performance with lighter loads in that twist?

Thanks and sorry if this was a highjack.


-- John

 

[JonB]

I have a RRA with 1-9" and it works well with 55gr. I haven't tried much else yet since I bought a ton of 55gr when they were 200$ / 1k.

 

[MarshallDodge]

My 1x9" twist barrel likes 60 grain bullets. I have never tried 62 grain bullets.

In a close range self defense scenario I have heard that the 55 grain bullets fragment better than the 62's.

 

[Soybomb]

If you're just plinking around I'd buy the cheapest.

I am looking at getting an AR in 1x7 twist with M4 feedramps to handle heavier loads. Would I experience any negative performance with lighter loads in that twist?

Your average cheap 55gr round will be just fine.

 

[briansmithwins]

Only way to know for sure is to buy a few and shoot them. Select what works best in your rifles.

For example, I'm running low on 5.56, so I just bought 100 rounds of 62gr Wolf, 62gr PPU, and 75gr PPU to try out in the 1/7 rifles. 55gr PPU works great (1.5MOA) in my AR (1/7 twist), but not so good (5MOA) in the AK (also 1/7 barrel).

1/9 barrel should handle pretty much any 55gr to 62gr, but you have to try it to be sure. Don't get stuck with 1k of rounds that just aren't accurate.

 

[strat81]

Gaahhh! This many responses about ammo and AR-15s and nobody has mentioned Ammo Oracle????

http://www.ammo-oracle.com/ Get thee hither, young ones.

More than you ever wanted to know about the subject, but highly informative.

 

[glockman19]

I have a couple of Stag's with 1:9 twist and shoot Federal American Eagle Lake City NATO stamped 55grain, & 62 grain. I alao have some 45, 55 & 62 grain Remington UMC. The 45 grain are hollow points I'd use for home defense.

I alos have 855 & 193 ball ammo

Almost anyting you shoot out of a 1:9 barrel will shoot just fine IMHO. I don't expect less than 2 MOA from my AR's at 100 yards anyway.

 

[HOLY DIVER]

jwarren 1:7 twist is prob not going to like the light bullets.i would not go lower than 62grain

 

[JWarren]

Soybomb and 000buckshot,

Thanks for those answers. I'll factor them into the mix.

-- John

 

[RockyMtnTactical]

M193 is better for fragmenting than the M855 vs. people, therefore I prefer 55gr ammo made close to that standard. Not to mention that not all 62gr ammo for the AR15 will have the same POI. Depending on if it is loaded with the SS109 bullet or strictly lead core ammo. Not to mention that in both cases you will find ammo loaded for .223 and 5.56.

 

[Rshooter]

I believe the military is having some issues with the heavier bullets in the shorter barrels. It appears that the heavier bullets perform better in 20 inch barrels, 16 inch is the outer limit and 14.5 inches is too short. In a 16 inch barrel I would go with a 55 grain bullet.

 

[H2O MAN]

I believe the military is having some issues with the heavier bullets in the shorter barrels.

ROT has more of an influence than barrel length or lack there of.

 

[Urbana John]

I have ( for now, only two ) AR-15's in .223 and have ONLY shot my reloads in both of them.
The first one I adopted was a Colt HBAR 24" SS and I'm very SURE, I can hit a golf ball at 300 yds. The second ( custom build ) is a Sabre Defense 16" chrome lined barrel, and it shoots VERY good with my reloads.
Without looking,I'm not sure what the rate of twist is, but I'm very happy with the accuracy of both rifles and MY RELOADS!!
Sierra 52gr. BTHP's on top of 24grs. of IMR3031,with CCI BR Small Rifle primers.

 

[Markbo]

mojojo, if you buy a huge quantity of ammo before having tested it in YOUR gun, what have you saved if it doesn't shoot? Not a danged thing. Now you got a few cases of ammo that shoots 5" groups. It would be a gamble pure and simple.

I have several AR's and since you are not a reloader that can test endless variations, you would be better served by buying once box of everything you can get your hands on to test - within reason of course.

All my AR ammo is for hunting, not defending or offending anyone so I could care less about military ammo - my chambers are .223 and .223 Wylde. Decide what you are going to use this for and test it. If you test correctly, you will undoubtedly it's preferences.

ETA: If you go with hunting bullets, I have had terrific results with Black Hills blue box