55gr vs 62gr

[Army GI]

Hello,

I just wanted some subjective observations on the lighter ammo vs heavier ones. I don't need a military history lesson, I know why the M855 came about.

I've only fired the 62gr ammo in an M16A2, so I have nothing to compare it to. But now in the civilian world, the farthest I shoot my M4gery is 100 yards. Is there any noticeable difference in accuracy at 100 yards from an M4 barrel?

What about recoil? Muzzle blast/flash? I doesn't seem to me that 7gr would make that much difference, but I guess in rifle cartridges traveling over 3000fps every gr counts.

[Fjold]

At 100 yards the weight of the bullet wouldn't make a bit of difference so use what ever weight bullet shoots the best in your rifle.

Muzzle flash, recoil etc. isn't going to vary enough to matter.

[rksimple]

At 100 yards, you won't notice a difference...especially killing paper.

[ViPER395]

The accuracy/POI will probably vary a little. I've heard heavier weights are more accurate in faster bbls.

1in9" twist like heavier grain bullets (i've heard 65gr+) than a 1in10" which will like a lighter band of weights.. something like 45-65gr. I forget. There's a chart someplace on the net about it i'm sure.

[Lon Moer]

Ammo Oracle (http://ammo.ar15.com/)

[1911su16b870]

The other day I actually tested this out with Fiocchi 55gr, Tap 60gr, Black Hills 68gr HPBT match and Federal 69gr Sierra HPBT match at 100-yards. 20-inch 1:9 barrel. All shot within 1MOA at 100-yards. Best results I obtained were with the 55gr at 1/2MOA and Tap at 0.6MOA. I did get one FTF with the Tap, the only one of the day.

The Ammo Oracle link has some interesting reading on it.

[dasARguy]

I couldn't help but respond to this... I recently read in a current gun mag about the initial mil spec twist rate spec for the m16 in the early days of its development. According to the article the M16 barrels had 1:14 twist rates and were incredibly devastating during their initial testing. During field tests the air force requested a 1:12 rate because of cold temp issues which lead to a complete change over to that twist rate and led to other changes in bullet weight/stability problems yada yada yada....The article summed up by saying that a return to that 1:14 twist would solve a lot of accuracy/stopping power issues. Can anyone enlighten me further regarding this?.... it appears that the most common twists are 1:8, 1:9 now. why is that???? Thanks

[Suvorov]

I've shot 55gr out of my 1:7 twist for years. Out to 100 yds I have never had any problem and often had sub MOA groups. Out at the longer ranges (to 300 yds), I never had any problems hitting the target.

[Jicko]

The major different is the "steel core". Most ranges will NOT let you shoot those.

POI varies, therefore stick with 1 kind of ammo, so that your zero is maintained.

[FlyingPen]

The steel core thing kind of sucks. 5.56 and 7.62x39 from Wolf is less than half the price of new brass.

[Gnote]

Please keep threads concerning ammunition under the Ammo and Reloading area.