55 vs 62gr ammo? Difference and issues with using either?

[RickyRoss]

Hi folks. I just recently bought an AR15 and I'm starting to look for ammo and I'm noticing there are different grains of ammo mostly 45/55/62. I know this is a very novice question but I live in PA and thought I might find some good info here and find others to talk about guns with. I'm not totally new to firearms by any means but haven't really been into it in a few years but my buddy convinced me to get one since he just did. I have a few rifles, shotgun, and a Glock so not total novice but I've never owned an Assault Rifle like this before so I'm just starting to learn more about it. Anyway, help would be appreciated understanding the differences and if there is anything to avoid when it comes to ammo grain. Thanks.

[Stampeed Valkyrie]

First determine what twist rate your AR Barrel is (1:7,1:9,1:12). It should be stamped on the barrel itself. Most newer rifles are 1:9 and are meant for the heavier rounds (62gr or higher) and may not shoot 55gr very well. Also don't be afraid to try different types before you buy in bulk.. some rifles like certain bullets and don't like others.

[Parrisk]

There is no safety issue.. just accuracy.

Question is your AR-15 a .223 CAL or 5.56?

A 5.56 can shoot either.. a .223 should ONLY shoot .223.. not 5.56

[solrac7]

First and foremost, IT IS NOT AN ASSAULT RIFLE. It is similar to an M16 or M4 which are assault rifles. Your Glock isn't an assault pistol right? They are both semi-auto, and while similar firearms can be used in warfare, don't fall into the trap of calling it an "assault rifle" .


The grains (or weight) and length of bullet affect accuracy and effects the wind has on the bullet - the heavier bullets (higher grain) do better with a slower twist, but all are safe to shoot as long as the caliber is correct for YOUR gun (5.56 vs. .223) try and see which works best in yours.

Cb

[Smilez226]

an Assault Rifle

TRIGGERED

[psweigle]

Make sure your semi auto sporting rifle is marked as 5.56, otherwise only use .223 Remington ammunition. That being said, he twist rate is key to finding the most accurate bullet weight. All bullet weights will give you acceptance accuracy in the "factory" rifle platform. There are many different type of ammo for your platform, and almost all will work sufficiently in it. There are custom things you can do to make it work better for a specific application but as far as any stock semi I've ever shot, they all work with just about any ammo you put in them. I hope the "short" untechnical answer helps. There are a pile of knowledgeable people here, so don't be afraid to ask questions.

[ExFlyinguy]

First and foremost, IT IS NOT AN ASSAULT RIFLE. It is similar to an M16 or M4 which are assault rifles. Your Glock isn't an assault pistol right? They are both semi-auto, and while similar firearms can be used in warfare, don't fall into the trap of calling it an "assault rifle" .

Cb

^This.

Now for the bullets. My personal favorite is 1-8 or 1-9. In my humble opinion not a lot of folks are forking over the coin for 68, 75, 77 grain 5.56.....My money says most folks buy 55grain full metal jacket due to price. A 1-7 twist rate is not optimal for that, but can still be used. Frankly it's been one of the reasons why I never scooped up a Tavor.

As far as the difference between 55 vs 62..... well the easiest answer is again price... 62 grain is going to cost you more. More technical information is available by research but to me it's not worth the effort or the price difference.

[dkf]

Most common 62gr is M855 (SS109) which is not known for th ebest accuracy. The 55gr XM193 or slower .223 with the same 55gr FMJ bullet is usually more accurate than the M855.(is for me) I would recommend just stocking up on Federal XM193. It is good decently priced range ammo, with decent accuracy and actually has good terminal performance to boot. If you want to reach out further and increase accuracy over the two rounds previously mentioned (and you have the twist rate for it) ammo with a 69gr-77gr BTHP bullet will get you there. I don't go lighter than 55gr for my ARs.(jacketed lead bullets)

[Fred762]

You can have some fun w yer AR..if you have a 1:12" barrel..[ie older ARs] maybe try some 62+ grain rds..you will find many will "key hole" at 25-50 yds..might make a great room cleaner ;-) Most newer ARs have at least a 1:9" twist..some new ones go to 1:8" or 1:7"..
A rule of thumb is that the slower the twist, the better they work for heavier bullets. They are NOT assault rifles...they are semi-automatic, sporting rifles.

[Manxdriver]

They are NOT assault rifles...they are semi-automatic, sporting rifles.

Mine is a sexy, sassy beotch.