What should I know about the difference between shooting 55 and 62 Gr. ammo in my AR?  And how does the rate of twist affect which ammo you should use and how it handles?

I'll just go ahead and do it...

read the ammo oracle.

Quoted: I'll just go ahead and do it... read the ammo oracle.

Yup check out the ammo oracle.

But before you go nuts trying to settle on a twist rate and type of ammo to go with, heres my take in a nutshell.

Stick with a 1in8 or 1in9 twist barrel, these are the best all around barrel twists, and both will handle 55 or 62gr fine.

IMO go with 55gr, usually cheaper and more plentiful.

Try out a few different brands to see what works good in your AR. I would recommend trying Federal AE, Wolf, Winchester Q3131, and S&B.  A few of this will likely work well in your AR.

Quoted: Yup check out the ammo oracle.... IMO go with 55gr, usually cheaper and more plentiful.

More plentiful? Seems like it's getting harder to find.

The ammo oracle is a valuable resouce. He is not God. Read him. Read other sites. Also, maybe someone here will add their original thoughts on this.

BTW, for some crazy reason, the US military issues 62gr,.... but of course, they're not the "ammo oracle".

Quoted: Quoted: Yup check out the ammo oracle.... IMO go with 55gr, usually cheaper and more plentiful. More plentiful? Seems like it's getting harder to find. The ammo oracle is a valuable resouce. He is not God. Read him. Read other sites. Also, maybe someone here will add their original thoughts on this. BTW, for some crazy reason, the US military issues 62gr,.... but of course, they're not the "ammo oracle".

I'm totally with you, Mazeman.  The Ammo Oracle is great, but I get tired of everyone considering it the end-all and be-all of ammo info.  That said, I only directed him there because I thought it would answer his question re: twist rates.  I didn't mean to indoctrinate someone else

I'm an M855 and 75gr BH SMK man myself.

Quoted: Quoted: Quoted: Yup check out the ammo oracle.... IMO go with 55gr, usually cheaper and more plentiful. More plentiful? Seems like it's getting harder to find. The ammo oracle is a valuable resouce. He is not God. Read him. Read other sites. Also, maybe someone here will add their original thoughts on this. BTW, for some crazy reason, the US military issues 62gr,.... but of course, they're not the "ammo oracle". I'm totally with you, Mazeman.  The Ammo Oracle is great, but I get tired of everyone considering it the end-all and be-all of ammo info.  That said, I only directed him there because I thought it would answer his question re: twist rates.  I didn't mean to indoctrinate someone else I'm an M855 and 75gr BH SMK man myself.

i agree