I'm a new guy on this group. Just put a M&P in jail today. It comes with a steel barrel. I'm concerned about the ammo to use. I was in the Army when the M16A2 was fielded. There was a safety message that came out about using the green tip ammo in the M16A1 and not to use in this weapon. However, the M16A2 could fire the A1 ammo and the green tip with the Chrome barrel. So, my question is this, seeing that my M&P has the steel barrel is it safe to fire green tip ammo in this rifle?
Many thanks,
Bill

I did a search but couldn't find it.

100% safe to use in you M&P. Your range may not like magnetic ammo though.

I believe the do not use in M16A1 came from the fact they originally had a 1:12" twist rate that wouldn't adequately stabilize the bullet. Since M855 (greentip) has a steel penetrator (which is less dense than lead) the bullet is longer and longer bullets need more spin to stabilize. In this case it likes at least a 1:9" twist or faster for optimum stability and accuracy.

That is my story... The A1 was well gone by my time. We had M4s

That covers it. The M855 round (NATO SS109 bullet) was originally designed for use in the M249 SAW, but the decision was later made to also standardize it for use in the M16. The very earliest M16s used a 1:14 bore twist, but that was a bit too slow to stabilize the M193's 55 grain bullet (standard at that time) in cold weather. Then the twist was changed to 1:12 which was OK for the M193 round with the 55 grain bullet. When the M855 round was authorized for rifle use, the twist rate was changed to 1:7 for the M16A2 which would stabilize not only the M193 bullet, but also the longer and heavier M855 SS109 bullet and the M196 tracer bullet. Actually for the M855, a 1:9 twist would be OK for stabilization, but not so good for the even longer M856 tracer bullet. And that's why a 1:7 twist is used - because of the M856 tracer round. In short, you can fire both M193 and M855 rounds in an M16A2 or any other rifle with at least a 1:9 rifling twist.

Do not expect match grade accuracy from green tip ammo. 55 ball shoot better in my rifle. Mainly I believe because it lack the third component the steel penetrater in the tip of the SS109/Green tip.

Good luck

Jerry

Yes, it is safe to use green tip in your rifle. If you can get it to go off, that is. In my experience, green tip has such hard primers that my AR, let alone my .223 bolt rifles, would only set off roughly 4 in 10 rounds. Plus, those rounds that did go off were VERY inaccurate in my rifles.

I had 1000 rounds of the green tip on hand....so I ended up pulling down all of it, re-priming the cases and reloading it with a powder I already used (IMR-4895). The bullets are actually quite consistent.

With my green tip reloads, I get about 1" groups at 200 yards. That is, with my .223 bolt guns. My AR was never that accurate.

So, the bullets (and brass) are not bad at all.

The answer you are looking for depends on your rate of twist your barrel has.
In Vietnam, Nov. 1967- Nov.1968 the M-16, Pencil barrel, 1/12 twist,, 55 gr. bullet.
1/7 twist = 62gr. (Green Tip) or Higher. U.S. Military.
1/8 twist=??, not sure. I believe 55 gr.
1/9 twist = 55rg., no 62gr. The bullet will spin too fast and loose accuracy.
My Colt M-4 M.P.C. has 1/7 twist.
My custom built, Colt Match Barrel has 1/9 twist. Non-Chrome Lined match Barrel.
The rate of twist will determine what weight bullet to use.
I have to use two different types of Ammo.

Bulk ammo is not very accurate, regardless of what color is painted on the tip.

HMMM, I had no problems getting the ammo to go off in my Mini-14. Now accuracy, that's a different story. I won't be buying any more of it.

First time I have ever heard anything like that. I have fired hundreds of thousands of rounds of M855 ammunition in about every rifle (both military and civilian) made for the 5.56. I have never experienced misfires. All U. S. military ammunition is made with less sensitive primers to prevent slamfires, although that is not as much of a problem today as it was back in the early days of the M16.

M855 is typically 2+ MOA. You don't use the terms "green tip" and "accurate" in the same sentence.

I'm wondering if K-framer lightened his trigger and hammer springs in an effort to lighten the typical military trigger pull on an AR?

I built an AR style rifle with a 1:9 twist and it shoots 62gr bullets just fine. I get better accuracy with them than with a 55gr bullet.

As a matter of fact I can shoot 62gr bullets in my 1:12 twist bolt action rifle too. A 1:9 twist barrel will most times stabilize up to a 75gr bullet depending on the bullet length.

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Howdy;
Been playing with these for a while- built my first just prior to the Bush Ban ( AKA Brady) . Have not found bulk pack ammo of any wt to give what most of us expect as "good" accuracy,. though some aqre closer than others. That first AR I built was a plain A-2 configuration; Colt had come out with their A-3 upper ( removable carry handle ) H-Bar , which was noce, but too rich for my wallet at the time. Equipped mine with a 1:9 twist barrel; handled 55 gr just fine, which was all we saw back then, except for handloaders, who had a variety of lighter bullets on the whole. Does well enough with 62 gr "Green Tip", but not my fav in non-match factory bulk ammo . To contrast, my Never Ending Project AR, a heavy barreled varmint style configuration, with a 1:8 twist and a chamber described as something other than "match" .223, or even "Wylde", LOVES the Winchester Match load with 69gr HP bullets, making pretty , tiny cloverleaves at 100 yards from a sandbag rest. If I shoot Fed 62 gr Green tip bulk pack ( From Wally World ) , poor results; odd inexplicable flyers,to the extent that I first thought something was wrong with my rifle, like a cracked upper receiver at the barrel nut threads or some such. Not he case, just hates that ammo. A the ammo shoots "dirty" for me- far more cleaning effort required. I do have a kit, not yet assembled, which came with a 1:7 twist barrel. Cannot say I understand the widespread current use of the 1:7 twist on current guns, as it was brought out by the military ONLY to better stabilize the one, long, tracer round, at the expense of accuracy with others. YES, I do know that the fast twist is the cat's meow for heavy, long bullets that are used in Service Rifle competition- the ones that are so long when hand loaded that the rounds will not fit in the magazines , and must be single loaded by hand. THERE, the fast twist is proved to be right at home. Shoot 55 gr. ammo through that twist? I'm thinking over stabilized, at best, perhaps to the point where small imbalances in each bullet, inducing more yaw in flight, and actually ENLARGE groups with non match bullets, you know, the kind most people shoot.
Just my 0.02

Quite to my surprise, I found the Colt 1 in 7" barrels shoot several 53- 55-grain varmint or target bullets accurately, perhaps as accurately as the much longer bullets like the 69 MKs. However, these have been handloads.

I have not tried developing loads with any bulk 55 (or 62 if available) FMJ bullets, but suspect they would provide at least a little better accuracy than the factory bulk loads.

Many years ago (I think it was late 80's) Dad and I bought a couple cases of American Eagle 55 gr ammo. One case = 50 boxes of 20, 1000 rounds. It was supposed to be cheap bulk ammo. It is some of the most accurate ammo I've ever shot in just about every rifle I've used it in. I'm down to only a few boxes, but it was great stuff.

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You may use any weight bullet you choose in any Firearm you wish?
My experience with my Colt M-4, 16 1/2in. barrel, is the 62 gr. is more consistently accurate at 100 yds., using a burris scope than the 55gr.
I took off the scope and installed on my 20 in. barrel.I haven't had a chance to shoot this one. The verdict is still out?

Typically, you want to use lighter weights in slower twist rate barrels (1:9) , and heavier weights in faster twist rated barrels (1:7)

I have a 1:8 match gun that shoots knots with just about anything it's fed. Accuracy depends on the barrel quality much more than the twist rate until you start doing something goofy like 77gr bullets in a 1:12. If the barrel is smooth even the lightweights will shoot well in fast twist barrels without tearing the jacket and causing a blue trace.

There are some long-range shooters who believe that very fast twists provide superior grouping for bullets of any weight, i.e., there is no such thing as "overstabilization," and that's probably true. A bullet in flight is either stable or unstable. The only requirement is that extremely well-balanced bullets be used, and I think many of those shooters use solid brass or other copper alloy bullets, not jacketed lead core bullets. Those will also not come apart during flight due to centrifugal force. I have read that some use twist rates as high as 1:3".