Why are 223/556 55 grain bullets so popular

[BigDmike]

Most of our AR 15's have a 16" barrel with 1/7 twist rate.
The most Popular bullet is a 55 grain FMJ bullet. Information I read states a heavier bullet is needed.
Heavier 223/556 bullets are harder to find.. Plenty of 55 grain bullets are available. Why is the 55 grain so popular? Are there that many bolt action 223 rifles out there with a faster twist rate?
I may be be completely wrong or confused about the whole thing. Let me know!

 

[jmr40]

55 gr was the original load for military 5.56. It is the cheapest and shoots well enough in most rifles. Heavier 62 gr bullets are pretty close in popularity IME. The original military M16's had either 1:10 or 1:12 twists which are much slower than more modern rifles. Those rifles shoot 55 gr and lighter bullets pretty well, but not heavier bullets. When the military went to heavier bullets, they needed a faster twist barrel. Traditionally most 223 bolt rifles used a 10 or 12 twist. But most newer ones are going to an 8 twist.

Your 7 twist is one of the fastest and is just barely adequate for 55 gr bullets but will shoot heavier bullets better. You won't get acceptable accuracy with bullets lighter than 55 gr. An 8 twist seems to be the best all-around and is what I see as the most popular. It does well enough from 50 gr to about 75 gr. If shooting heavier than 75 gr then a 7 twist or faster is needed. If you want to go lighter than 50 gr then you need a 9 twist or slower. But very few people actually shoot anything lighter than 50 gr or heavier than 75.

A good link with a chart showing best bullet weights vs twist.


5.56 Twist Rate Chart & Recommendations (ammoforsale.com)

 

[hdwhit]

I agree with everything jmr40 said, but just wanted to add that 55 grain bullets are so popular because they are 1) available, and 2) comparatively inexpensive.

 

[entropy]

Heavier bullets are recommended for 1:7 twist, they usually shoot 55 gr. just fine. Yes, you won't win Camp Perry with that combination, but mine shoot fine to 200 yards.

 

[Demi-human]

Why is the 55 grain so popular?

Because it is inexpensive. The economy of scale makes it so.

Are there that many bolt action 223 rifles out there with a faster twist rate?

Yes.

And even with a seven twist barrel, 50 grain bullets are perfectly accurate. Those and 75 grain being my favorite.

While the chart above is a decent overall guide, there are just too many options that work.

Some parameters don’t equate for all shooters the same. A Door-kicker-inner doesn’t care about the slight loss of accuracy at longer range with an over-spun bullet, like wise, a varmint hunter isn’t using tough jacketed FMJ bullets and does worry about bullet integrity at high RPM. A long range shooter will worry about his long bullets spinning fast enough to remain stabilized during their entire long flight.
While bullet jacket integrity is an issue at high RPMs, I don’t feel like bullet over-stabilization is a thing.

 

[kcofohio]

I haven't bought any .224" bullets in a while. I bulked up on them before stuff went bonkers. Mainly thanks to https://www.rmrbullets.com/.

But many times I found 62 gr bullets being offered at near 55 gr prices. Hornady's was quite common.

55 gr is like the 9mm 115 gr. Everyone makes them. But you can usually find 124 gr at near likeness prices if one searches for them.

 

[DMW1116]

I can’t say I’ve noticed any accuracy loss in lighter bullets vs heavier that is attributable to weight alone. My 1 in 7 twist 20” M16 A-Forgery shoots 52 grain Match bullets better than 77 grain Match bullets, though not by much. However it shoots 55 grain FMJ bullets quite a bit behind either of those.

In other words I don’t think the 1 in 7 twist rate matters that much for lighter bullets (shorter) vs heavier bullets (longer), as long as the bullet quality is comparable. Those 55 grain FMJ bullets are cheaper for a reason. Comparing them to 69-77 grain bullets virtually always means you’re comparing FMJ bulk bullets to HPBT match bullets. Parentheses indicate length of the bullet is the real consideration instead of weight. Since they’re all the same material, heavier bullets tend to be longer than lighter ones.

 

[Kaldor]

A quality 7 twist barrel will shoot a quality 55gr bullet with great accuracy. The limiting factor for twist rate isnt the bullet weight, but the bullet construction. Lightly jacketed varmint bullets will grenade if you over spin them, but a heavier jacketed bullet will hold together just fine. That being said, Ive pushed 50gr Vmax from a 7 twist at 3200fps with zero issues, and its pretty darn accurate.

 

[AJC1]

Cheap 55 grain bullets are so popular for the same reason as drum magazines, force reset triggers and bump stocks. The crowd here is precion based, my observations at the range say we're the statistical anomaly. Lots of guys at the range don't have sights of any kind. I'm not kidding.

 

[Kaldor]

Cheap 55 grain bullets are so popular for the same reason as drum magazines, force reset triggers and bump stocks. The crowd here is precion based, my observations at the range say we're the statistical anomaly. Lots of guys at the range don't have sights of any kind. I'm not kidding.

I love those guys! I used to pick up all their once fired 223 and 9mm they were shooting at the 17 and 7 yard lines!

 

[Bfh_auto]

A quality 7 twist barrel will shoot a quality 55gr bullet with great accuracy. The limiting factor for twist rate isnt the bullet weight, but the bullet construction. Lightly jacketed varmint bullets will grenade if you over spin them, but a heavier jacketed bullet will hold together just fine. That being said, Ive pushed 50gr Vmax from a 7 twist at 3200fps with zero issues, and its pretty darn accurate.

Plus one...
I've run 35-77 gr bullets. At full power 5.56 loads. The trust didn't seem to matter.
The only time I had a issue was 55spsx in 22-250 at nearly 4000 fps. Suddenly I had random ragged holes at 400 yards. I backed off 50fps and accuracy came back. The odd thing was it was still shooting good at 100 yards.

 

[DMW1116]

Cheap 55 grain bullets are so popular for the same reason as drum magazines, force reset triggers and bump stocks. The crowd here is precion based, my observations at the range say we're the statistical anomaly. Lots of guys at the range don't have sights of any kind. I'm not kidding.

Man I thought that was just me. I saw a guy a while back with a pistol frame for his Glock with no sights. He shot like 3 full magazines and hit a 14x8 target a dozen times or so at 10 yards. Scared the crap out of me. I asked his partner if he knew there weren’t any sights on it. I sure wasn’t going to ask him. No telling what he would have done.

 

[Fine Figure of a Man]

Scared the crap out of me.

What was scary about it?

 

[alsaqr]

55 grain bullets are relatively cheap, especially 55 grain FMJ bullets.

This year i will fire about 3 thousand .223/5.56mm reloads, all from rifles with slower rifling twist rates. Most will be loaded with 55 grain FMJ bullets.

 

[DMW1116]

What was scary about it?

The 36” group at 10 yards and the shots into my lane. Generally the lack of control.

 

[Charlie98]

I haven't bought any .224" bullets in a while. I bulked up on them before stuff went bonkers. Mainly thanks to https://www.rmrbullets.com/.

But many times I found 62 gr bullets being offered at near 55 gr prices. Hornady's was quite common.

55 gr is like the 9mm 115 gr. Everyone makes them. But you can usually find 124 gr at near likeness prices if one searches for them.

I've switched to the 62grn BTHP's, too, over the standard 55grn FMJ's. I don't load mass quantities of 5.56mm, anyway, I might as well spend a little more for better bullets.

 

[sisyphus]

inexpensive, shoot accurately out of a 1:8"

 

[Hooda Thunkit]

I've switched to the 62grn BTHP's, too, over the standard 55grn FMJ's. I don't load mass quantities of 5.56mm, anyway, I might as well spend a little more for better bullets.

I'm going to do the same. Well, after I burn through the thousand or so of the 55gr fmj that I have, which will take many months.
I just don't shoot a ton of 223. Using a bolt action may have something to do with that.

 

[kcofohio]

I can’t say I’ve noticed any accuracy loss in lighter bullets vs heavier that is attributable to weight alone. My 1 in 7 twist 20” M16 A-Forgery shoots 52 grain Match bullets better than 77 grain Match bullets, though not by much. However it shoots 55 grain FMJ bullets quite a bit behind either of those.

In other words I don’t think the 1 in 7 twist rate matters that much for lighter bullets (shorter) vs heavier bullets (longer), as long as the bullet quality is comparable. Those 55 grain FMJ bullets are cheaper for a reason. Comparing them to 69-77 grain bullets virtually always means you’re comparing FMJ bulk bullets to HPBT match bullets. Parentheses indicate length of the bullet is the real consideration instead of weight. Since they’re all the same material, heavier bullets tend to be longer than lighter ones.

Some time back I bought an RRA upper with a 24" bull barrel from a co-worker. He hadn't shot it much, only enough to zero the scope, and thought it was a 1/12 twist. So I threw it on a mil-spec lower and shot some 45 gr. Winchester USA varmint and some random 62 gr. reloads. The 45 gr. did really well (about 1 1/4" @100 yd.) compared to the 62 gr. (just under 2" @100 yd.), for the lower I was using. So I was convinced that it was 1/12 twist. Then I measured off 8" and 12" on a cleaning rod and found it is a 1/8 twist.

 

[derek45]

quality 55gr shoot fine out of a 1:7 twist barrel.

the tightest 100 yard group I ever shot was a 55gr VMAX loaded with surplus BLC2 powder.

Older rifles, like the Colt SP1 can't stabilize heavy bullets, but work well with 55gr because that's what the original design was.

I prefer 1:7 twist because I like 77gr SMK bullets, they buck the wind better on longer ranges, and flat out anchor coyotes and other varmits

 

[doubleh]

The most Popular bullet is a 55 grain FMJ bullet. Information I read states a heavier bullet is needed.

That depends entirely on what you intend to shoot with it. It is kind of the all around bullet for 223 but not always the best for the job. For long range you are better off with something heavier, for small critters something lighter. Then rifling twist has to be considered for accuracy. For playing close up games and plinking where accuracy doesn't have to be top notch the cheap 55 gr.FMJ is a good choice because of cost. For a lot of other things it isn't.

 

[entropy]

I took the sights off my PT145 and my G2C, I shoot better without them.

 

[N555]

55s are cheap. My 1:7 rifle doesn't shoot them very well, doesn't matter if it's full power or start load.

 

[rdnktrkr]

I surprised a friend when I let him shoot my 20" 1-7 AR with both 55gr and 62gr and the 62gr was a lot more accurate than the 55gr and then my 20"1-12 AR shot the 55gr a lot more accurate than the 62gr with either him or me pulling the trigger.
I have also found that either 55gr or 62gr sp bullets are more accurate than fmj and if on sale about the same price

 

[Walkalong]

I have also found that either 55gr or 62gr sp bullets are more accurate than fmj and if on sale about the same price

Yep.

My 1-8 AR shoots quality 50, 52, 53, & 55 Gr SP/HP/Tipped bullets very well. Would it shoot 69 or 75 Gr bullets better? Maybe, but those are rarely at sale prices I was able to buy 50 to 55 Gr bullets for. It might also shoot 69s & 75s better if it was a match barrel, vs simple a "good" barrel.

Bottom line is it shoots 50 to 55 Gr bullets well enough for me. I'm talking .5 to .75ish groups pretty consistently, which is plenty good enough to pop the hostage target paddle, the 3" middle plate, and run the 3", 2', & 1" mini KYL rack. Of course the better 55 Gr FMJ can do that much of the time.
So, how much accuracy do you need? What are you willing to spend on bullets for playing/plinking?