-
Forum Update: We've upgraded the software to improve security, performance, and the overall experience.
👉 Read why we made the change | Support the Forum
M&P 15 Caliber
- Thread starter russp1
- Start date
Register to hide this ad
dogzapper
Member
Hi Russ,
The most popular chambering in the S&W M&P 15 is the 5.56 NATO.
The 5.56 is actually the .223 Remington with a slightly longer bullet leade area. The 556 bullets tend to be heavier than are commonly used in the .223 round, hence the extended cut for longer bullets.
I'm a retired gun writer and I know the tech terms, but I'm trying to simplify it.
Commonly, the barrel rifling twist-rate is tighter in the 5.56. Where the average .223 has a 1-14" or 1-12" inch twist-rate, the 5.56s have a barrel rifling twist-rate of 1-9", 1-8" or 1-7", so as to stabilize the longer bullets. Personally, I prefer 1-7".
Can you shoot regular .223 ammo in a 5.56 rifle? Absolutely.
Shooting 5.56 ammo in the average .223 Remington chamber can be dangerous.
The 5.56 NATO (223 Remington) is simply a fabulous round and you will totally enjoy shooting it. The recoil is low and the fun factor is extreme.
For range use and for home defense, it's awfully hard to beat the Smith & Wesson M&P 15 in the 5.56 NATO.
You can spend a lot more money on ARs, but it is impossible to beat the incredible value of the S&W M&P 15.
My friend, you bumped into the friendliest, most civil forum on the internet. These folks are soooo helpful and to get a decent answer to any of your questions, all you have to do is ask.
Please feel free to contact me at any time.
God Bless You,
Steve Timm
The most popular chambering in the S&W M&P 15 is the 5.56 NATO.
The 5.56 is actually the .223 Remington with a slightly longer bullet leade area. The 556 bullets tend to be heavier than are commonly used in the .223 round, hence the extended cut for longer bullets.
I'm a retired gun writer and I know the tech terms, but I'm trying to simplify it.
Commonly, the barrel rifling twist-rate is tighter in the 5.56. Where the average .223 has a 1-14" or 1-12" inch twist-rate, the 5.56s have a barrel rifling twist-rate of 1-9", 1-8" or 1-7", so as to stabilize the longer bullets. Personally, I prefer 1-7".
Can you shoot regular .223 ammo in a 5.56 rifle? Absolutely.
Shooting 5.56 ammo in the average .223 Remington chamber can be dangerous.
The 5.56 NATO (223 Remington) is simply a fabulous round and you will totally enjoy shooting it. The recoil is low and the fun factor is extreme.
For range use and for home defense, it's awfully hard to beat the Smith & Wesson M&P 15 in the 5.56 NATO.
You can spend a lot more money on ARs, but it is impossible to beat the incredible value of the S&W M&P 15.
My friend, you bumped into the friendliest, most civil forum on the internet. These folks are soooo helpful and to get a decent answer to any of your questions, all you have to do is ask.
Please feel free to contact me at any time.
God Bless You,
Steve Timm
5.56/.223 is definitely the most common and cheapest (aside from .22) for a range gun and it's good enough for the military as a defense gun.
If you want to look into a fun gun that could also be used for hunting, range, and even defense, you might want to check out a .300 BLK (AAC .300 Blackout). They can be suppressed to be movie quiet. I have all three, 5.56/.223, .200 BLK/Whisper, and .22lr. I definitely shoot the 5.56/.223 the most and keep it cost effective with steel case ammo.
my_mp15-22_s&w
Member
5.56 or 22 for most all home needs. Bigger than that, wildcat a bolt action. Fun shooting at squishy things like oranges or grapefruits use 17 HMR bolt action. LOL
Last edited:
Ha !
So I'm comparing the base model M&P 15 (811000) to the M&P 15 Sport (811036) to decide if I want to go with the cheaper sport. Other than the rear sight, the only other thing that concerns me is that the Sport only shows 5.56 Nato while the standard shows 5.56 and 223. I definitely want to be able to shoot 223. Do all 5.56 guns also handle 223?
dogzapper
Member
Russ,
YES, all rifles chambered for 5.56 NATO WILL shoot .223 Remington ammunition with no problem.
The case dims are identical (SAMMI and CIP may show microscopic variation) ... it is only the leade, the area in front of the chamber that is relieved for the bullet, that is longer in the 5.56.
The .223 bullets typically have a shorter bearing area, so they use a shorter throating. Shooting the shorter bearing surface round in the long throated barrel is incredibly safe. You will absolutely have no problems shooting standard .223 ammo in the 5.56.
The reverse is not true. Not only is the 5.56 typically loaded to higher chamber pressure, but that bullet leade is working against you in this case. Do not shoot 5.56 ammunition in the typical .223 Remington chamber.
Not to confuse you, but there is a hybrid throating that is known as the "Wilde Chamber." The idea of the Wilde Chamber is to make the barrel safe for 5.56 ammunition and, at the same time, creating a decently short leade so that .223 ammo would shoot acceptably accurately.
Your Smith & Wesson M&P 15, no matter what configuration you buy, will have a 5.56 chamber. It will safely shoot both 5.56 ammunition and .223 ammunition.
By the way, I was the Lead Technical Feature Writer for Varmint Hunter Magazine for sixteen years, so I am vastly familiar with the .223 Remington, the 5.56 NATO, SAAMI and CIP.
Any other questions, simply ask away.
God Bless,
Steve Timm
YES, all rifles chambered for 5.56 NATO WILL shoot .223 Remington ammunition with no problem.
The case dims are identical (SAMMI and CIP may show microscopic variation) ... it is only the leade, the area in front of the chamber that is relieved for the bullet, that is longer in the 5.56.
The .223 bullets typically have a shorter bearing area, so they use a shorter throating. Shooting the shorter bearing surface round in the long throated barrel is incredibly safe. You will absolutely have no problems shooting standard .223 ammo in the 5.56.
The reverse is not true. Not only is the 5.56 typically loaded to higher chamber pressure, but that bullet leade is working against you in this case. Do not shoot 5.56 ammunition in the typical .223 Remington chamber.
Not to confuse you, but there is a hybrid throating that is known as the "Wilde Chamber." The idea of the Wilde Chamber is to make the barrel safe for 5.56 ammunition and, at the same time, creating a decently short leade so that .223 ammo would shoot acceptably accurately.
Your Smith & Wesson M&P 15, no matter what configuration you buy, will have a 5.56 chamber. It will safely shoot both 5.56 ammunition and .223 ammunition.
By the way, I was the Lead Technical Feature Writer for Varmint Hunter Magazine for sixteen years, so I am vastly familiar with the .223 Remington, the 5.56 NATO, SAAMI and CIP.
Any other questions, simply ask away.
God Bless,
Steve Timm
If you want the mil-spec look with dust cover and forward assist, get the standard. If those aren't important, sport. I wanted the full experience when I got my first one, so I got an optics ready version that comes with the dust cover and forward assist. I picked one up for $777 last July before everything happened.
jagular
Member
- Joined
- Dec 13, 2012
- Messages
- 448
- Reaction score
- 247
It's great that you are asking questions about your first AR. Google M&P 15 Sport and look for Nutnfancy's YouTube review on the Sport. He raves about its value and the irrelevance of a dust cover and forward assist. The Sport is a great value for a great shooting AR.
gunny4053
US Veteran
Buy the Sport, then spend the $300 you saved on more mags and ammo. 
The bolt assist and dust cover are features which serve a purpose, but if you keep your weapon clean, the need for their use should never occur.
Good Luck and good shooting.
The bolt assist and dust cover are features which serve a purpose, but if you keep your weapon clean, the need for their use should never occur.
Good Luck and good shooting.
stavman11
Member
I have a Sport... love it.. more accurate than i am...LOL...
get it.... take the $300 savings and get a S&W 15-22...... Stupid Fun gun... all the same features, look and function as the AR15 Sport but in a .22... cheap ta shoot and REAL fun
Either way you will LOVE the gun.... be safe and have a BLAST!!!
get it.... take the $300 savings and get a S&W 15-22...... Stupid Fun gun... all the same features, look and function as the AR15 Sport but in a .22... cheap ta shoot and REAL fun
Either way you will LOVE the gun.... be safe and have a BLAST!!!
The difference between 5.56 ammo and .223 is that 5.56 is loaded to higher pressures than .223. Barrels chambered for 5.56 have a longer leade to deal with the higher pressure from the 5.56. When the bullet comes out of the case it will slow slightly as it engages the rifling, which causes an increase in pressure. The longer leade of the 5.56 chamber allows the bullet to travel slightly more before it encounters the rifling, which provides more volume for the expanding gas to fill, and therefore keeps pressure within the rifle acceptable. That's why you can have issues shooting 5.56 in a .223 chamber, but shooting .223 in a 5.56 chamber is fine.
BroadSideOfABarn
Member
I would just be careful using a .223 as a home defense weapon. Depending on the construction of your house, if you unload on a bad guy and miss, you could possibly kill a family member on the other side of the house or ventilate your house and kill a neighbor.
shawn mccarver
SWCA Member
- Joined
- Aug 21, 2005
- Messages
- 7,990
- Reaction score
- 7,039
With the right loads, this is not correct. Gunsite did some testing several years ago because of this often repeated statement.
Bottom line, use a hollow point "varmint" type load and you will not penetrate as much as most pistol rounds.
rojodiablo
Member
- Joined
- Sep 17, 2011
- Messages
- 1,759
- Reaction score
- 1,190
rojodiablo
Member
- Joined
- Sep 17, 2011
- Messages
- 1,759
- Reaction score
- 1,190
My uncle was AF. He was issues one of the original AR15/ M16.
No FA....... It was certainly mil-spec. Had the rockstar switch on it!!
cyphertext
US Veteran
So will 00 Buck, or 9mm, or .40 S&W, or...
Anything that is guaranteed to penetrate deep enough to hit vitals and cause a large wound channel is also going to go through sheetrock.
Arik
Member
Not the most common but still cheaper is the 5.45x39. 1080 rounds delivered for under $200. S&W does/did make an upper.
Sent from my SCH-I545 using Tapatalk 2
Similar threads
Latest posts
-
-
-
-
-
-
FINLAND - The Winter War 1939 -> NATO member 2023 - general matter about Finland
- Latest: S&WshooterFIN
-
-
-
-
-
-
