Why do almost all of the M&P 15's have 1 in 9" barrels

[LoneStarWings]

Hi,

I'm looking to buy an AR, and really want an M&P 15T. However, I'm bothered by the lack of 1 in 7" barrel. Only the most expensive aftermarket branded M&P 15 models (vtac, ts) seem to have the 1 in 7" barrels. Is it somehow cheaper to make a 1 in 9" barrel? Is there some advantage to 1 in 9" that I'm missing? Sure, must people probably use 69gr or lighter bullets, but it's my understanding that 1 in 7" will handle light bullets just as well as as slower twists while giving the owner good 75gr capability as well. I might buy a noveske instead due to the lack of 1 in 7" twist.

 

[Grog]

Sure, must people probably use 69gr or lighter bullets

Yes, that would be most people. Loads of people shoot 55/62gr stuff, and some like even lighter than that.

 

[Deaj]

Depends on the intent for the carbine. I'm perfectly happy with a 1-in-9 rifled barrel. My M&P15T handles 69gr wonderfully. This said 90% or more of the ammo I'll put through this will be 55gr and most often at 200 yards or less. If I had need/want/desire to shoot ammo heavier than 69gr then I would have to have looked elsewhere. I'm a bit of a Smith & Wesson nut so I'm glad the M&P15T fits my intended use!

Given the price and reported quality I'm seriously considering purchasing a Spike's Tactical LE series middy AR. While the Spike's comes with a 1-in-7 rifled barrel I'm still not likely to have any real world use for the faster twist. It's really a matter of personal preference and intended use.

S&W's new M&P15TS will have a 1-in-7 barrel. Since they'll be producing the barrels in both flavors it's conceivably possible that 1-in-7 or 1-in-9 could be a factory option for other M&P15's in the future or maybe they'll move to 1-in-7 altogether given its increasing civilian popularity (speculation only - the TS is a result of customer feedback, S&W is listening). While they're at it maybe they can drop the M203 notched barrel profile (now this serves no civilian purpose and it looks silly on a 16" barrel).