Is M&P15OR (811013) a Picatinny Railed Gas Block or Same Plane System?

[dou2bleTap]

The product sheet says it is a "Gas Block with Integral Picatinny-Style Rail for Sight Mounting".

I'm looking at 2 different Troy folding front sights. One at Amazon is for Amazon.com : Troy Industries Front Folding Tritium M4 Style Battle Sight (Black ) : Rifle Scopes : Sports & Outdoors@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41EjuVC40qL.@@AMEPARAM@@41EjuVC40qL".

I think my M&P15OR is a same plan rail system and others here have said it is too. So now I'm confused with which one to get. Appreciate the help!

 

[Vinney47]

It can be both, and is in the case of your rifle. The OR has a same plane picatinny rail system

"same plane" means that the rails on the gas block are the same height (or on the same plane) as the receiver.

Picatinny is a style of rail, the style that all AR15 type rifles (which includes all M&P rifles) use. Picatinny rails can come in different heights. It is defined as a rail 20mm wide with slots every few mm to aid in attaching accessories. Weaver rails are very similar, anything meant for a Weaver rail will attach to a Picatinny, but not necessarily the other way around.

If the picatinny rail on the gas block is the same height as the picatinny rails on the receiver, then they are on the same plane, and hence "same plane rails". If the rails on the gas block of the OR were slightly taller than the rails of the receiver, then front and rear sights meant for "same plane" rails wouldn't work because of the height difference - they wouldn't line up right. I do not believe this to be the case on the OR model.

I do not own the OR model but I'm near certain that the rails of the gas block are of the same height as the rails on the receiver. Seeing as how OR stands for "optics ready", I can't imagine the gas block rails not being the right height for "same plane" sights, as that is what nearly all sights are.

Please see post #6 in this thread http://smith-wessonforum.com/smith-wesson-m-p15-rifles/274532-m-p-15-buis.html, where another member confirms that the OR is same plane rails. And remember! all rails for M&P rifles are Picatinny.

 

[dou2bleTap]

Thanks again Vinney47! I don't know what I'd do without this forum. All the googling made me more confused. Also thanks for articulating what picatinny is and mentioning that all rails for M&P rifles are Picatinny.