A Reader Asks About AR-15 Scope Mounts And Front Sight Interference

Reader Joe asks:

I’m Interested in purchasing the VXR Patrol, but want to make sure that my front iron sight post will not be in the way. Will a standard PEPR mount work, or do I need something else? Note: I’m shooting a Smith & Wesson M&P15 Sport.

Excellent question, Joe . . .

Many ARs (including yours and mine) are sold with fixed A2 front sights even though most of us put scopes or reflex sights on them. Removable or folding front sights are ideal for scoped ARs, but fortunately A2 front sights aren’t much of an optical obstacle for properly-mounted scopes.

As you probably know, standard A3 flattop rails aren’t high enough for most scopes or red-dots to co-witness with iron sights. EOTech holographic sights are an exception, since they’re tall enough to co-witness right out of the box. Most other optics will require some kind of riser mount to keep you from looking straight at the rear of your front sight tower, but these riser mounts are readily available and affordable.

This photo shows the VX-R Patrol scope you’re considering, mounted on standard medium-height 30mm scope rings and a $10 UTG riser. This solution is heavy and ugly, but it works. You’ve already hit on a much more elegant solution: a combination riser mount like the PEPR.

Burris’s ‘Proper Eye Position Ready’ mount shown here is designed specifically for AR pattern rifles, and it uses an offset scope ring to move your tactical scope forward and out of your eye socket. The PEPR is a great mount for around $100, but it’s not the only choice.

Leupold (the source of all things good and holy where optics are concerned) sells this bomb-proof Mk. 2 Integral Mounting System for about $150. At the lower end of the market is the $60 Primary Arms Deluxe AR-15 Scope Mount pictured at the top of the article. It has no frills and certainly no name cachet, but it gets the job done: Foghorn and I both trust it.

Any of these raised/offset mounts will lift a scope high enough to use with a fixed A2 front sight tower. The VX-R Patrol’s line-of-sight won’t clear the front sight completely, but you can barely notice it. The front sight will be dimly visible  in the bottom 1/3 of the scope’s field of view at the lowest power (and blurred to near-invisibility), and I can’t notice it at all at higher magnification.

My own AR wears fixed A2 front sights and a VX-R Patrol on the Primary Arms mount, and it works perfectly for me. The PEPR is a great scope mount for the AR, and the combination should work perfectly for your M&P15 Sport as well.

One last tip: if you do decide to go with the VX-R Patrol, be sure to order the PEPR with 30mm  rings.