Quoted:
All I need to finish my 18'' upper, is a rail and irons. I was gonna order a KMR15 but it's out of stock, should I hoard my pennies and wait for it to come in stock again or settle for the 13? My upper has an 18" barrel with rifle gas. Post pics if you have them
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I'd definitely go 15" on a rifle gas set up
V7 Weapons Systems let me add a 15" KMR to the cart plus they will sell you a Ti barrel nut with it if you want.....
Here is my 20" light wt rifle gassed with a 15" KMR
I just measured the KMR 15 rail and it slopes slightly backwards so that there is only about 1 inch of KMR covering the low profile gas block on a rifle gassed barrel....the 15KMR completely covers and protects
the lo pro gas block.
Here's a 14.5 mid gassed with a 13 KMR
13KMR on 20" upper
If you mouse over for a close up on the end of the rail you can see how much gas block is exposed with a 13 KMR on a rifle gassed barrel....the tube is protected though.
I prefer having the whole gas block covered that's just my preference.
15KMR on a rifle gas 20" BCM upper
If you click to make the pic larger you can see how much more the gas block is covered by the 15KMR