BCM rail weight vs OEM

[locknload223]

Does anyone have the weight difference going to a 13" BCM KMR Alpha from a stock M4 set up (USGI or Magpul handguards)? I'd be chopping the front sight post so really the only weight I'm losing is that and the handguards. Just curious what iincrease I'd be looking at.

Further investigation - It looks like the BCM set up with mounting hardware is 10oz total and my Magpul MOE carbine length is 6.8oz not counting sight post and barrel nut. So if these are accurate, looks like a wash. Not sure if BCM counts their barrel nut in that weight or not. Thoughts? Thanks.

[mtdawg169]

After you add the barrel nut and delta assembly weights, it would either be a wash or you might be slightly under the original weight. But you gained almost twice the handguard length and a whole lot more flexibility. Which is a win in my book.

[Uprange41]

The delta ring assembly is 2.4 oz, FSB is 5.2 oz. Add 6.8 oz for MOE, and the total weight is 14.4 ounces.

The KMR's weight includes the barrel nut, so adding ~3 oz for the shaved FSB (the chunk I have left from my FSB chop is 2 oz, and you also have whatever gets ground off, so 3 oz is my estimation), and you're at 12.9 ounces. Once you add a front sight to the KMR, it is somewhat of a wash.

[locknload223]

Thanks guys, that helps a lot. I installed a cheapo 15" eBay rail (15.2 oz per seller's auction) on another to see how I liked it. While that rail felt light in my hand, I'm sure it's heavy compared to the BCM. And of course it made the rifle feel nose heavy compared to my new Colt once installed, the reason for this thread. The KMR should be 5 oz lighter than my ebay rail. Thanks again.

[turnburglar]

I don't have the exact numbers: but I was VERY surprised how much weight I lost off the front of the gun going to a proper free float rail. Spend the extra $40 and buy a micro gas block. The front sight base, delta ring and hand guard caps weigh a lot compared to a barrel nut and micro gas block.

[locknload223]

I don't have the exact numbers: but I was VERY surprised how much weight I lost off the front of the gun going to a proper free float rail. Spend the extra $40 and buy a micro gas block. The front sight base, delta ring and hand guard caps weigh a lot compared to a barrel nut and micro gas block.

Those micros are light, no doubt. I just want a pinned block so I'll take the hit and chop my post. I may grind a little more off the front of this one, just beyond where the gas tube ends. What size rail and brand did you use? Thanks for the reply.

[locknload223]

I ordered a 13" KMR Alpha today along with some other goodies to fit my OEM-1. Thanks again!