This thing is pretty heavy for its size. I’ve been thinking about swapping out the KAC rail for something lighter, and possibly ff. I figure my options are a low pro gb and something like a KMR. But id kinda like to keep the fsp. What are my options?
The only way you will get any reasonable loss of weight is to get a LW barrel, and a KMR or similar rail. You could also consider an Aimpoint H1/T1 and replacing the VFG with a direct attach BCM grip.
BCM offers the KMR in a 7" length now, don’t they? That would allow you to retain your FSB at least.
KMR7 will let you keep the FSB. The RAS and barrel nut, delta ring assy., and handguard cap is 14oz, IIRC. A KMR7 with its barrel nut is 5.2oz. So, over half a pound right there.
You can also drop the PRO and move to a Micro, which’ll cut the optic weight by about half.
I guess you could swap the stock for a BCM or MFT, but you’d only lose a couple ounces at most… The handguard and optic changes alone would make a significant difference.
I had the same issue with my mod 1… Rather than changed parts I’m build a another SBR with on LW parts.
Wow! Kmr 7 looks pretty promising. Thanks fella!
I would ditch the FSB too…
OP, if I can ask- without mag, exactly how heavy is it?
What is the total weight as is?
ETA:already asked.
What light are you using? There are lighter options.
There are lighter optics, rails, VFG’s, BUIS’s, slings, and sling attachment points, to name a few. Some will save a little weight, while some will save more, but you could easily shave over a pound if you really wanted to. The two biggest weight savings I see are also the two most expensive, and that’s optic and rail.
KAC M4 RAS - 11.6 oz plus factory barrel nut (2.0 oz), delta ring/spring (.6 oz) - 14oz total
BCM KMR7 - 3.0 oz excluding mounting hardware (2.2oz) - 5.2 oz total
Net savings of -8.8 oz (+/- .1 as I’ve never weighed a delta ring and spring and found conflicting .5 vs .6 results)
Optic looks like a Pro, which ironically is also listed at 11.6 oz with mount. The T-1 body is (also ironically) 3.0 oz, plus whatever mount you chose. For lightweight, the DD Micro mount (lower 1/3) is 1.8 oz.
Pro - 11.6 oz total
T-1 plus DD mount - 4.8 oz total
Net savings of -6.8 oz.
So, those two items alone will net about a pound (15.6 oz) in savings. That said, a T-1, mount, and KMR7 will cost you almost a grand depending on what you can find plus shipping. This is also assuming you have the knowledge and tools to do the work yourself. The real question is, what’s it worth to you? As others have asked, what does it currently weigh without a mag? I’d guess around 7lbs.
Holosun RDS is a great alternative to Aimpoint Micro for range use for 1/3 of the price…
If your willing to get rid of your FSB you can save even more weight. I don’t have exact numbers, but when I swapped my FSB for a micro GB, I was blown away how much weight I was losing off the front of the gun. Any newer light weight rail, with a good BUIS would make ALOT of weight come off the front of the gun.
Get a gym membership and lift weights?
It’s already an sbr from the looks of it.
I’ll be that guy and say 10 or 20 rd mags… There. Boom. Weight loss with a mag change. Cost, 10$.
Save about 4-5 oz per 10 rds dropped.
Not to high jack the OPs thread but I think it would be nice if we could put together a matrix of sorts with actual weights of items. StraitR mentioned the PRO was listed at 11.6 oz. I was shocked, didn’t think it weighed that much, so I took mine off and weighed it, 12.85 oz. with mount and flip covers. I’m not that OCD about weight, but I’ll shed some ounces if given the chance. Just would be nice to have a place to go to to easily look up some accurate and actual weights of items before I buy.
Yes, your that guy, LOL.
Which stock is that? Of the SOPMOD style the Bravo is lightest followed by the regular b5 SOPMOD than the LMT which is significantly heavier than the B5s.
That could save you a few OZ but the majority or the weight is in the upper. If your going to get a new barrel and handguard might as well get a entire new upper assembly.
LW profile barrel. MI/BCM handguard w/ key mod or mlok, low profile GB, slick side upper receiver
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Looks like a B5 SOPMOD Enhanced, which is considerably lighter than either the LMT or B5 standard SOPMOD.