Originally Posted By alpha0815:
I definitely appreciate all the info here. I enjoy running drills and taking carbine courses and have run the finish off a BCM forged barrel. Just trying to determine if the KAC is a good choice to add to the stable.
Is there anything proprietary about the KAC barrel? What happens if you shoot out the barrel? Buy a complete new upper?
As mentioned above, the gas system is unique to the KAC SR15 line, so you would have to use the same gas tube.
Also, b/c it uses the proprietary E3 bolt, the barrel extension is unique to the SR15.
Basically, you can only use SR15 barrels.
I think I am one of the few people here who actually 'shot out' one of these SR15 barrels.
Back then, I was doing plenty of 90-150rds continuous mag dump with steel case Russian ammo, which has bimetal jacket bullet.
I shot exactly 4000 rounds of it through one of my SR15, as well as 8500rds of brass case copper jacketed ammo.
I noticed the rifle will start to 'keyhole' very slightly, or to be more informative, the bullets shot through the rifle will create non perfectly circular holes after 30-40rds of fire.
This is to be expected as LuckyGunner did a similar test which they've found about 4k rounds of steel ammo will wear out a barrel.
I sold the complete upper to another member, who then sold it to Geno.
KAC will not work on the upper as it was the older Mod1.
I think they can work on the Mod2, but IIRC it is a better idea to buy another upper and sell the old upper.
FYI, my current shooter SR15 Mod1 has 18,200rds of brass case copper jacketed ammo through it, and the barrel looks pristine.
At 300 yards, I was mostly getting ~1.5MOA 10rd groups using Magtech 77gr OTM, and occasionally ~1MOA 10rd groups.
Also, I emailed KAC about the barrel material and they did reply back saying "We do use materials that are named in the mil spec 11595".
I asked if they can specify which exact steel type in the mil 11595, but they can not disclose that information.
IMHO, the SR15 is the best factory built 'general purpose 5.56 rifle' currently available.
You should pick one up