6.5 Grendel build inspired by the military SPR Mk12

[spr mk12 mod 0]

Getting the barrel on will really start making this look like a rifle.

The barrel wasn't a light press fit into three different uppers like my last Proof barrel. I measured things to see how much "slopski" I'm dealing with. I have a .999" barrel and a 1.001" receiver. So there is .001" clearance around the barrel extension.



I've read tons about bedding a barrel with various compounds. Some say it helps, some say it doesn't but I don't recall anyone saying it hurts accuracy. So I'm giving it a try. The Loctite 620 is made as a, "retaining compound for cylindrical fitting parts with up to .008" clearance" so I'm trying it.

There are heavier duty barrel installation tools but my Geissele reaction rod seems to work fine for torquing a barrel to 40 foot pounds:



Here's my madness in progress. Reaction rod, receiver, barrel in the padded vise and angled downward for the excess Loctite to drip away from the receiver threads. The barrel nut has its threads and thrust face coated with Aeroshell 33MS grease. It's held at the ready with tape:



I always get nervous installing a barrel but once again it was simple. Apply Loctite, slide in barrel, wipe up excess (none of which went into the threads), hand tighten barrel nut and torque......done:



With the Geissele handguard I'm using there is no "timing" of the barrel nut to align any handguard mounting holes. Just torque it on and you're done.