I have a few of these (Block-Worx) upper block sets, they work with every flat-top I have tried them on (Standard mil-spec, Left hand (south paw uppers), 9mm, Vltor, LMT MRP… ECT.
They let you clamp the receiver sideways in the vice when you are installing or removing a barrel and hold it rock solid even on those pesky barrel nuts that require a bit more torque.
Plus you can use the bottom portion or the top portion to clamp the upper for stuff like cleaning, hand guard installs, scope installs… ECT… and you don’t have to remove the bolt and charging handle to use these blocks.
I’ll let one go for $39.99 shipped Priority.
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Email better than IM
