Rainier Arms is now selling the PinBlock, a lo-pro gas block that you pin yourself (instead of having a gunsmith pin it for you).
(pics at bottom)
http://www.rainierarms.com/?page=shop/detail&product_id=3939
Description:
Pinned Gas Block Kit
When building rifles, pinned gas blocks are definitely the way to go, but not everyone has access to a drill press or fixtures required to do it right.
With the PinBlock, practically anyone with a die-hard fixation on reliability can pin a gas block with as little as a hand drill.*
*Proper tools & fixtures are recommended, as is seeking the support of qualified gunsmiths.
Features:
Simplicity
Grooved Dowel Pins fit tightly without reaming, so you can install your PinBlock with less hassle. And they're plated black too, because we can.
Durability
Knurled Set Screws bite into the barrel for vibration resistance, and Loctite 262 (included) further insures that everything stays put. Critical dimensions are checked multiple times throughout manufacture and again before packaging. Noncritical dimensions are laughed at, and picked last for kickball.
Ease of Installation
With the Cobalt Drill Bit and dimpled pilot feature, pinning your barrel has never been easier.
Compatibility
The profile of the gas block has been optimized to fit within the widest variety of free-floated handguards and works for .223, .308, and most anything else under the sun.
Intent
The PinBlock was designed to be installed with the barest minimum of tools and resources. Think 'bunker scene' from Terminator. Hopefully you won't ever be in that position, wrenching rifles together for the resistance by candle-light, but if you do... we're here for you.
Specs:
Weight: 1.5 Ounces
Material: 17-4 PH Stainless Steel
Diameter: .750"