Troy .936 Gas Block SGAS936OOBT00. 936 Low Profile Gas Block is made specifically for bull barrel rifles that have a 0.936 gas block seat. The Troy .936 low profile gas block works on both .223 5.56 and .308 bull barrels and other calibers. An option for users who desire to replace their default gas blocks or fixed front sight gas blocks to utilize a free float rail system that installs over the gas block. Machined from 4140 pre-hardened steel finished with MIL-STD Manganese Phosphate. Gas tube roll pin not included. Specifications for Troy .936 Gas Block SGAS936OOBT00: Manufacturer: Troy Size: 0.936 in Condition: New Country of Origin: USA Package Contents: Troy .936 Gas Block SGAS936OOBT00 The Troy .936 Gas Block SGAS936OOBT00 is a quality addition to the Troy Industries lineup. For more great deals on AR Gas Blocks by Troy Industries please browse our Troy Gun Parts page. Troy .936 Gas Block