The Troy Industries Troy Gas Block in .936 diameter is a low-profile solution for shooters running bull barrel rifles who want to ditch the fixed front sight and go free-float. If you're building or upgrading a precision rifle with a bull barrel that uses a 0.936 gas block seat—whether you're chambered in .223, 5.56, .308, or another caliber—this block lets you mount a full-length free-float rail system without obstruction. It's the kind of upgrade that separates a good rifle platform from a genuinely versatile one, especially if you're splitting time between different shooting disciplines or want maximum rail real estate for optics and accessories.
Troy machines this gas block from 4140 pre-hardened steel and finishes it with MIL-STD Manganese Phosphate, so it'll handle hard use and corrosion without complaint. The low-profile design keeps the package compact and doesn't add unnecessary bulk to your handguard area. Whether you're swapping out an older fixed-sight gas block or replacing a standard profile block on a new build, this one gets the job done without fuss.
Keep in mind the gas tube roll pin isn't included, so plan to source one if you don't have spares in the parts bin. Proper installation ensures reliable gas cycling, so don't skip that detail during assembly.
Key Features
- Machined from 4140 pre-hardened steel for durability and reliability
- MIL-STD Manganese Phosphate finish resists corrosion
- Low-profile design enables free-float rail installation
- Compatible with .223, 5.56, .308, and other calibers using .936 barrel seats
- Purpose-built for bull barrel rifles
Specifications
| Brand | Troy Industries |
| Gas Block Seat Diameter | .936 |
| Material | 4140 Pre-Hardened Steel |
| Finish | MIL-STD Manganese Phosphate |
| Compatible Calibers | .223, 5.56, .308, and other bull barrel calibers |
| Profile | Low Profile |
| Note | Gas tube roll pin not included |
Frequently Asked Questions
Will this gas block work on my .308 bull barrel?
Yes. The Troy .936 gas block is designed for bull barrels in .308 as well as .223 and 5.56, provided your barrel has a 0.936 gas block seat.
Can I use this block if I want to run a free-float rail?
That's exactly what this block is designed for. The low-profile design allows you to install a free-float rail system that passes over the gas block without interference.
What's not included?
The gas tube roll pin is not included with this block, so you'll need to source one separately if you don't already have one on hand.
What makes this different from a standard gas block?
The low-profile design and .936 diameter make it compatible specifically with bull barrel rifles and allow you to run a full free-float handguard, which isn't possible with a traditional fixed front sight gas block.
