16", 18", and 20" Available Now!
16”, 18", and 20" Fulcrum .308 Win upper assemblies for LR-308 compatible rifles.
- Barrels are button rifled .308 Win chamber with 1:10" twist, 416 Stainless steel, fluted, and stress relieved
- Complete upper weighs 6.7 lbs
- 5/8-24 muzzle thread with 11 degreee target crown.
- Intermediate length gas system
- BAT Machine Barrel Extension
- Compatible with silencers from Elite Iron, AAC, Gemtech, YHM, Silencerco, and most others
- Aero Precision M5 upper receivers
- Forearms from Aero Precision and SLR
FULCRUM barrels have a larger overall diameter than our mid-weight barrels, but a smaller overall diameter than our heavy barrels. FULCRUMs are the only barrels on the market that are .825 diameter from the gas block to the muzzle, so you must use our proprietary FULCRUM gas blocks for now (more on that below).
All FULCRUM barrels are stress relieved 416R stainless steel and have precision made BAT Machine barrel extensions with M4 feed ramps. They are available now with threaded muzzles, with unthreaded on the way, and in both cases are cut with 11 degree target crowns.
So what do you get for these few extra ounces? A kick ass barrel. Here’s why:
The FULCRUM’s increase in diameter produces a barrel that is stiffer than our mid-weight barrels and has more surface area, both as a result of the larger diameter and the fluting. The increase in surface area produces better heat dissipation and a faster rate of cooling. The underlying increase in thermal mass also means FULCRUMs are less sensitive to fluctuations in temperature, which translates to more consistent shooting under all conditions.
The increase in diameter also pushes more mass towards the front of the FULCRUM barrel, which improves the harmonics and increases the overall stability and balance of the shooting platform. The extra mass decreases felt recoil, and its distribution increases the moment of inertia, which reduces angular acceleration for a smooth shot that helps you stay on target.
The preceding are all the reasons why standard heavy barrels shoot so well. The beauty of the FULCRUM is that you get all that performance from a barrel that weighs far less.
All FULCRUM barrels have a .825 diameter gas block journal, which means they will only work with Bison Armory FULCRUM gas blocks. There are no other .825 gas blocks on the market (yet). We didn’t design the barrels this way just to mess with you, we did it because it was the only way to achieve the optimal balance of weight and performance.
FULCRUM standard gas blocks are custom made to our specs by Elite Iron and SLR Rifleworks makes our adjustable blocks. We are very proud to have these outstanding US manufacturers work with us to develop this essential hardware. To learn more about Elite Iron visit their web page HERE and for more information about SLR Rifleworks visit their web page HERE.
Optional Bolt: We check every bolt / barrel for proper headspace before they leave our shop. For more information on our bolts click HERE.
Optional Bolt Carrier: Carriers ship assembled and include the gas key, firing, retaining and cam pins. If you purchase a bolt and a carrier, we will assemble the complete carrier group for you before shipping. For more information on our carriers click HERE.
Optional Gas Block Pinning: Only available for low-pro gas blocks. We drill and ream precise holes in the barrel and gas block then press-fit a dowel pin through so that the block will never shift on the barrel. Most military and police weapons are pinned. For more information on pinning click HERE.
More Information: Click HERE to see additional information about all our AR-15 barrels and other components on our “Product Information” page. If you are unfamiliar with AR-15 barrel maintenance and new barrel break-in, we encourage you to view our "Maintenance" page HERE for some tips on getting the most out of your firearm.
Shipping: In stock barrels (together with any additional parts ordered) usually ship within 5 - 10 business days from the date of purchase. Custom coating / bead-blasting and gas block pinning may delay shipping by a few days. We ship via UPS to addresses within the contiguous United States, and USPS Priority to Alaska and Hawaii.
Billing: Your credit card is charged for the full amount of your purchase at the time you place your order, not when your order ships.