Killer Instinct 405 Crossbows: Every 405 FPS Model Compared

Specifications below come from the product listings in the official Killer Instinct store (October 2026). Width is the cocked width; uncocked, the compound bows measure 18.75 inches and the X-Cam bows 10.375 to 10.75 inches.

How each one is cocked and de-cocked:

Kinetic energy is listed at 134 to 134.78 ft-lb across all seven, so none of them hits harder than the others in any way that matters on a deer. The differences are in width, weight, draw weight and how you cock and de-cock the bow.

Wide compound bows (Lethal 405 HD, Boss 405, Motive 405) measure 14.75 inches across when cocked and pull 210 to 220 pounds. They are the lighter, simpler and usually cheaper route to 405 FPS. The trade-off is width: in a tight blind or a small treestand the limbs take up real space.

X-Cam bows (Tempr-X, Tempr-X RDC, Boss-XDC, STX ProSeries) use Killer Instinct's synchronized X-Cam with 56% let-off. They are only 6.75 inches wide cocked and pull 190 to 195 pounds, which makes them easier to cock and easier to swing. They weigh a little more, and the RDC and STX versions carry built-in cocking systems that add weight again.

If you hunt from a ground blind or a lock-on stand, the narrow family is the one to look at first. If you want the least expensive way into a 405, start with the Lethal 405 or the Boss 405.

• Lowest draw weight and narrowest frame: Tempr-X at 195 lb and 6.75 inches cocked.
• No rope cocking at all: Tempr-X RDC (integrated crank) or the STX ProSeries, whose Gear-X drive draws and lets the string down with the handle.
• De-cock without shooting a bolt: Boss-XDC, which has the DC Triggerbox for hand de-cocking. On other models follow the de-cocking guide.
• Lightest to carry: Boss 405 at 6.7 lb.
• Longest power stroke: Tempr-X RDC at 15 inches, with the lowest draw weight of the group (190 lb).

For a ranking that includes the faster models, see the best Killer Instinct crossbow roundup.

These 405s are no longer in the official store's crossbow list but still show up at retailers and on the used market. Numbers are from the Killer Instinct 2024 product catalog.

• Fatal-X: Speed Ring 1.5-5x32 scope in the 2024 Elite package.
• Fierce 405: Lightest 405 in the 2024 catalog.
• Diesel X: Manual calls for 390-grain minimum bolts.
• SWAT X1 Elite: Crank included; shortest 405 in the catalog.
• Vital X (2024): The current Vital-XDC is rated 415 FPS instead.

Parts for these bows are still listed in the official store, model by model. See discontinued Killer Instinct crossbows for what is available for each.

Every 405 here uses a 20-inch bolt. The owner's manuals for the Lethal 405, Boss 405, Fierce 405 and Motive 405 set the minimum at 370 grains total (shaft plus point). The Diesel X and SWAT X1 manuals set it higher, at 390 grains. Current packages ship either 370-grain HYPR Lite bolts (Boss 405) or 390-grain Hypr bolts with the V-Track nock (Lethal 405 HD, Tempr-X, Boss-XDC).

Never shoot below the minimum in your manual: an underweight bolt behaves like a partial dry fire and can damage the limbs. Our bolt and arrow guide and the HYPR bolt page cover nocks, weights and lighted options.

Both threads come back to the same two topics: zeroing the second and third reticle lines, and bolt weight. The sight-in guide covers the first; the heavier-bolt question is fine as long as you stay above the minimum and re-zero.