Cci/Speer 4454 Bit #445-4, SD=.278, BT=.046
State-Of-The-Art Bits For The Gun Shop or Workshop
With Brownells MAGNA-TIP screwdriver, it is now possible for the gunsmith and firearms hobbyist to have a close fit in most any gun screw he will encounter – and darn near everything around the house and garage too.
DESIGN OF BITS
The TRUE hollow-ground bit transmits all the energy of twist (torque) evenly and smoothly, up the shank of the bit. Not only does hollow grinding permit this power transfer, it also gives complete metal-to-metal contact between the tip of the bit and the entire screw slot. Thus, maximum power can be exerted as in a finely tapered gun spring.
So-called “hollow-ground” screwdrivers which have been dubbed off square, result in all torque pressures concentrating at the square edge of the grind along the tip. As every gunsmith knows, such a flaw in a spring results in breakage! Standard, straight-tapered screwdrivers deliver all torque pressures to the fine edge of the screw slot. PLUS, being tapered, the laws of simple physics force the bit OUT of the slot.The complete sets include eleven bits for slotted screws, #1, #2 and #3 Phillips bits, plus ten hex bits for socket head screws.
You can get even more versatility, and an absolutely perfect bit-to-screw-slot fit by buying extra bits and grinding them to an exact fit using the special Shaping Stone shown on this page.
The bits used in the Brownells MAGNA-TIP screwdrivers are manufactured expressly for heavy industry. They are used in high-speed, production, impact-power drivers for setting screws in mass production applications. They HAVE to be built with the right combination of hardness and durability to give maximum strength and wear!
Additional part numbers for 429-240-GR MAG JSP BULLET: 76683044549 SPE4454 080-445-446WB