Modern Machine Shop

MAR 2017

Modern Machine Shop is focused on all aspects of metalworking technology - Providing the new product technologies; process solutions; supplier listings; business management; networking; and event information that companies need to be competitive.

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Page 104 of 156

BETTER PRODUCTION Shops Using Technology 102 MMS March 2017 (LBT) designed for the small bores of 0.17-caliber rifle barrels. This tool is said to quickly remove reamer marks, waviness, tight spots and other imperfections left by upstream processes. The LBT features metal-bond diamond or cubic boron nitride (CBN) superabrasives for productivity, long life and fast cycle times. Precision-machined from through-hardened tool steel, the LBT can produce bore accuracies of 0.000027 inch for diameter, roundness and taper. Honing also quickly removes reamer scratches and surface waviness. A typical 600-grit abrasive can produce a 6- to 10-microinch Ra finish in a reamed barrel blank. By producing a consistent bore diameter of ±0.0001 inch or smaller, paral- lelism, roundness and e n d - t o - e n d s u r f a c e f i n i s h, h o n i n g y i e l d s more consistent perfor- mance from rifling but- tons and cutters, result- ing in a constant groove depth. Accurate barrel- bore geometry reduces t h e d i s to r t i o n o f t h e bullet shape during firing for improved gyroscopic stability in flight. A f t e r h o n i n g , t h e barrel is inspected again before rifling with a pull button. Pac-Nor makes its own Accu-Twist car- bide rifling buttons and can provide dif ferent rifling styles, including polygonal, per the cus- tomer's choice. A button is attached to a rod and the rod is pulled through the barrel. The com- pany's hydraulic rifling machine uses a CNC- machined twist bar with a h e l i x a n g l e t h a t matches the twist rate requested by the cus- tomer. The final t wist rate is confirmed after- ward using an electro- optical twist measure- ment system. T h e b a r re l i s th e n stress-relieved in a tem- pering furnace, followed Sunnen, call 800-325-3670 or visit SharpVue T a i l o r e d T o F i t • Designed to maximize efficiency and operator comfort. • Large working distance. • Crystal-clear HD image. • Connects to HD monitor or computer. • Imaging and measurement software included. • Magnification range: 30x optical, 300x digital. • Wireless remote included. Your Eyes Will Thank You I n s p e c t i o n S y s t e m Item # 26700-135-TTB 360 Tilt Table Item # 26700-135-XYTB X-Y Gliding Stage Item #26700-135-4D SharpVue 4D Lens Item # 26700-135 SharpVue Inspection System Watch V | 734-973-0099 |

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