This affordable headspace gauge from Hornady Lock-N-Load Products (formerly Stoney Point) allows the handloader to measure changes to the headspace of cartridges with a dial/digital caliper. Different headspace bushing sizes (depending on cartridge family) insert into the Hornady Lock-N-Load Comparator Body, which attaches to a caliper. The handloader can then measure the changes between fired and sized brass. This enables the handloader to adjust his sizing dies for a proper cartridge fit in his chamber. When a handloader oversizes his cases it can cause excessive headspace problems, one of which will shorten the life of the brass.
A (.330") |
B (.350") |
C (.375") |
D (.400") |
E |
.17 Rem | 22 PPC | 6MM Rem | 223 WSSM | 6.5x284 |
204 Ruger | 22/250 Rem | 257 Roberts | 243 Win | 284 Win |
221 FB | 6PPC | 25/06 Rem | 243 WSSM | 7MM Rem Mag |
222 Rem | 250 Savage | 270 Winchester | 260 Remington | 7mm Ultra Mag |
222 Rem Mag | 7BR Rem | 7x57MM | 270 WSM | 300 WSM |
223 Rem | 280 Rem | 7MM-08 Rem | 300 Wby Mag | |
220 Swift | 30-30 Win | 308 Win | 325 WSM | |
30/06 | 338 Win Mag | |||
300 H&H | 350 Rem Mag | |||
7.62x39 | 375 H&H Mag | |||
6.5x55 Mauser | 264 Win Mag | |||
7MM WSM | 7MM SA UM | |||
30-40 Krag | 7MM STW | |||
300 RSAUM | ||||
300 Win Mag | ||||
300 Ultra Mag | ||||
8MM Rem Mag | ||||
338 Ultra Mag | ||||
35 Whelan |
Sinclair Bump Gauge Inserts are used to measure the amount of shoulder bump when setting up full length sizing dies. These Bump Gauges install in either the Hornady (formerly Stoney point) or Sinclair comparator bodies and are machined to fit particular shoulder angles of cartridges. Rather than measuring to the datum line, these gages indicate off of the shoulder of the case to get a better, more easily assessable measurement of how much you are actually sizing your cases. We usually recommend between .001" to .002" bump for bolt action rifles and between .003" and .005" for AR-15 type rifles. Also a useful tool for keeping your brass and loaded ammunition separated if you have multiple rifles chambered for the same cartridge and checking loaded ammunition.
Product-# | Shoulder Angle | Cartridge Suitability |
749011476 |
17 degree | 30-06 Springfield |
749011477 |
20 degree |
308 Family |
749011478 | 20 degree * | 338 Lapua Magnum |
749011471 | 21 degree | 220 Swift |
749011473 | 23 degree |
223 Family (222 Rem, 17 Rem, etc.) |
749011480 | 23 degree * | 6.8 SPC |
749011485 | 25 degree | Most Standard Magnums |
749011474 | 26 degree | 6MM Remington |
749011472 | 28 degree |
22-250, 223/243 WSSM, Some Ackley Improved |
749011484 | 30 degree |
17 Fireball, 22/6mm PPC and BR, 204 Ruger |
749011481 | 30 degree * |
7mm & 30 BR, Remington Ultra Mags Up To 338 cal |
749011475 | 35 degree |
284 Family, WSM Family |
749011482 | 40 degree |
Ackley Improved Up To 6mm |
749011483 | 40 degree * |
Ackley Improved Cartridges Up To 338 cal |
749011479 | 45 degree |
Wildcat Cartridges w/45° Shoulder |
* For larger shoulder diameters |
The most important use of a cartridge case gauge is for setting up 7⁄8"-14 press type full length resizing dies. A common error in reloading is to oversize your brass. Headspace of fired cases can
quickly and accurately be measured using this tool and a caliper.
Regular Style: This one piece gage will check overall length to indicate a need for trimming and datum to head length to assure correct headspace to prevent over sizing.
Adjustable Style: For belted mags. While the belt provides support for proper headspace, the life of the case will drastically shorten unless resizing is held to a minimum at the shoulder.
Pistol Max Gauges: Used to check all critical dimensions of the pistol case - mouth diameter, base diameter, rim thickness and diameter, case overall length and bullet diameter.
Regular Case Gauges | Adjustable Case Gauges | Pistol Max Case Gauges |
.17 Remington | 264 Winchester Magnum | 32 H&R Magnum |
.204 Ruger | 300 H&H Magnum | 32 S&W Long |
222 Remington | 300 Weatherby Magnum | 327 Federal Magnum |
223 Remington | 300 Winchester Magnum | 357 Magnum |
22-250 Remington | 338 Winchester Magnum | 38 Special |
22 Hornet | 7MM Remington Magnum | 380 Auto |
243 Winchester | 38 Super Auto | |
25-06 Remington | 9mm | |
260 Remington | 40 S&W | |
270 Winchester | 10mm Auto | |
30-06 Springfield | 41 Magnum | |
303 British | 44 Magnum | |
308 Winchester | 44 Special | |
338 Lapua Magnum | 45 Auto | |
300 Winchester Short Mag | 45 Colt |
This precision made tool allows a hand loader to quickly compare headspace and bullet seating depth within .001". The “Instant Indicator” lets you accurately check the headspace from the case
shoulder to the base in a couple of seconds. This information is critical for setting up your full length sizing die to allow the precise amount of shoulder bump. The use of a dial indicator with
this tool makes each measurement easy to read and also accurate. Using the Redding sizing bushing supplied, you can read seating depth for your cartridges.
The Instant Indicator enables you to compare bullets to each other by checking the bullet base to give dimension. This is a great feature for those wanting to sort bullets prior to meplat
trimming. Available with or without Dial Indicator.
Available for the following cartridges | |
.204 Ruger | 260 Remington |
222 Remington | 6.5/284 Winchester |
223 Remington | 270 Winchester |
22-250 Remington | 308 Winchester |
22-250 Improved | 30-06 Springfield |
220 Swift | 300 WSM |
243 Winchester | 300 Winchester Magnum |
243 Winchester Improved | 300 Rem Short Action Ultra Mag |
6MM PPC | 300 Rem Ultra Magnum |
6MM BR | 338 Lapua Magnum |
The "Range Adapter" makes this instrument more versatile and may now be used at the range or in the field without requiring the use of a reloading press.