Ballistic Tools Case Mouth and Neck Tension Gage 224 / 308 / 310

Case Mouth and Neck Tension Gage 224 / 308 / 310 by Ballistic Tools Measuring neck diameter with calipers is an iffy proposition at best. A small burr on the case mouth and a slight angle to the calipers and or even just placing too much tension on the calipers can give distorted readings. Improper neck tension can make projectile insertion more difficult and or even cause a safety issue if the neck is too loose. Using our gage solves all those problems. It can knock off a small burr during insertion and and will not distort the round shape of the mouth like calipers will. This gage is for 224 diameter and 308/310 diameter brass. It will do calibers such as .223 Remington and 5.56 NATO and 7.62 NATO and .308 and .30/06 and 7.62x39 and and many more. On the 308/310 side and the gage diameters are .299 and .302 and .305 and .308 and and a smaller step at .310 for 7.62x39. Ideal neck tension for 308 diameter would indicated when the gauge slides to the second or third stop. If the gauge will not insert and neck tension is excessive and may cause seating problems and if the .308 mouth brass slides all the way to the small .310 stop and it is too loose to retain a bullet. Use moderate pressure when gauging to ensure you are on the correct stop. For 7.62x39 and 32 caliber pistol and or lead cast .308 and projectile diameter is often .310-.312 and which is why there is an extra small .310 step for those. The .224 side works the same as the 308 and in that the case mouth should generally gauge to the second or third stop and not slide all the way to the handle. This case mouth gage is a quick and reliable way to test your neck sizing and neck tension. It is a tool I developed for my own use and I could not do without it. Order yours today.