Case trimming,annealling and tension

[tdroo]

Ive been dabbling in this shooting sport for about a year now and ive reloaded a couple times.Now im in the phase where im looking at my cases.(Winchester brass 45-70) Using a vernier the cases are measuring a little longer.When is time to trim them? Also ive read that they would need annealed. Finally this neck tension thing is a little confusing.Is their a way to measure tension?Do all these relate to one another. Thanks

[country gent]

Cases need to be trimmed when they are A over book specified length or as some do a close accurate chamber cast or measurement shows the actual chamber length allowed minus .010 length. The later is perfered by most. Be sure to also chamfer / deburr case mouths after trimming also. Use a tool or set up that insures a square true case mouth when to size. Annealing can be done several ways and will improve life of brass and accuracy at tmes. There are machines that do this with a tourch and low speed wheel. Cases can be stood up in a pan of water about 3/4" up the case and heated to color change with tourch by hand and knocked over. A socket that accepts the case head and extension can be used to rotate the case in the flame and on color change dropped into a pan of water. Another that works well is a lead pot set at 700*-750* dip lightly oiled cases into lead to depth wanted and when heated drop in water. I have a set up with a lymann big dipper 10 lb pot a stand in it and glass sand that I use for annealing. The sand never sticks to a case like lead can. Therack holds depth and alighnment consistently, the pot holds 750* consistently, and the top ring of 12 1/2" holes allows a consistent time / soak on the cases. The annealing machines are very consistent and accurate but also expensive to purchase. Plus is the only cases you handle are cool and once as they drop into the water bucket as part of the process. The 2 by eye and hand are not as consistent and can vary but what you see as color change and time doing it. As to measuring neck tension its not as easy to measure but you can experiment with it in several ways. Only size enough chamber / hold a bullet if your shooting a single shot then tensioncan start as light as a bullet that will still spin in the case. Increase this slightly bu sizing deeper into the sizing die thus increasing tension. A large expander can be purchased for your die set allowing it to be polished down in .001 incrementsto the sweet spot. Last is a sizing die that uses bushingto size the neck and bushing can be had in .001 increments. I perfer this as brass cases vary in thickness from lot to lot and brand to brand at times this allows "adjustments" to be made easy. Neck tension can make a diffrence in accuracy and consistency.brass hardness affects neck tension greatly.