Armory Sponsor
Posted: 1/31/2009 3:29:21 PM EDT
| I have heard the rule of thumb was to full length size your brass for your AR. I was reading a book on reloading for AR's that you only need to size your brass about .003 under your fired brass length. Can anyone tell me how much a 223 is sized when full length sizing. I am guessing more than .003. For my bolt gun I neck size only until I need to bump the shoulder with a body die to make the brass last as long as I can. When it comes to autos the brass will never last as long as a bolt. Would sizing the brass less than what a full die do be worth it. |
|
Yes, it is worth it to know you are sizing your brass just enough. As you said a bolt gun can serve as it's own gauge. If you over size brass, the case is too "loose" in the chamber. When fired, the thinner front part of the case expands and grabs onto the chamber walls. The thicker rear (head) part is pushed back against the breech face. This streches the case wall and makes it thinner. Eventually the case wall splits and the case head can separate.
In addition to the RCBS tool, Hornady makes a headspqace gauge which does the same thing and is cheaper if you reload multiple calibers for semiautos or lever guns. |
|
Cut the neck and shoulder off of a fired case and chamfer it. Stick it over the neck of 8 or ten cases fired cases and measure the total base to base length with your calipers. Average the measurements.
Start with your die adjusted to neck size only and start taking it down, measuring the case in the above manner each time. When you get the .003 reduction in the shoulder length lock the die down. Check several of your first cases for length and then go to town. ( The fired cases you measure with must be fired from your gun of coarse). |
|
Here is just one way to do it............
http://www272.pair.com/stevewag/headspace/headspace.html and tools for some of the other ways........... http://www.sinclairintl.com/cgi-bin/category.cgi?category=REMTHT&type=store Aloha, Mark |
| How necessary is it to do all of this? I have loaded and shot a few thousand rounds by just adjusting my LEE dies according to the directions (If I remember correctly I screw the die until it touches the shellholder and then back it off half a turn). Should I be doing this differently or can I get by using my current method? |
| Alright, thanks for the advice. I'm all about accuracy, brass life doesn't matter much to me because I usually only get 2 reloads from once fired brass before I stop bothering to pick them up. How do I get this all going, in other words what equipment do I need? Also, 1 of my rifles has a 5.56 nato chamber and 1 has a wylde chamber, does this make any difference on how I set up my dies. The wylde chamber is the one that matters most as that is my main accuracy rilfe. |
|
the chambers are quite a bit different. You should set up the die differently for each but choosing the wylde I think would be the better of the two. The wylde is larger at the neck where it meets the
shoulder, has a larger shoulder dia. and has a longer neck and throat. every other dimension is smaller than the nato. the base to shoulder length is 1.4316 on the wylde and 1.4380 on the nato. |
Armory Sponsor