Quote:
Originally Posted by HuntinGuy
Yes I'm just not sure why the shoulder is not hitting the chamber, maybe if I fire form the shells for the second time the case shoulders should be touching the camber?
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You are asking the right question and I will attempt to explain what is happening and how you can confirm that. There was a good thread asking why manufacturers are going to Non Belted cartridges where I tried to answer the question you are asking. If you did not get a chance to see that thread before it got blocked perhaps you can go back and find it.
This Saami drawing illustrates where the Minimum/Max HS is measured at 0.420" (shoulder datum). The Maximum Cartridge length, to the datum, is 2.1162" and the Minimum is supposed to be -.0070" or 2.1092". However manufacturers have been notorious for manufacturing belted and rimmed cases to minimum shoulder HS and in a maximum chamber, which should measure no more than 2.1353", this leaves a possible 0.0261". This is not uncommon and can be determined by measuring a new case and a fully fire-formed case and getting the difference.
However, as you found out, a low pressure load will not necessarily fire-form0.026" head-space out of a new case. I am assuming that you are using a fired brass in your measurements. If you have full Length sized your brass, with a minimum spec die perhaps you have already bumped the shoulder too far.
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The best way to determine what is going on is to get this Hornady Cartridge Headspace Gauge Bushing set and use your calipers to measure a new and once fired brass and compare these measurements against the Saami Drawings. The .420 bushing will get you close enough to determine if your brass is fireforming to your chamber. If it is not fireforming then back your die out a turn and FL the brass and them measure where you are at. The shoulder will likely move forward, at the datum, as you size the brass and if it does not touch the shoulder then load and fire again. The next time you FL the brass you may have to turn the die in to "bump" the shoulder.
This problem has been virtually eliminated in the 'Non belted" magnums as tolerance have been tightened up to where HS problems are virtually non existant. In fact they are so tight that some Factory Ammunition will not chamber,but that is another story.
Good luck and if you are able to come to Rimbey I can help you get started.
http://http://www.hornady.com/store/...h-Body-1-Each/