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Posted: 1/11/2015 10:56:37 AM EDT
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Need some help, I have a RRA AR10. I am trying to reload with RCBS 308 WIN SB/TC AR die set. I have the trim length and the C.O.L spot on and it still will NOT load in the gun. die is set correctly in my Hornady single stag press. Don't have a clue what is wrong, HELP !!! |
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Quoted:
Need some help, I have a RRA AR10. I am trying to reload with RCBS 308 WIN SB/TC AR die set. I have the trim length and the C.O.L spot on and it still will NOT load in the gun. die is set correctly in my Hornady single stag press. Don't have a clue what is wrong, HELP !!! This is a common issue, and it's related to sizing the case, despite set up according to the instructions, and it relates to the cartridge headspace, the length of the case from the shoulder to the case head. A case with headspace less than a thousandth of an inch too long will either not allow the bolt to go into battery, when in battery, can't be extracted without mortaring the gun. The cure is a headspace gage, a drop in gage at minimum, or preferably a comparator such as the Hornady/Stoney Creek set. The first thing to do is insure the inside of the case mouths have just the barest lubrication. During sizing, the die body pushes the case shoulder back, and upon withdrawing the case from the die, the expander ball expands the neck. If the expander ball is not lubricated, it pulls the shoulder back out slightly upon withdrawal, decreasing the headspace slightly. Since you have loaded rounds that need to be corrected, there are two methods possible, and I can get back to that later after breakfast unless someone else describes the process. |
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AeroE's advice is the answer to your problem.
The best way to set your dies up falls into two categories: 1. Resize your brass so it will fit in anyone's rifle chamber, that means at least -.001" shorter than SAAMI minimum headspace. 2. Resize your brass so that it's at least -.003" shorter than it's fired measurement. That ammo will be resized to the minimum needed for use in your rifle. It may or may not fit in another rifle. Semi-Auto rifles beat the crap out of the brass. I recommend option 1 above because the brass gets stretched and it can alter your readings. In order to get an accurate measurement you need a cartridge headspace gage that tells you in .001" increments how to adjust your dies to reach these goals. Hornady's Lock-N-Load system is the best value because it works with dozens of common calibers. Mo DeFina's and RCBS's micrometer headspace gages are the best caliber specific gages, they are not cheap. |
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Quoted:
Thanks for the info, I have ordered a drop in head space device. I think this will fix my issue. I would like to ask, I have loaded rounds that I need to take apart. Can I take the deprimmer pin out of the die to just resize and not lose the primmer? Yes you can. You can also carefully deprime live primers if you want to and reuse them. Wear eye pro and be careful. |
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Quoted:
Thanks for the info, I have ordered a drop in head space device. I think this will fix my issue. I would like to ask, I have loaded rounds that I need to take apart. Can I take the deprimmer pin out of the die to just resize and not lose the primmer? The drop in gages are the least accurate unless your eyeball is calibrated in .001" increments. They actually cost more than Hornady's Lock-N-Load provided you already own a set of calipers. |
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Quoted:
Thanks for the info, I have ordered a drop in head space device. I think this will fix my issue. I would like to ask, I have loaded rounds that I need to take apart. Can I take the deprimmer pin out of the die to just resize and not lose the primmer? There's another way, but it's relatively expensive and if you're willing to break the cartridges down, that is the way to proceed. That method is to use a body sizer die, or a bushing type full length sizer die. There are two other less likely causes, but we ought to discuss those, too. The most common of those two is a neck that is just so slightly swelled by over crimping the case mouth. This is caused by roll crimps, which is how a standard seater die is set up, taper crimps won't cause this issue. If you are crimping the bullet, seat the bullet then add a crimp in a separate step. The crimp ring is disengaged during setup of of the die by turning the die body down until resistance from the crimp ring is felt, then backing the die body out a quarter turn or thereabouts. After the bullets are seated, then back the seater stem out so it clears the bullets, and turn the die body down to engage the crimp ring, then adjust to apply just a bit of crimp. If the neck swelled, then the crimp is too aggressive. Consider loading without a crimp for this rifle. The next problem that is less likely, because you most likely would have noticed, is a case that deformed at the intersection of the case body and the shoulder. This is caused by having the crimp ring in contact with the case mouth while seating the bullet, the die is basically trying to crush the case. Winchester, WCC, LC, and Lapua cases have shoulders that are hard enough to support some load applied this way, Remington cases will fold like a cheap lawnchair; this is one that caught me by surprise a long time ago. It's possible to seat and roll crimp in a single operation, but the set up is more hassle than it's worth in my opinion. Every case must be exactly the same length to achieve a uniform crimp, so if you're applying a crimp to improve accuracy, then there is no short cutting the trimming operation by reloading cases that are shorter than maximum length but not the same length. |
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