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Reload Specs I am Using

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Replied by foxhunter on topic Re:Reload Specs I am Using

click on categories and go to the reloading section in the forum. There is a lot of good discussion on reloading the ar10. Hank From Arkansas has a discussion on small base dies, and I think some of your other questions are answered there. There is a reference to a good article in Western Shooter that might give you some good info as well.
15 years 2 months ago #1056

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Replied by Scaup58 on topic Re:Reload Specs I am Using

Hillbilly1053,

SAMMI has a spec. for each cartridge that describes all of it's dimensions including +- tolerances. Your RCBS std full length die restores the case to somewhere within these tolerances. A small base die is built to restore the base diameter to the - tolerance guaranteeing a fit in any SAMMI spec. chamber. If you can chamber a re-sized case and extract it by hand then you don't need a small base die. Do this by dropping case into open chamber and then closing bolt as an empty case will probably not feed from a mag as the mouth will get caught on stuff. Head space can be measured several ways. Several gauges are made of cylinders that set on the shoulder of a bottleneck case. You then use a caliper to measure from case base to opposite end of gage. You measure a case fired in your chamber and compare it to a re-sized case. The goal is to have your sized case to be .003 - .004" shorter than the fired case. To achieve this, you back your size die away from the shell holder, best done with precision shims under the die lock ring or with shell holders ground to different heights such as Redding's competition shell holder sets. This is more of a bolt gun thing when searching for the last .01" of group size. Having said all of that, I tried to do this and found that if I backed my die off at all, the base didn't get reduced enough and my cases would stick in my chamber. As to crimping, your bullet seater has a reduced diameter ring at the top that will roll the neck end into a cannelure, the little groove around some bullets, in the bullet as the case is pushed up during the seat operation. You adjust the die up & down to increase or decrease the crimp or for no crimp at all if you so desire. If you try to crimp to heavy or into a bullet without a cannelure, you will buckle the shoulder. I don't crimp with the seat die, I use Lee's factory crimp die. It has a collet inside that squeezes the crimp onto the end of the case. You can't buckle a case with this die and you can crimp into a bullet without a cannelure, the die simply forces the bullet jacked into the core to accept the case crimp. This thing is awesome and downright cheap for what it does. I never crimped for my bolt guns but crimp everything for the AR. A side benefit to crimping is that you get a more consistent powder burn, the crimp holds the bullet longer early in the burn letting pressure get higher before starting to move. Smokeless powder needs enough pressure to burn at it's design rate and completely. Bolt guys achieve this by seating bullets out so that they touch or are just shy of the rifling lands at the end of the chamber. We don't have that option as the magazine dictates max overall length. Kind of long winded but I hope this helps.
15 years 2 months ago #1057

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Replied by bigwheel on topic Re:Reload Specs I am Using

You should go to armalites technical section and do some reading on headspace. Nato
and 308 are different. I believe it's pdf #69 and #60. If you are buying headspace gauges you need the info they provide. Not being able to cycle factory ammo doesn't sound like
a headspace issue but know way of knowing from here. Light loads, (you were asked if
the bolt locks open on the last round and I didn't see your reply? ) and or proper lube
are more likely culprits. I have an email into lyman right now to get their advise on how
a properly sized case for the ar10t should fit into their case gauge. From the price you
listed you must have a non t model which has a looser chamber.

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Last edit: 15 years 2 months ago by bigwheel.
15 years 2 months ago #1133

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Replied by Hillbilly1053 on topic Re:Reload Specs I am Using

Thanks to all who have been kinf enough to respond. I am getting better results from my AR as I get better at reloading. More questions...

Do any of you have an opinion about any variances between a NATO Spec 7.62 x 51 (recommended by Armalite) vs. the 308WIN (quality factory ammo also recommended by Armalite)

Accepting that there are subtle differences, do you reload by NATO specs or 308WIN specs? In other words, do you think metric vs inch units matters....
15 years 2 months ago #1134

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Replied by bigwheel on topic Re:Reload Specs I am Using

I believe the speer and the hornady load manuals have separate 7.52x51 loads now.
308 loads are hotter and you can cause problems by not being careful. In addition some
of the 7.62 brass is thicker reducing case capacity and making the pressures even higher.
It's an expensive mistake if you blow a case and or bolt, and your eyes are priceless.
15 years 2 months ago #1135

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Replied by Hank in Arkansas on topic Re:Reload Specs I am Using

When I first shot my AR10, I experienced some ammo feeding problems. My chamber is very tight. Various milspec ammo I tried worked fine, but some handloads I had on hand did not. Also, Wolf ammo didn't work. Handloads that worked fine thru my M1A wouldn't feed well in the AR10. I finally settled on a set of Redding small base dies, and very careful case preparation. I found a Wilson case gauge in .308 to be a great help. They can be had at Midway. Now the rifle is 100% reliable. I strongly suggest you get hold of the latest Sierra reloading manual, edition V. There's a chapter on reloading service rifles. Of course, it also has lots of listed loads. Finally, be very diligent in checking primer seating, making sure each is seated fully, just below the surface of the case head. I also find the Lee collet case crimp die to be the best crimping tool around. I doubt very seriously that you'll need to send the rifle back to Armalite. Good luck.
15 years 2 months ago #1136

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Replied by Hillbilly1053 on topic Re:Reload Specs I am Using

Thanks again to everyone. I have been reading alot! At first it was confusing. Then I got back to KISS. My AR is clearly marked 7.62 NATO. It is not a 308WIN chamber. With that being said, I bought an RCBS Precision Mic and started checking. I checked my last twenty rounds of hand-loads. They were brand new Nosler 308 brass. My AVERAGE headspace was 1.635. Right in the middlle of the ANSI standard. Dead on the GO guage spec.

So I am thinking that I am going to set my dies to load my next rounds to a headspace of 1.633. Does this this sound right? Comments?

I am also going to follow foxhunter's advice to check the reloading forum category...
15 years 2 months ago #1138

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Replied by Hillbilly1053 on topic Re:Reload Specs I am Using

Thanks bigwheel...
15 years 2 months ago #1140

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Replied by Hillbilly1053 on topic Re:Reload Specs I am Using

You are correct BW, I do not have a 'T'. Looser specs...
15 years 2 months ago #1141

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Replied by Hillbilly1053 on topic Re:Reload Specs I am Using

I am getting lock-back on final rounds. I am also paying closer attention to this...
15 years 2 months ago #1142

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