Questions on reloading for semi-autos

[thejim2]

I had a few questions about reloading for semi-autos and I was hoping some people could provide some input. I've done quite a bit of searching the forums, but I havn't found anything that totally answers my questions:

I am reloading for a Rock River 223/5.56 AR and a DPMS SASS 308/7.62 AR. I am using RCBS small base dies for both calibers. I am playing around with different loads to try and find the most accurate. Once I find the most accurate, I am going to load that for a stock of ammo in case of a SHTF situatoin where ammo is not available. Given that, my priorities of importance are; 1. not exploding my guns, 2. reliablity in cycling/function, 3. accuracy.

So my questions are...
1: What is the best way to figure out the resizing length of my fired brass, should I just do the standard screw the die in till it touches the shell holder, then a little further, or should I do like bolt actions where I re-size just enough to get the round chambered. If I do the latter; 1. how do I make sure the bolt is closing forward all the way and not stuck back partially, and 2. will that reduce any reliability/consistency if im mixing once fired and new brass/will it cause less problems if I just resize the standard way.

2. what should my seating depth be? I understand I am limited to magazine restrictions, but should I be seating to standard oal, or seating a certain depth off the lands (or as close as the mag will let me). If I am to seat close to the lands, what is the best way do dermine that ogive length.

Thanks everyone for any input you can provide, I know that was a lenghty read but I wanted to be specific on what I was asking. Feel free to provide any other input you feel is pertinent, I've been reloading for a while, but I'm quickly finding out AR's are a different ball game.

 

[JGorski]

Re: Questions on reloading for semi-autos

I load for my son's RR Entry tactical and I set the dies(Redding) and theyre not small base dies either to just touching the shellholder and lock it in. I seat the bullets to manufactures specs or a bit longer or so they fit the magazine. Id say not to seat close to the lands since the faster burning powders youll be using with the 223 might create higher pressures whereas slower burning powder dont mind a short jump as much. If you want a good economical load, try 20-21grs RE7 with 55grainers, if you want more speed try 24grs Benchmark with the same 55s, I use Vmaxs with the Benchmark, 55fmj for the RE7 loads, 20grs with LC brass works best, 21 if youre using Rem, Fed or Win brass. Stay about 1 grain away from max loads. Hope this helps

 

[amk]

Re: Questions on reloading for semi-autos

I load for similar rifles as you have. I have found that ARs tend to be easier on the brass than my past rifles, as in the M1A. My brass does not tend to grow much after firing. Fired brass only tells part of the story tho, the brass expands during firing and then contracts a bit to allow for extraction, so measuring a fired case can be misleading, even tho there are plenty who do just fine and base their re-sizing on it. A gauge can tell you what your chamber is as in headspace needed, for instance, your 308 chamber could measure 1.632, you would want to size the case 1.630 or another thousandth smaller, to allow the case to expand slightly for reliablity for extraction, resize more than 3 or 4 thousands and your brass will not hold up as well, which could lead to failures as well. I have found my CLE chamber in my Ar15 reacts differently than the 308 ar10 chamber, it is relatively tight other than a long lead, the fired cases measure nearly the same as a fresh case, my ar10 brass grows 3 thousandths, so I knock the shoulder back 2 thousandths in my ar15 or so, and it is very reliable and consistant, plus the brass is not getting oversized. For reliablity, use a bullet with a cannalure and slighly crimp it, therefore you will not need to worry about how close the bullet is to the lands. It will be consistant and reliable, some say a crimp adds to the accuracy by just putting a consistant hold on the bullet, plus helps in reliablity.

 

[Squid284]

Re: Questions on reloading for semi-autos

For you AR15, I would look at samples of your fired brass and size the shoulders back .003", make some dummy rounds and make sure the bolt closes and locks 100%. COAL really depends on what bullets you're using.

Zediker's book on handloading for competition is a good one for you to read. Good book for bolt and gas gun reloading.

 

[BCP]

Re: Questions on reloading for semi-autos

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: thejim2</div><div class="ubbcode-body">
So my questions are...
1: What is the best way to figure out the resizing length of my fired brass, should I just do the standard screw the die in till it touches the shell holder, then a little further</div></div>

That's what I do and all my loads run 100%.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">
2. what should my seating depth be?
</div></div>

Mag length. 2.25" and 2.82" are the numbers I get with magpul mags in 223/308. Also seating them a little deeper usually pays off more than farther out at least for me.