questions-reloading for AR's

[thejim2]

I also posted this in the "reloading" forum, just checking to see if I get any additional opinions in here:

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.

 

[mtrmn]

Re: questions-reloading for AR's

I own several AR's. In my experience(30 yrs reloading) I have always used the small base dies set the standard way. Touch the shellholder and then just enough to allow the press to cam over.
I always seat bullets to .010-.020" short of max mag length. This way my ammo works in every gun I put it in.

 

[Zachklr]

Re: questions-reloading for AR's

^^ what he said... I just FL size to be safe. Plus I havent lost any accuracy or speed that way

 

[wrhunter]

Re: questions-reloading for AR's

If I was reloading for a stash of ammo I'd pick up a Wilson case guage. Use it to set up your fl die and then spot check every 10-20 cases.

 

[jeff1383]

Re: questions-reloading for AR's

+1 on the Wilson case gauge...and pick up a hornady or Sinclair oal tool. Figure out the seating depth for different bullets and you won't have to guess on the sweet spot anymore

 

[leadbullet]

Re: questions-reloading for AR's

what mtrmn said plus a case gauge, sometimes brass develops a little burr on the edge of the rim, a case gauge will catch it and a light filing of that pesky burr will make it go in all the way.
cheers.

 

[mtrmn]

Re: questions-reloading for AR's

I also use a case gage--JP case gages for 223 and 308. These are made using actual chamber reamers whereas others (not sure about Wilson) only measure critical headspace and case overall length. The JP's measure ALL dimensions critical to your ammo fitting your chamber.

 

[fireEMT5]

Re: questions-reloading for AR's

I've been using a RCBS precision mic for .223 for my reloads shot out of my S&W MP15 AR.

What I did was take 20 empty brass that I shot through the gun and measured them with the mic. They averaged .004 over spec. I set my full length resizer to push them back to .001 over spec.

Have had zero problems with this method and I'm not working my brass any more than needed. Have fired several thousand rounds and not a single issue.

 

[USW.260]

Re: questions-reloading for AR's

Get rid of the small base dies...just use the regular dies. Buy a head space gage like from Lyman turn in the die untill the brass falls in the gage and is level with the back of the gage trim, load, shoot and repeat. I load for cmp matches and never have any problems. If I ever build Autos I will make a custom gage with the reamer that cut the barrel for the rifle that is used for sizing. Its soooo simple, don't worrie about measuring or micing or any of that. If the brass falls in and is level with the back then the bolt will close and the gun will run, if its not level then it won't. Simple.

 

[mtrmn]

Re: questions-reloading for AR's

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USW.260</div><div class="ubbcode-body">Get rid of the small base dies...just use the regular dies. Buy a head space gage like from Lyman turn in the die untill the brass falls in the gage and is level with the back of the gage trim, load, shoot and repeat. I load for cmp matches and never have any problems. If I ever build Autos I will make a custom gage with the reamer that cut the barrel for the rifle that is used for sizing. Its soooo simple, don't worrie about measuring or micing or any of that. If the brass falls in and is level with the back then the bolt will close and the gun will run, if its not level then it won't. Simple. </div></div>

If you get out your Lyman gage and find a drill bit that corresponds to the hole size in your gage, you will find the hole in the gage is STRAIGHT--not tapered like your chamber. Yes, they are good for checking the headspace and overall length dimensions, but they don't check EVERY dimension of the tapered case wall. Something out of spec other than headspace and your ammo may be troublesome in the chamber. Over-crimping to the point of bulging a shoulder comes to mind as one example. Just sayin' cuz I didn't realize the difference either for a long time.