Reloading for the AR-10

[pyrotechnic]

Got a question or reloading for a Gas gun. I've been reloading for my .308 bolt gun for a several years now and am going to help a friend get started on a load for his DMPS AR-10. Got a couple questions.

Besides ensuring I fully re-size the brass (instead of just bumping back the shoulder) and seating the bullet to ensure it will feed from the magazine, is there anything else that I need to take into account?

Are the pressure signs going to be similar to that of a bolt gun, or is there something else that I need to be watching out for?

I will be loading the 190gr SMK with RE-15 and believe he's got Remington brass. I'm going to start a 36gr witch is just barely above the minimum load listed in the sierra manual. I'm currently running 43gr with the same components in my bolt gun. Anybody have any experience with this powder/bullet/rifle combo?

Thanks,

Maarten

 

[Pat M]

Re: Reloading for the AR-10

Get a set of match chamber dies, you may need them (my DPMS chamber is tighter than my PSS)

R15 and 175's are what my gun likes - ? never tried the 190's (i save them for my 300wm)

 

[JSTARSZ]

Re: Reloading for the AR-10

36 grains is way too low and a waste of time. I would start at 41 minimum and work up to 43 or 44.

 

[BCP]

Re: Reloading for the AR-10

What the above guy said, 36 grains might not cycle the gun.I would start at 40 and work to 42.

Edit: my experience with 190's was okay, 41.5 in LC brass. I prefer 175ish weight stuff though.

 

[pyrotechnic]

Re: Reloading for the AR-10

Thanks for the responses guys. I'm not sure where I started on my load development for my bolt gun I do believe it was around 39-40gr. 36gr did seem awfully low, but since I've never reloaded for a gas gun and its not my rifle I figured I'd start at published minimum. I'll start at 40gr and work up though.

Any pressure signs specific to AR-10's or self loaders to look for?

I'm going with the 190's because I have a bunch on hand and have had very good luck with them in my rifles.

Thanks,

Maarten

 

[BCP]

Re: Reloading for the AR-10

You'll see marks on the case head pretty clearly when you hit pressure.

 

[Falar]

Re: Reloading for the AR-10

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BCP</div><div class="ubbcode-body">You'll see marks on the case head pretty clearly when you hit pressure. </div></div>

If you mean the semi-circle/circular marks those are not signs of pressure. ArmaLite has a tech note on this and how it is caused by the ejector since extraction begins before all of the pressure has disspated from the chamber. I've noticed that lots of factory ammo does this in all of my ARs.

ETA

It is tech note #17

 

[shoepop]

Re: Reloading for the AR-10

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Falar</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BCP</div><div class="ubbcode-body">You'll see marks on the case head pretty clearly when you hit pressure. </div></div>

If you mean the semi-circle/circular marks those are not signs of pressure. ArmaLite has a tech note on this and how it is caused by the ejector since extraction begins before all of the pressure has disspated from the chamber. I've noticed that lots of factory ammo does this in all of my ARs.

ETA



It is tech note #17 </div></div>

Exactly right.

 

[citabria]

Re: Reloading for the AR-10

I was having trouble with my new gap ar-10 not extracting fired case and i had full length sized mine so i got a small base die and that solved the problem.

 

[BCP]

Re: Reloading for the AR-10

The little half circle mark is fine, the oh shit mark is the shiny line from primer with metal missing. Another good thing to do is take your shell holder to the range, I had some that looked perfectly fine but wouldn't go in the shellholder either warm or cold...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: citabria</div><div class="ubbcode-body">I was having trouble with my new gap ar-10 not extracting fired case and i had full length sized mine so i got a small base die and that solved the problem. </div></div>

Same I had about 1:10 resized LC brass that wouldn't chamber, small base die fixed that.

 

[JSTARSZ]

Re: Reloading for the AR-10

Blown primers out of their pocket or flattened primers is a big sign of pressure. Failure to extract can mean several issues.