How to make a precision load for AR-15 style rifles?

nchiker1

nchiker1

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In a bolt action, and the like, OAL is determined by the available space in the chamber. But what do I do when loading for an AR-15 or AR-10?

Assuming that the rifle is capable of sub-MOA, how would I determine OAL? Just go with the standard recommendation and work off of that? Do I need to sort bullets by weight, cases by weight/head stamp, or anything like that?
 
What I do in gas guns is typically run them mag length. I haven't chased the absolute in a gasser yet, but will start making a load shortly for a 6 creed once I clear the bench off and have a week at home.
 
If you determine how long you can seat the bullet before it touches the lands, and it leaves the bullet longer than mag length (2.260" for an AR15) then you can just seat to mag length, as long as there is enough bullet in the case neck. If you have a high twist rate (1:7") you can go up to 80gn bullets and seat them longer than 2.260", but you will have to chamber them like a single shot bolt action.
 
Toprudder;n81239 said:
If you determine how long you can seat the bullet before it touches the lands, and it leaves the bullet longer than mag length (2.260" for an AR15) then you can just seat to mag length, as long as there is enough bullet in the case neck. If you have a high twist rate (1:7") you can go up to 80gn bullets and seat them longer than 2.260", but you will have to chamber them like a single shot bolt action.
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Thanks Rudder! That's helpful. Just doing that, and working up the load, do you think I could get it to MOA (depending on my rifle of course)? Or would I need to get a little more in depth?
 
nchiker1;n81585 said:
Thanks Rudder! That's helpful. Just doing that, and working up the load, do you think I could get it to MOA (depending on my rifle of course)? Or would I need to get a little more in depth?
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Depends on the rifle, of course, but certainly possible. I've gotten less than 1 MOA doing nothing more than using matching headstamp brass (LC) and trying different bullets and charge amounts.
 
Toprudder;n82436 said:
Depends on the rifle, of course, but certainly possible. I've gotten less than 1 MOA doing nothing more than using matching headstamp brass (LC) and trying different bullets and charge amounts.
Click to expand...

Awesome - thanks. Been reloading for a few years, but I've never stepped too deep. We'll see how it goes!
 
With a gasser you will need to match the bullet shape to your chamber's parameters. Simply put you'll need to find the bullet your rifle likes at mag length.

There is quite a bit of work that goes into finding a good combo for a gasser. Just remember there is no need to wear a barrel out searching for something that isn't there.

Weighing brass, bullets, etc for a gasser just....Don't. Do use one lot of brass of decent quality. Lapua is great, Lake City, Winchester is one of my favorites, Nosler is really good. If I am using Lapua or Nosler I don't want to lose it, so keep that in mind if a match is shot, you will lose about a third if it's a common caliber.

You are not using a platform that will make it worth your time and effort. Find a match of some kind to shoot that is suited to your gasser and put good ammo downrange. Time spent shooting is magnitudes more valuable to shooting better groups or hitting more targets, than time spent obsessing over perfect ammo. I know that is not a popular sentiment but I have shot a lot of matches and won a few.
I don't tell you that because I just don't believe in obsessing over ammo. I have done all those things to my ammo, it has its place.

If you want all you can get out of your gasser out are going to have to single feed. That has its place even in a gasser. Slow fire portions of High Power is where I always used my best ammo single loaded. If all you are looking for is making the best group,then treat your gasser like a single shot bolt rifle and load up a long sleek bullet about .015" off the lands. Do not jam the lands in a gasser, unless you want trouble. I don't reccomend ever jamming the lands in anything. If you ever have to pull that cartridge out unfired you can end up with a mess.

Will a gasser shoot sub MOA? Sure, it can. It isn't as common as some bench jockeys like to believe though.

It's far more satisfying to be able to hit a 2 moa target at 600yds, than it is to show off a 5 shot group shot at 100yds.
 
The Green Heron;n85520 said:
With a gasser you will need to match the bullet shape to your chamber's parameters. Simply put you'll need to find the bullet your rifle likes at mag length.

There is quite a bit of work that goes into finding a good combo for a gasser. Just remember there is no need to wear a barrel out searching for something that isn't there.

Weighing brass, bullets, etc for a gasser just....Don't. Do use one lot of brass of decent quality. Lapua is great, Lake City, Winchester is one of my favorites, Nosler is really good. If I am using Lapua or Nosler I don't want to lose it, so keep that in mind if a match is shot, you will lose about a third if it's a common caliber.

You are not using a platform that will make it worth your time and effort. Find a match of some kind to shoot that is suited to your gasser and put good ammo downrange. Time spent shooting is magnitudes more valuable to shooting better groups or hitting more targets, than time spent obsessing over perfect ammo. I know that is not a popular sentiment but I have shot a lot of matches and won a few.
I don't tell you that because I just don't believe in obsessing over ammo. I have done all those things to my ammo, it has its place.

If you want all you can get out of your gasser out are going to have to single feed. That has its place even in a gasser. Slow fire portions of High Power is where I always used my best ammo single loaded. If all you are looking for is making the best group,then treat your gasser like a single shot bolt rifle and load up a long sleek bullet about .015" off the lands. Do not jam the lands in a gasser, unless you want trouble. I don't reccomend ever jamming the lands in anything. If you ever have to pull that cartridge out unfired you can end up with a mess.

Will a gasser shoot sub MOA? Sure, it can. It isn't as common as some bench jockeys like to believe though.

It's far more satisfying to be able to hit a 2 moa target at 600yds, than it is to show off a 5 shot group shot at 100yds.
Click to expand...

My end use for the rounds is for matches...I've done a lot of IDPA & the like, and would like to try carbine. So I know just what you mean when you say software trumps hardware.

Thanks for the help!! That clears some things up for me.
 
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