Reloading unfired Semi-Auto AR 10 style rifles

[Mogas]

I started with a AR custom 6.5 Grendel then graduated to a Rock river 308 and now about to get started reloading for a Aero Precision 6.5CM. What I have run into (with all these AR's) is the Bolt being hard to eject my dummy rounds until I have run 30 0r 40 dummy rounds (from the magazine) in and out of the rifle. The first few dozen on both the Grendel and 308 were a bugger to eject using the charging handle. Eventually the rifle would get easier to eject rounds the more I used it. These are my first experience reloading these type of rifles. Is the normal ? All my experience with reloading is with bolt actions rifles. Any pointers reloading these Semi Auto will be welcomed.

 

[12Bravo20]

Are you using a full length sizing die?

 

[billybob44]

Be sure of your brass size on your "Dummy" rounds. Especially on a totally NEW action..A LOT of things need to break in..

For most AR actions, best to use a SMALL BASE Full Length Size Die for most all loads, untill
"Break In" is done..
I Small Base size all of my AR loads with good performance..Bill.

 

[billybob44]

Also be sure to note that a FIRED case opens everything up in a chamber=Unlike a Dummy round..
Make some live rounds, and SHOOT IT...HA.HA...Bill.

 

[Charlie98]

I built a 6.5CM AR-10 on AP parts for a friend... yes, it took a little persuasion to get the bolt open on the test rounds... until we ran about 200 rounds through it, now it's not a problem. First time out on any AR, -10 or -15, I hose the BCG down pretty good with CLP. Yes, it makes a mess, but it seems like it helps get everything moving, and allow it to wear in.

 

[MEHavey]

If a commercial round will chamber/hand-eject without problems, then "breaking in the rifle" * is irrelevent.
You have a reloading problem.
(Either in sizing, or in simultaneous seat/crimp shoulder bulge)

- Full-length resize** (and test empty case for load/eject)
- Don't crimp at all. (Not req'd)



* No 'break-in' is ever going to wear clearances associated with cartridge fit enough to fix the problem.
** Sizer/shell-holder contact + 1/8 turn/cam-over in a non-springy press

.

 

[papajoe222]

If it's factory new brass you're using for dummy rounds, full length size it first.

 

[Thomasss]

Did you bother to clean the entire rifle with a good barrel wash like Hoppes or CLP before playing with your new toy. I was surprised at how much clear preservative was in every nook and cranny on my Bushmaster 5.56 before I shot it for the first time. Lucky I wiped it down and lubricated it while listening in detail to a Desert Storm Vet.

 

[Kaldor]

I started with a AR custom 6.5 Grendel then graduated to a Rock river 308 and now about to get started reloading for a Aero Precision 6.5CM. What I have run into (with all these AR's) is the Bolt being hard to eject my dummy rounds until I have run 30 0r 40 dummy rounds (from the magazine) in and out of the rifle. The first few dozen on both the Grendel and 308 were a bugger to eject using the charging handle. Eventually the rifle would get easier to eject rounds the more I used it. These are my first experience reloading these type of rifles. Is the normal ? All my experience with reloading is with bolt actions rifles. Any pointers reloading these Semi Auto will be welcomed.

All ARs bolts move a little difficult when unlocking when new. Its just the nature of the system. Once you get a couple 100 thru it and the bolt and lugs find their home, it will move much easier. Oil it up and shoot it.
If using an adjustable gas block, you may have to open it up a little bit until it finds it home, but once broken in, youll likely be able to turn the gas down a bit and it will still cycle fine.

 

[GW Staar]

Every brand is different. I have a Remington R25 AR10 clone.....and it requires small base dies. My chamber at least, does. Very accurate whatever they did. Not at all loosey like most go to war rifles......more for hunting. Heavy....I wouldn't want to carry it all over the mountains and certainly not all over the Ukraine, but it's fun to shoot.

I probably wouldn't have chose it, except that I bought it the day after Obama bin Biden was elected, and it was the last AR of any kind left in the city.....and I wanted a AR-10 for Christmas.

The first indication of a tight chamber was that Federal Factory cheap blue box, would only feed the first round. Of course Remington factory fed and shot like a champ.

Testing with a black magic marker determined it was a diameter problem very near the base.

Found a little vid on youtube on my rifle....gives an idea how an R25 shoots.....and maybe indicative of any AR-10 clone. They don't recoil like an AR15, do they!

 

[Jeff H]

* No 'break-in' is ever going to wear clearances associated with cartridge fit enough to fix the problem.
** Sizer/shell-holder contact + 1/8 turn/cam-over in a non-springy press
.

Agree with this.
I had issues with some brass when resized on a progressive. Changed my process so that my rifle resizing is done on a Rock Chucker and all of my brass drops beautifully into the cartridge gage now. Do you have a cartridge gage? They are handy things to have.

 

[Charlie98]

Do you have a cartridge gage?

Cartridge gauges are not the end-all, either. I have a Wilson .308 gauge... my fired M1a brass will drop right into it without problems. If I'm not mistaken, my Wilson gauge is really only supposed to measure case length off the shoulder, measuring both neck length and headspace, not necessarily all SAAMI case dimensions... I didn't know that at first... so it depends on which specific gauge you get.

 

[Jeff H]

Cartridge gauges are not the end-all, either. I have a Wilson .308 gauge... my fired M1a brass will drop right into it without problems. If I'm not mistaken, my Wilson gauge is really only supposed to measure case length off the shoulder, measuring both neck length and headspace, not necessarily all SAAMI case dimensions... I didn't know that at first... so it depends on which specific gauge you get.

Fair point, but the OP is getting cases sticking in the chamber and using the charging handle to pull the sticking case out. If this is the way he is gauging loaded rounds, a case gauge, any gauge, will be a step up. I personally have the Hornady gauges .

 

[bigpower491]

Be sure of your brass size on your "Dummy" rounds. Especially on a totally NEW action..A LOT of things need to break in..



For most AR actions, best to use a SMALL BASE Full Length Size Die for most all loads, untill

"Break In" is done..

I Small Base size all of my AR loads with good performance..Bill.

Exactly

 

[Charlie98]

If this is the way he is gauging loaded rounds, a case gauge, any gauge, will be a step up. I personally have the Hornady gauges .

I understand what you are saying... and I was not criticizing what you posted, my point was to make sure you get the right gauge. The gauge I have, for example, would do very little for the OP except show him if his necks were too long, or if he wasn't pushing the shoulder back far enough. If I am understanding the OP's OP correctly, he hasn't even fired it yet... just cycling dummy rounds through a new rifle.