Need guidance on reloading for AR

[Chiquita]

I am starting to get into reloading for an AR rifle and have some questions that need your advice on.
I like to use the magazine to feed so I know the bullet seating is limited.

1. Can I use the same full sizing die that I use for the bolt gun or I need a small base die?
2. From my readings I learned that I need to bump shoulders back about .004". Sound about right?
3. How do I determine what neck tension is needed so when the bolt slams home the bullet does not move forward?
4. Can I use regular 168 or 175s bullets or for AR I need the cannelured type?

I am sure I will have more questions.

Thanks for your guidance and replies.

 

[Hohn]

I am starting to get into reloading for an AR rifle and have some questions that need your advice on.
I like to use the magazine to feed so I know the bullet seating is limited.

1. Can I use the same full sizing die that I use for the bolt gun or I need a small base die?
2. From my readings I learned that I need to bump shoulders back about .004". Sound about right?
3. How do I determine what neck tension is needed so when the bolt slams home the bullet does not move forward?
4. Can I use regular 168 or 175s bullets or for AR I need the cannelured type?

I am sure I will have more questions.

Thanks for your guidance and replies.

1) you probably won’t need a small base as long as the brass fired in the AR stays used in that. Small base is for when a case stretching a big chamber won’t size down enough to fit into a tight one.
2) that a good bump. 4-5 thou is a good range for gas guns.
3) USAMU recommends starting with 0.003 neck tension.
4) you don’t want a cannelure on any match bullet. They generally only decrease accuracy.

 

[jelenko]

I've always set my shoulders back 1-2 thousandths. I do only use mine in competition. In over 50,000 rounds there has been 0 jams because the round wouldn't chamber [except for the few times the top half of a case has been left in the chamber].

 

[Chiquita]

These 7.62 M1A were fired through an AR and will be dedicated to it. Howvwould I make sure that my sized brasd will fit jyst fine vs it got stock becayse I did not use a small vase die.

FWIW, it is a Smith & Wessen M&P10.

 

[whatsupdoc]

So from your post you are loading for a large frame AR so here goes.

Regular dies will work for MOST setups if you have cambering problems it
usually is the base not the shoulder and you will need small base dies to fix that.

If you use range brass you may need a small base die.

Bump the shoulder .002-.003. Not that it matters much because the bolt carrier slamming the round home
will adjust that number for you. Run a little test at the range, measure the shoulder to base then load the
round in a magazine and let the bolt slam home. Carefully extract the round and measure the shoulder to base again.

For neck tension .003 has worked for me, no issues.

No reason to use cannelured bullets you do not need to crimp.

 

[Chiquita]

If you use range brass you may need a small base die.

No range brass, 7.61 M1A has been shot through this rifle.

I can always do a dummy round and check to see if it fits and if the bullet moves forward.

Thank you all for yoru replies

 

[Chiquita]

I guess to be 100% sure that the bolt will close and the lugs will lock I need to use a small base die.

On an AR if the lugs don't lock and I am not aware of it and pull the trigger, will the primer go off?

 

[TheCZKid]

I guess to be 100% sure that the bolt will close and the lugs will lock I need to use a small base die.

As far as whether you need a small base or normal FL die, I'd size a case with each (no primer) and seat your preferred bullet in each. Measure the base to shoulder datum on a shot case from that rifle. Then size one with normal die, one with small base die (if you have both) for each. You should set dies to do the same shoulder bump, say .003, in order to compare how they chamber, so the only difference is the base diameter, and NOT the shoulder length.
Then, with the BCG in the upper only (take it off the lower), slide the dummy round into the chamber, and by hand push the bolt forward until the bolt goes into battery. If you feel significant tension, and the brass does not want to chamber, and you have to force it forward, that should be your indicator. If they both chamber the same, then you probably don't need to use a small base die.

On an AR if the lugs don't lock and I am not aware of it and pull the trigger, will the primer go off?
I'm not sure, but a probability, especially if it's really close to being in battery. Not a good thing to happen!

 

[karrarararararar]

I've reloaded thousands of rounds (on barrel number 4) for my ar15 with no issues using normal dies. I recently built a 308 AR and also use a normal die for that with no issues.

On the topic of canneluer, it's not needed. It also doesn't seem to hurt on good bullets, mk262 is sort of the gold standard for 223 across the course ammo and it uses canneluered bullets.

 

[fkimble@charter.net]

You mentioned "These 7.62 M1A were fired through an AR and will be dedicated to it" Can you please explain this statement.

Thanks
Frank

 

[Chiquita]

You mentioned "These 7.62 M1A were fired through an AR and will be dedicated to it" Can you please explain this statement.

Thanks
Frank

The M1A were fired through this particular AR that I will be loading for. The cases will stay with this AR and will not see another chamber.

 

[fkimble@charter.net]

MRB, that part I was fairly certain of. M1A to me is a semi-auto version of the m14. You seem to be using it to name ammo? Can you elaborate on this M1A ammo? Sorry my question was not worded better.
Tks
Frank

 

[Liven The Dream]

I just love the Small Base replies.
#1 Read a old Speer #8 Reloading Manual .. That should but the Small Base to sleep...
I shot and Built a Lot of AR'S for shooting NRA Matches as Service Rifle and Match Rifle.
I did my share of Winning.
#2 Why ? does RCBS make Dies Just for AR'S
Using a standard Die is Hit and Miss. For Rapped Fired Mag. Stings !

There will be a list of replies stating BS .

Best of Luck

 

[robert8904]

AR rifles won't fire before the bolt rotates closed unless there is maybe a high primer or a broken firing pin. The firing pin is captured in the bolt carrier. The cam slot in the carrier rotates the bolt closed before allowing the carrier to move forward enough for the firing pin to reach the primer.

 

[Chiquita]

MRB, that part I was fairly certain of. M1A to me is a semi-auto version of the m14. You seem to be using it to name ammo? Can you elaborate on this M1A ammo? Sorry my question was not worded better.
Tks
Frank

If I remember correctly the M1A cases that I have are from American Eagle ammo that I had shot about 2-3 years ago.

ETA:
FWIW, I don't do rapid fire.

 

[dellet]

Is this the ammo you are talking about?


In general the only reason you would need small base dies would be if the rifle is over gassed, fired cases extracted too fast. An off the shelf AR and factory ammo is a good combination for that to happen. Both the rifle and ammo manufacturer are more worried about customer complaints of cycling issues than they are of complaints of their rifle being hard on brass.

You can control that somewhat with handloads, but what’s already been fired may need some extra attention.

 

[Chiquita]

I just love the Small Base replies.
#1 Read a old Speer #8 Reloading Manual .. That should but the Small Base to sleep...
I shot and Built a Lot of AR'S for shooting NRA Matches as Service Rifle and Match Rifle.
I did my share of Winning.
#2 Why ? does RCBS make Dies Just for AR'S
Using a standard Die is Hit and Miss. For Rapped Fired Mag. Stings !

There will be a list of replies stating BS .

Best of Luck

I don't have access to an old manual.

If I understand your reply, you are in favor of small base die. If yes, please explain why?

 

[jelenko]

Bump the shoulder .002-.003. Not that it matters much because the bolt carrier slamming the round home
will adjust that number for you

++. I've had rounds that were 5/1000 larger than the chamber 'resized' by the closing bolt.

 

[robert8904]

I guess to be 100% sure that the bolt will close and the lugs will lock I need to use a small base die.

On an AR if the lugs don't lock and I am not aware of it and pull the trigger, will the primer go off?

The answer is no. If you pull the trigger with the lugs not locked, the hammer will will hit the firing pin and carrier, but the firing pin won't reach the primer. However, the firing pin can dimple the primer after the bolt rotates closed because of its forward inertia. This is normal. I believe your M&P 10 has a spring on the firing pin to slow its forward motion as BCG slams into battery.

 

[fkimble@charter.net]

Jelenko, I assume you mean .005 longer headspace, not .005 oversized base at the .200 line.

Frank