Help with Cooper and AR-15 Loads

B-RAD · June 16, 2011, 08:32 PM

Hello,

I'm looking for some help on some better loads, loads that you think will beat my top groups.

I will do your loads and report back with pictures if they are worth the battery in my camera

As you can see by my load data, I show you twist and barrel length.

Cooper Load Data

AR-15 Load Data

All ammo will be reloaded in a CO-AX press with Redding Comp Dies.

CherokeeT · June 17, 2011, 10:47 AM

Welcome to the forum. So you want to get .25" groups at 100 yd from your custom build AR15. From looking at your load data, I would be really happy with the first couple. Not knowing anything about your custom AR15, I would not know if it is capable of any better groups. Your Cooper data implies you are capable of shooting good groups, maybe the AR 15 is at its peak. Sorry but I don't have any more suggestions.

TATER · June 17, 2011, 11:26 AM

I am thinking that the second load on the AR-15 load data is a typo?

Need to know a little more, What brass are you using? What does the brass look like?
I would ditch those primers and use CCI primers. (personal preference)
You may not get there using the magazine as you will need to start playing with the seating
as you tune the load.. Move the load in smaller moves as .5 is too much, it sounds like you are
Almost there. Try .2 up and .2 down from 23.0 grains and see if it moves.

Good shooting by the way,
and welcome to the board

cracked butt · June 17, 2011, 01:18 PM

Give Varget a try in the AR. And I agree with Ttater, try CCI primers.

B-RAD · June 17, 2011, 06:00 PM

@CherokeeT: Everyone tells me the AR is at it's peak, and they actually can't believe the groups I'm getting, that said I just bought a LimbSaver barrel de-resinator for the AR as I've always used one on my Cooper, I'm also looking at getting the barrel crowned, and I just bought a new tubbs flatwire spring, haven't tried it out yet tho. I also think my test loads I have on that pdf for the AR - I think those will get me where I'm going

@TATER: was a typo - it's fixed. Good catch!

Quote:

Need to know a little more, What brass are you using? Remington - I do have lake City but haven't used it for tests What does the brass look like?Freshly Prepped brass or once fired, depends, but I always keep the same fired brass with each 5 lot group I use for testing
I would ditch those primers and use CCI primers.I have some cci mags, I planned on testing with all the same primers and brass, then once I find a load I just can't beat with a new set of test loads, I then will play with brass and primers. (personal preference)
You may not get there using the magazine as you will need to start playing with the seating
as you tune the load.. as my cooper is seated waaay out, I'm use to playing with seating depth, but yeah I'm limited to the magazine in the AR, I may end up screwing around with manual loading once I find a good load, just to say that my gun as gotten a ___ fill in the blank group.Move the load in smaller moves as .5 is too much, it sounds like you are
Almost there. Try .2 up and .2 down from 23.0 grains and see if it moves. Ok, I wasn't sure how much .2 would change things, I may go back and make some more test loads for the Cooper, even tho I doubt I can beat that load, it just seems to perfect.

Also Varget has never done very good in either of my guns, I've never shot groups with it really, only prairie dogs.

Thank you everyone!

CherokeeT · June 18, 2011, 11:33 AM

Let us know how you progress. Will be interesting to see if you get to .25" groups. I have not found mag primers to be a benefit but you may. I use CCI in all my loads and LC brass.

B-RAD · June 18, 2011, 12:08 PM

I choose mag primers due to using H335 alot, and I don't see that it hurts when using stick powder either. I want all the help I can get to burn all the powder.

TATER · June 20, 2011, 12:10 PM

B-Rad,
When trying to achieve the accuracy you are going for, when you change one
Verbal everything can/will go to crap. In other words, You will literally be starting over.
Remember that the Lake City brass has less internal volume and the Mag primer can add as much
As 1 grain in performance/pressure. Right off the bat, that is a 2 grain reduction from where you are at now.
(Just to be safe), then work your way back up….(Starting Over)

B-RAD · June 20, 2011, 07:27 PM

I didn't know that - wow...

Do you have any links showing some research?

Thanks!

PA-Joe · June 20, 2011, 07:55 PM

I would try some 55s or 52s in that 1/9 AR barrel.

B-RAD · June 20, 2011, 08:04 PM

I was learning toward 55's, just not sure on the bullet of choice just yet, The reason I started heavy and worked backwards was because I'm mostly shooting over 250yrds with my AR and trying to get the heaviest bullet for that reason alone. I have shot some 55gr dog towns out in the field, and they seemed to shoot good, but never shot them at a target... I do have some 52gr A-Max's sitting around....

TATER · June 21, 2011, 04:38 PM

Military brass is made a little thicker and heavier than that of Commercial, Because
Of that, Military brass has less internal volume and loads should be reduced. Your
Manual should have a section that explains this as well as primers and their relative values.

I can't point to a source right at the moment, but a search function should turn up plenty for ya.
HTH

June 16, 2011, 08:32 PM	#1
B-RAD Junior member Join Date: June 16, 2011 Location: Right behind you Posts: 23	Help with Cooper and AR-15 Loads Hello, I'm looking for some help on some better loads, loads that you think will beat my top groups. I will do your loads and report back with pictures if they are worth the battery in my camera As you can see by my load data, I show you twist and barrel length. Cooper Load Data AR-15 Load Data All ammo will be reloaded in a CO-AX press with Redding Comp Dies. Last edited by B-RAD; June 19, 2011 at 07:15 PM.

June 17, 2011, 10:47 AM	#2
CherokeeT Senior Member Join Date: April 23, 2008 Location: Medina, Ohio Posts: 258	Welcome to the forum. So you want to get .25" groups at 100 yd from your custom build AR15. From looking at your load data, I would be really happy with the first couple. Not knowing anything about your custom AR15, I would not know if it is capable of any better groups. Your Cooper data implies you are capable of shooting good groups, maybe the AR 15 is at its peak. Sorry but I don't have any more suggestions. __________________ God Bless America US Army, NRA Endowment TSRA Life, SASS

June 18, 2011, 11:33 AM	#6
CherokeeT Senior Member Join Date: April 23, 2008 Location: Medina, Ohio Posts: 258	Let us know how you progress. Will be interesting to see if you get to .25" groups. I have not found mag primers to be a benefit but you may. I use CCI in all my loads and LC brass. __________________ God Bless America US Army, NRA Endowment TSRA Life, SASS

June 17, 2011, 11:26 AM	#3
TATER Senior Member Join Date: November 19, 2002 Location: Mississippi Posts: 666	I am thinking that the second load on the AR-15 load data is a typo? Need to know a little more, What brass are you using? What does the brass look like? I would ditch those primers and use CCI primers. (personal preference) You may not get there using the magazine as you will need to start playing with the seating as you tune the load.. Move the load in smaller moves as .5 is too much, it sounds like you are Almost there. Try .2 up and .2 down from 23.0 grains and see if it moves. Good shooting by the way, and welcome to the board

June 17, 2011, 01:18 PM	#4
cracked butt Senior Member Join Date: December 22, 2001 Location: southeastern wisconsin Posts: 537	Give Varget a try in the AR. And I agree with Ttater, try CCI primers.

June 18, 2011, 12:08 PM	#7
B-RAD Junior member Join Date: June 16, 2011 Location: Right behind you Posts: 23	I choose mag primers due to using H335 alot, and I don't see that it hurts when using stick powder either. I want all the help I can get to burn all the powder.

June 20, 2011, 12:10 PM	#8
TATER Senior Member Join Date: November 19, 2002 Location: Mississippi Posts: 666	B-Rad, When trying to achieve the accuracy you are going for, when you change one Verbal everything can/will go to crap. In other words, You will literally be starting over. Remember that the Lake City brass has less internal volume and the Mag primer can add as much As 1 grain in performance/pressure. Right off the bat, that is a 2 grain reduction from where you are at now. (Just to be safe), then work your way back up….(Starting Over)

June 20, 2011, 07:27 PM	#9
B-RAD Junior member Join Date: June 16, 2011 Location: Right behind you Posts: 23	I didn't know that - wow... Do you have any links showing some research? Thanks!

June 20, 2011, 07:55 PM	#10
PA-Joe Senior Member Join Date: June 9, 2010 Location: NEPA Posts: 663	I would try some 55s or 52s in that 1/9 AR barrel.

June 20, 2011, 08:04 PM	#11
B-RAD Junior member Join Date: June 16, 2011 Location: Right behind you Posts: 23	I was learning toward 55's, just not sure on the bullet of choice just yet, The reason I started heavy and worked backwards was because I'm mostly shooting over 250yrds with my AR and trying to get the heaviest bullet for that reason alone. I have shot some 55gr dog towns out in the field, and they seemed to shoot good, but never shot them at a target... I do have some 52gr A-Max's sitting around....

June 21, 2011, 04:38 PM	#12
TATER Senior Member Join Date: November 19, 2002 Location: Mississippi Posts: 666	Military brass is made a little thicker and heavier than that of Commercial, Because Of that, Military brass has less internal volume and loads should be reduced. Your Manual should have a section that explains this as well as primers and their relative values. I can't point to a source right at the moment, but a search function should turn up plenty for ya. HTH