help with groups on my ar10

[cruze5]

GAP ar10.


41.8 grains of4064 loaded at 2.830 with 175smk

if I shoot them singlefed into the magazine I get AMAZING groups( 5 shot group on the left side). if i shoot magazine fed with pretty much any load they are all over the place.

any suggestions?

 

[KYpatriot]

Re: help with groups on my ar10

Ado your groups have any pattern to them? ie are they all vertical stringing or just all over? Do they group in one place and then group in another, or is every shot random?

 

[cruze5]

Re: help with groups on my ar10

Always random, I only tried shooting individually from the mag because I read it on here. It's been a long struggle since last November since I got it

Where do you shoot?

I've not seen many from Lexington on here

 

[KYpatriot]

Re: help with groups on my ar10

I'm out in the country. I shoot privately, not a member of any range. Do you shoot at BGSL or out a Elk Creek or somewhere?

Sounds like if it will group loading singles that your mount and scope are good, and presumably your trigger pull...

When you say load singly do you mean the bolt is locking back on every shot? If so maybe it is a follow through issue?

Hopefully someone with a little more semi-auto experience will be along to help...

 

[command450]

Re: help with groups on my ar10

groups can change with barrel,temp.....but this seems odd.

makes me wonder if has to do with consistency. in other words,when you release yourself from the weapon and hand load each round vs continuing to hold and fire rounds from the mag.

try setting the rifle down, after each shot when you are firing from the mag....wait a while then pick it up.see if you get the same groups,as when you manually load each round.

maybe your first rounds,you are more focused on the basics

remind yourself of the basics,when you get ready to fire each round

 

[cruze5]

Re: help with groups on my ar10

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KYpatriot</div><div class="ubbcode-body">I'm out in the country. I shoot privately, not a member of any range. Do you shoot at BGSL or out a Elk Creek or somewhere?

Sounds like if it will group loading singles that your mount and scope are good, and presumably your trigger pull...

When you say load singly do you mean the bolt is locking back on every shot? If so maybe it is a follow through issue?

Hopefully someone with a little more semi-auto experience will be along to help... </div></div>

Yep, i shoot at BGSL.

I put the magazine in the gun, push the round through the ejection port into the mag. I take my time between each round. I only shoot in the prone position..

 

[jcal73]

Re: help with groups on my ar10

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cruze5</div><div class="ubbcode-body">GAP ar10.


41.8 grains of4064 loaded at 2.830 with 175smk

if I shoot them singlefed into the magazine I get AMAZING groups( 5 shot group on the left side). if i shoot magazine fed with pretty much any load they are all over the place.

any suggestions?

</div></div>

Have you cycled some rounds from the mag and inspected the rounds when you eject them (unfired)?
The bullets may be getting dinged up/adjusted some coming from the mag up into the chamber.
I'm new to this sort of stuff so if I'm way off please look over me.

Jeff

 

[JimGnitecki]

Re: help with groups on my ar10

You COULD have insufficient neck tension.

If so, the recoil from a shot being fired can set back the bullets on the rounds that are still in the magazine.

In addition, the feeding of rounds from the magazine into the chamber can further set bad the bullets as they "crash" into the ramp and chamber.

On an AR-10, ideal neck tension is more than what is needed in a bolt rifle. Whereas a bolt rifle might be good at .001" or .002" neck tension, a semi auto will require .003" or even more.

To calculate how much:

Take bullet diameter in thousandths

Add 2 times the neck wall thickness (in thousandths again) of the cases you are actually using (varies by brand and batch)

Subtract .003 inch.

That should be the OUTSIDE diameter of the neck of the case after sizing.

If it is more than that, you have insufficient neck tension.

Do NOT measure after seating the bullet. Measure BEFORE seating the bullet. This is because during seating of the bullet, the neck wall stretches somewhat to accommodate the bullet being stuffed in.

I may be wrong about neck tension being the issue here, but it is something you should check before doing more difficult diagnostics, as t is pretty easy to check.

Jim G

 

[JoshcBoucher]

Re: help with groups on my ar10

I think Jim G., nailed it.

 

[Lockdown1243]

Re: help with groups on my ar10

How are you groups with factory ammo? This to me would automatically tell you if your problem is the person behind the gun or something else. By no means am I trying to be insulting, just throwing ideas out there.

 

[cruze5]

Re: help with groups on my ar10

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lockdown</div><div class="ubbcode-body">How are you groups with factory ammo? This to me would automatically tell you if your problem is the person behind the gun or something else. By no means am I trying to be insulting, just throwing ideas out there. </div></div>
No offense taken, this rifle shoots the same with hsm 155 palma. Federalgmm 175, black hills 168 and 175. And of course the reloads ive tried.

I understand what your saying about neck tensioning but match box ammo dorsnt shoot accurately.

Then i pull out my h2 harbinger and shoot sub moa allday

 

[cruze5]

Re: help with groups on my ar10

after a few emails. I am off next week to buy a Lee Factory Crimp Die

thank you for the responses

 

[echo3]

Re: help with groups on my ar10

Correct me if I am wrong.
You shoot just fine on your boltgun?
You also shoot just fine when you single load your 10?
Not so fine when you shoot your 10 semi auto from the mag?
Then.
Do you have much experience shooting precision ARs?

 

[cruze5]

Re: help with groups on my ar10

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MST</div><div class="ubbcode-body">Correct me if I am wrong.
You shoot just fine on your boltgun? <span style="color: #CC0000">yes sub with good handloads</span>
You also shoot just fine when you single load your 10? <span style="color: #CC0000"> yes as of my last range trip after reading to try single loading the rounds</span>
Not so fine when you shoot your 10 semi auto from the mag?
Then. <span style="color: #FF0000">correct </span>
Do you have much experience shooting precision ARs? <span style="color: #FF0000"> first ar10 I have owned and shot</span>


</div></div>

 

[echo3]

Re: help with groups on my ar10

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cruze5</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MST</div><div class="ubbcode-body">Correct me if I am wrong.
You shoot just fine on your boltgun? <span style="color: #CC0000">yes sub with good handloads</span>
You also shoot just fine when you single load your 10? <span style="color: #CC0000"> yes as of my last range trip after reading to try single loading the rounds</span>
Not so fine when you shoot your 10 semi auto from the mag?
Then. <span style="color: #FF0000">correct </span>
Do you have much experience shooting precision ARs? <span style="color: #FF0000"> first ar10 I have owned and shot</span>


</div></div>

</div></div>

Cool. Shooting technique and fallow through should fix it.

It may be something like a neck tension being off, but you have included well known performing rounds so..

I see a bunch of dudes that are solid on their bolt hit a wall when they back a gasser.

It may be that your 10 likes a lot of pressure or tension on it all the way through the entire recoil impulse.

Try pulling it in tighter in your shoulder, leaning into it more to load it and lay dead on it all the way through your fallow through. Pay attention to trigger control and make sure you do not reset until well after you have settled. Try shooting the dot drill with it too. Try it single feed and semi. See if you spot a change.
Fallow through is where I see the biggest issue with new to AR shooters.

It looks and sounds like just that and easy enough to get dialed in on.

You are used to the single setback recoil of your boltgun. It is very forgiving too. It just goes bump.
Your gasser is moving back and forward and for a lot longer.