Tuning .223 AR15 Reloads for Accuracy

[dnellans]

These are 5 shot groups from my AR15 "competition" rifle. I haven't measured them but I'm sure they're .0x sized groups.

While I’d be peachy happy with those groups from my AR - if those are at 100, they’re definitely -not- zeros. Maybe at 300, probably not at 200 either.

223 cal bullet holes can not even be seperated by one half a bullet (.223/2) and be in the zeros. Two of those groups have more than a bullet between some of the shots.

 

[jelenko]

neck mandrel to expand your necks

What does a mandrel do differently than a 'button'?
Thanks

 

[garandman]

My best luck with the AR platform in 1:7 or 1:8 twists has come from 73 grain Bergers, or 77 grain Bergers. 69SMK have given me good results, but not as easily as Berger.

Small tips for the AR:
1.) Bed the barrel extension in Loctite.
2.) Accu Wedges cannot hurt and occasionly help.
3.) Before installing the barrel polish the feed ramps, Flitz and a Dremel work well with a .30 cal bore mop.
4.) Align the gas tube, plenty of spots on the internet explain this.
5.) Adjustable gas blocks are super nice, especially when they are clamp on instead of using the barrel for support.
6.) Most magazines will allow 2.265 - start there. That leaves 0.040 for seating depth tuning.
7.) If an optic is used, bed it.

Just a few tips.

Good stuff. I gotta get me another one of those Accuwedges

I tried and tried (1:7 bbl) with 73 Bergers and 77 SMK's Really tried. The 69 SMK's got me 06 - 1.2" consistently, in about 5 ladder / incremental loads (02 gr variance) . Luck of the draw.

 

[LVLAaron]

What does a mandrel do differently than a 'button'?
Thanks

They're "easier" on the brass. When you yank a button through you deform the neck and shoulder a bit.

 

[Coyotefurharvester]

I have a couple 18" cheap barrel uppers with 1/8 twist. They were pretty easy to get sub moa with soft point flat base bullets 50-60 gr, using benchmark powder and CCI 450's. One has a carbine stock, I throw a suppressor on it and the neighbor kids shoot small balloons at 100 yards.

 

[257Roberts]

Lots of good suggestions. Thanks. I think I will hold off on things like bedding the barrel extension and squaring the action until a last resort. Like others mentioned, its a carbine, and Im just hoping to make it better than 1.5MOA.

I kind of blew of seating depth while thinking mag length. I get tunnel vision thinking about seating depth while chasing the lands, but yes its valid that a seating depth change, even with a sizeable jump can make a difference. I will try that.

I don't sort my Lapua or Petersen brass with my bolt rifles. What do all do with LC brass? Is it worth a weight sort? I've heard maybe 2.5gr variation in any given lot of LC...

Primers, in my ARs I've always used CCI400 due to the hard primer cups. Typically in my bolt guns I'll run BR2 or BR4 for better consistency. I'll have to play with some other primers once more become available. Any brands to stay away from in an AR?

 

[garandman]

... Im just hoping to make it better than 1.5MOA.



I don't sort my Lapua or Petersen brass with my bolt rifles. What do all do with LC brass? Is it worth a weight sort? I've heard maybe 2.5gr variation in any given lot of LC...

I'm thinking you s/b able to get well under 1.5 MoA just with bullet weight, type / powder charge / seating depth testing.

Annealing, sorting, bedding shouldn't be necessary ( I don't think...)

 

[decastle]

Started off my competitive shooting career with a Fulton Armory CMP Upper with a 1-7 Krieger. That beast was a hammer and took me to master long range. My go to load was 24.5gr H4895, LC brass and a 77gr Sierra at mag length. I would load the same recipe with 75 AMAX past mag length for long range. It was an honest 0.5MOA setup if I did my part.

Back in 2014 I built my first AR15 upper, a shorty carbine. 16" 1-7 WOA barrel with a mid length gas system. I used a Yankee Hill back-up flip front sight with gas block included, I don't think its adjustable. Need to go back and look. I've ran my old leftover reloads thru it, and accuracy is just "ho hum" 5 shots 1-1.5" at 100 yards with a 10X scope. Not terrible, but not what I had hoped for either. Occasionally can get 3 or 4 into 0.75", but there is always a flyer that will open up a total group. I'd love to use this for some short course NRA prone practice, but at 1.5MOA, I don't trust it well enough for proper feedback on a scoreable target.

I'm going to have to dig out the Zediker books again.

What are some tips you guys do to squeeze on sub MOA in your AR15/carbine platforms?
Can't really tweak seating depth for a mag length set up.
Do you tweak your charges and primers until you hit a node?

Going to be building a 6ARC once I get a barrel that's on order.
Figured Id better re-study up on AR15 loading before I tackle that one.

I've read through the reply's to date and there are some good points. No one has mentioned torque of the barrel nut to the upper. I find that usually a torque of 45 ft lbs gives better accuracy than the suggested 32 lbs. Before you bed the barrel extention in the upper, try changing the barrel nut torque to find the best setting, then dissemble apply your loctite and reassemble . You may even have to remove a tooth on the nut for the gas tube clearance.

 

[LVLAaron]

I've read through the reply's to date and there are some good points. No one has mentioned torque of the barrel nut to the upper. I find that usually a torque of 45 ft lbs gives better accuracy than the suggested 32 lbs. Before you bed the barrel extention in the upper, try changing the barrel nut torque to find the best setting, then dissemble apply your loctite and reassemble . You may even have to remove a tooth on the nut for the gas tube clearance.

Good point! - I believe if you have a trued receiver face the torque shouldn't be a huge issue, but seasoning the threads is one of those things you need to do on a new setup.

 

[Old Navy]

The loads that shoot great in my 20" RRA Varmint barrel with the Wlyde chamber absolutely suck out of my 16" 5.56 mil-spec.

 

[RegionRat]

I don't sort my Lapua or Petersen brass with my bolt rifles. What do all do with LC brass? Is it worth a weight sort? I've heard maybe 2.5gr variation in any given lot of LC...

Then you probably don't need to do it for an AR platform either...
Unless you are detecting a variation of greater than 3 grains within a loading batch in your LC brass, you cannot shoot the difference at 600 yards with an AR. In fact, things like bullet pointing have a greater effect than a 3 grain weight difference in LC brass at 600. The difference between the old un-pointed 80 SMK and the newer pointed ones is less than half an MOA at 600. I wouldn't mix those within a loading batch, but I don't sort brass (I shoot at Master Level in SR, but would be High Master if my offhand would improve).

So while I'm suggesting that getting a high quality AR upper to perform, you don't need to sort brass, at the same time you must learn to sample a fresh batch to make sure it meets standards because sometime they don't.

Here is the free internet advice that is worth about what you paid for it....
When you open a fresh batch of 1000 pieces of LC brass, you randomly select 30 samples and weigh them. Run the stats and estimate the ES by taking the SD and multiplying by six. If the estimated ES threatens your sleep at night, find 10 of the heaviest and 10 of the lightest and go test at 600 yards and see if your average elevation is affected.

My guess is your time will be better spent learning to control your case prep and shooting skills rather than sorting brass. If an AR upper intended for accuracy won't shoot small enough to hold the X on the 300 yard SR targets with a decent box of something like Black Hills 69, or 77, then something else is wrong.

Sometimes you need to cut losses on an upper in terms of trying to make a silk purse out of a sow's ear...

 

[Metal God]

Facing off/squaring up the receiver is important

Bedding the barrel extension in the receiver is good idea as well .

Those two things will likely help you out a good bit . IMO you are getting those flyers do to the the barrel heating up in those areas and if not faced/squared up and bedded . The barrel expanding in that area as it heats up after every shot can push the muzzle ever so slightly off axis to your POA .

As for adjusting seating depth deeper ???? Sure I guess with light loads , lighter bullets or ball powders maybe . However when I'm loading 77's and using stick powders ( which most use when looking for accuracy and consistency ) while also trying to get max velocities . Every single one of my loads is compressed at least a little and some like when using IMR-4064 is very compressed .

I forget what powder this is ( 4064 I think maybe 4895 ) I know the pic was taken to make this very point . Note how full the case is , then note how deep a 77gr smk seats into the case to allow for feeding from a mag . Where is all the room for this seating deeper idea . I know this load goes CRUNCH when I seat the bullets to mag length . I'm not getting another 10 , 20 or 30 thou deeper . The bullet just pushes back out or you take the chance of bloating the case body . If your talking only playing with .002 here .005 there , that ain't going to make a difference when you likely have a .100+ jump you are starting with .

https://imagizer.imageshack.com/v2/800x600q90/923/83lzpN.jpg

https://imagizer.imageshack.com/v2/800x600q90/924/Pvw2X6.jpg

Get your barrel all trued up and re-work the load and you'll be shooting sub moa in no time

 

[whatsupdoc]

View attachment 1275429View attachment 1275430View attachment 1275431

These are 5 shot groups from my AR15 "competition" rifle.


The first things I do to the rifle to make sure it's a shooter:
1. Bed the barrel to the upper.
2. Adjust the gas. I adjust it a little "hot"
3. Single feed. I can take the same load pictured, mag feed, and get very different results. Drop the bolt on every round. Accuracy is about repeatability. Mag feeding is not consistent.
4. Related- always load the bipod the exact same way. Many ways to load... No load, heavy load. Pick a method and commit.
5. Check your pin protrusion
6. KEEP IT CLEAN. KEEP IT LUBED. AR's are dirty guns. Clean the bolt carrier assembly after every range trip. Make sure the pin travels freely. The pin easily gets gunked up and consistent ignition matters. You're using it as a precision rifle, not an AR. Run it like a precision rifle.
7. Check, and correct if needed, the bolt lug contact. AR's have a lot of lugs. Easy to 2-3 of them to be out of true.
8. True the upper receiver face.
9. Use a WOA or BAT Machine shrink fit barrel extension


About the ammo
1. Sort bullets. Don't get wrapped around the axle thinking about it. I just pick one method and sort. Might be OAL, might be base to ogive.. Just pick one to cull the obvious bad ones out. Just measure something and be ready to use 5-10 percent of "off the shelf" bullets as foulers or sighters.
2. Use a neck mandrel to expand your necks. This probably made the biggest difference in 223 I've ever found.
3. Use a stick powder
4. Use a magnum primer.
5. Keep in mind your lot to lot variances. Commercial bullets can vary by as much as 20 thou from box to box...

A dozen other little things I do to the rifle to make sure things are how I want them...

Is it not the point of an AR15 to shoot out of a magazine and let the rifle reload itself?
All other accuracy tips I agree with.

 

[jelenko]

Is it not the point of an AR15 to shoot out of a magazine and let the rifle reload itself?
All other accuracy tips I agree with.

Not if you're shooting some competitive disciplines where single loading is required.

 

[LVLAaron]

Is it not the point of an AR15 to shoot out of a magazine and let the rifle reload itself?
All other accuracy tips I agree with.

Is the point of enjoying a sports car to go fast, or enjoy going fast? "Fun" cars are fun when you push them to their limit. Places they aren't meant to be. You can have more fun in a VW Golf than a 50k BMW.

You expect one hole groups from a $5k bolt rifle. Isn't it fun to shoot one hole groups with a 1,500 dollar gas gun... that you can build at home?

I should be clear that the things I want from and do with an AR are polar opposite of Chad from School Of The American Rifle (SOTAR). He'd say everything I mentioned is stupid, wrong, and illegal. He focuses on reliable battle rifles.

My focus is a an accurate long range target rifle.

To answer your question directly... The point of an AR15 is different for everyone. The steps I take are for my purposes. I also have AR's built completely differently that live with slings, lights, red dots, and only get fed MK262 ammo.

 

[RegionRat]

As for adjusting seating depth deeper ???? Sure I guess with light loads , lighter bullets or ball powders maybe . However when I'm loading 77's and using stick powders ( which most use when looking for accuracy and consistency ) while also trying to get max velocities . Every single one of my loads is compressed at least a little and some like when using IMR-4064 is very compressed .

If I take a LC case with a dead primer installed, and I mandrel the neck so a 77 SMK just slides in and out on its own, then take 24.0 grains of RL-15 and throw it in, that bullet will sit at roughly 2.28". However, if all I do is buzz the case with vibration to allow the powder to stack under the bullet and flow up around the boat tail, that same bullet drops down to 2.245 without any compression.
That leaves several steps from 2.260, 2.255, 2.250, 2.245, to experiment with for any signs of group tightening without real compression. Roughly the same for Varget.

 

[Metal God]

If I take a LC case with a dead primer installed, and I mandrel the neck so a 77 SMK just slides in and out on its own, then take 24.0 grains of RL-15 and throw it in, that bullet will sit at roughly 2.28". However, if all I do is buzz the case with vibration to allow the powder to stack under the bullet and flow up around the boat tail, that same bullet drops down to 2.245 without any compression.
That leaves several steps from 2.260, 2.255, 2.250, 2.245, to experiment with for any signs of group tightening without real compression. Roughly the same for Varget.

I agree short cut stick powders like Varget , AR comp , RL-15 maybe H4895 with a drop tube and vibration may give you some wiggle room . I've done it and you can get the powder to settle quite a bit , good point and important the OP considers that . It's a lot a work per round for a general purpose load but definitely doable if you want to take the time . The only thing I'd do different is jump in .010 increments , I could be wrong but when you have a looong jump I'm not so convinced a .005 adjustment is all that noticeable . Could it make a difference , yes but I'm thinking small enough to get lost in the noise of other variables . Keeping in mind we're not talking a custom bench rest rig here shot from a rest with a 2oz trigger ;-)

 

[RegionRat]

It's a lot a work per round for a general purpose load but definitely doable if you want to take the time

The point I am trying to make, is that 24.0 RL-15 with the 77 SMK isn't compressed in reality.

The boat tail will typically shove the powder around, but it isn't really compressed and you wouldn't need a drop tube or vibe in a regular loading scenario.

I just did that to show why there is room to experiment with an AR and a 77 SMK near mag length.

I don't load with a drop tube or vibe. That 24.0 is a pet load and it doesn't cause seating problems like an actual compression load can, and that is why it leaves no seating stem issues if you want to seat down a little deeper. Too many competitors using the same loads for years and the charges with the 77 SMK are well known.

http://www.radomski.us/njhp/cart_tech.htm

So as to be clear, I completely agree with the build craft accuracy measures folks have listed, and also with typical load development for the OP to see if his 16" will go less than 1.5 MOA.

I am also pointing out that typical carbine barrels don't usually perform at the same levels as Service Rifle Match barrels or 16" WOA accuracy barrels. If the upper is well built and the bbl is good, he will get there.
As always, YMMV

 

[GuitarmanNick]

I put my builds together to be used as service weapons that could use NATO ammunition, be 100% reliable, and reasonably accurate. The 20" A2 wannabe(heavy barrel required by Marylandistan), 16" carbine(also heavy barrel) and 10.5" pistol w/carbine gas system are 1:7 twist. The first build is a 16" HBAR carbine that is 1:8 twist.

Recently, I decided to develop some loads for the 1:7s, beginning with some defensive loads for the pistol. Using what I have, I came up with a pretty accurate round using Hornady 55 gr. soft points and almost have the 62 gr. bonded dialed in. Another objective was to minimize the muzzle blast that comes from using full power ammunition which is a waste in the shorter barrel.

I was surprised to get such good groups using a green dot reflex system. Much better than with any factory ammunition I have tried and should end up with very nice defensive rounds for this toy.

Currently chasing down the nodes for the 16" using 69gr. HPBTs. It has a decent scope, so I can dial this round in with a little more precision. When I am finally content with it in this carbine, the plan is to try it in the 20". I may end up searching for a compromise between the two, that gives the best overall performance in both builds.

Trying to avoid the urge to have a special load for each AR and find loads that work well across all my similar builds. I do not want to fight rounds into the USGI mags, so 2.260" is the max OAL I plan to use for any AR load.

I no longer hunt, and do not shoot competitively, but it is fun making progress and getting smaller groups with the ARs.

Perhaps a .223 bolt gun with which to experiment is in my future for more flexibility and greater accuracy.

You guys are all a bad influence on me!

 

[257Roberts]

Appreciate all the advise. Lots of things to try to for sure. Using all your comments to plan for the future!

This was my first 'home built' AR. Its a RRA A4 upper, RRA carrier group, WOA barrel and bolt. I haven't done anything fancy with regards to bedding or fitting the barrel extension. I will try some more loads first before I dig into it too deeply. Its currently carrying a Vortex PST which I have used elsewhere to shoot sub 0.5MOA groups.

Very little has been stated about an adjustable gas block? Can slowing down the unlock aid in accuracy very much? I know there is a limit there, while still allowing the semi-auto function to work properly.

This build I used a Yankee Hill flip front sight with built in gas block, and its not adjustable.

I ask about the gas block, because my next "home built" upper will be a 26" 6ARC once I get the barrel in. I want that thing to be a tack driver, so sky is the limit on what I will use. Is there a particular brand of upper receivers you all recommend starting with? I was considering something like a DPMS lo pro or equivalent. Don't need forward assist or load port dust door etc.