Accuracy Testing & Barrel Cleaning

[Tex S]

I have worked up a bunch of loads for my new AR.

I have 12 different powders I will be testing. Each powder will have 10 rounds each of 3 different charge weights. This equals 360 rounds.

I will be testing 2 different bullets, so the total number of loaded rounds is 720.

What is the best way to go about testing all of these? I was thinking about firing the first bullet in a round robin fashion at 12 different targets. I would have one target for each powder type, but use 3 different points of aim per target (for each different powder charge within the same powder type). Obviously I would start with the smaller charge and work up to the largest. When the first bullet is done, 360 rounds will have been shot.

The problem is barrel fouling. At what interval should I be stopping and cleaning? Should I shoot the first bullet (360 rounds), then clean and shoot the next 360?

Maybe more frequent cleaning is required?

Would a quick pass with a boresnake be beneficial?

New to the AR scene and don't really know what to do.

[ShootistPRS]

I would clean before switching to a different powder.
You are going to the extreme in testing so many combinations but as long as it works for you.

[Stats Shooter]

Wow that is a lot of testing. If you were shooting 222 or 7 mag, your barrel would be half worn out by then.

Might I ask you why so many different powders? There are a handful of common AR powders that work well in .223, and some work equally well as others from different Makes like hodgdon vs alliant

Plus 3 charge weights from 1 powder really isn't giving that powder a fair shake unless you are simply testing for velocity. In my match grade AR upper, 24.3 gr Varget is very accurate while other charge weights throw shotgun patterns.

But to your actual question, on fouling, I usually clean every 200 rounds and I clean the barrel lightly.
Also, don't forget to take "Barrel fouling shots" before testing a new batch, AR's like other guns shoot different clean bore vs fouled bore. I have 3 ARs and they take 10-20 fouling shots before they settle in.

Sounds like you have some fun times ahead. Good luck!

[stagpanther]

I build a fair amount of AR's and also hand-load all my ammo--so I go through the same thing you are with each new build. I'm no expert--and the following are just my "hobbiest opinions."

I would drop the "mass test" approach and carefully work up each bullet and powder combination at a time. The goal, presumably, is to find the best combination of performance and accuracy for your particular weapon. My approach would be rather than use three different charges of ten shots--I would spread the combinations out over more charge weights with fewer shots--I typically do my initial ladders of at least 6 different weights of 4 to 5 shots (depending how financially tight my ability to use bullets is). The probability is higher that you'll come across probably 2 combinations (I've found that most of the time the best loads occur within a 10% range of the bottom and top range of test charge weights) that will perform better than the rest this way. I then will "fine tune" with at least a second batch of ladder tests but with charge weights closer to two best ones from the first test. I also like to use software (and a chrono when I can) to get an idea of the actual velocities since that will effect how a bullet performs at different ranges and energy delivery upon impact--pretty important when considering hunting loads.

Just food for thought--not suggesting that I think this is the only right way or what you should do--but it has worked fairly well for me.

[5whiskey]

Well, you have decided to undertake quite the effort. This is a TON of work to just work up a load in an AR. You may have your reasons, and that's fine... but powders vary enough lot to lot that "the most accurate" powder will likely not be the most accurate when you buy your next can from a different lot.

At any rate, I mirror the opinions given by others that the "mass" approach is not necessary. If you are committed and have your reasons, that is fine. In that case I would clean the rifle after each 10 round test group, then fire a fouling shot. This is the only real way to control fouling as a variable. BUT...

Plus 3 charge weights from 1 powder really isn't giving that powder a fair shake

This is very true and good advice. 3 test groups from one powder would assume 1 min charge, 1 middle weight charge, and 1 max or almost max. In my experience, none of the above have ever been the best charge weight for accuracy in my workups (I usually encounter best accuracy about 2-4% from max, but it is variable).



As an aside, I use a "fine tune" method similar to what Stagpanther describes. I'm only working up for one or two powders though (when I work up).

[JeepHammer]

What is the 'OBJECTIVE' here?
Is it bullet or powder testing?
Is it testing the repeatability/consistancy of the firearm or shooter?
What bullet weights/types are you testing?
What is the twist rate of the barrel in your testing?
What is your objective here, paper punching @ 100yds or 1,000yds or hunting?

As discussed before here at length, some loads with some barrels are 'Inherently Accurate', accurate with a wide range of bullets/powders,
Some have very narrow/limited capability when it comes to bullets/velocities.

[cw308]

I would agree with JeepHammer., It's easier to help with more information.

[Tex S]

Larue Tactical OBR 16" 1 in 8 twist caliber 5.56

Will be testing the 77gr SMK for longer range shooting.

Will be testing the Hornady 55gr FMJ for general shooting and plinking, but still want it as accurate as it can be. The price is right on this bullet, but I've heard of others having accuracy issues with it.

Looking for top velocity with both loads, thus I have only selected powder weights near the higher end of safe load data.

Looking for a powder that gives good accuracy and velocity. Something clean burning would be nice too.

Have the following powders...
IMR 3031
IMR 4064
H322
H335
TAC
IMR 8208 XBR
CFE 223
Varget
AR Comp
RL15
N135
N140

I know it is a bunch of powders, but I had several of them already on hand and then bought a few more that were "AR/223 specific".

Plus, I'm looking forward to shooting this thing. Figure I may as well do some testing while I'm at it.

[Stats Shooter]

Tex,

Be cautious about some of them, like CFE and RL, they are temp sensitive. CFE gives excellent velocity and good accuracy but once the chamber warms up the poi will shift

[highrolls]

Wow. You are getting some good advice here. Seems most of your responders are into the test game. Given the proposed number of tests, I think ShootistPRS is right about the cleaning between the powders lest you have a non-reproducable fouling condition that really affects things.

Mississippi has a great question about your selected charge weights. But I will add that other than velocity, that could give you a handle on proper cycling by the selected powder. For example, using two powders not on your list, IMR 4198 gives good accuracy in my Thompson Center, but I have not found it to cycle any AR well at any lyman charge level. IMR 4895 does not fare well in great velocity but virtually every charge level will cycle well.

Read stagpanther's comment more then once to compare his approach to whatever your own goal is. He is the one who first mentions the chrony. If you plan to do that much testing, chrony data is worth the effort.

5whiskey must be quoted: 'but powders vary enough lot to lot that "the most accurate" powder will likely not be the most accurate when you buy your next can from a different lot.' My hardest worked up accuracy loads have been lost simply with a new lot of powder. Not sure if that situation can even be fixed.

JeepHammer and cw308 are the first to address the magic questions.

And here, my own contribution: Invest a few cents in a fine point sharpie marker. Whatever test loads you finally decide on, as you prepare each load, mark the case base to identify it. The marking when dry will be greatly appreciated by you if you spill the cases out of the test carrier box and want to salvage all that work rather than guess which is which.

[JeepHammer]

In no particular order...

The cases MUST be prepped CONSISTANTLY, this includes annealing or starting with all new brass.

Point of aim in your optics can be adjusted to meet point of impact, so DO NOT crank knobs while testing!
ANY ADJUSTMENT of the optics will invalidate your test since not all optics are graduated correctly, or for yards vs meters,
And ONE lens misaligned will screw you for an accurate test.
Same with a pulled adjustment thread, burr on a thread, spring pressure on the reticle lenses carrier, and about a hundred other things that can go wrong with optics.

Doesn't matter the money you paid for that optic, 'Stuff' Happens...
Taking any fiddling with optics out of the test simply requires a little larger backboard for your 'Dot' since groups are what counts during testing, not POI matching POA.

Dot your target, start about 300 yards since you are talking 'Long Range'.
Put a dot on the target, shoot carefully aimed 10 round groups.
Shooting 100 yard & 200 yard targets will tell you the difference between point of impact (POI) vs point of aim (POA), (bullet drop, right shift, etc.)

This will give you GROUPS with enough rounds (large 'Sample') to get you started on a custom ballistic table.

Trying to shift point of aim is pointless with new rounds, and it only confuses things.
You are looking for grouping anyway!

Keep in mind with 10 round groups, you WILL have a flyer from time to time, simply ignore fliers, 10 round groups give you a good sample of what the ROUND is doing, instead of the shooter.

Keep in mind that 300yds is where you are going to eliminate most optic parallax, even with the 'Lesser' quality optics, that's why I recommend 300 yards, to take most of the optical induced issues out of your test.

Traditionally, 55 grain bullets don't do well at 'Long Range',
Out to about 400-450 is the traditional 55 grain bullet range.

The 1:8" barrel probably won't help you with 55 grain bullets.
1:8" twist barrel works much better with heavier bullets, and heavier bullets is exactly why the faster twist rates were developed.

Some people can shoot further with 55 grain, but that is the 'Generally Accepted' range limitations.
For example, I don't know anyone that shoots beyond 600 yards using 55 grain bullets.

'Inherent Accuracy' doesn't happen with a fast barrel twist, you will have to work up a load that works.
Core shift in a bullet, throat erosion that lol-sides the bullet, etc will seriously effect a faster spinning bullet,
While a slower twist rate stablizes can often stabilize a wider range of bullet weights & flaws.

Now I KNOW there will be all kinds of 'One Of' stories out there, so this is general rules, specific to no particular rifle/bullet in particular.

Generally, if I want to shoot beyond about 600yds I simply pick up a .308 rifle that shoots dead on published ballistic tables at those longer ranges instead of trying to work up 'One Of' rounds for a specific rifle from scratch...
It's a LOT less work!
But, at the same time every long range shooter should burn up 2,500-5,000 rounds at one time or another figuring out the the stuff that normally comes spelled out in ballistics tables.
Makes you appreciate the work put into those tables and the consistant of ammo that shoots on the tables!

[Tex S]

Thanks for the replies guys.

I'll definitely be shooting over a chrony. No sense in blasting this much ammo with no data.

Cleaning after each powder sounds like a good idea. It would also be a great time to let the barrel cool since it is warming up here.

Also, while the brass isn't new, and I'm currently not set up to properly anneal, I have deburred all flash holes and uniformed the primer pockets. Additionally I have weight sorted all of this LC brass and culled oddball cases. I was actually surprised at how consistent the weights were on this once fired brass.

Anybody care to take a guess on which powder will work the best? I've heard of guys having good luck with the VV powders and RL15 with the 77gr SMK.

I have no idea what to expect with the 55gr pill.

[stagpanther]

My opinion only--don't get caught up in over-think of what you're doing with standard 5.56, you should be happy with a commercial grade rifle (non race gun) if you find a combo that gets you consistently MOA at 100, or .5 to 1 if you really find the sweet spot. Another thing I would recommend is getting a primer pocket swager or turner, chances are good you'll come across crimped pockets.

[243winxb]

Cleaning between different powders is needed, if not in the same "family"

Here is an example. http://www.imrpowder.com/msds.html

Look up 3031, 4064, same family, different amounts of ingredients.

I linked to info, so hope its not copyright infringement?

[cw308]

Nice collection of powder, with your setup 16" 1/8 twist 77gr.SMK & 55gr. I would start with powders no slower then Varget you will probably find 10% below max. will shoot best. What brass are you using ? F/L sizing no less then .002 case headspace without jamming your rounds.

[ToolAA]

Originally Posted by Tex S

Thanks for the replies guys.



I'll definitely be shooting over a chrony. No sense in blasting this much ammo with no data.



Cleaning after each powder sounds like a good idea. It would also be a great time to let the barrel cool since it is warming up here.



Also, while the brass isn't new, and I'm currently not set up to properly anneal, I have deburred all flash holes and uniformed the primer pockets. Additionally I have weight sorted all of this LC brass and culled oddball cases. I was actually surprised at how consistent the weights were on this once fired brass.



Anybody care to take a guess on which powder will work the best? I've heard of guys having good luck with the VV powders and RL15 with the 77gr SMK.



I have no idea what to expect with the 55gr pill.

I'm a new member here trying to compare notes on loading 6.5cm. This is my first post. I just wanted to comment on your question about 55gr Hornady FMJ-BT projectiles.

I've loaded over 800 rounds using H355 which I use for my range plinking ammo. I find that it is very consistent. Across several lots.

My rifle is an AR-15 with a stock Delton 16" 1:9 barrel

Typically I see about 1.5 MOA without tightly controlling seating depth and only checking powder weight on 20% of the loads. For plinking ammo I don't waste much time weighing cases. For reference Federal Factory 55gr loads average about 3.0 MOA under the same conditions.

However when first testing H355 to find a decent accuracy node I was able to achieve 1.0 MOA average for several test groups by tightly controlling as many loading factors that I could.

Additionally I have used H355 for match loads using 69gr Nosler Custom Competition projectiles. When controlling powder charges within 1gr and holding the seating depth within 0.002" from head to Ogive the groups are better than 0.9 MOA. However I think I'm at the limit of my shooting ability. I try not to ignore fliers unless I'm 100% sure I really shanked the shot.

I have since switched to AA2230 for the 69gr match loads and after initial testing my last range trip seems to be performing slightly better than H355.

So for the record I've been pleased with H355 for 55 loads in my rifle.

Since I'm new here I'm not sure if others have mentioned OCW load testing methods. If you are not familiar with this method you can read about it here. http://www.shell-central.com/Powder1.html. I am just learning about this myself and plan to perform my next load test using this method.

Enjoy your testing and be sure to post a full report of your results. I'm tagging this thread.

[Nosler guy]

I do a ton of load development. Lately it's been mostly for friends and coworkers. I use printer paper and sticky 1" target dots to save money and so it's easier to store in a filing cabinet. I write down all of the pertinent information about the load, rifle and who's it is on the top of the target so it matches the index card with all the info for each string so nothing can get mixed up or lost. There's nothing worse than losing a good load because the target got thrown away (there's a reason why I do this now) Might save you a buck or two considering the volume of testing you're doing.




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[ed308]

Thats a lot of loads to work and track. I usually fire 100 rounds through a new barrel then work up a couple combinations. I think you'll find bullets in the 68-77gr will be the most accurate out of your barrel. But you never know. Hornady's bulk 55 FMJ are cheap but not known for accuracy. I've had great luck with Varget, CFE and Tac and Nosler's 69 and 77 gr Custom Comp HPBT bullets. They give me .5 MOA. But just about any HPBT in that weight range is the same out of my .223 Wylde ARP barrels.