Have you ever wondered what would happen if you took 10 different kinds of Pistol Powder, where there is literally ZERO load data, and then loaded up 20+ different loads and went to range?  We just wanted to find out how it all worked, so we tested, massively.  We chose the most accurate bullets we are aware of, Berger 55 Grain, flat base.  We took the time to measure each case for internal capacity close to one another, and then we bought a bag of cotton balls and started loading ultra precision, hopefully subsonic (4) 5.56 loads for the AR15.  Read on to see if we lived, because many told us this was incredibly dangerous.  But of course, do NOT use this load information, and DO NOT do what we do.  Always, always, follow load data from Manufacturers.  We are experts in reloading, and experts in a few calibers.  We use precautions when going where no man has gone before... Do not do what we do.  This is for scientific testing purposes only.  This seems like a good lot of powders to test?  If you like this test and others like it, please donate to our site if you can, it helps us make more tests and grow the site.  We want to start making videos, but don't have the know how:(
How did we do this?
With precision, first of all. But more than that, we stuffed cotton into each case, so the powder was pressed tightly directly against the primer.  See illustrations.....
Illustration #1
Consistent burn, lower Standard Deviation (SD)
After cotton is stuffed in case
Cotton actually only comes up to about 1/2 or 2/3 of case.
Cotton out the barrel?
The cotton gets SHOT OUT! see it?
Blue Dot Ladder test
First things first.  This test has NOTHING TO DO with SUBSONIC!!! Lets take a slower burning, more bulky pistol powder called BLUE DOT, from Alliant.  And lets load up the following:
6.5,7.5,8.5,9.5,10.5,11.5,12.5 and finally 13.5.
Shooting at same exact spot, here is result.  2 shots PER LOAD, for a total of 16 shots here.  The lightest load, the 6.5 was the very bottom left, and "generally" the more load the groups moved upwards toward the right.  Not just UP.  
None of the shots cycled the rifle.  Not even the 2700+ FPS ones at 13.5 grains. 

Uh Oh...Debunking myths again
Wow. Look how Linear that is.  Its about ~157 FPS for every 1 grain of Blue Dot on average.  Now Blue Dot is not a good powder if you want tight standard deviation.  But this is only 2 shots each load, so its not saying much except after all this ladder, we can pretty accurately predict velocity using this combination. 

Of note.  NONE of these loads cycled the AR15.  The 2748 FPS load ALMOST cycled it, but I think it needs minimum 1 grain more to barely cycle it, and more like 1.5 grains more to consistently cycle it, just guessing. 

BTW, never, ever try these loads, follow manufacturer data.  This could be extremely dangerous.  Lets  look at primers next...
Blue Dot Primers
11.5 at top two
12.5 middle two
13.5 bottom two

Immediate takeaway.  Those are very rounded primers, and the brass is not bulged.  Very rounded primers.  And these are CCi41.   So we have not seen pressure yet to worry about.  Also, look at the cases.  Not chewed, and as clean as anything lower pressure would be.  Obviously, we don't have equipment to measure pressure.  But looking at these primers and measuring the case, and based on our experience, we would guess not SAAMI max pressure yet.
Shilen 7.5:1 20" AR15 Rifle
Not  many were subsonic, but only because there was no load data and we didn't know exactly where to start, but after all this, now we have ballpark to get under ~1,100 FPS.

Ok, remember when we told you the best Pistol powder on this planet is probably N330?  How about a .2" group at 50 yards with a standard deviation of "1"?  Huh?  Granted, 3 shot groups isn't that end all.  However, it is definitly an indicator, because unlike if the 3 shot group was 1", it cannot ever get better than 1". 

Lets be honest.  All the groups are acceptable really.  Because with loads like this, you are not shooting past 100 yards, we are guessing, right? 

You see that "test" in upper left, anove 3N37 label?  That is after scope was adjusted 2" UP, and it needed 4 more inches.  So at 50 yards, the IMR Target which was ~1125 FPS shoots about 6" low compared to ~3180 FPS normal 55 grain Bullets.  We adjusted the scope after first shot, so we could get closer to center of bull, for remaining.  No more adjustments after the Cleanshot, which was 2nd group. 

So we can see, the N320, which was vastly lower velocity than the N330 was about 2" lower.

Shilen 7.5:1 20" AR15 Rifle
Slightly increased loads from target above...just to understand ballpark for each powder in this rifle.  Notice the N320 group hit higher about ~3/4 inch with slightly more powder.

what about the data?
And there we have it...
Ladies and Gentlemen....Standard Deviations that are GOOD.  Why?  because the COTTON, that is why.  We are NOT saying use cotton, its just what we used.  We are not sure what is best.  The cotton, pressed the powder directly against the primer, and consolidated the powder in the case in the exact right place.  If you do not do this, or something like it, the case sitting in rifle, will have barely any powder all the length of the case, and flame burn will be erratic at best, leading to GIANT swings in velocity.    This is what the powder "Trailboss" is for, it fills the case so you don't need cotton, and you will still get consistent burn.  Trailboss also does not require load data, as if you go research the powder, you can see it gives guidlines on how to use it for "any" cartridge.  We don't like trailboss because its not a versatile powder.  LIke for example, its not for 9MM at all, and also you cannot compress it.  It has a more singular purpose for lighter loads.  So since we use cotton, we can make any pistol powder shoot, with good SD and ES, in a rifle like 5.56 AR.  If you like Trailboss, please buy it, its a free market, do as you like.

We actually shot more loads of the 3N38 6.0 grain, as this was our sight in ammo too, and the other 2 sight in shots?  Were 1531, and 1532.  So across 5 shots, this load was Standard Deviation of "1".  5 SHOTS.  This is probably not repeatable, but it just goes to show, when you measure each case, and be super careful about placing almost exact amount of cotton in it, and pressing powder tightly against primer, similarly,   using consistently OAL, and good primers, with superior powders measured out with precision, you will "generally" get better than average results. 

This is just the beginning, probably going back to range to test using 77 grain bullets to get close to subsonic, and then ladder test a few different bullets using the Holy Grail of Powders, called VV N330.  Damn that powder is good.

Also, notice stability was good?  No issues.

If you like this test and others like it, we appreciate any donation.  Videos coming we hope!
Donate to us through PAYPAL or VENMO. Thank you for supporting our site!
Contact Me