Ball Propellant, the good the bad and the ugly.

[Humpy70]

As a general rule BALL PROPELLANT tends to be more erosive on barrels than stick propellant.

To be accepted by the gov't for 5.56 and 7.62 it has to be certified by Aberdeen Proving Ground and the following is what happens to get any propellant certified.

The candidate is sent to Lake City, about 350,000 rounds are loaded and sent to Aberdeen where it is first chronographed in a machinegun and also fired at 100 yards for dispersion from a machine rest which some call a vise, cradle but we referred to them as "hard mounts"

The worst test is high temp. Three guns are shot and recorded as above and then sent to the "cold room" which can take you to -65 below zero to 160F and the barrels are shot a 140F in bursts of 50 rounds IIRC from all three guns and for 10,000 rounds and cleaned at a specific schedule which I think was 600 rounds.

The guns are removed, cleaned and taken back to the indoor range and all three are fired again for velocity and dispersion. Three things fail propellant or weapons.

1. a drop in velocity of 200 FPs.

2. an increase in dispersion of 50% (lets say you have a weapon that gives you a 8" dispersion average on three ten round bursts and it now gives in excess of 12". The propellant fails.

3. the bullets yaw at 25 yards. There are overlays with circles and if the 15 degree circle won't cover the a bullet hole the propellant fails.

As it turns out a velocity drop rarely occurs in excess of 200 fps.

Dispersion and yaw fails it.

That means the remaining 300,000 or so rounds is sent to the burning ground, cans opened, ammo piled up and the pile is fueled with diesel fuel and burned up.

OK next you have all ball ammo is loaded with ball propellant and the spec for M80 Ball is below. You will note it calls for three different propellants, one ball and two stick. Ball propellant works best the the SCAMP lines at LC and FAIK all ball is loaded with this number.



The above is the spec sheet for M80 BALL ammo.



This is the spec for M193 ball ammo

Note they both call for WC846

Unless something has changed I am not aware of M855 is also loaded with it. That would lead you to believe that was THE propellant that took out the barrels, right?

When the M16A1E1 (adopted as M16A2) was submitted to Aberdeen Proving Ground I was assigned as the Test Director to this Project and the XM855 ammo was loaded with WC846.

The Marine Corps Requirement was for a 12,000 rd barrel life and I stopped testing at 6000 rounds because the barrel were shot out so bad that we could not hit a 8ftX12ft target FRAME from 800 or 700 meters and at 600 meters the groups were barely inside the 8X12 target FRAME.

Rejection for M16 family is 4.5" or less at 10 yards and rejection is 12" at 100 yards. At 4800 rounds the groups were 7" so were right at rejection.

This led to a huge test matrix where we fired 10,000 rounds a day for 14 straight days with XM855, M193,and SS109 ammo we got in from Canada and we had to hand delink 100,000 rounds. The SS109 was delivering right at 7.2" at 12,000 rounds. and the others failed as they had previously with WC846. So the spec was met but FAIK the M855 and variants are still loaded with WC846.

The SS109 ammo was fabulous and was the best ball ammo I had ever seen.

Bottom line here is ball propellant is not as kind to barrels as stick propellant which is all I load for my ARs.

[Steve Shannon]

This might be the most interesting post I read today. Thank you!
I’m sorry if I missed it, but is the powder used to load ss109 available commercially?


Sent from my iPad using Tapatalk

[Humpy70]

Good question, don't know but I suspect it is a stick propellant and if I had to guess I would surmise it might be Vihtavouri. I forgot to add when LC loaded the XM855 ammo they used FN manufactured bullets just as the SS109 was loaded with and here is the kicker. The 100,000 we got from Canada was loaded in 200 round belts with tracers. We did find out however LC used WC846 in the stuff they loaded for us.

You will not IMR 8208M was qualified and I have seen it for sale surplus but have never been able to get any.

[mack7.62]

I had to pull down almost 1600 Canadian SS109 rounds because they were popping primers in Colt AR's, powder was a flattened ball, ammo can marked Ball C77 IVI86A01-14. I don't think you can say all ball powder is as bad as WC846, also I recall hearsay from the time that SS109 bullets were higher quality than M855 and were more accurate of course that doesn't matter since you were using 109 bullets. I still have the IVI power in a jug, sounds like it was pretty good powder might have to work up a load with it. The two cans I got were also linked but no tracers all ball.

[Humpy70]

Interesting, do you know what the striker indent depth was on the AR?

Reason I asked we had ARs come into Aberdeen that were not up to spec on striker indents and I got misfires.

If you don't have your striker indent to spec you will get reverse primer flow where the primer material wants to run up into the striker opening on the bolt face and if it gets weak enough you will "blank" a primer which means the primer cup gave way and insert the primer material into the striker channel which will cause even more problems.

[mack7.62]

No I don't, this was years ago but I do recall that I locked up two different Colt AR uppers using Colt BCG's a 20" and a 16" on first range trip firing this ammo. After that I stopped shooting it and several years later started pulling it down a little at a time. I always figured it was reject ammo or maybe it worked OK in Minimi's, 86 dated so fairly early in the change over.

[Humpy70]

I am confused, could you describe "locked up" more for me? Blown primers? case ruptures????

[mack7.62]

Blown primers, IIRC the 20" got a primer stuck in the bolt lugs and I couldn't retract the bolt, the 16" had a primer in the FCG so trigger was stuck. I didn't figure all this out until I got home and tore them down, once I found the primer in the 16" I looked at the fired brass and found about 6 or so of the 30-40 rounds fired without primers.

[Humpy70]

I assume this was on new unfired ammo? Was there evidence of primer's being crimped in? I have had primers fall out of cases with soft heads on firing first shot but they were not crimped in place. They fell out when bolt was opened but there was no overpressure involved. Very interesting.

[mack7.62]

Yes new ammo, on links in 50 cal ammo cans, primers were crimped in, I still have the components, cases, powder and bullets and could take pictures but I don't have any way of posting them.