M855 clone issues

[Lionel]

Hello, its my first post in FLF, thank you for reading.

A few years back in the 2012 scare, I purchased ALOT of pulled 62 grain SS109s amoung other things. I spent some time learning since then working with other things and decided that I probably should start doing SOMETHING with them. I did a lot of reading and found that H335 seems to be the best powder to work with and I have enough on hand. I also have a large amount of H322 left over from another project.

Here is the issue: As part of a trade, a friend gave me a 5 gallon pail full of deprimed brass that he "trimmed" to the minimum. He said he does that so that all his cases are uniformed when he loads them. At the time, it sounded fair enough, but now after I cleaned them all up and actually measured them I found that they range from 1.741 to 17.49 alot of them seem to be around 1.744/5 but its really hit or miss.

Here is the question. My best understanding for the COL with the mil 62gr bullet is 2.260; should I:

a) Drive on with this projecting using H335, blazer primers I'd set aside and these mixed cases

b) Drive on with this project using H322, blazer primers and these mixed cases because the longer bullet in the shorter case, with H322, will take less room.

c) Leave the M855 project for another day until I get more brass. Use my left over H322, leftover Winchester primers and a bucket of plain jane FMJ 55grn Hornady bulk bullets with these mis-matched cases and make them into a nice target load.

If we were talking about a few hundred, I wouldn't care, but likely this is going to be thousands of rounds. Thanks for your advice.

[rg1]

With pulled SS109 62 FMJ's they are probably from several different lots and maybe even different manufacturers and the bullets themselves will have slightly different tip profiles and lengths. While 2.260" is maximum length for magazine loading I'd keep the overall length a little shorter. I would try to keep the maximum length of the longest round at 2.255" with some ending up at 2.250" plus or minus. If you try for 2.260" you'll end up with some longer and may cause magazine feeding issues? Bucket of brass trimmed a little short I wouldn't worry about their lengths. May want to measure and sort them by manufacturer and case lengths. H335 is a little fast and H322 even faster for the 62 FMJ but H335 will do well with them but it will be difficult to get military velocity without running into pressure problems. I wouldn't try for M855 velocity and keep pressures less and looking for decent accuracy. I prefer powders a little slower like Win 748 for 62 FMJ's. While your cases are trimmed shorter than recommended 1.750" they will cause no problems firing them.

[Lionel]

RG1

That is great advice, thank you. My number one concern is safety, followed by performance. My only concern is that with the large difference in cases, that I would inadvertently create a compressed or dangerous round. Good to know that the 2.260 is the max; I will definitely be staying under that; your suggestion seems to be a safe number.

[IMtheNRA]

Have those 5 gallons of cases already been resized or simply deprimed? They will get longer after you resize them. Trimming is done after resizing.

In any case, trimmed length variation in your brass will have no impact on your finished cartridge overall length.

[RickD1225]

CAUTION: The following post includes loading data beyond or not covered by currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.


Go to American Reloading, WC 844 powder and open this

Army Ammunition Data 5.56 PDF for full 5.56 data

WC 844 is the military designation for H335.

26.1 GR at a COAL of 2.26, but l would start a little shorter like previously noted to be sure the max is 2.26 or less. 3025 FPS at 78 ft from the muzzle

[Slamfire]

Trim length will not affect the internal volume of the case. Trim length is a safety consideration if the case neck is too long. If the case neck is too long, and goes into the chamber throat, the case neck will pinch the bullet, creating a bore obstruction. This will raise pressures. Over trimming the case neck, that is shortening the case neck, does nothing much at all, unless the case neck is trimmed so short that the bullet falls out.

I would absolutely stay away from any US Army Ordnance Department pressures or velocities. The US Army Ordnance Bureau has since the very first day the M16 was issued, has raised pressures and velocities in order to compensate for the dismal ballistics and stopping power of the 5.56 round. I am of the opinion that Stoner designed his locking mechanism for 50,000 psia and shorter after the Army started playing around with his AR15, they bumped the pressure up to 52,000 psia for the cartridge. As the decades have increased, so has the pressures the Army loads their cartridges. Unfortunately, they have not redesigned the bolt or barrel carrier. Now pressures are in the middle 60,000 psia range for some 5.56 cartridges. That high of a pressure will crack bolt lugs in under 10,000 rounds and will cause extraction difficulties.

Instead of replacing the current inventory with a more lethal round and a better combat rifle, the US Army Ordnance Department simply takes the path of least resistance by bumping up pressures. This creates function issues for the troops in the field, and increases the logistical support costs of the weapons. Simple, easy, and stupid. Just what you would expect from a clock watching Government Agency interested in expending the least effort during the work day.

The proper solution for a civilian is not to attempt to copy Army folly but to reduce powder and pressure levels and stay within SAAMI specs.

[overthere]

Lionel, I would not worry about the trim lengths of those cases. The minimum SAAMI case length for 223 is 1.730 so the ones you have are well above that minimum.

http://www.saami.org/PubResources/CC...0Remington.pdf

Either H322 or H335 should work fine with the 62gr projectiles and those cases, at least for plinking rounds.

Do a load workup with each powder and see which one ends up working best for you in your rifle.

[Unclenick]

Some confusion here.

First, Slamfire is correct that technical manual information as Rick referred to IS NOT LOAD DATA. I put a warning into Rick's post because of this. TM information is supposed to reflect a report on one lot of cartridges, but its editors are not ballistic technicians so it has confused units and often fails even to report an historical load correctly. For example, if you look at the last full version of this manual from 2005, it is still reporting copper crusher numbers as "psi" and giving charges of powders the military no longer uses. On page 5-9 it says M2 Ball's 150 grain bullet was loaded to 50,000 psi with 50 grains of IMR4895, then on page 5-21 it says Match M72's 173 grains bullet was loaded to 50,000 psi with 50 grains of IMR 4895. Well, not only would the two bullets not produce the same pressure with the same charge, the M72 charge was never used that I am aware of. It would take one extra-extra slow burn rate lot of 4895 to do that. I believe the fastest 4895 lot was loaded by Lake City in 1964 to 46.0 grains, and the slowest lot used was loaded to 48.5 grains by Frankford Arsenal in 1961.

The bulk powders used by the military vary in burn rate such that no two lots produce the same load data. Instead they rely on pressure guns to test both chamber pressure and gas port pressure and adjust the charge to meet both and meet the velocity requirement for the round. If the powder cannot achieve all three, it's rejected for the particular load and is set aside for other loads, and if none are found, it is surplussed out (so don't trust what you buy surplus until you test it carefully). Canister powders have to be more consistent, despite the added expense, because most handloaders rely on databooks rather than pressure measurement to determine their loads. If canister powder burn rates varied as much as bulk powder burn rates do, published loading data would frequently prove invalid for many powder lots.

On top of that, anyone who has looked at the SAAMI standard knows 60,000 psi is used as peak pressure for 30-06, not 50,000 psi. Is the TM giving that pressure incorrectly as an upper limit? Yes and no. Yes, 50,000 is correct for a copper crusher, and SAAMI has 30-06 at that limit of 50,000 CUP even today. But the TM says "psi". Nope. It's CUP. Board member PhilFAL's brother used to work in a lab at Aberdeen Proving Grounds, and he says the lab was using the improved M11 Copper Crusher through the 1980's and the lab boys all said "CUP" because they already had some piezo transducers they were experimenting with and needed to make the distinction. DuPont and others were already using the diaphragm type piezo transducer in the 1960's to make precise pressure curves on oscilloscopes. But the TM manual editors kept putting "psi" after copper crusher results like we were still living between the World Wars. I'm sure some bureaucratic rule made them do it, but it has caused mounds of confusion about what actual pressures have been used in cartridges.

Here are 5.56 NATO and .223 Remington Maximum Average Pressures to the best of my ability to discern them:


M193

52,000 psi (really CUP) by M11 copper crusher
52,000 CUP by SAAMI copper crusher
3700 bar (53,664 CUP) by NATO Europe copper crusher
3800 bar (55,114 psi) by U.S. conformal transducer (SCATP 5.56)
4300 bar (62,366 psi) by Kistler channel transducer (EPVAT)

Yes, the above pressures are actually all the same; only the instruments making the measurements are responsible for the differences in reported pressure magnitudes.


M855/SS109

55,000 psi (really CUP) by M11 copper crusher
No listing by SAAMI
3700 bar (53,664 CUP) by European NATO copper crusher
4000 bar (58,015 psi) by U.S. conformal transducer (SCATP 5.56)
4300 bar (62,366 psi) by Kistler channel transducer (EPVAT)

Again, the above pressures are actually all the same; the differences in instruments making the measurements are responsible for the differences in pressure magnitudes.


.223 Remington

52,000 CUP by SAAMI copper crusher
3700 bar (53,664 CUP) by CIP copper crusher
55,000 psi by SAAMI conformal transducer
4300 bar (62,366) psi by CIP channel transducer.

Again, the above pressures are actually all the same; the differences in instruments making the measurements are responsible for the differences in magnitudes reported for Maximum Average Pressure.

If you notice one thing in all that, it is that the European bar measurements never change for the type of measuring instrument for any of the cartridge designations. They've never gone up or down, and this is despite the fact the NATO and CIP transducers take their gas samples at different locations. Their calibration is that consistent. They believe their piezo transducers instrumentation to be accurate within 2% of absolute, though I don't know how they arrived at that conclusion. I can tell you their copper crushers and channel transducers work more similarly than ours do. They drill the same size holes at the same locations in the cases to sample the pressures in either, except for the NATO transducer which samples pressure just past the case mouth and needs no hole in the brass. The U.S. copper crusher SAAMI spec makes case hole drilling optional and the conformal transducer measures over top of the brass without the brass breaking through, so no hole is used. Why this matches the European transducers pretty well in .308/7.62, but not in .223/5.56, I don't know. It's something in the dynamics, apparently.

[IMtheNRA]

Lionel, I think there is another issue in trying to replicate military 855 loads. As you can see from Slamfire's and Uncle Nick's posts, these are high pressure rounds no matter how the pressure is actually measured.

This military ammo that you want to replicate is made with brand new Lake City brass and Lake City bullets, both of which are held to extremely high standards of metallurgy, dimensions, weight, thickness, treatment, manufacturing and handling.

You're starting with a bucket of mixed used brass of unknown history and many manufacturers. You also intend to load USED bullets of unknown manufacturer(s) and unknown reasons for them being scrapped in the first place.

This may not be a safe or reliable method to replicate actual military 855 loads. If I were in your place, I'd consider developing a safe and comfortable plinker load with these components and not push them to maximum load data specifications.

[Lionel]

First, thanks for all the replies. There is a lot of great information here and I'm learning alot. I'll clarify a couple of points. First is that I'm a 24 year military vet. I've done a lot of shooting in and out of a uniform. I'm acutely aware of the limitations of the M855. At the time I acquired some of these components back in 2012 was during the "scare". I do have other resources and choices for reloading and the reason I've been sitting on this for four years was because of all the reasons some of you guys have already noted: poor performance, unsafe pressures and so on. The second reason that its sat for so long is that I considered this not something for someone with NO experience to tackle. I've done *some* other loading with my 650 and am seeking to continue to expand my knowledge.

My number one priority is safety. If I really had a burning lust for 5000 M855s I could just do a few OT shifts and details and work and buy them. My goal is to make a safe, reasonably accurate round and in the process of doing so, increase my knowledge.

To answer a few questions, they were de-primed and trimmed by my friend with his 1050. Some of the cases have dents on top (which I've tossed aside as I've found them). I since have cleaned almost all and have a few thousand of them bright and shiny. Due to the variances in the rounds, I'm starting to think that perhaps he didn't resize them. Why he wouldn't have is beyond me. The next time I see him I'll ask. All other brass that I have will be processed by me.

I'm not intending this ammunition (or even the AR platforms I'm using for that matter) to defend my life.

As far as the numbers quoted go, thanks for the second on the COAL and also thanks for the reassurance on the short cases. I'm going to use the recommended 2.255 and will keep a close eye. I'm also going to leave the H322 for another day. As far as a "target" weight, I'll just work up and see how it goes. I may not break 25.5; we'll see how it goes.

[rg1]

I've only tried one load work-up with pulled 62 FMJ bullets in RP and WCC brass using H335 powder and RP 7 1/2 primers. In my tests my maximum load was with 24.6 grains of H335 for a velocity in a 20" barrel AR at 3035 fps. Chrono was 10 ft in front of the muzzle. I'd be cautious going higher than 25 grains. Results in your rifle may differ?

[Unclenick]

Lionel,

One tool you should have is either a case gauge or a case comparator. Either may be used to tell you pretty quickly if the cases were sized adequately for shooting in a different chamber or not. It is possible, for example, to have once-fired brass that was fired full-auto that just will not get small enough for an AR.


Some differences in SAAMI and Military specs.

SAAMI:

Maximum Average Pressure (meaning average peak pressure, not average overall barrel pressure) for 10 rounds of new ammo not to exceed 55,000 psi on pressure transducer and with no more than 11,300 psi extreme spread among the 10 rounds. Highest single cartridge limit above MAP +10,000 psi.

Maximum Average Pressure for a 10 round sample from the same lot during its expected shelf life, 58,500 psi on conformal transducer with the same extreme spread limit.

Maximum 24" test barrel velocity spread among standard bullet weights: ±90 fps


Military M855 numbers:

Maximum Average Pressure 55,000 CUP (M11 copper crusher), 58,114 psi on conformal transducer or 62,366 psi on channel transducer. Tolerance: No individual cartridge in the test may exceed 61,000 CUP (64519 psi by conformal transducer and 69,170 psi by channel trandsucer), nor shall the average pressure + three standard deviations exceed those same values.

Gas Port Pressure 12,000 psi minimum with ±2000 psi maximum variation in sample.

Maximum 24" test barrel velocity spread for cartridges conditioned at 70°F: ±40 fps with velocity SD <40 fps.

Maximum 24" test barrel velocity variation from -65°F to +125°F: 270 fps.

Additionally, the military has visual inspection requirements and accuracy requirements which SAAMI and the CIP don't address.

A good resource for the handloader is the SAAMI drawing of a cartridge and its chamber. These drawings have unilateral tolerances. That is, the cartridge linear dimensions are given as a maximum value with a minus-only tolerance, while the chamber linear dimensions are given as minimum values with a plus-only tolerance. This is standard engineering practice where exceeding the tolerance at one end of the range completely prevents functioning (a critical dimension). Using maximum cartridge and minimum chamber numbers as the critical dimensions ensures the two can be put together to fire. I said "linear dimensions" to exclude corner radii, which can need the opposite sense to guarantee fit, depending whether they are inside or outside radii.

SAAMI .223 drawing is here.

The SS109 and M855 have the same projectile weights and same pressures, but the projectiles themselves are slightly different. The SS109 has an ogive that is further forward and has the potential to jam into the lands of some .223 chambers with shorter commercial throats. The M855 doesn't appear to be at risk of doing that, but keep an eye peeled, YMMV.

[Lionel]

Some of these numbers you're posting unclenick are making me dizzy and I've got to read them a couple time to understand what you are talking about. But I'm getting it. I'm careful enough that I want to know exactly what I'm doing at before I load anything and I'm not getting anywhere near the max pressures. At some point, I have a M1903 springfield issue and I would really like your advice on it. Its a question about loads and pressures and the low/high SNs after this project is done I'll move onto it.

RG1, thanks for the advice; thats a pretty hot round and the load is a lot less then what others stated. I've loaded 55gr hornady fmj-bt before and the hornady book states their max reccomended for H335 is 23.1gr for 3100 feet per second. I've read all over people loading up to 26gr and I thought that hornady was just being lawyer safe. They definitely were not. I was getting noticeably felt recoil out of the M16 rebuilt into an AR15 that I use as my test platform. I can't remember the exact weight that I worked up to, but I won't be doing anything like that again. What do you recc as a starting point for the load? 21gr and then jumps of .5gr?

[Unclenick]

Loading for pressure you can go in steps of about 2% of expected maximum. If you get a pressure sign, back down 5%. So 0.5 grains is a reasonable step for this powder.

Loading for accuracy (finding a sweet spot load) 0.7% to 1.0% are about where you need to be to avoid jumping past a sweet spot and failing to identify it. So, about 0.2 grains per step for finding an accuracy load for your charge range.

Hodgdon says they use the SAAMI MAP as an absolute pressure limit, and their maximum load is what results from adjusting their data so the highest pressure they saw in testing would not exceed the SAAMI MAP number. That's not how SAAMI intended the number to be used. They intended for it to be the limit of the average, not the worst case peak, and they allow for higher variation than Hodon's practice does. I'm not sure this is all about lawyers. i think at least part of it is about not knowing the exact burn rate your lot of powder will have as compared to their test lot, and therefore not knowing the exact pressures it would produce in their test gun. A manufacturer tests pressure from every lot of powder they use.

[Jimro]

Lionel,

It should be noted that M855 has several lot acceptance standards that you won't find data for in a reloading manual. It should also be noted that the pressure standards for M855 have changed with revisions to the MILSPEC over the years, for both port and chamber pressures.

The accuracy spec isn't too hard, essentially 4 MOA, although the actual mil standard is calculated in Mean Radius at 600 yards with a maximum vertical and horizontal standard deviation from the reference lot.
The port pressure needs to be enough but not too much to function in M4, M16, and M249 weapons, and this number has lowered in the most recent revision.
The primers are crimped.
The necks are sealed.

The best thing to do is to do a load workup with your components to verify that the max charge is safe in your rifle. Then do a ladder charge in half grain increments from starting to max with ten loads each. Get ten rounds of M855 surplus, and then watch the ejection. When you find the 10 handloads that eject closest to the M855, you've found the closest clone you can with a little refining.

You can't really crimp the primers, but you could seal the necks if you wanted.

If that doesn't get you as close a clone to M855, I don't know what will. I doubt accuracy will be anything to write home about, but then again, most lots of M855 aren't anything to write home about either from an accuracy standpoint.

Jimro

[Road_Clam]

I have about 400 SS109's did some testing and tried to argue the common "steel core's don't shoot worth a crap" mindset. I loaded my tried and true W748 from 25 to 26.2 gr and at the end of the day, "steel core's don't shoot worth a crap". The best I could get from my Bushmaster 16" heavy bbl carbine was 2.3 MOA at 100 yds. Maybe some more powder testing could yield better accuracy but my gun club does not allow steel core ammo at most of the ranges so no sense for me to persue.

[Jimro]

The triple material construction of the SS109 projectile ensures that there is always more "bullet imbalance" than is good for accuracy. They generally fly better out of 1:9 twist barrels than 1:7 twist barrels, but still there are limits on how good they'll group. One of the best points about M855A1 is much better bullet balance that goes with a better BC and more consistent terminal ballistics, of course the downside is barrel wear. The original M855 was spec'd at 10,000 rounds before barrel changes, but I don't know what the difference is for the A1 version.

2.3 MOA is perfectly acceptable for military use, that's still a tennis ball shot at 80 yards if the rifleman is a good enough marksman, and still center mass out to 600 meters. But, we don't ask match bullets to punch through a Soviet helmet at 600, and we don't ask SS109s to be match bullets. Heck, if you are good enough 2.3 MOA is accurate enough for Master level High Power scores.

Jimro

[wpsdlrg]

You should:

Do what works for your particular rifle !

As others have said, avoid trying to duplicate the M855 overload. Not necessary....and just leads to excessive wear and tear. In addition, I seriously doubt that you'll find the best accuracy that way.

I took a bunch of M855 ammo, actual Lake City military stuff, in trade a while back. Hard primers....accuracy sucked, charge weights varied widely, etc., etc. I'll go so far as to say that the ammo, as loaded, is garbage. Serves a need for the military....but not so good, really.

But, nothing whatever wrong with the COMPONENTS.

So, I pulled all of it down. I worked up new loads, using the components....suited to my rifles. Voila ! Very good ammo.

I'd strongly recommend doing the same. Forget the "M855" nonsense.....and just load for your gun(s).

[Lionel]

Alright, more good information. .5 grain jumps is safe, but .2 grain jumps to catch the sweet spot. Also, I just want to clarify that my lawyer comment was a thought in my head, but after actually experimenting with their ammunition, I came to the conclusion that I did not need 26.1 grains of H335 as is widely quoted.