SS109 / M855 load info

[mrtoyz]

These are my experiences, not claiming to be an ammo guru...

It wasn't as easy as I thought to find reliable SS109/M855 load data, so I thought I'd post what I found and have tried.

After tearing down many Winchester and Federal SS109 labeled rounds I found that these are the average specs:
COL:2.247"
Grains:26.8
It was an eye opener to see how much variability there is in powder charges from this factory loaded ammo. I saw a 1.3gr spread. WOW My Dillon 550 has about a .2gr variance load to load.

My research showed that Hodgdon H335 is the same powder Winchester and Federal use in their production. Visually it does look identical.

I decided to back down the grains a little. I had good results with this clone recipe:
H335
26.4gr
2.247"COL
Mixed brass
Whatever primers... Still not sure primers make much difference. Maybe some else has other ideas.

Good Luck!

-T

 

[sinister]

Re: SS109 / M855 load info

Off the Army Small Caliber Ammunition Data Sheet (TM 43-0001-27) for M855:

CARTRIDGE, 5.56MM, BALL, M855
Type Classification: STD - MSR 05826003.

Use: Machine Gun, 5.56mm, M249E1; and Rifle, 5.56mm, M16A2. The cartridge is intended for use against personnel and unarmored targets.

Description: BALL Cartridge. The cartridge is identified by a green bullet tip.

Tabulated Data:
DODAC 1305-A059
UNO serial number 0012
UNO proper shipping name Cartridges for weapons, inert projectile
Weight 190 gr
Length 2.26 in.
Primer Percussion
Propellant:
Type WC 844 <span style="color: #FF0000">(as of 1994 when Winchester/Olin were running lake City -- once ATK got the ontract they would most assuredly have changed it to their own powders to stay at spec'ed velocity and pressure)</span>
Weight 26.1 gr
Projectile:
Weight 62 gr
Performance:
Chamber pressure 55,000 psi
Velocity 3025 fps, 78 ft from muzzle

 

[mrtoyz]

Re: SS109 / M855 load info

Thanks

Its my understanding that H335 is the same as WC844. True or false?

Its interesting that they say 26.1gr. Not at all what I saw.

Also interesting that my loads with 26.4gr chrono at an ave of 2871fps, 15ft from the muzzle. Temp 50deg

 

[sinister]

Re: SS109 / M855 load info

Lake City and the Army use the nominal data on the performance sheets but vary powder charges to get optimum pressure, velocity, and accuracy.

H335 may or may not be WC844 -- it depends on whose powder mill the contractor and the government use. Note that Hodgdon bought out DuPont's IMR line, Federal still uses IMR 4064 in some of their 308 loads, and Winchester buys some of their Powders from General Dynamics.

Also note the data dates back to 1994, and the government changed contractors from Olin to ATK back around 2000.

 

[07yzryder]

Re: SS109 / M855 load info

I came across a site that has military loads listed, they say 26grs of ramshot tac, but the Ramshot site has 25gr as a max.


http://www.ramshot.com/wp-content/uploads/2010/09/ramshot_handgun_rifle.pdf


http://www.frfrogspad.com/miscellq.htm#duplicate

 

[rg1911]

Concerning WC844 and H335, I don't believe they are the same, at least with the batch of WC844 I have. It definitely burns dirtier than my H335.

Richard

 

[supersniper]

WC844 is NOT the same as H335

They are close in burn rates but you need to work up your load with WC844 as it is not a commercial canister powder - each lot can be very different.

Primers DO make a difference - I have seen a 50fps increase when switching from Win to CCI primers - everything else being the same.

 

[Suasponte]

Here ya go.

Terry