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Posted: 11/6/2003 12:18:31 PM EDT
hy 2 every1 on the forum...
can some1 tell me if the amount of propellant in M855 and M193 is the same?
and if not , how much is there in each 1?

10x in advance...
Link Posted: 11/6/2003 1:15:39 PM EDT
Don't know the answer to your question, but welcome to the forum! Don't know if you've been browsing the site for long, but there's lots of good info here. Have fun!
Link Posted: 11/6/2003 2:10:37 PM EDT
Welcome to the forum! Straight off the label of my 8 pounds of WCC-844: 5.56mm M855 62 grain Green Tip - 26.1 gr. Out of Military Manual available online for the M193: 5.56mm Ball M193 WCC-844 - 28.5 gr. Now, these loads must be reduced and worked up to. *Normally* powder mfgs. recommend 10%. Let your concience be your guide. I use 27.5 grains of WCC-844 with the Win. 55 gr. FMJ bullet. Posted for informational purposes only! Danny
Link Posted: 11/6/2003 2:12:43 PM EDT
The US Military specification for M193 calls for either 28.5gr of WC-844, or 26.5gr CMR-170. M855 ammunition is supposed to have 26.1gr WC-844. Quality control tolerances allow for a slight variance above or below the stated powder charge, but I can't seem to find the numbers at the moment as to how much variance is allowed before it is considered to be out of spec.
Link Posted: 11/6/2003 2:27:36 PM EDT
Link Posted: 11/6/2003 3:13:54 PM EDT
Neither M193 nor M855 Ball is loaded to a spec for powder weight, nor is any US military ammunition. They're all loaded to a [b]velocity standard[/b]. The Army Ammunition Sheets list the [i]nominal[/i] powder charge needed to achieve the velocity spec; the ammunition is [i]test fired[/i] several times during production to ensure it meets this spec. Actual powder charge is varied to maintain velocity standard. -- Chuck
Link Posted: 11/6/2003 4:03:33 PM EDT
hi all ' and 10x 4 the warm greetings. also i would like to thank u for the help... another question - if the M855 velocity is higher , how come there seems to be less propellant , let alone that the bullet is heavier and the pressure in the barrel is higher. p.s - excuse me for any typing error , i'm from israel.
Link Posted: 11/6/2003 6:35:01 PM EDT
M855 velocity (62gr and ~3120fps [i]at the muzzle[/i]) is lower than M193 (55gr ~3265fps). There's more room in the case for more powder with the shorter M193 bullet and the projectile is lighter. Note the milspec calls for velocity measurement of 3025fps @ 78' and 3250 @ 15' respectively, so it's hard to make direct comparisons of the [i]muzzle velocity[/i] without some ballistics software. -- Chuck
Link Posted: 11/7/2003 1:51:04 AM EDT
indeed , now that i have checked , the muzzle velocity of the m855 is lower. but according to what i know after about 200 yards the M855 starts to preform better then the M193 , is it due to bigger leak of speed of the M193?
Link Posted: 11/7/2003 3:30:15 AM EDT
[Last Edit: 11/7/2003 3:14:00 PM EDT by Chuck]
At 200 and 300 meters M193 Ball is still faster than M855. [From the M4 Carbine.] [s]I'm not sure what data your're reading which indicates otherwise.[/s] Reliable fragmentation range of M193 is longer than M855 as fragmentation potential is linked to velocity. The window opens about 2500 fps. -- Chuck Edited for too many years shooting the M4! [;)]
Link Posted: 11/7/2003 8:38:26 AM EDT
its written in the ammo oracle FAQ http://www.ammo-oracle.com/#m855vm193 that the crossover point of the M855 speed over M193 is at 200 yards.
Link Posted: 11/7/2003 3:11:07 PM EDT
I typed too fast: You're right on the 20" 2500fps crossovers with 20" bbls. The 2700fps window in the M4 Carbine closes at 100 yards with M193 and at 75 with M855 Ball. They both run out of the 2500fps window right aroung 150 yards. -- Chuck
Link Posted: 11/7/2003 9:58:44 PM EDT
Originally Posted By Chuck: M855 velocity (62gr and ~3120fps [i]at the muzzle[/i]) is lower than M193 (55gr ~3265fps). There's more room in the case for more powder with the shorter M193 bullet and the projectile is lighter. Note the milspec calls for velocity measurement of 3025fps @ 78' and 3250 @ 15' respectively, so it's hard to make direct comparisons of the [i]muzzle velocity[/i] without some ballistics software. -- Chuck
View Quote
The reason for the difference in powder quantity between the two is not directly related to the volume in the case due to bullet seating depth. Everything revolves around pressure. I don't remember the exact number right now, but the pressure limit for .223 is over 50,000 psi. (It may be more for 5.56.) They drive both kinds of ammo as fast as they can without breaking that pressure limit. That is what the amount of powder is based on. The reason the lighter bullet gets more powder is because it will accelerate quicker down the barrel and pressure won't build as much.
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