Norma 203B in M1 Garand

S

Sharpshooter284

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Picked up a CMP "re-manufactured" M1 Garand around Christmas, which is all the Garand experience I have. Anyone have any experience with Norma 203B in the M1, specifically a M2 duplicate load. I found a pound at the local range. Apparently since it wasn't their "normal" powder no one wanted it.

Looking at Norma Data, they start at 50 grains for 2897fps. My idea is to start there and not go any higher. Burn rate charts show it between RL-15 and Win 748.
 
It's a bit slower than IMR4320 which is the slowest powder safe for Garands. Reduced loads may be ok. I would not take the chance. Port pressures can be too high.
 
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If 4320 is the slowest for Garand then a reduced load of a slower powder is a Bad idea . Who knows where that pressure will be with an unknown slower powder . Be careful is all can say , strange things can happen when reduce slow powders.
 
Thanks. That's were I was getting confused. Most charts put 203-b between RL-15 and Varget but 4320 comes in faster on one chart and slower on the next. I think I do have a little 3031 and 8208 XBR I was shooting in 338 Federal. I'll keep the 203-b for 308 and 7mm-08.
 
Sharpshooter284 said:
Thanks. That's were I was getting confused. Most charts put 203-b between RL-15 and Varget but 4320 comes in faster on one chart and slower on the next. I think I do have a little 3031 and 8208 XBR I was shooting in 338 Federal. I'll keep the 203-b for 308 and 7mm-08.
Click to expand...
Those charts can be confusing , I guess it's hard for the manufacturers to agree . They are a good starting point for research though .

3031 in the Garand is another one folks can't agree on . Many debates on the web about that one.
 
An old rule of thumb for the Garand is that any powder whose maximum pressure load uses over 53 grains of powder is too slow and should be avoided, but this doesn't work in all cases. The LC M2 with 56 grains of WC852, which was originally disqualified for the Garand based on gas port pressure, was later found not to produce excessive operating rod velocity and was issued for DCM activities using the Garand. So, while 203B is just over the line for that 53-grain rule of thumb with its 53.8 grains maximum, it is probably tolerable by the rifle.

To duplicate M2 ballistics, you need a 150-grain bullet going 2740 fps when you average the 2-yard and the 52-yard velocities (this is how the military 78-foot velocity was originally measured). To do that with a Hornady 150-grain FMJ BT, the equivalent right-at-the-muzzle velocity from a tight chambered 24" pressure and velocity test barrel would need to be 2805 fps, and that drops to 2793 fps at 5 yards (15 feet, where SAAMI measures velocity). So the Norma starting load is already going about 100 fps too fast. You would need about 48.3 grains to match M2 ballistics, based on the velocities Norma published. The bulk density I have says that's about 85% case fill in an LC case. Not great, but safe. The peak pressure will perhaps be lower than the powder likes, which means you may have dirty burning, and the velocity spread may not be very tight. I would be using a magnum primer. If you can find them, the CCI #34 primers are made to have the same sensitivity spec the military #34 primer does, and that is good protection against slamfires. Any kind of primer seated high (above proud with the case head) is an invitation to slamfires or worse in the Garand.

You can virtually guarantee being able to shoot slower powders without damaging the operating rod if you install one of the Garand Gear gas plugs or use a plug with an adjustable vent to bleed off some of the excess gas cylinder pressure (though you have to adjust these for each load, where the first one works with all loads, AFAIK).
 
I ran QuickLoad for 203B for the same 46,000psi chamber pressure as 4895.

11,400psi port pressure (at 20") for 4895
11,300psi port pressure (at 20") for 203B

I'd call it a tie
 
Garands don't operate at 30-06 Max Pressure -- far from it.
Mostly low-mid 40's

Classic 175grSMK/IMR4895/46.8gr/44,000psi/2,580fps
PortPress @ 22" = 9,900psi

Same 175grSMK/Norma203B/47.6gr/44,234psi/2,576fps
PortPress @ 22" = 10,000psi

Pretty much a wash... (for "practical" purposes)
 
No specs
Rather Fact of life from the load data/bullet weight/match-velocities/powders used,

If you want, I'll take the 175 up to 2,640 fps*
or the 168SMK to whatever you desire....and compare the two powders

~~~~~~~~~ SIDENOTE ~~~~~~~~~~~
*The M72 Match load recipe/Army technical manual of cartridge data TM 43-0001-27
lists it as 50 grains of IMR 4895 with 173-grain bullet
https://www.308ammo.com/30-06-M72-30-MATCH-LAKE-CITY-1967-LOT-12251-p/m7212251.htm
NOTE: "M72 cartridges were actually around 48 grains of IMR 4895 and seldom,
if ever, reached a full 50 grains."
~~~~~~~~~~~~~~~~~~~~~~~~~

Modern IMR4895/48gr does produce 47,000psi/2,638fps at the muzzle/10,100psi at the 22" port
-- but you tell me where the chronograph is and we'll recalculate

For same velocity, Norma-203B/48.9gr/47,600psi/2,638fps muzzle, and 10,000psi at the 22" port


.
 
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TM 43-0001-27 lists 30-06 ball and match ammo with max chamber pressures at 50,000 cup using the old erroneous psi number. That's about 60,000 psi. Current SAAMI specs list the same pressure for each type.

Modern IMR4895/48gr cannot produce 47,000 psi at the muzzle if there is 10,000 psi an inch plus back at the gas port.

Screenshot_20210226-084236_Adobe Acrobat.jpg
 
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Take a look at your Lyman manual and see what kind of velocities you're getting (from a 24" barrel no less) when you hit the 50,00-CUP level w/ IMR4895.

But this is actually a digression from the OP's question of whether Norma 203B would be suitable.
In the end, the pressure profiles down the barrel are all but identical.
(Y`all might be interested in this: http://bulletin.accurateshooter.com/2015/09/alliant-reloder-15-vs-norma-203b-the-numbers-tell-all/)





postscript: remind me where the velocities are recorded for military ammunition and I'll rerun the numbers
 
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Thanks for all the info! The load doesn't have to be an exact M2 or M72 match load. That was where I was starting so I could get a feel for the rifle

I loaded 4 clips worth with the H4895/150fmj combo just to play with the rifle and get the sights regulated. I have shot a good bit of AR-15/M16 (not my favorite platform). I am really enjoying the reloading and research on the
M1 as much as shooting it.

I am using the CCI #34 primers mainly because I had a box and why not. I also have some Wolf primers from playing with my 308. They seem to have a harder-than-US manufactured cup. My 284 and 308 just did better with CCI BR.

I may try the 168/175 match loads. My theory was the 203b would work better with the heavier bullets if it would work at all. Our local range has a 1000 yard range. I might try stretching the M1 out a little. The only problem is I need to increase my skills with open sights before I burn up my 308 bullets that are hard to replace right now. Ha!

Mehavey - Thanks for the Quickloads info and the "digression" of my question is actually turning out to be more informative than my question.
 
Caliber 30 Ball M2: New flat-based bullet that had a gilding metal
jacket and a different lead alloy, and weighed 152 grains
Click to expand...
I'll run the projectile and velocity for loadout to get 2,750 @ 78 feet.
 
OK... (I'll post screenshots later)

Using a 155grSMK (weight reduced to 152) and a default case volume of 68.2gr H2O
(also ran 67.9 for LC brass no appreciable difference):

IMR4895 requires 52.5gr to achieve a muzzle velocity of 2,894 --> 2,731 at 25m
Pressure = 50,448 psi (not CUP)... so it looks like it's not a PSI/CUP mistake.



* postscript: Norma 203B requires add'l 400psi
 
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Lyman manual says IMR4895 52.5 grains, 2952 fps, 58,400 psi for a 150 grain bullet. Other 30-06 maximum loads are over 59,000 psi.
 
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OK, I'll take the Garand out this weekend w/ IMR4895/50gr/Sierra 150gr Spitzer/HXP case/OAL 3.35"
...and set a record point for the LABRADAR at 25 yds this weekend.

We'll calibrate on that point.

Given what I'm seeing in QuickLoad/ArmyTM-43-001-27 both saying 49-50,000psi for that velocity,
...I'm far more likely to think Lyman got caught in the CUP/PSI switch.



Quick note (pun intended)

Compare & Contrast Re 4895: Norma 203B is slightly faster/slightly less Energy density.
All other burn characteristics identical.

Norma203-B-v-IMR-4895-sm.jpg



.
 
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