RCBS 200 Sil -WC872- Powder Coated in 308 Winchester

[MUSTANG]

Shot 5 rounds of Duplexed WC872 Powder today. Boolit was RCBS 200 Sil, completely coated with Eastwood Green Powder Coat. Baked for 45 minutes - then water quenched. The base was sized to .310 with an aluminum gas check applied after PC process. The nose only was sized in a Lee .301 Sizer die. Powder was 37 Grains of WC872 (this is a 20mm Vulcan Surplus Powder). A 5 Grain "Kicker" of 700X powder was used as a kicker on top of the Flash hole to get a 100% burn of the WC872 Powder.

Rifle: Remington 700 ADL Varmint .308
Barrel Twist: 1 in 12
Wind: 5 Mph left to right.
Temp: 85 degrees F.
Boolit: 308 RCBS 200 Silhouette
Ballistic Coefficient: 0.255
Brinnel Hardness: 20
Bullet sized: .310
Nose Sized: .301
Alloy: 96% Lead, 3% Antimony, 1% Tin
Bullet Powder Coated: Eastwood Green
Gas Check: Ameri-max Aluminum 0.14”
Powder: 37 Grains WC-872
DUPLEX: 5 Grains 700X powder
Primer: Remington Large Rifle
Case: Mixed military and commercial Brass
OAL: 2.80 inches
Distance: 100 Yards.
5 Shot Group Size: 2.658

303457

[MUSTANG]

As a "Control" I fired 5 rounds of WC872 Powder only today. Lots of unburned Ball Powder kernels in the barrel and by 5th round starting to get some unburned kernels in the neck/chamber area. This is why most people DO NOT shoot WC 860.870.872 powders.. Boolit was RCBS 200 Sil, completely coated with Eastwood Green Powder Coat. Baked for 45 minutes - then water quenched. The base was sized to .310 with an aluminum gas check applied after PC process. The nose only was sized in a Lee .301 Sizer die. Powder was 42 Grains of WC872 (this is a 20mm Vulcan Surplus Powder). This CONTROL 5 grain string DID NOT use a kicker.

Rifle: Remington 700 ADL Varmint .308
Barrel Twist: 1 in 12
Wind: 5 Mph left to right.
Temp: 85 degrees F.
Boolit: 308 RCBS 200 Silhouette
Ballistic Coefficient: 0.255
Brinnel Hardness: 20
Bullet sized: .310
Nose Sized: .301
Alloy: 96% Lead, 3% Antimony, 1% Tin
Bullet Powder Coated: Eastwood Green
Gas Check: Ameri-max Aluminum 0.14”
Powder: 42 Grains WC-872
DUPLEX: NONE
Primer: Remington Large Rifle
Case: Mixed military and commercial Brass
OAL: 2.80 inches
Distance: 100 Yards.
5 Shot Group Size: 2.250

303458

[MUSTANG]

Interesting notes:

For this limited 5 and 5 test series - the WC872 powder load only shot a slightly better group than Duplex Load; about 0.4 inches smaller.


The 5 round Duplexed load averaged 1926 feet per second - as measured on my new LabRadar chronograph.
The 5 round WC872 powder only (No Duplex) averaged 2079 feet per second on the LabRadar chronograph. That was a big surprise!
Perhaps the Kicker is causing a more rapid pressure curve and pressure is dropping off as the boolit exits the barrel; or ....??
Given how dirty the Barrel is from unburned Kernels without using a Duplex Load (Kicker); I will stay with the kicker as it make life easier not having to clean the barrel/chamber after 3 to 5 rounds without a Kicker. Accuracy comparison is so close that I am expecting a reversal on accuracy next testing just because of shooter error potentials as well as environmental differences.

When compared to results in my RCBS 200 Sil in 308 winchester tests using BLC2 and LeverEvolution powders; the 1st attempts with this Boolit and WC-872 should not be discounted. See other thread at:

https://castboolits.gunloads.com/showthread.php?438595-RCBS-200-Sil-Powder-Coated-in-308-Winchester/page2

[Nobade]

I would suggest a slower kicker. I find that powder in range from Blue Dot to RE7 works the best with less pressure spikes and better accuracy. It's good to see somebody else besides myself playing with this kind of stuff.

[lotech]

I've had this same mould, perhaps an early one, for more than thirty years, maybe a lot longer than thirty years. Mine casts bullets with an undersized nose (and maybe base), though I have none cast at the moment to measure. I lube conventionally and run the bullets through a .311" die, though I'm pretty sure the bullet is smaller than that, maybe .310" at the most. Using ww alloy, these bullets weigh 207 grs. Best 100 yard groups have averaged about 1 1/4" using 24 grs. RL7 with a muzzle velocity of around 1700 fps in a couple of .308s. I have other moulds that will do better than this one, but the RCBS 200 mould with the right dimensions should make a very accurate bullet.

[MT Gianni]

Try a rifle powder in the 4198-3031 range as a kicker. 4-6 gr.