WMR powder.

Paul B. · August 9, 2001, 06:24 PM

Has anyone had problems with this powder by Winchester? I loaded some .300 Win. Mag. ammo last year in July with temps running in the 100 to 110 degree range. Loads were safe. When I retested them in September at 82 degrees, they gave signs of very high pressure, stiff bolt lift, shiny ejector marks, ect. All loads were in a batch of new Winchester brass.
A query to Winchester a month ago has brought no response, but the powder has been discontinued? Is this stuff unsafe at cooler to colder temperatures?
Thanks for any help.
Paul B.

Stonesheep · August 11, 2001, 02:07 AM

Sorry, can't help you on the WMR query, but I was wondering if you had a favourite load for your 300. I shoot a 300 win mag, and she really likes 190 gr. BTSP's backed with 74 grains of Reloader 22, loaded to 3.4" OAL.

Paul B. · August 11, 2001, 02:04 PM

Stonesheep. I thought I did until the cooler themps shot me down. (No pun intended.) 180 gr. Sierra SPFB bullets shot into an inch at almost 3100 FPS. I didn't chronograph the 200 gr. Speer SPFB but three groups of five shots averaged .75 inch. That probably would have been my elk load if it hadn't developed the problem.

Paul B.

EchoFiveMike · August 12, 2001, 11:58 AM

Is it a compressed load? I had some problems with 7mm Rem Mag and WMR in a certain rifle that I was zeroing for someone else(yeah, they'll need to adjust for their eyes but it's pretty much academic with hunting guns) I got hangfires, and that's really annoying. If it is a compressed load, I think you need to pull a few and check to make sure the powder isn't caking, which is a problem with ball powders and high temps and compressed loads. I haven't had any other problems with this powder, and I do like it in my 300Wby with 180gn Barnes X-BT's at 3060fps from 24inch barrel and 3/4" accuracy.

The only other thing may be that the rounds have "grown", recheck OAL just for giggles and grins. Pushing the bullet closer to the rifling has lead to pressure problems in the past. Semper Fidelis...Ken M

Paul B. · August 14, 2001, 03:22 PM

No, the load is not compressed. It is about 95 percent of the case capacity. You can shake the load and feel the powder move, albeit very slightly. Bullet is about .020 off the lands. I'm begining to think this powder has a temperature sensitivity problem like it's forunner, W-785. That one could very temperamental at times.
Paul B.

August 9, 2001, 06:24 PM	#1
Paul B. Senior Member Join Date: March 28, 1999 Location: Tucson, AZ Posts: 3,802	WMR powder. Has anyone had problems with this powder by Winchester? I loaded some .300 Win. Mag. ammo last year in July with temps running in the 100 to 110 degree range. Loads were safe. When I retested them in September at 82 degrees, they gave signs of very high pressure, stiff bolt lift, shiny ejector marks, ect. All loads were in a batch of new Winchester brass. A query to Winchester a month ago has brought no response, but the powder has been discontinued? Is this stuff unsafe at cooler to colder temperatures? Thanks for any help. Paul B. __________________ COMPROMISE IS NOT AN OPTION!

August 11, 2001, 02:04 PM	#3
Paul B. Senior Member Join Date: March 28, 1999 Location: Tucson, AZ Posts: 3,802	Stonesheep. I thought I did until the cooler themps shot me down. (No pun intended.) 180 gr. Sierra SPFB bullets shot into an inch at almost 3100 FPS. I didn't chronograph the 200 gr. Speer SPFB but three groups of five shots averaged .75 inch. That probably would have been my elk load if it hadn't developed the problem. Paul B. __________________ COMPROMISE IS NOT AN OPTION!

August 14, 2001, 03:22 PM	#5
Paul B. Senior Member Join Date: March 28, 1999 Location: Tucson, AZ Posts: 3,802	No, the load is not compressed. It is about 95 percent of the case capacity. You can shake the load and feel the powder move, albeit very slightly. Bullet is about .020 off the lands. I'm begining to think this powder has a temperature sensitivity problem like it's forunner, W-785. That one could very temperamental at times. Paul B. __________________ COMPROMISE IS NOT AN OPTION!

August 11, 2001, 02:07 AM	#2
Stonesheep Member Join Date: March 14, 2001 Location: N58-48, W122-41 Posts: 75	Sorry, can't help you on the WMR query, but I was wondering if you had a favourite load for your 300. I shoot a 300 win mag, and she really likes 190 gr. BTSP's backed with 74 grains of Reloader 22, loaded to 3.4" OAL.

August 12, 2001, 11:58 AM	#4
EchoFiveMike Senior Member Join Date: February 12, 2000 Posts: 416	Is it a compressed load? I had some problems with 7mm Rem Mag and WMR in a certain rifle that I was zeroing for someone else(yeah, they'll need to adjust for their eyes but it's pretty much academic with hunting guns) I got hangfires, and that's really annoying. If it is a compressed load, I think you need to pull a few and check to make sure the powder isn't caking, which is a problem with ball powders and high temps and compressed loads. I haven't had any other problems with this powder, and I do like it in my 300Wby with 180gn Barnes X-BT's at 3060fps from 24inch barrel and 3/4" accuracy. The only other thing may be that the rounds have "grown", recheck OAL just for giggles and grins. Pushing the bullet closer to the rifling has lead to pressure problems in the past. Semper Fidelis...Ken M