Who has WC872 (50 cal powder) working in their 7x57?

[Whiterabbit]

Here's the data:

http://www.castpics.net/LoadData/Surplus/Datapages/7x57.htm

The day I saw this I quested for an RCBS mould and did not stop until I had it. My MarkX likes 175 grain jacketed and 140 grain barnes (longer than normal lead core) and can even shoot 100 grain varmint bullets decently when shot at warp speed. It's an easy going rifle for jacketed. an inch is not too difficult, on a great day the holes touch, hitting a man sized target at 700 yards is no big deal.

I want a load with 872 and the RCBS that does 2-2.5" at 100 yards with reasonable reliability.

I've tried 54, 53, 52, 51, and 50 grains so far, with the bullet seated right down on the powder for each charge (after settling, the powder likes to settle a lot.). Best I'm getting is 4+ inches at 100 yards, I know this can do better. At the moment I have no accuracy load for this bullet or powder. I've shot the LEE soupcan to 50 yard accuracy (but not 100) with trailboss.

I want to make this combo work. Any advice from the folks who use 872 in particular? Any clues here as to what I could change to eeke a little more accuracy out? Does 872 like to be compressed? likes a little more air in the cartridge? Shoot the bullet a bit slower? Any obvious guidance or tips when using 872 in the 7x57?

Thanks!

[sd61]

Not sure if this will help you, but I've played a bit with surplus WC867 (new powder for Wideners). I've heard this is quite close to WC872, so it may apply to some degree...
Most of my work was done on a k31 using a Lee160TL boolit. My alloy is COWW with some Sb and Sn added - about 13 BHN. My goal was to get an accurate load with a velocity in the range of 1600 - 1800 fps.
First problem encountered was unburned powder left in barrel. Went first to magnum primers - no good. Tried then fillers (dacron and PSB)- a bit better, but still some granules left. At this point a new problem surfaced - lead around the case mouth.
I wanted to solve the unburned powder first, and so I went to kickers (mainly AA5744, but also IMR4759) under the main load and fillers to keep everything in place. Started off with 5 grains which was an improvement, but still some granules left.
Finally ended up with 9 grains of AA5744 + 18 grains of WC867, the rest of the case (7.5X55) filled with PSB (about 2.1 cc) and fired off by a regular WLR primer. This load gives me good accuracy (for my abilities anyways) with groups of about 1 - 1.5" at 50 yards and leaves a clean barrel. The boolit (Lee160, tumble lubed with 45/45/10, gas checked and sized to .309") flies at about 1750 fps with this load.
In order to solve the other problem (lead ring on the case mouth), I had to water quench my alloy to about 18-19 BHN.

[MT Gianni]

I use 872 in the 30-06. I do not compress but use a load that fills the case. I have played with a 3 gr-6 gr kicker in the form of 4198 but settled on plain 872. It has shown accuracy with 215 to 155 gr boolits. I used ww, rem and cci primers.

[Whiterabbit]

Gianni, Anything else you do? doe syour load really fill the case? almost full? you seat the bullet right down on the powder, or is there space left?

I ask because the max load of 872 comes right up to the top of the neck before settling, there's really only .2" of space left to seat the bullet after settling the powder in the case. So how full is full for you?

[Tatume]

I've used WC860 in the 7x57 mm with excellent accuracy at 2100 fps. Keep trying, you'll get there.

[MT Gianni]

Gianni, Anything else you do? doe syour load really fill the case? almost full? you seat the bullet right down on the powder, or is there space left?

I ask because the max load of 872 comes right up to the top of the neck before settling, there's really only .2" of space left to seat the bullet after settling the powder in the case. So how full is full for you?
Bottom of the case neck. It works great in the 06, not so much in 308. I am not sure how that transfers to a Xx57 case.

[xacex]

http://www.patsreloading.com/patsrel/prices.aspx

http://www.gibrass.com/gunpowder.html

Dont know if it is really in stock, but it appears that it is for those that want to try some.

[brstevns]

http://www.patsreloading.com/patsrel/prices.aspx

http://www.gibrass.com/gunpowder.html

Dont know if it is really in stock, but it appears that it is for those that want to try some.

Anything new on WC872 in the 7x57

[pacomdiver]

ive got 3 8lbers and looking to try it in 762x54

[Hamish]

Fill Em up to the bottom of the bullet. Keep the unburned powder out of the chamber. If the unburned bothers you, start replacing one grain of WC 860, 870, 872, whatever, with one grain of medium fast powder, up to no more than 5 grains. I have not felt the need to duplex, just don't let unburned roll back into the chamber.

Loading in the neighborhood of 90-100% has given me very good accuracy with cast in 7.92x57, 7.65x54R, 7.62x51. One of these days I'll drag out an ought-six and a 35 Whelen to burn up a couple of pounds.

Whiterabbit,,

After trying it in the .243 with 105 grain cast, (even though Maven has been very clear several times posting) I strongly suspect that if you use a standard 135-145 grain cast bullet in the 7mm Mauser, you're going to need to duplex with a little hotter powder. A heavier bullet will help get the pressure up for a cleaner burn.

[brstevns]

Thanks, One of these days I am going to try it in the 250 savage. In the mean time going to give it a try in the 7x57 with a 160gr cast and the 30/40 Krag with 180gr or heavier.

[skeettx]

OK, my two cents, I have found with the SLOW burning powders, I need to seat the bullet out to contact
the rifling. This aids in powder consumption and increases accuracy.
Mike

[brstevns]

OK, my two cents, I have found with the SLOW burning powders, I need to seat the bullet out to contact
the rifling. This aids in powder consumption and increases accuracy.
Mike

I must remember that,Thanks