257 Weatherby Mag w/ MRP or MagPro

[SofaKing]

Looking to recreate the factory weatherby loads. I've got some once fired wby brass and Barnes ttsx 100's. What's the coal length on the factory loads? I'm fairly sure weatherby uses its own blend of powder but with what I have maybe I can get close.
Available powders are:
magpro, norma mrp, h4831sc

Thanks

 

[SofaKing]

So I'm leaning towards MRP or MagPro. Anyone have any experience with those powders?

 

[Quintus]

MRP is similar to RL22. I run RL22 in my 100 TSX load and it beats the Weatherby published factory load with a fair amount of pressure to spare. I do not know what the factory COAL is but mine are a touch longer, seated to functional mag length.

 

[SofaKing]

MRP is similar to RL22. I run RL22 in my 100 TSX load and it beats the Weatherby published factory load with a fair amount of pressure to spare. I do not know what the factory COAL is but mine are a touch longer, seated to functional mag length

what's your load your running?

 

[Quintus]

70.7 grains RL22 Fed 215M in a WBY case.

 

[FEENIX]

Looking to recreate the factory weatherby loads. I've got some once fired wby brass and Barnes ttsx 100's. What's the coal length on the factory loads? I'm fairly sure weatherby uses its own blend of powder but with what I have maybe I can get close.
Available powders are:
magpro, norma mrp, h4831sc

Thanks

So I'm leaning towards MRP or MagPro. Anyone have any experience with those powders?

I have all the powders you noted, but I have only tried the MagPro and am very pleased with it thus far. While it is not Barnes TTSX 100, the 145 BH is being propelled out of 22" 1:7" at 2955 FPS with 64.5 MagPro (9 1/2M, WBY/Norma brass, .011" off the lands) with more room to spare. Don't be afraid to try it; the result might surprise you. As with anything else, YMMV. Good luck.

 

[Fotis]

Some of my best loads. WBY MK V Ultralightweight

 

[Calvin45]

No experience yet with those powders in a .257 bee.

I will say, with bullets 100 grains and up me and my local fellow .257 wby shooter have found nothing better than the old school IMR 7828.

100 grain b tip at 3720 fps out a 24 inch.

 

[Gary in MD]

I have mostly used RL22 in my 257 over the years but have lately been using 7828. I would have to pull out my records but I'm getting in the mid 3500s with the 100 grain ttsx and very good accuracy. I load the Barnes ttsx out to .050" off the lands of my rifle.
When my supply of RL22 & 7828 runs out then I will probably see what is available from the less temperature sensitive powders that will also supply the high velocities.
I pushed the 100 grain Sierras over 3700 fps years ago using RL22 but found pressures to be too high and it ruined brass. That was a couple barrels ago, I haven't really pushed my current barrel very hard. I loaded the 87 grain Sierras to just a touch under 3900 fps some years ago. It was amazing what the impact on a large ground hog or a fox was like..... There were pieces of critter literally decorating the landscape for a 10 foot area!!
Gary

 

[Fotis]

Do not discard Ramshot Magnum. Very temp stable and very available not to mention cheap.

 

[Outlaw6.0]

Do not discard Ramshot Magnum. Very temp stable and very available not to mention cheap.

Magnum has been a very well kept secret for quite a while. I really like it.



t

 

[Fotis]

Me too! Works well just as stable as H1000

 

[K.E.C. Darkside]

Here are some pictures.

 

[Haydad77]

Looking to recreate the factory weatherby loads. I've got some once fired wby brass and Barnes ttsx 100's. What's the coal length on the factory loads? I'm fairly sure weatherby uses its own blend of powder but with what I have maybe I can get close.
Available powders are:
magpro, norma mrp, h4831sc

Thanks

I fired more rounds than I would have liked trying to find reasonable accuracy with acceptable velocity. When I changed primers from Federal gold medal 215 to Fed 210 match I got what I wanted. Using N560 powder with Hornady 117 SST's 3350 FPS and great accuracy. Just as good Nosler 115Bal tip. I'm sure there will be many nay sayers but I'm happy.