300 wsm

[mrbill2]

Anyone on here shoot a 300 WSM with cast. I'd be interested in any info that would help get me started on load development.
Thanks

[Larry Gibson]

Probably not much been done yet with cast in the 300 WSM. Taking a look at 300 Win Mag data and results would probably be a good place to start.

If i were loading cast in the 300 WSM I would look at the heaviest bullet possible given the case neck length and the magazine length. I would have to take a hard look at 311299 because of the short neck of that case and magazine length. That bullet fits perfectly in the .308W in short magazines. The .308W has about the same neck and cartridge AOL as the 300 WSM. I would start with a medium burning powder like 4895 starting at 33 gr and working up in 1 gr increments until accuracy started deteriorating. I would use a 3/4 gr dacron filler over the powder to increase ignition consistency and reduce powder position sensitivety. After finding an accurate load with 4895 I would then switch to slower powders (AA4350, RL19 and H4831SC) using the accurate 4895 charge weight as the start load with the slower powders. If loading density got above 80% I would dispense with the dacron filler.

Of course well fire formed cases that are neck sized only would be used. I would use a Lyman .31 M Die and size the cast bullets at .311". Use Hornady GCs and a softer lube like Lar's 2500+ or Javelina. For alloy I would want something in the 18 - 22 BHN range that is maleable not brittle. WWs + 2% tin water quenched would be good as would be an alloy of 70 -80% linotype + 20 - 30% lead for air cooled cast bullets. Lymans #2 alloy wouldn't be bad to use either. You've a 10" twist in your rifle so expect the best accuracy to be in the 1800 - 1950 fps range. You can push it with the slower powders (if you also do every thing else right) and get useable accuracy upwards of 200 - 2100 fps.

Let us know what you do and your results please.

Larry Gibson

[mrbill2]

Larry
This rifle belongs to a friend and we are just getting started. He'll be using the gun for target shooting only. The chamber has a short, tight neck. Bullets need to be sized .3085 or less. I have made some dummy rounds up with Lyman 311644 and 311679. Others like the 311284 would have to be seated deep past the case neck. I try to avoid that when ever I can. Another fellow on another form suggested 4895 also, so 4895 and #2 alloy is what I'll start with. I'll post results when we get going. Thank for the help !!

[whitetailsniper]

this is a good question,and subject. i to have a browning 300 wsm bolt rifle,,recently got,have shot factory fushion 165 and they were impressive groups for factory,,i them loaded some of the 300 wsm with varget,and 4895,,i got best result with the varget. id have to refere to my reloading manuals for exact data. i also have 3 30 cal molds(lyman) but yet had the time,, as the season draws near,, i really dont see me finding the time untill spring of next yr. but id be interested in your findings. good shooting to ya

[Larry Gibson]

mrbill2

Either of those bullets should be a good choice also, espeically the 311644. I'm looking forward to your results.

Larry Gibson