Ejector marks on 300wm

[Driller54]

Got a 300wm shootin 2 time fired brass switched bullet weights from 168's to 190's usin h-1000 78.5grns and today was my first test with this load and I've got some very faint ejector marks on the case head. Wondering why this would be if it's a starting load and all my brass I've mic'd (provided I'm doin it right) looks to measure just fine

 

[Broz]

Some rifles just wont shoot as large of a charge as others. 78.5 gr and a 190 is not what I would call a starting load. Most 300 wm's I load for would be well over max with that load and a 210. Some factory sendero's I have had would only go to 75 gr. I take it you got a bit of a stiff bolt lift too. Thats over pressure and I would back off 2 or 3 grains. Plus, it has been posted here lately that recent batches of H-1000 and Retumboare running very hot. Some have had to reduce proven loads by 3 or 4 grains.

Jeff

 

[7stw]

Driller54, even though it may be a starting load( as far as the book goes), that is high pressure! Did you get sticky extraction, or stiff bolt? If there is a "print" of the ejector plunger, brass is flowing. Back her down a little bit. And try some brass that has not been printed yet. It will probably goe away. P/S, those 190 bullets are awesome! Have fun, be safe. AIM SMALL, MISS SMALLgun)lightbulb 7STW

 

[Driller54]

Man I love them too and i noticed less recoil with the 190's vs the 168's and no boss no sticky extraction no stiff bolt lift (that I notice). I'm also afraid that I wont be pushing it fast enough (dangerously low psi) guess i don't have to worry about it with where I did start. Thanks for the info on the powder I use both I've thought about gettin another powder but bein a new guy to this I read good things about both a few bad vuz they're so slow burnin but unlike the fact that they're temp stable down her in new Mexico it can go from freezing in the mornings to 90 degrees in the day( and they are listed to be the fastest in the manuals

 

[RockZ]

My Sierra manual lists 77.6gr h1000 as max for the 190smk

 

[Mutt]

My Sierra manual lists 77.6gr h1000 as max for the 190smk

Yes sir. Lyman's is a little less conservative.

Lyman's has the Sierra HPBT 190 (#2210) & H1000 at
76.0 START
83.5 MAX (compressed)

Careful, there!

Out of curiosity, Driller54, where did you read that 78.5gn is the starting load?

Also, man...I have to mention; changing components without reducing your charge is a no-no. If I'm wrong about that and you didn't do that I apologize but your post certainly reads that way.

ETA 83.5 - 10% is 75.15g so you're not close to Lyman.
Seems a little hot to me though.

 

[Driller54]

Got that "starting load" from someone on this very site. Not upset at all!! The plunger marks are very very faint so I'll back it off some and hopefully have a good load