300 WSM High Pressure Loads

[Benjblt]

So I worked up some loads for my 300 WSM with some 174 gr hammer bullets. They shoot really well, about 3/4" groups. I'm using 70 grains of RL22 out of my Remington 700. . definitely on the high end. Really, probably a few grains above max. I noticed, even at the RL22 68.5 grain load, that I see a little round mark on the back of the brass. I'm guessing this is the ejector plunger. Should I be worried?

 

[Wrench]

Anytime you flow brass you're not doing yourself any favors. Rl22 isn't known for its ability to handle temp swings, so if its hot it could be worse.

Many rounds have been fired and left case head marks, but it is telling you that you're over pressure.

If theres a chance you can kiss at that pressure things can spike even more.

I personally wouldn't sweat it if it was a hunting load that did everything else I wanted....but if you expect to get more than a couple of loads....back off.

 

[cjl2010]

Does it rain a lot in western Oregon? Pretty good chance you will have a rodeo on your hands if your shit gets wet and you miss your first shot. Seen it a few times with high end loads and wet weather.

 

[hodgeman]

So I worked up some loads for my 300 WSM with some 174 gr hammer bullets. They shoot really well, about 3/4" groups. I'm using 70 grains of RL22 out of my Remington 700. . definitely on the high end. Really, probably a few grains above max. I noticed, even at the RL22 68.5 grain load, that I see a little round mark on the back of the brass. I'm guessing this is the ejector plunger. Should I be worried?

Yes. If you're seeing the ejector mark...you're over pressure.

 

[Benjblt]

Anytime you flow brass you're not doing yourself any favors. Rl22 isn't known for its ability to handle temp swings, so if its hot it could be worse.

Many rounds have been fired and left case head marks, but it is telling you that you're over pressure.

If theres a chance you can kiss at that pressure things can spike even more.

I personally wouldn't sweat it if it was a hunting load that did everything else I wanted....but if you expect to get more than a couple of loads....back off.

I'm not sure what you're saying; "flow brass", "kiss at the pressure", and your last sentence. Hammer bullet said to back it off a grain, which drops me from (70 grains RL22) 3,200 fps to 3,120 fps at 68.5 grains of RL22. I told him that I get ejector marks on both loads and he said that Norma/Nosler brass is soft and he said it was an indicator of high pressure but he was less worried about it.

 

[Benjblt]

Does it rain a lot in western Oregon? Pretty good chance you will have a rodeo on your hands if your shit gets wet and you miss your first shot. Seen it a few times with high end loads and wet weather.

What do you mean? Like I won't be able to open my bolt?

 

[Benjblt]

Yes. If you're seeing the ejector mark...you're over pressure.

Hammer bullet said to back it off a grain, which drops me from (70 grains RL22) 3,200 fps to 3,120 fps at 68.5 grains of RL22. I told him that I get ejector marks on both loads and he said that Norma/Nosler brass is soft and he said it was an indicator of high pressure but he was less worried about it. I don't know. I'm a nube. I just want to do it right and not blow my face off.

 

[Wrench]

"Flowing" brass is moving brass from one location to another due to pressure.

"Kiss" is touching / jamming the throat with the bullet.....which has an increasing effect on pressure.

Brass flowing into the ejector hole isn't uncommon, but it is unsustainable and potentially dangerous. It won't help you keep primer pockets tight and WILL lead to case head separation much earlier in your brass life.

 

[Wrench]

Fwiw, I've been over pressure by enough to lock a bolt below published maximums. Get a lot # of heavy brass and it can change your case capacity and raise your pressure.