Pressure sign and 300wm load

[92xj]

72-74.4 grs was crap accuracy. 1.8"+, then bam, .75" at 75.
My plan is to do 74.6, 74.8 and 75 going to .15 off the lands and seeing if I keep the accuracy and fps.

And I agree @bullblaster 200 grs at over 3000 fps should kill whatever I can hit, hopefully a bear is first on the list.

[BULLBLASTER]

It looks like rl25 is next to imr7828 on the burn rate chart. You might give it a go, it’s a bit faster burning and would take a bit less than the h1000. Couldn’t hurt if you have it on the shelf.

[buckfvr]

The primers are flat, its a compressed load, and the bullet is deep into the powder column.......if I was stuck on that load, Id at least slide it out to .008 off the lands to reduce pressure and see if data for es and sd are still good, and not focus on velocity.

[92xj]

I will bump out the seating depth closer to the lands, keep the 75gr charge and pray the accuracy stays.

[b23]

Just be careful not to get to close to the lands using the same load because once you get inside of about 5 thou off, pressure while start to rise and can spike up. 

When you're loading that close to touching with a load that is already on the warmish side you really should measure every loaded round off of the ogive with a bullet comparator because if one slips by you and goes from being a few thou off to touching, you can get a pretty healthy pressure spike.

Are you using a drop tube?  If not, you'd be surprised how much a drop tube can change how full the case looks and could help some of the crunching.

[92xj]

Negative in the drop tube.

I'm not worried about me missing one in my process.

I'm stupidly over anal. I measure ever charge and also measure length on every final round.

Will order a drop tube and load some up and see what happens

[BULLBLASTER]

You can also tap the case to help settle the powder some after putting it in the case. Just put your finger over the mouth so none spills out.

[b23]

You can tap the case and it helps a little but nothing like a drop tube.

I have this one https://www.midwayusa.com/product/293879/forster-blue-ribbon-powder-funnel-with-long-drop-tube as well as one that is longer I bought from Defensive Edge Rifles.

[92xj]

Ordered that Midway drop tube. Thanks for the link.

[yorketransport]

Don’t worry about the powder compression, it just a reality when dealing with heavy bullets in a 300 Win Mag.

For load data Hammer recommends using Noslers published loads for similar weight bullets. In my experience that’s been pretty accurate. The bearing surface on the Hammers is actually pretty short since very little of the shank is actually making contact with the rifling. I typically get about 75 fps higher velocities with the same weight Hammer bullet compared to a comparable weight Accubond. Let the velocity tell you when you’ve hit your max pressure, and I’d say your pretty much there now.

I’d just consider the load you have as a max and leave as is if it’s shooting well. Don’t worry about messing around with your seating depth. It likely won’t make enough of a difference to be worth burning up the bullets.

[92xj]

Thanks Yorke, you are the one who convinced me to try the hammers. I blame you in everything that happens from now on!


A question for you way more experienced guys... Please explain letting the velocity tell me what max pressure is. 

[NWShooter]

Your average velocity return on your powder charge increase diminishes.

[Reidus]

Don’t worry about the powder compression, it just a reality when dealing with heavy bullets in a 300 Win Mag.

For load data Hammer recommends using Noslers published loads for similar weight bullets. In my experience that’s been pretty accurate. The bearing surface on the Hammers is actually pretty short since very little of the shank is actually making contact with the rifling. I typically get about 75 fps higher velocities with the same weight Hammer bullet compared to a comparable weight Accubond. Let the velocity tell you when you’ve hit your max pressure, and I’d say your pretty much there now.

I’d just consider the load you have as a max and leave as is if it’s shooting well. Don’t worry about messing around with your seating depth. It likely won’t make enough of a difference to be worth burning up the bullets.

I was thinking the same thing. Even though "bearing surface" is long it will build pressure like a bullet with a short bearing surface.

[yorketransport]

Thanks Yorke, you are the one who convinced me to try the hammers. I blame you in everything that happens from now on!

I accept this. 

For the velocity, look at the published velocities given by the powder and bullet companies. These are operations with the tools and knowledge to accurately measure chamber pressures. If Hodgdon and Nosler both say they got 2875-2900 fps with a max charge of H1000, it’s safe to believe that a 200gr bullet at max pressure should be around 2900 fps. You can absolutely get higher velocities but it will be at higher pressure. Bullet designs can change pressures a bit, but not usually a huge difference

[92xj]

OK,
One more round of pictures.
Is there any harm in shooting this load as my go to load.
The two rows in the center both produced the best grouping at .6" and averaged 3015fps with the 199gr sledge hammer.
The bolt opened with zero resistance and I don't see any other signs of pressure besides the flattened primer.
Am I going to die or should I try something else?
This is going to be my spring bear load and I am limiting myself to 600 yards max for shots this spring.