Pressure sign and 300wm load

[92xj]

At what point during your inspection do you say, yep, that's too much pressure not load any more powder?
Is it the first sign of flattened primer?
Is it when your finished comes apart and you see your armbflyimg through the air?

Thoughts on pressure signs before reaching the manufacturers max powder charge?

300wm, Bertam, H1000 75gr, 199sledge hammer, .024 off lands, crunching powder when seating, 3015fps, sd5, es10. .75 group.

Going to repeat this load and hopefully repeat the grouping and if so, I'll call that load a win for my hunting rifle and be very satisfied.

The other part of me wants to keep going up to the 79gr max but crunching at 75 and also the primer flattening a frog nut hair has me holding up on that thought.

[Jonathan_S]

Idk much about those bullets bearing surface etc. but 75 sounds light for h1000..

@BULLBLASTER

[92xj]

Idk much about those bullets bearing surface etc. but 75 sounds light for h1000..

@BULLBLASTER

It is according to all publishings.
The bullet is the opposite of really pointy ultralong range bullets making the oal shorter because of lands contact instead of the point being able to bypass the lands in longer range style bullets. If that makes any sense.

[BULLBLASTER]

Seems like you are running out of powder space before you hit pressure and top velocity. I would look to a slightly faster burning powder and see what you get.
Or possibly look at having the chamber freebore lengthened if you have magazine space.

There may be a powder that will surpass velocity and not be so compressed.


Also I’m not sure what you are using for load data but typically mono metal bullets hit pressure at a lower charge than lead core. Does hammer have data?

FWIW I am shooting 215 Berger’s loaded long (3.75 oal) and am at 78 grains h1000 and still can shake the case and bear powder.

[BULLBLASTER]

Can you post a picture that shows how much bullet you have seatdinto the case?

[92xj]

Hammer does not have data but talking with them, they suggested the norm...start at 72 and work up.

Here is a picture.  I only have .024 more to extend the hammer before hitting the lands.  Mag box length is no issue.

Browning hells canyon speed.

though if I can repeat my 75gr groups, I am very satisfied with that load for my hunting needs 600 yards and less is my range.

[b23]

That actually sounds pretty fast for only 75gr of powder so you could be creating more pressure than you think.

Are you noticing any kind of a ejector swipe?  After you fire a round are do you listen to see if you can hear any clicking as you lift the bolt handle up?  Do you notice an increase in bolt lift after a fired round?  All can be indicators you're starting to get into the red.

[jasnt]

I’d call it good or try a slightly faster powder

[Magnum_Willys]

Any bolt lift resistance or brass head marks/swipes or significantly flattened primer.  I use Quickload to give me an idea where Im at keeps me from going crazy  ( - lapua brass won’t show signs until you get way up there.)

[92xj]

That actually sounds pretty fast for only 75gr of powder so you could be creating more pressure than you think.

Are you noticing any kind of a ejector swipe?  After you fire a round are do you listen to see if you can hear any clicking as you lift the bolt handle up?  Do you notice an increase in bolt lift after a fired round?  All can be indicators you're starting to get into the red.

I thought it sounded fast as well. I'm using a magneto to measure so feels it's accurate.  No I crease in bolt lift, no clicking and no ejector marks that I can see.

[b23]

Those are seated pretty deep and taking up a good amount of case capacity.  These things are basically a pressure chamber, decrease the volume but keep the powder charge the same and it creates more pressure which explains why you are getting the FPS you are with only 75gr of powder.  Not saying your load is hot, but that's just the physics of it and you can't have velocity without burning more powder or creating more pressure.

If you aren't experiencing any pressure signs and you're happy with how it's shooting, you can call it good and be done.  Or, if that is the bullet you want to shoot, you can take your gun to a gunsmith and they can increase the freebore so you can stretch those bullets further out of the case before you touch the lands.

[92xj]

to me the primer has started to slightly flatten compared to a non fired primer.  Not sure enough to matter to me though.
The biggest thing to me is crunching powder when seating the bullet creating a compressed load but with almost now more room to seat the bullet less, I don't really have another option beside different powder.  And if I go that route, I have no idea what powder to try.  MY experience is only with h1000 and rl25.

[b23]

Any bolt lift resistance or brass head marks/swipes or significantly flattened primer.  I use Quickload to give me an idea where Im at keeps me from going crazy  ( - lapua brass won’t show signs until you get way up there.)

I think QL is a very useful tool and use it a lot.  Majority of my experience with QL has been if I input all the correct parameters, it'll nearly always match my real world experience. 

Lapua brass will still show the regular signs of pressure, ejector swipe, clickers, increased bolt lift, but if you start stretching primer pockets with Lapua brass, you are definitely correct, and you're way over pressure.

[BULLBLASTER]

This primers especially the left one look pretty flattened to me. The edges aren’t as round as unfired. If primer pockets hold up keep doing it.

Those bullets have lots of bearing surface length (not all of it actually bearing surface with the ridges) with a short nose section so will eat into powder space.

I’ll agree that that is a pretty high speed and I wouldn’t expect a whole lot more than that. Just looking at the primer picture I’d say you are on the edge pressure wise. 

A 200 grain bullet at 3000 is no slouch! 

[b23]

to me the primer has started to slightly flatten compared to a non fired primer.  Not sure enough to matter to me though.
The biggest thing to me is crunching powder when seating the bullet creating a compressed load but with almost now more room to seat the bullet less, I don't really have another option beside different powder.  And if I go that route, I have no idea what powder to try.  MY experience is only with h1000 and rl25.

Those appear to be getting flattened a bit but I'm not all that convinced flattened primers are a great indicator of pressure because other things can cause primers to flatten.

For me, RL25 would NOT be an option so I'd definitely stick with the H1000.

Have you measured the case capacity with water of one of your cases yet?  Bertram brass is known for having reduced case capacity, versus others.

And not trying to be a smarta$$ but if you are concerned about being over pressure with your load and the crunching, maybe you're overlooking the obvious and you should reduce it a little.  I'm not a big fan of a lot of crunching so I'd either try using a drop tube to see if that helps or reduce the load a little.