Is This Excessive Pressure??

[nmbarta]

What rifle is it?
How long is the barrel?

 

[RevJim]

Don't go past the 79gr charge. Velocity is "right there" as some barrels are faster/slower than others. 3000fps/175gr from a 7mm Rem Mag is very, very good. You have to move up to a longer barrel in Mashburn, 7mm STW and the RUM to go faster...but no need to really. Very few rifleman can take advantage of higher velocity and approx. 3000fps is a crusher in the Rem Mag.

 

[Dosh]

Ing, you didn't mention accuracy you're getting with the load.

 

[Ingwe]

What rifle is it?
How long is the barrel?

M700 26" Criterion 1:8

 

[Ingwe]

Ing, you didn't mention accuracy you're getting with the load.

I didn't shoot a group yet, as I am just trying to see what my max load is.

 

[SMK1000plus]

I didn't shoot a group yet, as I am just trying to see what my max load is.

Looks like you've found your maximum charge for your rifle with that powder, bullet, case, primer, OAL combination. Now its time for some OCW or Ladder testing to continue to develop an accurate load.

 

[okie man]

In my 308 ,Winchester and fed gmm brass show no signs of pressure with the same load but put that load in rem brass and my primers start looking like your first pic, back it off a grain and back too normal

 

[thatguyshm]

Silly question but is the brass new or once fired? Did you use a head space gauge or a piece of brass to set head space? I'm assuming it's a Remage set up?

 

[Heavyiron]

I went back and re-read your opening paragraph. Any 175 out of a 7mm Rm packing over 2900 is great. You are up in art mashburns 7 mm velocity window. Congrats on a fine load. I have a 7mm rm myself but can only get about 2850 from rl 25. May try rl 33 myself.

 

[Ingwe]

Thanks so much for the replies fellas!

Yes it's a remage action and I didn't measure the shoulder, I took the new cases and ran them through a Redding FL Sizing before I loaded them.

I think that I will use 78.0gr as a baseline and load .2gr incriminates lower and higher and see what kind of groups I get.

I am very happy with the velocity range I'm in so I won't push my luck and get greedy for 3,000

 

[jasonco]

Velocity = pressure - pressure = velocity, they're one in the same and you can't have one without the other. That's why the chronograph is the most essential tool we have as reloaders! And if you have access to a pressure system all the better.

Never use only primers as a pressure indicator, it's only a part of the whole.

ANY brass you use over the intended design limits, won't last beyond 2, maybe 3 firings.

 

[FURMAN]

Velocity = pressure - pressure = velocity, they're one in the same and you can't have one without the other. That's why the chronograph is the most essential tool we have as reloaders! And if you have access to a pressure system all the better.

Never use only primers as a pressure indicator, it's only a part of the whole.

ANY brass you use over the intended design limits, won't last beyond 2, maybe 3 firings.

This is simply not true. If this were the case NO ONE would be using large overbore cartridges. We would most likely be using a 6BR case in our favorite caliber, stuffing it with with roughly 30-33 grains of the appropriate powder, seating our favorite bullet, and calling it done. Powder charge, burn rate, and barrel length play a large role in the equation. As others have said from the pics it appears as if you are at or near max pressure. I find it better to judge with the extraction effort(click at the top of bolt lift). RL33, as reported by roughly half or more users, is temp sensitive. My little experience with it was not good as far as stability goes. H1000 will get 180s between 2900 and 3000 fps in all most any 26" 7 rem mag and is one of the most temp stable powders available and will require far less charge weight to do it.

 

[bigedp51]

Below is what my last Remington 700 bolt face looked like with a beveled firing pin hole. So the primer flow around the firing pin may have nothing to due with high pressure. And you may be better off measuring the case expansion just above the extractor groove.

Simple Trick for Monitoring Pressure of Your Rifle Reloads
http://www.hodgdonreloading.com/rel...-trick-monitoring-pressure-your-rifle-reloads

 

[MudRunner2005]

Personally, I don't think your loads are excessively overpressure. They might be fairly hot, but until you really see some flattened primers that start filling in the edges of the primer pockets, I wouldn't say that you're at excessive pressures. I'd be very careful though, if you plan on progressing from there. If you want more velocity, maybe try a different powder. 7828 SSC has been great for me in the 7mm RemMag, and 7977 has also been a great powder, with super low SD's and ES's. Very consistent.

About 5 years ago I had a round go nuclear at the range in my .25-06 AI, and it caused a massive pressure spike. I had just shot 3 rounds of the same charge weight with no issues, and then all of a sudden, the 4th shot sounded funny and had a funny recoil impulse... Popped out the case, and it had completely disintegrated the primer... Then popped out the bolt, and saw the perfect headstamp imprint... Stopped shooting it, and took it to the smith the next day. He magnafluxed everything and it was fine. I got lucky, all because of some weird freak thing that made the round go super hot. Only 2 things I can come up with that caused it was either 1) my scale acted up and dumped too much powder, or 2) I had an overcharged primer.

Had this been a magnum cartridge, it could have been a catastrophic failure, and could have ended up getting someone hurt. So, be careful out there when pushing the line.

Either way, this is what happens when your loads accidentally go over the threshold...