Spike Camp

7mm Rem Mag Pressure 4000 less than all other 7mm Mags?

Re: 7mm Rem Mag Pressure 4000 less than all other 7mm Mags?
« Reply #15 on: August 01, 2018, 10:04:22 AM »
I was digging to and I found something along what Chet was saying and I think Wyoming mentioned spikes. This says that for unknown reasons the 7mm rem. mag along with the .243 win. Are prone to spikes in pressure and on the side of caution there psi are lower ??
Mark

zonie

Re: 7mm Rem Mag Pressure 4000 less than all other 7mm Mags?
« Reply #16 on: August 01, 2018, 10:15:27 AM »
Dano thanks for checking,   Remingtons reply was about as I would expect.    This begs the question who actually is saami and are they regulated by federal law ?    My understanding correct me if I'm wrong companies  do not have to be a member of saami.   This is where I have some questions do the  saami member companies set guidelines and standards for all member cartridges,  OR does the member company set the standards for their cartridges and then submit to saami for testing ?  I almost bet it's the latter, and I doubt they are regulated by federal laws  ?

eford

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Re: 7mm Rem Mag Pressure 4000 less than all other 7mm Mags?
« Reply #17 on: August 01, 2018, 12:40:03 PM »
I think the sponsoring company sets the limits and submits it for testing.
Example: the 416 Remington is loaded to a much higher pressure than a 416 Rigby but the Rem has lower muzzle velocities. Nosler’s recent cartridges based on the 404 Jeffrey case are at a much higher pressure than the .423 caliber was designed for. I believe it was Dubyam who said to get the velocities they were after Nosler pushed the pressures way up. It’s simple physics. Remington and Nosler squeezed out what they could from the limits of the case in a modern action.
« Last Edit: August 01, 2018, 12:59:04 PM by eford »
Of all the gin joints in all the towns in all the world, she walks into mine.

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danno50

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DosEquisShooter

Re: 7mm Rem Mag Pressure 4000 less than all other 7mm Mags?
« Reply #19 on: August 01, 2018, 03:38:39 PM »
These old Weatherby load data sheets I emailed some of you years ago have the avg. breech pressure for each load side by side with the other data. I wish every body did that. But it does add more questions for me on page 2 it says that loads at or over 55,000 p.s.i. should not be used and are for reference only. and I believe them because I missed that part and loaded the 84 grains of 4350 in my 300 wby. and the bolt wouldn't open. so those got pulled.
but anyway if all these loads are not tpo exceed 55,000 p.s.i where does the 65,000 p.s.i. or even 61,000 p.s.i. come into play ??? or are we not talking the same p.s.i. ??
Mark

badsection

Re: 7mm Rem Mag Pressure 4000 less than all other 7mm Mags?
« Reply #20 on: August 01, 2018, 04:17:59 PM »
Ah, the days of litigation where the only winners are the lawyers!   ;D

Re: 7mm Rem Mag Pressure 4000 less than all other 7mm Mags?
« Reply #21 on: August 02, 2018, 02:09:13 PM »
I believe the 55.000 psi you are referring to is actually 55.000 cup not psi,as mentioned before a lot of production bolt action rifles have no freebore in the 7 rem mag chambering which imo accounts for some pressure spikes that were mentioned previously and the second thing that I think comes in to play is the wide variety of action types it is chambered in especially the auto loader which cant handle as much pressure as the bolt action,not surprised that Remington pleaded the 5th but as the cartridge designer if they don't know the reason then nobody does