Need help on understanding Gas volume and Chamber pressure

[hoythitman]

I am building a new rifle. Pretty set on going 7 SAUM. Here is the problem, I prefer shooting suppressed, I have a SilencerCo Omega 300. Rated up to 300 win mag.

300wm uses significantly more of the same powder at basically the same chamber pressure as the SAUM.

I sent an email to SiCo they said it’s not rated for any ultra mag. I clarified it was short action UM and said no. I can’t imagine something using less of the same powder at the same pressure being unsafe but I want to figure out a way to tell gas volume because that is what he referenced.

Any help greatly appreciated

For reference 7SAUM 180 load data says 65 grains of H1000 being max.

300 WM starting load for 180 is 78 grains of h-1000




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[LWD]

I'd wager the person heard ultra mag and stopped there probably not knowing the difference between ultra mags and short action ultra mags. I'm not a silencer expert, but I do know a lot about reloading and can't imagine that silencer not handling the 7 SAUM.

LWD

[treestand]

Interesting. I can't see how the gas volume could be greater with the 7 SAUM but since the 7 will be higher velocity, the silencer would need to dissipate the gas over a shorter period of time. Chamber pressures may be equal but the pressure in the suppressor could be higher with the 7. Like anything else, the manufacturer will err on the side of safety to minimize risk of being sued. Be sure to let us know what happens when you shoot it ��

[Zen Archery]

Communication!? I’d call back! Main thing is not going against manufacturers recommendations for warranty sake (assuming suppressors have warranties).

[westtexducks]

Call em back up and ask them if it will run a 7 wsm or 300 wsm. No way a 7 saum is running more pressure than either of those 2 cartridges.

[hoythitman]

Update. It is safe with the WSM’s


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[Horitexan]

Wouldn't the best thing to do is run your load through quick load to find out the specific pressure in the 7saum? I don't know enough to answer the question but I think there's a lot of factors that go into pressure but quickload should give you an accurate number to compare with 300wm. I would not be disregarding SiCo's advice easily. It's potentially an expensive experiment; and if they figure out your Omega was over pressured, you might be kissing your suppressor goodbye.

I'm interested because I'm considering a 6.5saum and one of my cans is an Omega.


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[treestand]

It's not the chamber pressure, which is what a calculator will tell you, but the pressure in the can you need to consider. You can go by what the can manufacturer says or you can experiment.

[hoythitman]

It's not the chamber pressure, which is what a calculator will tell you, but the pressure in the can you need to consider. You can go by what the can manufacturer says or you can experiment.

I know. I’m just perplexed is all. On paper it looks the same or less that other rounds that are safe. 7 mag 180 Berger loads are using 10-15 more grains of powder. Going 100fps or so faster and it’s safe to shoot that through a 20” barrel. But I can’t shoot a lighter powder charge a little slower through a 28” tube and be safe. Doesn’t make sense.

I talked to someone else at SiCo who said they were going to look further into it because it should be susafe through the Omega. Said their list says all UM’s long and short but the short is, in his opinion lower volume, lower speed, and same pressure as 7 win mag or 7/300 mag which it’s ok for


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[LWD]

I know. I’m just perplexed is all. On paper it looks the same or less that other rounds that are safe. 7 mag 180 Berger loads are using 10-15 more grains of powder. Going 100fps or so faster and it’s safe to shoot that through a 20” barrel. But I can’t shoot a lighter powder charge a little slower through a 28” tube and be safe. Doesn’t make sense.

I talked to someone else at SiCo who said they were going to look further into it because it should be susafe through the Omega. Said their list says all UM’s long and short but the short is, in his opinion lower volume, lower speed, and same pressure as 7 win mag or 7/300 mag which it’s ok for


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Makes sense. The 7 SAUM shouldn't be much, if any, different, than those. Can you let us know what they say?

LWD

[hoythitman]

Makes sense. The 7 SAUM shouldn't be much, if any, different, than those. Can you let us know what they say?



LWD

Ok. So, the SAUM has an almost identical uncorking pressure and less volume than the wsm. But “I still can’t say yes.” I think they are afraid to give the go ahead to something with “ultra mag” in the name in case someone ran a regular UM through it. So I’ll be shooting through it.


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[hoythitman]

He said I can buy a program that will work all of it out but it’s $150 and I’m not. Lol


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