Building a 7RSAUM for 3 different bullets - dumby rounds and Google Sheets

[steffen707]

Yes you can run either one. I'm running the 190s out of a 7 saum. I use a ec tuner brake on it, does a good job considering the rifle weighs 9 lbs.

Thanks. I bought an EC tuner break myself just to see what its like. I'm interested to see what the recoil is like in the 7Saum. My 7RM without break or suppressor started to hurt after 7-9 shots. That's not a problem for a hunting rifle.

 

[steffen707]

I should add that I assumed you’d be getting the longer bolt stop and running longer mags for the SAUM. 190s in a true short box doesn’t sound like fun.

Well my Tikka has 3.3" mags. I think all Tikkas have the same long action.

 

[steffen707]

Iv just been useing Redding dies for all my stuff. I am not a benchrest shooter and dont want to spend crazy money on all typed of dies. Most benchrest guys use willson dies anyways.

I was having troubles finding a FL die AND micrometer seating die from the same company. I know they don't have to match, but I figured i'd get a slight discount with buying both in a set.

H1000 and SAUMS go hand in hand, but the last time I saw an 8 lb jug of that a Bigfoot and a Leprechaun were fighting over it.

I’m not gonna press any harder on your bullet choice. I ultimately needs to make YOU happy, but I’d sure rather shoot the hybrids than that nasty Barnes.

I think 7 SAUM is a great choice, you’ve already got a 7 LRM, don’t need the belted 7 mag if you don’t just “want one,” which is reason enough!

yeah H1000 has been hard to find. I got 2-1lb jugs of it recently. I think i'll have a 7RM again one day, but for now it'll be the donor for this project

I appreciate your input about the bullets and everything else. Your advice isn't falling on def ears more like stubborn ears. lol

Hmm, I'm hearing two "flags" that are worthy of a few questions.

1. short action and 190s? The SAUM really responds well to longer seated heavy bullets, and i would think the 190 would benefit; though it's doable from a 2.825" mag; it's similar to a 77gr in a 223; takes up a lot of boiler room. I'm meaning that 2700fps from a 24" barrel would be what I'd expect is very near max and you're not going to want to see what the brass looks like with an 18" barrel and 2700fps.

2. 18" barrel? 7saum and 7RM (30saum and 30WM) are near equivalent; and I'm sure that the 18" barrel will suffer reduced max velocities with h1000; even h4350 may not burn well leaving a large fireball for the suppressor. It's absolutely doable; but the combinations of components are countering what I'm thinking your ultimate goals are. Yes the bullets will make it to 1000y, even at far slower velocities no concerns there.

I'd recommend 24" min barrel length, it can always be cut shorter; but my barrel stretcher design is still in the works; right next to the board stretcher and wire lengthener. In my experience, SAUM velocities are really hindered by shorter barrels. Again, it's doable; but with a short barrel, that's taking away some of the magnum advantage and maybe a different cartridge would be a better idea.

-Mac

Well i have 3.3" mags in my Tikka so number 1 isn't an issue.

The short barrel issue, yeah we're going to find out I guess.

What will happen to the brass with 18" and 2700fps?

 

[mac86951]

I was having troubles finding a FL die AND micrometer seating die from the same company. I know they don't have to match, but I figured i'd get a slight discount with buying both in a set.

yeah H1000 has been hard to find. I got 2-1lb jugs of it recently. I think i'll have a 7RM again one day, but for now it'll be the donor for this project

I appreciate your input about the bullets and everything else. Your advice isn't falling on def ears more like stubborn ears. lol

Well i have 3.3" mags in my Tikka so number 1 isn't an issue.

The short barrel issue, yeah we're going to find out I guess.

What will happen to the brass with 18" and 2700fps?

Keep us posted; great that your Tikka is a longer mag; so you're right longer seatings are solved. As to 2700, I'm guessing you will get pressure signs before this; or brass will loosen the primer pockets and make them short lived; only one way to find out, but IME you're looking closer to 2500-2550 with 190s. Still fine for long range shooting btw. Brass is hard to get for SAUMs and all my brass is lovingly named, tracked, monitored.

N560 seems to be working well with SMK 168s if you need an H1000 alternate.

-Mac

 

[steffen707]

Keep us posted; great that your Tikka is a longer mag; so you're right longer seatings are solved. As to 2700, I'm guessing you will get pressure signs before this; or brass will loosen the primer pockets and make them short lived; only one way to find out, but IME you're looking closer to 2500-2550 with 190s. Still fine for long range shooting btw. Brass is hard to get for SAUMs and all my brass is lovingly named, tracked, monitored.

N560 seems to be working well with SMK 168s if you need an H1000 alternate.

-Mac

I'm cool with those velocities for the 190gr, i'm just concerned what my 145LRX will be going at MV. Only one way to find out. Oddly enough there's not a lot of 145LRX 7RSAUM rolling with 18" barrel builds out there. =P

How does one figure out if their barrel can be re-chambered? I assume compare the desired cartridge to the current one, and if all the dimensions of the chamber are wider/longer you might be good?

I'm just curious if my franken-SAUM doesn't work out, if I can rechamber in 7RM. EH, i'll cross that bridge if I need to. I'm optimistic it'll work out.

For sake of making the story more simple, I said I had Saum brass already. I don't, but feel pretty confident I'll be getting some in a few weeks.

The dies are on their way. Got several powders to choose from, have Federal 215 and CCI450's to try out. so far i'm loving my Vortex LHT 3-15x42 scope.

Mesa stock is in, and while there are a few dings and the bottom metal doesn't sit as flush as I'd like it, it should work out. I sure hope its stronger than the factory stock, because they're the same weight, although the Mesa has a 4" pic rail on it, so maybe its a few ounces lighter.

I guess that's everything for now.

 

[steffen707]

UGH. I've been watching for months for ADG 7saum brass. The moment it went available today I was reading to my son. less than 15 minutes it sold out. =(

Now i'm thinking of changing back to 7mm rem mag and running the AICS mag with a Mountain tactical gen 2 bottom metal. ugh, flipping and flopping

 

[steffen707]

My 7saum project is back on!

I've secured 4-6 boxes of ADG 7saum brass. Once they come in, i'll mock up some dumby rounds and send the barreled action and new barrel out. Exciting!

 

[Ned Ludd]

H1000 and SAUMS go hand in hand, but the last time I saw an 8 lb jug of that a Bigfoot and a Leprechaun were fighting over it.

I’m not gonna press any harder on your bullet choice. I ultimately needs to make YOU happy, but I’d sure rather shoot the hybrids than that nasty Barnes.

I think 7 SAUM is a great choice, you’ve already got a 7 LRM, don’t need the belted 7 mag if you don’t just “want one,” which is reason enough!

Just out of curiosity, which one ended up with the 8lb jug? Obviously, the size and strength advantage go to the Bigfoot. But the Leprechaun has "magic".

 

[Clancy]

Just out of curiosity, which one ended up with the 8lb jug? Obviously, the size and strength advantage go to the Bigfoot. But the Leprechaun has "magic".

Leprechaun, wasn’t even close.