7MM LRM vs. 7MM SAUM

[Mr_Happyface]

I went back and read 20+ threads on 7mm SAUM so I have a decent idea what that cartridge is about, but it's a little harder to find info on the 7mm LRM.

The pros of the LRM seem to be:
1) Increased case capacity for eventual release of 195 Hybrids.
2) Readily available brass (1.34 each from Gunwerks)
3) More easily fed from long action AW mag.
4) Longer neck than SAUM


Although SAUM has on it's side:
1) Better dies available (as well as micrometer seating dies).
2) Larger selection of brass (although less available).
3) More efficient case design.
4) Potentially better barrel life?

Am I wrong or missing anything here?

This is my 2nd thread on this subject - looking to rebarrel a long action AW to one of these two calibers, mostly because the case heads should fit the .300WM boltface without modification. The goal of this rifle is to make reliable hits out to one mile, with the majority of the shooting done between 1000-1500 yds.

Does anyone have experience with both of these cartridges?

 

[The_FNG]

I may be mistaken, but isn't the LRM a proprietary cartridge, meaning you can't buy the reamer and build your own? Not sure..

You might be better off just doing a straight up 7mm/375 Ruger or a 7mm Practical (300wm necked to 7mm)

Or yet again, wait to see what this 26 Nosler is and neck it to 7mm.

 

[DDoug]

You can in fact by a reamer from gunworks. They also have dies available. Brass is a little spendy but they have plenty of it. So no need for case forming. I have all the parts gathered up for one as I can see no down side to this cartridge. It should get the 180s close or over 3100 and my get the new 195 close to 3k while fitting in a aics mag with room to spare.

 

[Forgetful Coyote]

IMO instead of the 7 SAUM Id be looking at the 6.5 SAUM. I think theyve really struck gold with that round. Like the 6mm BR for long range shooting. Barrel life is great if you keep pressure low and 140s at 3150 isnt real difficult. Whats real promising with that case is the 160gr Matrix bullets at 3000-3050fps. Thats a stout load. Fairly equivalent to 215gr Bergers at 3000fps ballistically.

7mm LRM wouldnt be a bad choice at all. Shouldnt have too much trouble getting 180s to 3200fps. Not sure if its proprietary either. As far as a straight up 7mm-375, its not impossible by any means but thats alot of work prepping that brass and IMO unnecessary with other cartridges out there so similar. If it is proprietary though, you could always go with a 7mm Dakota which is much of the same. Think Remington Ultra Mag case chopped down to .30-06 length and necked down to 7mm. You end up with a round thats gonna have a bit more case capacity than 7mm-300 WM or 7mm LRM. Basically a .30-06 length beltless round with 7mm STW performance. Want to say ~91gr H2O. Again, shouldnt be too much trouble to get 180s at 3200(+) fps depending on load/barrel length.

And if you like wildcats, elkaholic on LRH has his .280 Sherman which is a sweet round. Basically a .280 Gibbs with a longer neck. Instead of .30-06 brass, you use .270 or .280 brass and end up with the same case body dimensions as a Gibbs but as I said with a longer neck. Im pretty sure people are getting ~3000-3050fps with the Sherman.

 

[Mr_Happyface]

Yeah, in all honestly I don't like wildcats. It just looks like the LRM is a good cartridge to settle on for this rifle - which really should pay off whenever Berger releases the 195s.

The brass should be easy to get (gunwerks said they have a ton in stock) but I don't like being limited to Hornady dies, and I especially don't like that I won't be able to get neck bushings for the die or a micrometer seater.


The 26 Nosler looks interesting, but I'm sure the barrel life is measured in hundreds if they're pushing the bullet that fast. Introducing 26 Nosler | Flat to 415

 

[gewehr]

If you don't like wildcats, the 7 Dakota is a option that can match or beat the 7 lrm and is a perfect fit for the future 195 we are all waiting on, I personally can't wait to give it and reloaded 33

 

[HodgdonExtreme]

Why hornady dies?

A number of outfits will make you custom dies off of a few pieces of fired brass.

Load a couple, seating with whatever die you've got that can cram a bullet in that case, touch them off, and ship the spent cases off to Whidden (or similar).

 

[HuntnPack]

Mr. 7mm LRM is a good cartridge choice as you pointed out in the plus column.
Also non-belted, a plus as well for me.
I am currently putting together a 7lrm build. 200 pcs of brass look pretty good & consistent, dies aren't bad, came with bushing, micrometer head is available from hornady. Run with it.

 

[Mr_Happyface]

came with bushing, micrometer head is available from hornady. Run with it.

I'll be damned, getting closer to that being the one then.

 

[18Echo]

The better option than the 7LRM is just the plain old 7-300WM. Neck down 300WM brass using a bushing die and then seat using a 7mmRM seating die or a redding competition seating die for a 300 WM with a 7mm replacement stem. I went with the 7-300WM because of the ease, it's sitting at Robert G's shop in GA right now. The 7-300WM will push the 180gr Berger VLD 3150+ with retumbo or H1000. I can't find either so picked up 7828ssc which has a burn very close to H1000. Search for Skykings post on his 7-300, lots of good info in there.

 

[Swamplife]

I have both and for what your looking for I'd go 7LRM. You can get everything from Gunwerks. The reamer, bushing dies, go gauge and brass. The LRM brass is cheaper than Norma saum brass and has had very consistent neck thickness on the 300 plus cases I mic'ed. The case itself is designed very well. No belt, 30 degree shoulder and a very long neck. They feed perfect from a AI 300wm mag with no mods needed and 180's can be loaded with the bearing surface up and out of the doughnut area but still have about .150-.175 reliable clearance in the mag. The neck is .380+ long, so if you plan on running the 195 's when or if they ever become available. You'll be able to throat the freebore longer to get the 195's up and out the doughnut area and still have alot of neck/bearing contact (.300 +or-) when seating the 180's out to the lands on the 195 based freebore. You might even be able to load all the way down to the 140vld's or possibly/maybe 120 Vmax's with the 195 freebore if you wanted to, because of the extremely long neck. The 195's loaded long will still be able to be fed from a std (non CIP) AI 300wm mag with no problems. The LRM with equal barrels and max load will push a 180 @ 150-200fps faster than a SAUM. Making it a better choice for the 195's. Also on a final note, my LRM will shoot .3 moa to 600 which is the farthest I've had a chance to take it so far. So the accuracy using the Gunwerks package is there.


Darren

 

[Mr_Happyface]

I have both and for what your looking for I'd go 7LRM. You can get everything from Gunwerks. The reamer, bushing dies, go gauge and brass. The LRM brass is cheaper than Norma saum brass and has had very consistent neck thickness on the 300 plus cases I mic'ed. They feed perfect from a AI 300wm mag with no mods needed and 180's can be loaded with the bearing surface up and out of the doughnut area but still have about .150 clearance in the mag. The neck is long .380+, so if you plan on running the 195 's also. You'll be able to throat it to get the 195's up and out the doughnut area and still have alot of neck/bearing contact (.300 +or-) to seat the 180's out to the lands on the 195 based freebore. And both 195's & 180's will still be able to be fed from a mag with no problem. The LRM with equal barrels and max load will push a 180 @ 150-200fps faster than a SAUM. Making it a better choice for the 195's. Also on a final note, my LRM will shoot .3 moa to 600 which is the farthest I've had a chance to take it so far. So the accuracy using the Gunwerks package is there. Darren

DUDE, YES, thank you, this is the post I was searching for!

That's all I needed to hear. Who did you go with for the barrel?

 

[Swamplife]

Happy

That rig has a 28" 8.4 twist Obermeyer but Bartlien, Rock, Kreiger, Brux etc etc etc...... would all do you right. I buy what I can find when I need one.



Darren

 

[dworrel]

Yeah, in all honestly I don't like wildcats. It just looks like the LRM is a good cartridge to settle on for this rifle - which really should pay off whenever Berger releases the 195s.

The brass should be easy to get (gunwerks said they have a ton in stock) but I don't like being limited to Hornady dies, and I especially don't like that I won't be able to get neck bushings for the die or a micrometer seater.


The 26 Nosler looks interesting, but I'm sure the barrel life is measured in hundreds if they're pushing the bullet that fast. Introducing 26 Nosler | Flat to 415

Whidden will make you a custom micrometer die if you send them some fired cases.