Seeking practical experience with 7 mm RUM

[Daneren]

Hi Forum,

I'm in the planning phase, of building a new rifle.

I wan't a magnum 7 mm. And I'm very curious about the 7 mm RUM. However, the posts I find on Google, are mostly about hunting. Which this gun will never be used for.
The barrel life, is very limited, and I'm perfectly fine with that. It's mainly for +1000 m shots. I've pushed my 6.5 past a mile, with somewhat decent succes, but I want more.

Sierra makes some 183 and 197 gr pills for it. Which should give some pretty spectacular range. But the only report I could find was the article from Rifleshooter.com. His results were not very impressive, accuracy-wise. I sent him a message, and the answer was, that he did not play around with those anymore. He found that the 183 gr was the most accurate.

So my question is; Do YOU have any experience, that you care to share? Should I go with a different (7 mm) caliber? - If yes, which, and why? Please keep in mind, it's for ELR shooting.
If there's something worth noting, please let me know.


Sincerely.

 

[redneckbmxer24]

A RUM is not a good choice for a target rifle, they torch throats... BAD, and the 7mm is about the worst. 700-800 rounds is about the norm if you're somewhat easy on it.

A mild 30 cal magnum like 300WM or a 338 Lapua is a far better choice. They both have very high BC bullet options and usable barrel like will be about double of a RUM, or more. You can expect 1500+ rounds from a 300WM pushing it hard, if you choose a high BC bullet and keep pressure mild 2000+ and the same with 338 Lapua. I know people who have gotten 3000 rounds from the Lapua.

 

[Daneren]

As I wrote in my post; I'm fine with short barrel life. I'm very aware of it. I don't fancy a larger caliber, I wan't a fast 7 mm.

 

[Dirty D]

Tom Sarver can get you all set up with a 7mm Hulk which is essentially a 300 Norma necked down to 7mm, Tom has a bit of a successful track record in the long range game and is a very helpful guy to talk to.

I don’t have any personal experience with the RUM but read several reviews and none of them were flattering.

Gunwerks also makes a 7mm variant that is a 375 Ruger case necked down to 7mm. Read up on the Hulk and Gunwerks variants, my minimally informed opinion is that either one is a better choice than the RUM.

 

[Gooldylocks]

What about a 28 nosler? Might get a little better life with slightly less barrel murdering?

 

[Dirty D]

What about a 28 nosler? Might get a little better life with slightly less barrel murdering?

I like the Nosler case design but Nosler is the only one making brass and damn is it expensive, Norma is the only one making the 300 NM brass but the parent case is successful enough that I don't have to worry about them stopping production unlike Nosler, same with Hornady and the 375 case.

 

[Daneren]

I think you're right. There are way better choices, than the 7 RUM.

The 28 Nosler looks like a great competitor. But the brass is pretty pricey, and not-so-stellar. My friend has a 26 Nosler, chambered by Hardy Engineering. He had cracked casemouths from the very first load. Which I find unacceptable, though he might just have had bad luck. Maybe it can be resolved by annealing before loading, even the first time. (I handload btw.)

I'm currently reading up on the 7 mm Practical, which sounds like a pretty amazing performer. But I'm not to keen on the Lee dies, and fireforming. I would also prefer not to have belted cases.

The 7 LRM also looks promising. They all look very interesting. More so, than the 7 RUM. The 28 Nosler is probably the one with the least brass prep, but I'm not a fan of Nosler brass. Would prefer Lapua or Norma. (Which is also easier to get a hold of, here in Europe).

Lapua, Hornady, and Peterson also makes brass for the .300 NM.
I'll read more into the 7 Hulk, and see what that is about. If you have contact information to Tom Sarver, please pm me.


All your feedback is highly appreciated.

 

[M338]

I’m using Bertram 28 nosler brass,it’s miles ahead of the nosler stuff.

 

[Daneren]

I’m using Bertram 28 nosler brass,it’s miles ahead of the nosler stuff.

How many reloads do you get out of those? Where do they fail, when time comes? How's the consistency?
It certainly makes the 28 Nosler a lot more attractive, if the brass is up to the job.

 

[Dirty D]

...If you have contact information to Tom Sarver, please pm me...

http://thundervalleyprecision.com/about/

 

[Ackley Improved]

I have a 28 nosler, using 195 Berger's. I also have some Bertram 28 nosler brass. If I were to use the Bertram brass I would weight sort it and neck turn it. I measured case capacity, neck wall thickness, case weights between it and the Nosler and the Nosler was far more consistent. Enough so that I'd be happy to load and shoot. Case life between the two I can't say, but from memory I believe the Nosler stuff is about 20 grains heavier. I only have three firings on the Nosler brass, primer pockets are still right, and I FL size everytime. I will anneal after the 3 firings. I have a long Freebore to suit the 195 Berger's, use federal primers and 78.7 grains of 2225/retumbo for 3060-3070fps.

 

[steve123]

I'll tell you what happens with barrel burners. There's a high risk of bullet failure which only gets worse as the throat gets trashed shortly after load work is done, especially with the heaviest bullets and the faster twists needed to properly stabilize them. I've experienced this with two different cartridges, both with the heavier bullets available at the time. My goal of course was maximum velocity, and like you I was disregarding barrel life, but there were the downsides I didn't see would be a problem going into those projects.

Think about it, there's only a few clicks difference in dope, both for windage and elevation between a total barrel burner and a cartridge that has a bit less powder capacity and offers more of a balance as far as the other aspects go.

That being said you can load any cartridge down. That worked for me for one of those cartridges I mentioned but not the other using the bullet I had originally intended to use.

Looking at your choices I'd consider the 7mmLRM foremost but I haven't looked at brass price nor know of the strength of that brass.

IMO one of the best balanced cartridges will be that 300PRC coming out but that's OT so I'll leave the subject alone.

 

[surgeon260]

I would go with 7-300 Norma improved if I were to build another take no prisoners 7mm. Lapua brass, fits in a CIP mag, and all the velocity you could ever want.

 

[Daneren]

I would go with 7-300 Norma improved if I were to build another take no prisoners 7mm. Lapua brass, fits in a CIP mag, and all the velocity you could ever want.

Is it not the same as a 7 mm Hulk?

 

[cav has been]

Or you could just go with a boring old 7-300wm. Terrible old RWS brass and all.......

 

[Dirty D]

Is it not the same as a 7 mm Hulk?

No, the Hulk is based on the Norma Mag case IIRC.

Knowing that Bertram makes 28 Nosler makes my decision that much more difficult.

 

[Barney88PDC]

You are approavhing this incorrectly IMO. Pick a bullet you want to shoot, then pick a speed you want to shoot it. Then after that the caliber picks itself. If you are sticking with not fire forming or a certain brand of brass then, that's fine but it further limits your options. A 7-300 Norma Mag 30 degree improved on a 8 twist 28" barrel can shoot a 195 Berger 3250+. I have one you can buy and be done.

 

[10ring1]

7 mm rem mag is my creedo

 

[Dirty D]

7 mm rem mag is my creedo

The 7mm RemMag still gets it done nicely.

 

[surgeon260]

Is it not the same as a 7 mm Hulk?

I think the 7mm Hulk is a version of 7-300 Norma, but I am not that familiar with it. There are many different versions with different takes on shoulder angle, body taper, etc. I think pretty much any of them will get the job done.

 

[9x23w]

I had a Sendero and an XHR both in 7mm RUM. They both worked fine, but I never did any ELR shooting with them.

I don't believe in any "magic" cartridges. More capacity means more power, less barrel life, and probably some minor loss of accuracy. As you see everyone has their opinions about how big you should go in 7mm. Some say the RUM is too big while others like the 7mm Hulk which is even larger. Years ago there were complaints about the RUM's because of brass uniformity, not sure that is still the case, If you can live with a Remington rifle the 7mm RUM is about as big as you can go without going custom, which will greatly increase the cost. With other actions the 7mm RUM is a little long, so that's where the 28 Nosler and 7mm LRM come in. Brass and dies are still cheaper and more readily available for the RUM than it's competitors.

In truth there is no real world difference between any of the big 7mms. Any performance difference between the 7mm RUM, 28 Nosler, 7mm LRM, or 7mm Hulk will be from the rifle itself and not from the particular cartridge it is chambered for.

 

[Daneren]

In truth there is no real world difference between any of the big 7mms. Any performance difference between the 7mm RUM, 28 Nosler, 7mm LRM, or 7mm Hulk will be from the rifle itself and not from the particular cartridge it is chambered for.

The rifle will be a full custom, with all the bells and whistles.

I'm still trying to decide on caliber. But I believe you're right. I will be making the caliber choice between those listed, based on ease of loading, brass availability, and manufacturer. Thank you for contributing.

 

[Barney88PDC]

In truth there is no real world difference between any of the big 7mms. Any performance difference between the 7mm RUM, 28 Nosler, 7mm LRM, or 7mm Hulk will be from the rifle itself and not from the particular cartridge it is chambered for.

I disagree. There may not be an accuracy difference in group size at short range. But there most certainaly are differences in the ability of the aforementioned calibers to get equal bullets up to equal speed. The 7LRM for instance is optimized for shooting 180 grain bullets. Trying to put a 195 in a 7LRM is counter productive. If you seat the bullet to be able to mag feed, then you use up powder column and reduce the charge weight you can put in the case which limits its speed.

If you want more speed, you need more powder, and a barrel as long as you can stand. However, this added speed comes at a cost of barrel life. There is no way to cheat physics.

 

[Barney88PDC]

They way the Norma based cases (7-300NM, 7HULK) beat the 7RUM, 28 Nosler, 7LRM is that they use the Lapua bolt face 0.585" and not a smaller magnum bolt face 0.550". So a fatter case = more volume with equal case length.

 

[Daneren]

Thanks for all the guidance guys (and gals..?). I will be building the rifle in 7-300 Norma Improved.
It will be fitted in Cadex action and chassis. Going to be a stellar rifle.

 

[Desert_Racer]

Thanks for all the guidance guys (and gals..?). I will be building the rifle in 7-300 Norma Improved.
It will be fitted in Cadex action and chassis. Going to be a stellar rifle.

7-300 Norma Improved? Are you trying to hit shit in the next galaxy over?? I'd be blown away if you get any more than 700 rounds before the barrel is toast.

 

[Daneren]

7-300 Norma Improved? Are you trying to hit shit in the next galaxy over?? I'd be blown away if you get any more than 700 rounds before the barrel is toast.