7mm RUM Re-barrel Options?

Doug in Alaska

Well-Known Member
May 31, 2009
Wasilla, Alaska
If a guy was going to have a Remington 700 in 7mm RUM re-barreled, and wanted to get better barrel life and not go with a wildcat, what cartridge would make the most sense with this platform? Something that wouldn't require a bunch of modifications and be used for maybe 500 yards max distance.

I'd appreciate your suggestions if you have time.
I have been tutoring a couple of guys in LR hunting for a while, not that they need much of my help anymore, very fast learners, very keen. One guy shoots a .300 Win Mag, the other shoots a 7mm Rem Mag. Both cartridges have performed exceptionally well and the guys are currently obtaining clean one shot kills/ good groupings at 700 yards which is a couple of hundred yards beyond the 500 yards they anticiapated being able to shoot to.

The hunter with the 7mmRM has put 1000 rounds through his barrel since last August. When its time to re-barrel, he is thinking about doing the 7mm Rem mag again but withy a longer barrel so that he can shoot the 180 grain VLD at a comfortable velocity.

My wife has a 24" barreled 7mm Rem mag. Velocity with the sleek 180 grain VLD is 2900fps. For every inch of barrel added, you would obtain another 35fps. With a 28" barrel, 3000fps would be quite obtainable with plenty of room for obtaining the right load (not having to push it).

As for any differences between the 300 and 7mm. At the ranges of 500 to 700 yards, I can't tell the difference between the two. Both perform well and success comes down to whoever can read the wind the best.If you shoot a lot of tougher animals or game weighing over 200lb, the .300 will give you a little more room to play with heavier bullets or simply 180 grain controlled expanding bullets.
Thanks much for sharing your opinion! I've been shooting a 7mm RM since I was 12 years old (40 years) and believe me, I have been seriously considering this cartridge. The barreled action is at Hart but I have plenty time to choose. I may stick with the RUM since I am really impressed with the capabilities. However, the barrel life just doesn't fit in with my shooting habits. I spend most of my weekends at the range and this is my whitetail rifle; I take it to Idaho once a year. Don't use it for hunting very much up here, that's what my .338 Win Mag is for. :)

Thanks, Doug
Doug,if you want to stick with the RUM, you could go to a 300 RUM and load it on the light side and get some descent barrel life out of it, or, you could go to a 300 WSM which would have great barrel life and an all around great cartrdige. They have basically the same head diameter.

I am in the same boat with my RUM, using it too much. I would like to go to the simple wildcat 7mm-300 win mag. Velocities are actually pretty much the same as my RUM simply because you can only push things so far with the 7mm bore till the gains get smaller with huge steps up in powder. I stand to lose about 100 to 130fps with 180 grain bullets from the step down which isn't too bad. The 162 grain bullets will lose 25-50fps from what I am getting now which is nothing.

I would like to use the existing neck/shoulder juntion of the .300 Win mag case as an unchaged reference point, utilize the belt for fireforming which actually gives the belt a purpose, blow the shoulder forwards slightly but not enough to arrest case growth, reduce the body taper and let the case neck grow a tad (no trimming for a while). No special dies, just use a standard 7mm neck die, neck the .300 brass down to 7mm and shoot. The fireforming loads should be accurate out to 400 yards or so, perhaps out to all ranges, will have to have a play when I get it all done. Having said all of this, the same can be achieved with a long barreled 7mm Rem mag. Its just a case of how you want to go about things.
I agree with Kiwi Nate on the 7mm Rem with a long-ish barrel. I've been processing the info on a hot 7mm, but i really like to shoot and those super-hot chamberings simply can't last as long as their slower brethren. I initially thought about going with a 300 Win mag (i have a fair bit of experience with it), but in the end decided to initially go back to the 7mm Rem for smaller to mid-size game and a 338 Edge for big stuff (at long-range that is).

There have been threads and alot of info how to prolong the barrel on RUM type chamberings. However, almost all concede the point that no matter what these super-hot loadings simply do not allow for long barrel life (upwards of 2000-3000 rounds).

A notable 'smith who posts here alot has mentioned that it's nearly impossible to predict how much life a barrel will have so.....fyi.
338 RUM. If you reload 338 Edge. It is considered a wildcat but is simply 300 RUM brass necked up to 338. Easy as any non wildcat to reload for.
Thanks for your opinions and recommendations guys. I've considered many options but the fact of the matter is I truly love the 7 RUM. I might just continue to look forward to the new Hart barrel and may just have to leave it in the safe for longer periods of time.
Enjoy that big 'ol 7mm boomer!!!!

Maybe shooting with it will be like dessert - it's the sweetness you enjoy a little at a time, but maybe not the "main meal"...

If you do a search, i know Kirby Allen wrote a big, long post about what he does to help prolong barrel life.
Some guys (myself included) have to learn from not one but TWO burned out barrels before we decide to suck it up and go with a larger bore.

The fact is that the 7RUM is freakin awesome on paper. With it's super high BC bullets and hyper velcoity it is easy to become mezmerized and hypnotized by it's mystical charm but in the end, it leaves us broke and frustrated.

Think of all the bullets, powder and primers you could buy for the price of one 7RUM barrel. By the time you have it fluted, shipped, chambered and braked youre in the $1K range. For what? A high BC bullet that get to 1K yards in about a second. The 7RUM will conquer the throats of those smooth custom barrels as fast as they conquer a deer at 1K yards. It seems like alot of money, pain and frustration for a shooter that wants to draw the line at 500 yards. For a 500 yard gun, you could even have a short mag that would last you 2500+ legitimate rounds AND cleanly harvest anything in North America with the exception of the largest of brown bears out to 500 yards.

The 338 Edge running 300 SMK's at 2800 FPS will be within 2" at 1K yards in a 9:00 wind in a full 10 MPH wind of a 7RUM running 180 VLD's at a extremely optomistic 3300 FPS. You will buy three 7RUM barrels for every one 338 Edge barrels. Many will argue that they are both good for 1000 rounds with the 338 maybe going 1500 rounds. Maybe physically that is true but dynamically there are not going to fare the same at all.

Good luck with whatever you decide. I am not trying to beat you up for your decision, just hoping to make you aware by sharing an experience from a guy who had 2 barrel burners and ended up very frustrated in the end with both.
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