7 rum

[J E Custom]

7 Rum is a fun round though! I don't know the velocity but I was shooting the 162 amax and it only took 18 MOA to get to 1000 yards! Thats moving pretty quick. I can't say about barrel life because I sold mine at about 400 rounds.

I purpose built a 7mm STW with a 31" barrel to reach max velocity with a 140grain bullet.
the problem was that anything over 3750 would destroy the bullet before it reached the target
so I backed down to 3650 in order to improve accuracy. (I was looking for the flattest trajectory
possible and this beast filled the bill).

After just over 1400 rounds I saw no deterioration in the accuracy but Decided to re barrel to
the 7mm RUM to see if the velocity was possible with less pressure indications and longer
brass life. it also has a 31" barrel.

So far I am above 3600 ft/sec with the 140s and no signs of pressure or brass failure.

The 160grain bullets are approaching 3500ft/sec with no signs of pressure and very good
accuracy It will probably be the bullet of choice for the RUM. Testing is not complete yet
and all of the votes are not in yet.

There is another post by Kirby that talks about barrel life and I am a believer in what he
has to say about keeping the barrel clean and not letting it get hot. This philosophy has
served me well and barrel life has not been an issue.

I even go to the trouble of pulling a bore snake through the barrel after each shot in the field
so that the next shot is through a "Clean Barrel" (It removes the powder residue and some
of the carbon that is very abrasive.

J E CUSTOM

 

[dancoman]

JE, I'm lookin for a 7rum load using the 160 AB. Started to start another thread but it seen to fit here. I have a fac sendero that is very accurate. Lookin for a long range whitetail rifle. Long range to me ( for hunting) is the 700 to 800 yd range. I have had good luck with the AB and also the scirocco bullets. The jury still out for me on the berger as a hunting bullet. I tend to lean toward an exit wound. My 300rum is loaded with 200AB and 92.5 grs RL25. This rifle is also a sendero and prints 11/4'' groups at 300 yrds if I do my part.
Any load info for the 160AB and 7rum will be great. Also include MV and most accurate vel. range etc.
thanks,DM

 

[J E Custom]

JE, I'm lookin for a 7rum load using the 160 AB. Started to start another thread but it seen to fit here. I have a fac sendero that is very accurate. Lookin for a long range whitetail rifle. Long range to me ( for hunting) is the 700 to 800 yd range. I have had good luck with the AB and also the scirocco bullets. The jury still out for me on the berger as a hunting bullet. I tend to lean toward an exit wound. My 300rum is loaded with 200AB and 92.5 grs RL25. This rifle is also a sendero and prints 11/4'' groups at 300 yrds if I do my part.
Any load info for the 160AB and 7rum will be great. Also include MV and most accurate vel. range etc.
thanks,DM

As I said , I am still in the testing stage and have started to try RE 25 and so far it seems to
be doing ok with 89 grs @ 3354 ft/sec but I have a long barrel (31") and you should approach
this load very carefully because I have seen some temperature sensitivity with temps near 100o.

The 7828 and 50Bmg seem to be doing better but it takes about 10 more grains of these
powders. (Note I also have lots of freebore and .0005 headspace).

If you are seating close to the lands these loads will be to hot.

The accuracy node for my rifle seems to be a little over 3400 ft/sec with the 160 AB and around 3600 for the 140.

Remember these loads are in my rifle and should be approached with caution.

My goal is to find the fastest velocity that will produce the best accuracy as long as the working
pressure is withen SAAME specs.

J E CUSTOM

 

[dancoman]

I'm currentlly shooting 94.5grs of RL25 with the 150 scirocco out of my fac sendero 7rum. Any guesese on approx. MV.

There is no signs of excessive presures and was wondering how much of a differance it would be movin up to a 160 gr bullet. when workin up scirroco load groups didn't start comin in untill the 92 gr mark. My 300rum also shoots better with RL25 (92.5) with the 200Accubond.
Startin to find several 160AB/7rum loads with retumbo.
I'm thinkin with the 160Ab/7rum combo with a MV of 3200 - 3400 should make a good 7-800 yrd wt set-up.

 

[J E Custom]

I'm currentlly shooting 94.5grs of RL25 with the 150 scirocco out of my fac sendero 7rum. Any guesese on approx. MV.

There is no signs of excessive presures and was wondering how much of a differance it would be movin up to a 160 gr bullet. when workin up scirroco load groups didn't start comin in untill the 92 gr mark. My 300rum also shoots better with RL25 (92.5) with the 200Accubond.
Startin to find several 160AB/7rum loads with retumbo.
I'm thinkin with the 160Ab/7rum combo with a MV of 3200 - 3400 should make a good 7-800 yrd wt set-up.

My guess would be arround 3300 ft/sec With a factory barrel.

Just a guess though.

J E CUSTOM

 

[kdog70]

Cool lots of response. Well the 700 SPS is in the mail got a decent deal and got an email response that the 200grain are about 6-8months out. Should be a lot of fun even 3200 out of a factory barrel should be plenty for me for now.

 

[NZ Longranger]

I've been shooting big 7mm's for many years now and have taken many 100's if not 1000's of big game animals with them. The RUM is the biggest factory 7mm by some margin and will outrun the STW by 100 to 150 fps or so with 160gns and heavier.

The biggest issue with the factory 7mm RUM's is the throat is way too long on most of them. You can't seat 180gn Bergers out anywhere near the lands without the bullet falling out of the neck. I have only found one factory 7mm RUM of the many I've worked with that would shoot the Bergers jumping. The rest shot way better with the 175SMK, which is far more forgiving of the 100 thou plus jump necessary in the factory chamber with the 175 SMK seated only 100 thou into the neck. Any less in the neck and the ammo will be too fragile and the bullet will fall out too easily if you drop it or suchlike. The 175gn SMK is the go-to long range bullet in factory 7mm RUM's with too long throats in my experience.

Now, a custom 7mm RUM with a shorter throat is a different story. With something like 100 thou freebore, you can easily touch the lands with the 180gn Berger, and drive them at around 3200fps out of a 26" barrel with H50BMG or even faster with US869. Out of a 30" barrel, you can get well over 3300fps, but if shooting bare bullets, you may start to blow bullets up in flight at this velocity as the throat roughens up. Moly bullets seem to handle this issue for longer, before you have to change back to the thicker jacketed 175 SMK or similar. The Berger is the best long range bullet in our experience though, killing quicker and better in the wind. The old 200gn Wildcat ULD's performed similar to the 180gn VLD, but didn't really offer much more ballistically. They were accurate but only a tiny smidgin better in the wind and dropped more, so when Richard stopped making them we switched back to 180's and 175's. And at sea level they need an 8" twist to stabilize them out to 1000 yards. I know Kirby can stabilize them with a 9" at his altitude, but we do most of our range work at not far above sealevel before hunting up to 6000' or so, and its a pain when you can't shoot them on the home range. Your factory 9" twist probably won't stabilize the 200gn ULD's at sealevel.

As to barrel life, it all depends on what powder you use and how hot you drive it. The most temperature consistent powder H50BMG (or 2218 as its called down here) is harder on barrels. I'd expect 600 to 800 rounds. US869 will give you nearly double the barrel life with more velocity but more temperature sensitivity. You can minimize this by keeping your ammo at a consistent temp by carrying it against your body or something similar, or if you want to get really high tech, having different drop charts or PC inputs for different ammo temps. Another way we've dealt with a very temperature sensitive powder like H870 was to have different loads for different temperatures, but you need to be on the ball to work this system.
This is all only an issue beyond 800 yards on big game, as inside 800 its not really an issue if you pay a little attention to not letting your ammo get too hot or cold.
Good luck, short of the big 338's there's nothing beats a big 7mm!!!
Greg

 

[JD338]

I have been playing with a M700 LSS 7mm RUM
Loading the 160 gr AB with 94.0 grs Retumbo, R-P case and CCI 250 mag primers.
Average MV of 3337 fps, ES 63 and SD 27
Accuracy was .75" for 3 shots with a COL 3.625"

JD338

 

[kdog70]

I can hijack my own thread right?

Anyway I ll move it its a problem. I went to the gun store to buy my rem 700 XCR 7 Rum and it was no longer there but on the used rack sat a Rem 700 in 7 Rum no model (xcr, sps, i.e) but plastic stock stainless action and barrel and aftermarket brake for $660 or something similiar.

Next to it sat a Win mod 70 super shadow in 300 WSM for $500 now my brain is thinking since they didn't have my first choice do I continue for the perfect gun. I am looking for a whitetail/steel gun.

 

[liltank]

I can hijack my own thread right?

Anyway I ll move it its a problem. I went to the gun store to buy my rem 700 XCR 7 Rum and it was no longer there but on the used rack sat a Rem 700 in 7 Rum no model (xcr, sps, i.e) but plastic stock stainless action and barrel and aftermarket brake for $660 or something similiar.

Next to it sat a Win mod 70 super shadow in 300 WSM for $500 now my brain is thinking since they didn't have my first choice do I continue for the perfect gun. I am looking for a whitetail/steel gun.

Though the 300WSM is a very good caliber for your shooting desires, it is a better option to really buy what you want in the first place. Otherwise you will end regretting your decision after you come down off your "I just got a new rifle!" high. Be patient and buy what you really want. You'll thank yourself later!

Tank