A RUM question

[Mike Matteson]

I have one word of advice for you,

STOP!!!

STOP shooting that load immediately!!!

Quick loads says, that load that you're shooting in your 7 MM ultra mag, has 93,500 psi

The maximum pressure for a 7 MM ultra mag is approximately 64,000 psi

so you are approximately 50% over maximum

I am literally surprised that that gun has not blown up when your wife was shooting it

STOP Shooting that load immediately!!!

I looked at and didn't find 7mmRUM reloading data in my Sierra Manual 8th printing. It does show 300RUM loading. 1- 10 twist 26", 178 gr bullet, Rem 9 1/2 primers. There max with H1000 is 96 grains of powder. That wouldn't be much different between a 7mm and 308 caliber in powder loading for either for the RUM's, because of the case size. Looking at an older Hornady 7th edition it does show 7mmRUM, 26" 1-9 twist barrel, with Fed 215 primers, 162 gr bullet, H1000 powder a 87.3 grains max.
It's my understanding that quick loads can give you some bad reading at times. I looked over use blogs above and I don't see anybody up in the air about the powder loads.

 

[Cowboyblaster]

I looked at and didn't find 7mmRUM reloading data in my Sierra Manual 8th printing. It does show 300RUM loading. 1- 10 twist 26", 178 gr bullet, Rem 9 1/2 primers. There max with H1000 is 96 grains of powder. That wouldn't be much different between a 7mm and 308 caliber in powder loading for either for the RUM's, because of the case size. Looking at an older Hornady 7th edition it does show 7mmRUM, 26" 1-9 twist barrel, with Fed 215 primers, 162 gr bullet, H1000 powder a 87.3 grains max.
It's my understanding that quick loads can give you some bad reading at times. I looked over use blogs above and I don't see anybody up in the air about the powder loads.

Ya thanks mike it's quite a cartridge nosler called it the highest performing 7mm ever made commercially available though its alot of poder to gain a couple of hundred fps on a 7mm mag but im sure in the right hands it could realy reach out there and touch anything. Thanks for your inputwe loaded just below what was said to be max but i see alot of guy's claiming you should load to max with it. From what i understand you need a 30 inch barrel on it to get the full power out of that caseing and ive never seen a 30 inch barrel

 

[Mike Matteson]

Ya thanks mike it's quite a cartridge nosler called it the highest performing 7mm ever made commercially available though its alot of poder to gain a couple of hundred fps on a 7mm mag but im sure in the right hands it could realy reach out there and touch anything. Thanks for your inputwe loaded just below what was said to be max but i see alot of guy's claiming you should load to max with it. From what i understand you need a 30 inch barrel on it to get the full power out of that caseing and ive never seen a 30 inch barrel

They make them over 30" by special order from several manufactures are able to built them. I have two coming in 32" 6mm. Look up Bartlein barrels. There a whole world up there, and this is a great place to be. You will never stop learning here. There is a lot of people here that are smarter than me. I use to think I knew a lot until I started to look at Long Range Shooting hard. Never to old to learn, and a great day to learn something new.

 

[M T Shell]

I know im probably wrong about this

You are not wrong; you are, in fact, limited to the size of your magazine.

 

[Mike Matteson]

You can get custom action at are longer than a Rem 700 long action (example). The magazine can be modified somewhat to allow for longer COAL to load from the magazine into the chamber. How much that is, you would have to talk to a gunsmith. It's beyond my pay grade.

 

[Paladin300]

Wyatt's extended mag box.

The wyatt's box is the answer. I am running one in my 338 RUM. It allows two in the Mag and one in the chamber. I also have a side saddle plus 2 cartridge holder that allows me to have two extra rounds loaded quickly if needed. As others have stated the wyatts box has to be fitted.

 

[Cowboyblaster]

They make them over 30" by special order from several manufactures are able to built them. I have two coming in 32" 6mm. Look up Bartlein barrels. There a whole world up there, and this is a great place to be. You will never stop learning here. There is a lot of people here that are smarter than me. I use to think I knew a lot until I started to look at Long Range Shooting hard. Never to old to learn, and a great day to learn something new.

You bet im all about learning and your right there is an amazing weath of knowledge here ill definitely be checking out the bartlien site i thout i was screwed when i heard

You are not wrong; you are, in fact, limited to the size of your magazine.

M T i realy don't think there would be any gain to putting anything heavier than a 168gr bullet in that cartridge using my 700LA because im already pushing that bullet quite a ways back int the case with the 168 but as i say im here to learn and could be very wrong

 

[Lefty7mmstw]

I would expect blistering velocities if we wre that much over pressure but 10 rounds were consistently 3240 or within 40 fps thereof . My buddy has one hes shooting 140gr out of at 4400fps and claims hes not over pressure. Like i say i dont reload i leave that to guys with far more knowledge and experience than i.and i do trust them wholy

I wouldn't be taking advice from someone who has been trying to get over 4,000 fps from a 140 in a 7rum... The fastest I've ever gone in a 7rum (I'm currently on my 4th 7rum barrel) was a few fps shy of 4,000 avg. with a 120 Sierra and AA8700... That load beat the snot out of the cases and I stopped using it after I worked it up as the accuracy wasn't great.

 

[Cowboyblaster]

I wouldn't be taking advice from someone who has been trying to get over 4,000 fps from a 140 in a 7rum... The fastest I've ever gone in a 7rum (I'm currently on my 4th 7rum barrel) was a few fps shy of 4,000 avg. with a 120 Sierra and AA8700... That load beat the snot out of the cases and I stopped using it after I worked it up as the accuracy wasn't great.

Ya no thats not the guy doing reloading for me haha he's just one of these guys that has enough money and knowledge to get him in trouble and not enough sense to keep him out of it ha-ha

 

[Mike Matteson]

Flatten primers is the limits. Your Primers pocket will be going in a few rounds anyway. Creator Primers are to much, and ejector marks is over pressure too. I check out each fired case each and every time I shot anyway. For every watching for problems that may come up. Exceeding is crazy, and I don't want to be around that person. I very seldom lose a case even when hunting. Most of the time I make one shot kills, I am not saying I don't screw up, but generally being very careful about making the shot. The last time I was in Africa except to checking my zero, I was four to four, and one running shot, not that I take animal running. The guide and owner want that animal dead and gone.

 

[Cowboyblaster]

Very good ideas and as far as hunting I've seldom in my life ever had to hit an animal a second time aside from 1 wolverine that took 4 from a 4570 and an elk that refused to believe it was dead first shot

 

[M T Shell]

Im relatively new to building long range rifle's. The 7mm remington ultra mag im working on now being my second. Im working with remington 700 actions because I know them to be excellent. My question though is this.
When a 7mm 168gr berger bullet has to be pushed furthe into the case neck than desired to be held in the magazine how can you load this case with say a 190gr or furthermore how can this action accept a 300 Rum shooting a 200+ grain bullet. I do realize that is a larger diameter bullet but only by 2 thou and a long action is what it is. The way it looks to me is if i wanted to use 180 gr bullets in my 7mm i would have to operate the rifle as a single shot . I know im probably wrong about this so please if you have the time and knowledge please educate me . Thank you

"I do realize that is a larger diameter bullet but only by 2 thou." The diametrical difference between 7 mm and 300 Rum is 0.024 ", not 0.002".