7mm rum vs 300 rum

[Hunt7112]

Question for you guys I have a remington 700 sps 7rum going to build a new gun around the action thought about changing it to a 300 rum is this a mistake or should I keep it a 7mm. Thanks

[firstcoueswas80]

7

[rcdinaz]

Keep it a 7 or trade me for my stainless 300 RUM model 70 with a borden stock, muzzle break, action trued and trigger reworked.

 

I really like the 7's, shooting a 7mm Dakota right now with a 7mm RM in the works.

[308Nut]

If you can handle the recoil, neither. The best way to improve either of those is to stick a 338 bullet in the case. More energy, more bbl life and LESS windage.

 

If I had to choose between the 7 and the 300. Then the 300 is an easy answer. More energy than the 7, more life than the 7 and less windage. Dont let anybody tell you any different. The downside is of course,,,,,,more recoil. Equal bullets weight for bullet weight, the 7 will win out (assuming the use of similarly designed bullets). That said, the larger caliber will always have heavier bullets with higher BC's available then the next caliber.

 

M

[Couzer]

If you can handle the recoil, neither. The best way to improve either of those is to stick a 338 bullet in the case. More energy, more bbl life and LESS windage.

 

If I had to choose between the 7 and the 300. Then the 300 is an easy answer. More energy than the 7, more life than the 7 and less windage. Dont let anybody tell you any different. The downside is of course,,,,,,more recoil. Equal bullets weight for bullet weight, the 7 will win out (assuming the use of similarly designed bullets). That said, the larger caliber will always have heavier bullets with higher BC's available then the next caliber.

 

M

 

+1 the 338 rum is nice!!!

[Hunt7112]

Thanks for the reply's so far. Another question why do the 300 rum and 7rum burn barrels faster than say a 338 rum or are all rums barrel burners when you say 338 should I consider a lapua, or edge. Thanks again.

[rcdinaz]

Either 338 is awesome!

 

The bullet is moving faster in the 7 and the 30 so the barrel life is decreased. 3,200 to 3,300 fps is tough on a barrel.

 

 

308 nut I agree with your take on the 338 but I am not sure what you mean regarding .308 bullets, they tend not to have higher BC's than the 7's. The 180gr Bergers have a .337BC which you can't get to in the 308's, even the 7mm 168's are very close to the big 210's in 308. It seems that it is tough to get the big 300's up to the speeds you can achieve with the 7's?

 

I realize from your other posts you know the the ballistics topic very well but everything I have seen shows the 7's have an edge on the 308. Again the 338 is almost impossible to beat.

 

Interesting article on the 30 caliber bullets from Berger:

http://www.longrangehunting.com/articles/30-caliber-1.php

[.270]

the 7 has the same amount of gas going out a smaller hole. it's going to cause more erosion. as big as the case is, i would imagine the 7 rum will be a real barrel burner. only experience i have with the cartridges in question is with the .300 rum. it's a cannon and shoots a long ways. i killed a deer at 635 and an elk at 740 in the same year with my son's christensen. he shot a bull with it at 855. if i was going to shoot that much powder, it would be in the .300 or .338. you're sorta overpowdered with the 7mm bore and a case that holds 100 grains of powder. Lark.

[sjvcon]

Gotta agree with 308 and Lark on this. Same case with two different bores ... the smaller bore is going to have the same volume of hot gases pushed out at higher velocity (and probably pressure). That equates to quicker erosion ... and bingo the 7 RUM is known as a real barrel burner. If I were doing something on this case, I'd do the .338 Edge 1st Choice. Maybe even an 8MM RUM (and now thinking about that makes me want to research it). I'd do the .300 next ... and since I own one I am a little biased, but I'll tell you that when that barrel is gone it is going to wear a custom barrel in a bigger bore. If I were doing the 7, it would be the 7 RM. The RUM and STW are just too hard on barrels from all accounts. Plus, in a pinch, you can get 7 RM at just about any WalMart in the country.

[TAM]

You can't take a .338 into Mexico... perhaps not a factor for everyone but it is for me. I'd stick with the 300 RUM.

[rcdinaz]

TAM good input I did not know about Mexico restricting bullet size.

 

I am taking my 7

[TAM]

I believe the limit in Mexico is 8mm.

[308Nut]

 

308 nut I agree with your take on the 338 but I am not sure what you mean regarding .308 bullets, they tend not to have higher BC's than the 7's. The 180gr Bergers have a .337BC which you can't get to in the 308's, even the 7mm 168's are very close to the big 210's in 308. It seems that it is tough to get the big 300's up to the speeds you can achieve with the 7's?

 

I realize from your other posts you know the the ballistics topic very well but everything I have seen shows the 7's have an edge on the 308. Again the 338 is almost impossible to beat.

 

Interesting article on the 30 caliber bullets from Berger:

http://www.longrangehunting.com/articles/30-caliber-1.php

 

Bullet weight for bullet weight and equal form, you are 100% correct. The 7mm will beat the 30's hands down. For the same reason the 338 offers heavier and higher BC bullets over the 30 cals, the 30's have higher weight and BC bullets available over the 7mm. Look at the difference between the Berger 7mm 180 grain versus the 30 cal 230 grain. .674 versus .743. More energy at the muzzle, more energy down range and less windage. The downside is of course, is recoil. 7mm can be a better caliber in that regard but if one wanted to fill the gap between the 7mm's and the big 338's, a big 300 is a good place to be. The 30 cal will alway get my vote over the 7mm. I do understand the BC to bullet weight ratio is not as optimum for the 30's as it is the 7's, but the fact remains, a larger bore will have heavier bullets with higher BC's available than the next caliber down.

 

You also have to factor in that with equal barrel lengths, equal case volumes and equal bullet weights, where one bore is larger than the other (such as the 300RUM and 7mmRUM) the one with the larger bore will have higher velocity potential. This allows for slightly heavier bullets to be driven at the same speeds at the next caliber down. For example, Hodgdon lists the 7mmRUM running 175 grain bullets at 3077 FPS and the 300 RUM running 200's at 3068 FPS. The same applies for the 338 Edge versus the 300 RUM. Same case. All else being equal, the 338 will run equal weights faster or heavier weights equal to etc....

 

Everything is a trade off. The 7mm will have less recoil but less barrel life and less energy. The 300 will have better barrel life and more energy yet more recoil. Windage will be close.

 

Even with all that said, I have a new .264 caliber barrel arriving next week. Who would have figured that?

 

 

M

[Hunt7112]

Thanks again for the info. I shoot a 7mmRum and my son killed his Bull this year with it at 780 yds, so this is his rifle that I am building. With him being 13 years old I believe I will go with the 300 Rum for him, and when my 7mm barrel is shot out I will build a 338 edge or lapua for that. From the sounds of your replys you cant go wrong with any of them. Thanks.

[rcdinaz]

Good choices! I am looking at changing my 300 over to 338 when the barrel starts getting tired. I probably have a couple of seasons before it is an issue. There is so much info on the Edge now and a lot of good feedback, I will probably go that route.

 

Good luck with your build and getting your son up and running. You may want to do barrel break in with the Remington reduced loads and get him used to shooting the gun before you graduate to full charges and heavier bullets. Just a thought.