300 RUM or 7mm with 180 bergers at 3000 fps

[MontanaRifleman]

I will just add that I do think the 300 barrel will last longer, but for a few hunting shots every year , I will never wear it out.

Looking back I wish I had bought a 338 LM for LR. There are so many good reasons to buy one and the fact that it can reach out another 2-300Y past the rums with those huge BC's, is one of them. However I would not want to hunt with one...too heavy and gotta have a MB. The Rum truly is one of the largest usable hunting rifles IMO. How many other shoulder fired rifles contain up to 100G of powder?

For the price of a CT, I'd rather shoot my 50, that is just me. The 338 Guys were jealous of me hitting 2200Y and seeing the hits.....

I wish I had a 338 LM as well. But as long as I have the RUM, it's down my list of priorities for a while. The 7 RUM is a real nice cartridge, but like you say, ti eats barrels. The 300 is a little better.

 

[Jordan Smith]

This thread is about 300 RUM vs 7 RM. The 7 RUM is a different animal.

Comparing the 7 180 to the 308 210 isn't apples to apples. Apples to apples would be the 180 and the 230.

Also your velocity for the 210 is a little low. I get 3150 in my RUM. If we were to compare the 308 215 Hybrid to the 7 180 Hybrid the 215 has a G7 of .356 to the 7's .345 Typical velocities for the 7 and 300 for these bullets from these chambers would be similar which would give the 300 a slight ballistic edge over the 7 with a significant terminal edge. With the 230 hybrid, the ballistics would be similar with an even greater terminal edge. Bigger is bigger and when comparing apples to apples, bigger will come out on top of smaller.

Nah, apples to apples would be the 195 Hybrid vs. the 230 Hybrid

 

[MontanaRifleman]

Nah, apples to apples would be the 195 Hybrid vs. the 230 Hybrid

What 195 Hybrid?

 

[MontanaRifleman]

Nah, apples to apples would be the 195 Hybrid vs. the 230 Hybrid

Yeah, that would be a better comparison.

 

[Jordan Smith]

Yeah, that would be a better comparison.

The .338 300gr and the .308 230gr were first introduced as members of the heavyweight Hybrid lineup that Berger came out with, followed by the .270 170gr. The 7mm 195 will complete the series of heavy Hybrids from .270 to .338, and will be a much better comparison for the 230 and 300, like you said.

The 7RM firing the 195 at ~2850fps will be fairly equivalent to the 230 from the .300 RUM (QL predicts that 2850-2900fps is about the top end with a 26" barrel) and the 300 from the .338LM as far as wind drift and drop are concerned. Of course momentum on target gets higher and higher as you move up the bullet weight ladder.

Prior to the heavy Hybrids showing up, the 180gr 7mm bullets were compared with the 210gr range of .308 bullets, which was as good as it got for an apples to apples comparison. QL shows around 3000fps being about max for the 210 in the .300RUM, as well as the 180 in the 7RM.

 

[MontanaRifleman]

The .338 300gr and the .308 230gr were first introduced as members of the heavyweight Hybrid lineup that Berger came out with, followed by the .270 170gr. The 7mm 195 will complete the series of heavy Hybrids from .270 to .338, and will be a much better comparison for the 230 and 300, like you said.

The 7RM firing the 195 at ~2850fps will be fairly equivalent to the 230 from the .300 RUM (QL predicts that 2850-2900fps is about the top end with a 26" barrel) and the 300 from the .338LM as far as wind drift and drop are concerned. Of course momentum on target gets higher and higher as you move up the bullet weight ladder.

Prior to the heavy Hybrids showing up, the 180gr 7mm bullets were compared with the 210gr range of .308 bullets, which was as good as it got for an apples to apples comparison. QL shows around 3000fps being about max for the 210 in the .300RUM, as well as the 180 in the 7RM.

Interesting, It's been a little while since I loaded for the 7 RM, but 3000 out of a 24" tube was tops for a 160 bullet using IMR 4831 which was my powder of choice back then. Little doubt that Retumbo or RL17 could push those velocities some. I would be impressed to see 2850 from a 7 RM pushing a 195 gr pill. For the RUM, Retumbo gets me to 3150 pushing the 210 before I start seeing signs of acceptable pressure, no sticky bolt or flowing primers. I back off a half gr for a 3130 working load.

Yup, back in the day, the 210 or the 240 SMK were the tickets, They've come up with some good bullets in the last couple of years.

 

[Jordan Smith]

Interesting, It's been a little while since I loaded for the 7 RM, but 3000 out of a 24" tube was tops for a 160 bullet using IMR 4831 which was my powder of choice back then. Little doubt that Retumbo or RL17 could push those velocities some. I would be impressed to see 2850 from a 7 RM pushing a 195 gr pill. For the RUM, Retumbo gets me to 3150 pushing the 210 before I start seeing signs of acceptable pressure, no sticky bolt or flowing primers. I back off a half gr for a 3130 working load.

Yup, back in the day, the 210 or the 240 SMK were the tickets, They've come up with some good bullets in the last couple of years.

Just so you know, QL is showing 99.5gr of Retumbo at 3122fps in a 26" barrel with the RUM and 210gr VLD. It is saying that the load produces an estimated 80k psi. I've also seen guys that push over 3200fps with a 160gr bullet in the 7RM, and 3100fps with the 180. I don't think I'm brave enough to push that hard. The problem with traditional pressure signs, is that they often don't show up until well over 70k psi of chamber pressure, if using strong brass and hard primer cups. A strain gauge would be a useful tool to tell how much pressure you're actually running to get that 210 to 3130fps, just for your own safety, if nothing else.

I don't mean to preach, but I thought I'd at least mention it. We may not know each other, but I'd hate for your hide to get peppered by shrapnel from the barrel or action. The load may not have any negative side effects right now, but metal fatigue is a cumulative process, and enough 80k psi loads will eventually weaken the action (assuming that's what you're running- only a strain gauge or other pressure testing equipment will tell the true story).

BTW, your signature is awesome and very true.

 

[MontanaRifleman]

Just so you know, QL is showing 99.5gr of Retumbo at 3122fps in a 26" barrel with the RUM and 210gr VLD. It is saying that the load produces an estimated 80k psi. I've also seen guys that push over 3200fps with a 160gr bullet in the 7RM, and 3100fps with the 180. I don't think I'm brave enough to push that hard. The problem with traditional pressure signs, is that they often don't show up until well over 70k psi of chamber pressure, if using strong brass and hard primer cups. A strain gauge would be a useful tool to tell how much pressure you're actually running to get that 210 to 3130fps, just for your own safety, if nothing else.

I don't mean to preach, but I thought I'd at least mention it. We may not know each other, but I'd hate for your hide to get peppered by shrapnel from the barrel or action. The load may not have any negative side effects right now, but metal fatigue is a cumulative process, and enough 80k psi loads will eventually weaken the action (assuming that's what you're running- only a strain gauge or other pressure testing equipment will tell the true story).

BTW, your signature is awesome and very true.

I appreciate the heads up. Here are 3 of my loads with Retumbo, all without any visible pressure signs.

180 E-Tip, 98 gr, 3400 +
200 AB, 94 gr, 3200
210 Berger, 93 gr 3130

Not sure why QL is showing 99.5 gr for 3122, but I was nowhere near that charge and never expected to get near it with the 210's. I did a lot of research in both online manuals and threads in this and other forums before working up these loads. I had a good idea of the start and max range and the expected velocities. If you search the threads for 300 RUM load data, you'll find my charges and velocities are similar to a lot of others.

 

[Jordan Smith]

I appreciate the heads up. Here are 3 of my loads with Retumbo, all without any visible pressure signs.

180 E-Tip, 98 gr, 3400 +
200 AB, 94 gr, 3200
210 Berger, 93 gr 3130

Not sure why QL is showing 99.5 gr for 3122, but I was nowhere near that charge and never expected to get near it with the 210's. I did a lot of research in both online manuals and threads in this and other forums before working up these loads. I had a good idea of the start and max range and the expected velocities. If you search the threads for 300 RUM load data, you'll find my charges and velocities are similar to a lot of others.

Yeah, there are lots of variables that QL factors in, and I just did the default values for most of them, not knowing your actual numbers. That could be part of the reason why there is so much disparity between the two numbers. Assuming an OAL of 3.598", usable case capacity of 99.8gr, and a 26" barrel, it's saying that 93gr of Retumbo should be around 63k psi and 2940fps. Lot to lot variation in the powder also plays a part here, and it's saying that a lot that is 10% faster than average would produce 3041fps.

This is also assuming a SAAMI chamber and throat, which you may not have, and your land and groove diameters could vary from what QL assumes, as well. Lots of factors involved, but it serves to give a ballpark. Strain gauge data would be very interesting to compare to what QL is saying.

 

[captacademy]

Just got my 7mm mag rifle from Travis at Rbros and it's at 3050fps with the 180 Berger VLD's, 27" barrel and Retumbo. The rifle shoots this load under a 1/2"

Chronoed 12' from the muzzle

 

[pyroducksx3]

RBROS is who I went with also for my 7 mag build. I'm the OP and Im not regretting my decision to go with a 7mag vs the 300 RUM. I went with a 26" rock creek barrel and Im getting 3060 (verified drops out 1100 yards)with 71.5 grains of retumbo using the 180 berger vlds. I am using norma brass vs the winchester he normally recommends. The norma is great but the problem with it is the brass neck nickness is a little more so I have to neck turn all my brass. I love my RBROS 7 rem mag. I've shoot groups down to .308 CTC. It shoot every load I tested to pretty much 1/2" groups, he builds a great rifle.

 

[captacademy]

I agree, my Rbros 7 mag rifle is shooting the 180 VLD's under 1/2" at 3056 fps. It's a very accurate rifle, just like my Rbros 7 WSM. These rifle are tac drivers! I can't wait to take a game animal with it.

 

[brentc]

The 7mmRM/Retumbo combo seems to like running in the 3060 range with adequate bbl length and the right chamber. That's where my rebarreled Rem 700 runs too. I've also gotten great accuracy from 69 grains of H1000 running up to 3000 fps.

 

[MontanaRifleman]

RBROS is who I went with also for my 7 mag build. I'm the OP and Im not regretting my decision to go with a 7mag vs the 300 RUM. I went with a 26" rock creek barrel and Im getting 3060 (verified drops out 1100 yards)with 71.5 grains of retumbo using the 180 berger vlds. I am using norma brass vs the winchester he normally recommends. The norma is great but the problem with it is the brass neck nickness is a little more so I have to neck turn all my brass. I love my RBROS 7 rem mag. I've shoot groups down to .308 CTC. It shoot every load I tested to pretty much 1/2" groups, he builds a great rifle.

I hunted with a 7 RM many years and killed a lot of critters with it. It's a fine cartridge. That said it is no where near a 300 RUM. I've shot both. Your 7 mag can push 180's with a G7 BC of .345 @ 3060 fps and a 300 RUM can push 215's with a G7 BC of .356 @ 3100 fps. The RUM is pushing a heavier bullet with a higher BC at a greater velocity. In other words, it is leaving the 7mm bullet behind in all categories. Flatness, TOF, Windage, and Energy. Not a slam on the 7mm, just putting things in perspective.