Why 7STW over 7RUM?

[cohunter14]

First and foremost, I am not a proponent of one of these calibers or another. I simply wanted to see what the real differences were and why most everyone who views these threads chooses to shoot the 7STW. From just a numbers perspective, I see that the RUM has the ability to have higher muzzle velocities, so is barrel life something that comes into play then? Just curious and I'm hoping to learn a little bit about the STW

 

[MudRunner2005]

I chose to shoot the 7mmSTW 11 years ago, before I ever knew this forum existed. I worked in an outdoors store, and I had a fellow employee that worked with me, who had a custom one made. I shot it and fell in love with how flat shooting and smooth the recoil was for how big of a cartridge it was. Plus, I was already a huge proponent of the 7mm calibers since I was about 12, when I got my first bolt-action deer rifle, which was an old Ruger 77 stainless skeleton stock mountain rifle in 7mm-08, and I put the whompin on quite a number of deer for those years I used that rifle. Then I jumped to another Ruger 77 stainless skeleton stock in a 7mm RemMag. LOVE that caliber, even to this day, my main deer rifle is a 7mm RemMag. I still have both of those Rugers, BTW...They're just sitting in the safe these days. Occasionally I bring them out and warm up the bore at the range. After I loved that 7RemMag so much, the guy at the outdoors store came up to me and said, "Hey, since I know you like 7's so much....Check out my new toy..." And handed me his newly finished 7mmSTW that he had just picked up the day before from the gunsmith (we both use the same gunsmith). So we took it to the range the following Sunday and shot it. Man, that thing was sweet! So then I decided to start thumbing through our (the store's) Bangers and Ellett Brothers catalogues to see what all Remington 700's were offered in 7mmSTW. The only one listed at the time was the Sendero SF. So I told the boss I wanted to order one for myself. He said that was cool with him. The rest is a long story (some of you have heard the rest), but I got it, and over the last 11 years have learned to love that cartridge more and more, discovering new things I can do with it at different ranges. The flat trajectory is phenomenal.

Soooooo, that's how I ended up with a 7mmSTW. And after discovering it's abilities, I have no need for a 7RUM. The STW is already harsh enough on throat erosion, and the RUM is supposed to be worse. After all these years or shooting and not keeping track of my round count, I am bummed that I probably only have 1/2 my barrel life left....But it is what it is. Barrels will always wear out...That's part of life.

 

[Archery1973]

I just had a 7mm STW built by McWhorters. I had been shooting a 7mm RUM. Allan said he can get comparable speed but with better accuracy out of the 7mm STW. So, I went with that.

It does 3189 fps with 180 berger. 0.227" average group at 100 yards.

 

[MudRunner2005]

What powder and charge are you using to get 3,200 fps with 180 Bergers?

 

[marioq]

Alan likes the vithvuri powders. At least he did on my 338 Lapua and my buddies 300 RUM

 

[7stw]

MY, best take on it is, the STW is SHOOTABLE. I have been shooting this caliber since about 1997 or so. About two years ago, I bought a 7 RUM, brand new, just to see what all the hoopla was about. I found it to be finicky, never mind the muzzle blast. By the time I finally found a load that it would shoot consistently, I was less then 80 fps faster then the STW, and a lot more powder burnt to boot!
My bottom line all boils down to the fact that you CAN have TOO much of a good thing. I feel that the STW is about as much overbore as a 284 diameter can be, and still remain SHOOTABLE. Any more is just more fuss, WAY less barrel life, and muzzle blast .
Everyone has their thoughts, those are mine, but I have lots of company. And, I haven't seen any websites, dedicated to it either! Imagine that!

 

[cohunter14]

Interesting responses so far. Nothing real definitive as far as a good reason why, but keep the responses coming!

 

[Black Sheep]

To echo what 7stw said, the cost of the upgrade from STW to RUM isn't worth it. When I was looking into buying a 7, I was going to go with a RUM. More powder, more speed, more manly testosterone!!!!! Then I started to research the rounds. I shoot Barnes, so using their data, here is an example on a 175 gr tsx:
7mmSTW 71.5g max of RL25 @ 2898fps. 75.0g max H1000 @ 2908fps
7mmRUM 84.0g max of RL25 @ 2985fps. 84.0g max H1000 @ 2943fps
Rum uses 17.5% more RL25 for 3% more velocity
Rum uses 12.0% more H1000 for 1.2% more velocity.
Even assuming barrel life, and load workup not being any different for either cartridge, the math nerd in me says its just isn't worth it. For fun, here's the 7RM:
7mmMAG 62.5g max of RL25 @ 2738fps. 64.0g max h1000 @ 2697fps
STW uses 14.4% more RL25 for 6% more velocity
STW uses 17.2% more H1000 for 7.8% more velocity
Better velocity for powder upgrade from 7RM to STW then from STW to RUM.

 

[cohunter14]

To echo what 7stw said, the cost of the upgrade from STW to RUM isn't worth it. When I was looking into buying a 7, I was going to go with a RUM. More powder, more speed, more manly testosterone!!!!! Then I started to research the rounds. I shoot Barnes, so using their data, here is an example on a 175 gr tsx:
7mmSTW 71.5g max of RL25 @ 2898fps. 75.0g max H1000 @ 2908fps
7mmRUM 84.0g max of RL25 @ 2985fps. 84.0g max H1000 @ 2943fps
Rum uses 17.5% more RL25 for 3% more velocity
Rum uses 12.0% more H1000 for 1.2% more velocity.
Even assuming barrel life, and load workup not being any different for either cartridge, the math nerd in me says its just isn't worth it. For fun, here's the 7RM:
7mmMAG 62.5g max of RL25 @ 2738fps. 64.0g max h1000 @ 2697fps
STW uses 14.4% more RL25 for 6% more velocity
STW uses 17.2% more H1000 for 7.8% more velocity
Better velocity for powder upgrade from 7RM to STW then from STW to RUM.

I hear what you are saying on this, but do you realize that to load the extra powder of the RUM, you are talking an extra $.045 (4 1/2 cents) per round with the RL25, which has the larger powder difference? Again, I am not trying to start arguments or anything, just trying to learn! I wasn't sure if it was the powder, the barrel life, etc that had people shooting this round...

 

[7stw]

I hear what you are saying on this, but do you realize that to load the extra powder of the RUM, you are talking an extra $.045 (4 1/2 cents) per round with the RL25, which has the larger powder difference? Again, I am not trying to start arguments or anything, just trying to learn! I wasn't sure if it was the powder, the barrel life, etc that had people shooting this round...

There is a mathematical formula that comes into play here. And, the law of deminishing returns also comes into play. The latter is the most important one here, and it's application. In the firearms available, and that being with 26 inches of barrel, a good bit of the powder is burned OUTSIDE of the barrel given no more push, just more blast, and felt recoil. The deer don't care either way!

 

[284nut]

There is a mathematical formula that comes into play here. And, the law of deminishing returns also comes into play. The latter is the most important one here, and it's application. In the firearms available, and that being with 26 inches of barrel, a good bit of the powder is burned OUTSIDE of the barrel given no more push, just more blast, and felt recoil. The deer don't care either way!

Faster cars, younger women older whiskey more money! My middle son has the urge for the 7 RUM, he believes that it will be just slightly better than the STW..

The overbore scenario is at its peak in the STW piggy backing on 7 STW's earlier comment. You are already on the outside edge of what several bullets can handle in the velocity conversation, if you compromise by adding weight you will pay in recoil and get little gain in velocity from the 7 RUM to show for it.

I guess to each there own, but those who own, load and shoot the STW seem very content with what we have seen be dramatically effective on game.

 

[Archery1973]

What powder and charge are you using to get 3,200 fps with 180 Bergers?

80.5 of N570.

 

[MudRunner2005]

I'll have to wait till my local store gets some more Viht in stock, and I'll have to give it a shot...

Thanks!

 

[Black Sheep]

cohunter14--Yeah, I get that. Granted, over 1000 round barrel life, it works out to $45 more. Insignificant, I know but still--its more than a pound over the life of the barrel. 15% more powder will produce more recoil. Exactly how much, I don't know. It will also burn out the throat faster, again how much I don't know. I also have two buddies with Sendero SF STW's that handload, so I knew going into a cartridge I really didn't know about, that I would at least have experience to go off of developing a load. So for me, the math and the intangibles made the decision for me to go STW. I bought a semi-custom RUM sight unseen off of the internet. When it showed up, I was less than impressed. Right after that, I found my Sendero STW on Gunbroker. The guy didn't have it listed as a sendero, so I think thats why I got it relatively cheap. (that, and it had a disgusting paintjob on it--Bright orange with gold metalflake!!!) So I sold the RUM at a $50 loss, and jumped on the STW. Have never looked back.