7mm???

[MudRunner2005]

Not to get sidetracked here, but I understand where you are coming from. However, one thing I cannot ever understand is why the 7 RUM is so bad compared to the 7 STW. When comparing the cost of barrel life and extra cost of powder compared to the extra velocity you get (give or take 100fps), why is it so much different than the 300 Win versus the 300 RUM? Granted, you get closer to a 200fps gain with the 300RUM, but it is also a much bigger difference in the amount of powder you burn and barrel life. Just seems a little weird to me.

I don't own either one of the 7's, but if I ever did I would think that the extra five cents per round for the RUM and maybe 100 rounds less barrel life would be well worth the extra 100fps. Just my opinion I guess...

Actually, we're talking 15-20gr of powder difference and about 500+ shots less barrel life. There are several guys out there getting 1,500 rounds out of their STW's. I'd be willing to guess the average is probably more like ~1200 rounds. One of which, Lefty7mmSTW, is a member here. Maybe he'll chime in... 7RUM's usually don't average more than ~800 rounds of barrel life before the throat is cracked, burnt, and trashed.

They are both barrel burners, but to lose that extra 400+ rounds of barrel life for a gain of 80-100 fps is not worth it to me. Once again, just my opinion. Everyone has a different one.

If I get a great shooting rifle, I don't want to have to start over from scratch after only 800 shots down the tube. But that's another of my personal reasons I won't own a 7RUM.

 

[cohunter14]

Actually, we're talking 15-20gr of powder difference and about 500+ shots less barrel life. There are several guys out there getting 1,500 rounds out of their STW's. I'd be willing to guess the average is probably more like ~1200 rounds. One of which, Lefty7mmSTW, is a member here. Maybe he'll chime in... 7RUM's usually don't average more than ~800 rounds of barrel life before the throat is cracked, burnt, and trashed.

They are both barrel burners, but to lose that extra 400+ rounds of barrel life for a gain of 80-100 fps is not worth it to me. Once again, just my opinion. Everyone has a different one.

If I get a great shooting rifle, I don't want to have to start over from scratch after only 800 shots down the tube. But that's another of my personal reasons I won't own a 7RUM.

I completely hear where you are coming from, and I can't comment on actual barrel life as I don't own either of them. But again, the comparison of powder difference is similar to powder difference in a 300 Win versus a 300 RUM. So that is where I get confused I guess...a 300 win compared to a RUM gets approximately 200fps difference, the STW versus a RUM gets approximately 100fps difference with everything else being similar (added powder, reduced barrel life). Anyway, was just throwing it out there for the OP. As I said, any of the calibers mentioned will be great for what you are looking for!

 

[MudRunner2005]

I mean, it's possible to burn up any magnum caliber barrel in 250 rounds if you keep shooting it into a red glow. LOL

So, barrel life is one of those things that has too many factors to really give a definitive number on. If you say 1200 and someone is irresponsible or doesn't know how to treat an overbore magnum barrel, and burns it out in 800...They're gonna be ****ed tou told them 1200.

The numbers i quote are generized observations taken from people who took care of their rifles.

 

[cohunter14]

Yep, I gotcha. I guess I'm just surprised the 7 RUM doesn't get more of a following. I hear the same argument for it (reduced barrel life, increased powder), but it seems so similar to arguing a 300 RUM over a 300 Win that I guess it confuses me. There are a ton of people who prefer the 300 RUM over the Win, and yet the STW seems to win out over the RUM in most conversations. As I said, just interesting to me. If I got a 7mm cal, I would want to push the heaviest bullets the fastest I could, same reason I would choose a 300 RUM over a Win. That's why they make all the different calibers I guess!

 

[MudRunner2005]

Yep, there's something out there for everyone.

I understand what you're saying. The STW has magical properties since Layne had the caliber blessed by an indian medicine man while also performing religious and voodoo ceremonies at the same time.

Seriously though, it is just one of those calibers you just have to shoot and own to really get the appreciation for it. It has a cult-like following for a reason. It is just simply THAT badass of a caliber.

I think every true 7mm fan should own one.

 

[cohunter14]

The STW has magical properties since Layne had the caliber blessed by an indian medicine man while also performing religious and voodoo ceremonies at the same time.

LOL!!! That is what I've been missing, no one explained THAT part to me! Now I get it!!

I understand it's badass, but let me ask you this: have you owned a 7 RUM? I would love to hear from someone who has owned both just to hear their opinion. Either that or I guess I'll just have to buy one of each and make a decision on my own! Now to come up with an explanation for the wife...

 

[MontanaRifleman]

Yep, I gotcha. I guess I'm just surprised the 7 RUM doesn't get more of a following. I hear the same argument for it (reduced barrel life, increased powder), but it seems so similar to arguing a 300 RUM over a 300 Win that I guess it confuses me. There are a ton of people who prefer the 300 RUM over the Win, and yet the STW seems to win out over the RUM in most conversations. As I said, just interesting to me. If I got a 7mm cal, I would want to push the heaviest bullets the fastest I could, same reason I would choose a 300 RUM over a Win. That's why they make all the different calibers I guess!

I think if you took a poll on this site the 300 WM would come out on top of the 300 RUM in popularity. It's a little cheaper to run and it's just been a long time favorite cartridge as well as a little better barrel life.

In the case of the 7 RUM, I think a couple of the main factors are, that it is so overbore that there are very few powders that are very efficient in it... and it has such a short barrel life. When the 195 EOL comes out, along with the development of RL33, you might see some renewed interest in the 7 RUM. It will crush the other 7's, but it will still come with the price of harsh throat wear.

 

[cohunter14]

I think if you took a poll on this site the 300 WM would come out on top of the 300 RUM in popularity. It's a little cheaper to run and it's just been a long time favorite cartridge as well as a little better barrel life.

In the case of the 7 RUM, I think a couple of the main factors are, that it is so overbore that there are very few powders that are very efficient in it... and it has such a short barrel life. When the 195 EOL comes out, along with the development of RL33, you might see some renewed interest in the 7 RUM. It will crush the other 7's, but it will still come with the price of harsh throat wear.

I guess what I am getting at though is this: is the short barrel life that much more significant than the STW? I would think it would be similar to comparing the 300 Win to the 300 RUM. I know the Win is extremely popular, and Broz makes a hell of a case for it, but the 300 RUM does have a pretty good following as well on here. The barrel life between those two calibers can't be that much more significant than the STW versus the RUM, especially when you are 'only' increasing the velocity 100fps versus 200fps.

It just seems to like it's more 'hearsay' than anything with the 7 RUM. People read that it's more expensive per load, when it is really only 5 cents of powder more. Barrel life is worse, but is it really 500 rounds different? Or are we talking 100 rounds? Tough to know for sure as there are a lot of variables in there.

All in all, I just see a lot more people open to the 300 RUM over the 300 Win, for example, but people are completely against a 7 RUM over an STW and it just doesn't seem to be that much different of an argument between the two, in my opinion.

 

[MudRunner2005]

LOL!!! That is what I've been missing, no one explained THAT part to me! Now I get it!!

I understand it's badass, but let me ask you this: have you owned a 7 RUM? I would love to hear from someone who has owned both just to hear their opinion. Either that or I guess I'll just have to buy one of each and make a decision on my own! Now to come up with an explanation for the wife...

I almost bought a used 700 BDL 7RUM from a local store because I was gonna get it for about $550 out the door, just to help complete my 7 collection. But they sold it recently, according to a buddy of mine, which means they might not have, and he's just holding out to buy it by eliminating me from the list of people interested in it... LOL

 

[angus-5024]

for a hunting rifle barrel wear is a minor factor. look at Kirby Allen's little 7AM that he shot all kinds of game with, last I heard it was like 10 years old and had 900+ rnds down the pipe? I could be misremembering, but it think it was something like that.

Barrel life is a concern for Target shooting, and so is cost of powder. If someone wants to "plink", look for something that only cooks 30-50 grains at a time!

 

[MontanaRifleman]

I guess what I am getting at though is this: is the short barrel life that much more significant than the STW? I would think it would be similar to comparing the 300 Win to the 300 RUM. I know the Win is extremely popular, and Broz makes a hell of a case for it, but the 300 RUM does have a pretty good following as well on here. The barrel life between those two calibers can't be that much more significant than the STW versus the RUM, especially when you are 'only' increasing the velocity 100fps versus 200fps.

It just seems to like it's more 'hearsay' than anything with the 7 RUM. People read that it's more expensive per load, when it is really only 5 cents of powder more. Barrel life is worse, but is it really 500 rounds different? Or are we talking 100 rounds? Tough to know for sure as there are a lot of variables in there.

All in all, I just see a lot more people open to the 300 RUM over the 300 Win, for example, but people are completely against a 7 RUM over an STW and it just doesn't seem to be that much different of an argument between the two, in my opinion.

There are a lot of factors in barrel life but overall you can reasonably predict what to expect based on how you shoot it and take care of it.

The RUMs have about 107 gr of H2O capacity. The STW about 93 and the 300 WM about 87, So there is a little bigger step between the 300 WM and the RUM vs the STW and the RUM. If you calculate an overbore index based on the bore diameter and volume of the case you will get 1468 for the STW, 1689 for the 7 RUM, 1436 for the 300 RUM and 1167 for the WM. Volume to bore ratios don't tell the whoule story in that case design plays a part as well. These case are not too different with the RUMs having slightly sharper shoulders. So you can see the 7 RUM has a very high overbore index and the STW a little higher than the 300 RUM. I think the "burnout" factor is more exponential than linear the higher you go with overbore factor.

So if you accept that you can get say 1000 rounds of good accurate life from a 300 RUM, you might deduce that you can get 900-950 out of an STW running at the same pressures and a good bit less from a 7 RUM. How much less... who knows? but I've read some reports of guys toasting them in about 500 rounds.

Another consideration is when do you consider a barrel burned out? 1/2 MOA? 3/4 MOA? 1 MOA?

As mentioned, the 7 AM is more overbore than the 7 RUM. I'm guessing it be about 115 gr or so H2O in capacity. That said, it does have a sharper shoulder. I just read yesterday I think, that Kirby's AM had over 1000 rounds through it and it's still shooting good, good meaning sub 3/4 MOA. He says he never shoots it hot (more than 1 or 2 rounds at a time) and takes very good care of it. Some guys consider a barrel toasted once it exceeds 1/2 MOA accuracy. But 3/4 MOA is plenty good for hunting out to a good long distance.

So I think you can expext 200-300 rounds less out of a 7 RUM than an STW under the same conditions.

 

[WildRose]

Not to get sidetracked here, but I understand where you are coming from. However, one thing I cannot ever understand is why the 7 RUM is so bad compared to the 7 STW. When comparing the cost of barrel life and extra cost of powder compared to the extra velocity you get (give or take 100fps), why is it so much different than the 300 Win versus the 300 RUM? Granted, you get closer to a 200fps gain with the 300RUM, but it is also a much bigger difference in the amount of powder you burn and barrel life. Just seems a little weird to me.

I don't own either one of the 7's, but if I ever did I would think that the extra five cents per round for the RUM and maybe 100 rounds less barrel life would be well worth the extra 100fps. Just my opinion I guess...

No 100fps is not worth it. With the high bc bullets we have today that 100fps gain but 500rds less barrel life won't gain you anything appreciable down range.

There is a point of diminishing returns when it comes to stacking more powder in a bigger case for the sake of more speed. With the 7's you reach that point with the 7mm STW case. Beyond that the minimal gain simply isn't worth the additional cost.

Run it through any ballistics program you like and you'll see that 100fps at the muzzle is costing way too much for a very minimal gain.

 

[WildRose]

Actually, we're talking 15-20gr of powder difference and about 500+ shots less barrel life. There are several guys out there getting 1,500 rounds out of their STW's. I'd be willing to guess the average is probably more like ~1200 rounds. One of which, Lefty7mmSTW, is a member here. Maybe he'll chime in... 7RUM's usually don't average more than ~800 rounds of barrel life before the throat is cracked, burnt, and trashed.

They are both barrel burners, but to lose that extra 400+ rounds of barrel life for a gain of 80-100 fps is not worth it to me. Once again, just my opinion. Everyone has a different one.

If I get a great shooting rifle, I don't want to have to start over from scratch after only 800 shots down the tube. But that's another of my personal reasons I won't own a 7RUM.

Pretty much but you also have to factor in the additional muzzle blast and recoil.

When you add up the positives and negatives, to me, you are going backwards trying to push the 7mm bullets out of a case larger than that of the STW .

 

[WildRose]

I mean, it's possible to burn up any magnum caliber barrel in 250 rounds if you keep shooting it into a red glow. LOL

So, barrel life is one of those things that has too many factors to really give a definitive number on. If you say 1200 and someone is irresponsible or doesn't know how to treat an overbore magnum barrel, and burns it out in 800...They're gonna be ****ed tou told them 1200.

The numbers i quote are generized observations taken from people who took care of their rifles.

I've always stuck tot he rule, "No more than 3 shots in one minute, no more than 5 shots without letting it cool with an open chamber for 10 minutes" and as a result barrel life has never been a big issue.

My original STW exceeded 1,900 rounds last year and I sent it to a buddy of mine who is a very good gun smith to have him decide for me if it was time to rebarrel or maybe just cut it off and rechamber. He scoped it and told me flat out there was no reason for either yet.

From now on I'll stick to that same rule, but I'll go one step further, after proper break in plus a hundred rounds or so I'm going to have them all melonited.