I'm wanting a mountain rifle that I can carry in rough country in Utah, as well as Alaska and the Yukon. Needs to be light and compact

I have a 300 WM for bear. This gun will be for Muleys, Elk, Caribou etc

I found a 7 mm Mag that I really want but it's got a 20" barrel. It's a purpose built mountain gun so I get why they did 20 inches, but man that seems short. It's got a break on it, but I'm concerned about flame, recoil and the ability to burn powder in just 20 inches

What say the Rifle experts around here?

I wouldn't want a 20 inch 7 mag. The muzzle blast would be hellacious.

A 280 or 7/08 would be my choice for something that short in 7mm caliber. Maybe a 7wsm if you like oddball calibers and reload but even then 22 inches would be better.

I always like looking at this guy's articles on velocity/barrel length. He basically just chronos a Couple of loads, cuts and inch off the barrel, repeat.
https://rifleshooter.com/2015/04/7mm-remington-magnum-7-rem-mag-barrel-length-versus-velocity/

I would tend to agree with your concerns. A 20" 7mm Rem Mag would be hellacious with a brake!

How do you hunt? Do you want to shoot across canyons or are you committed to closing the distance and have a max range in mind? Regardless I'd give the 20" 7mag a hard pass. Unless maybe you were planning to suppress it... that could be cool!

Hard pass on the 20" 7 RM.

I agree with the negatives on the 20" barrel. The short barrel will also cost you velocity and therefore ballistics. I for one also detest breaks and would never have one in a hunting rifle. All that aside, I only use a 7MM Rem Mag. for any game species in NA. I have one that was purpose built as a light weight mountain rifle. I reload for it and have a muzzle velocity of 3250 fps (160 gr. Nosler Accubond). It has a 24" barrel and weighs 5.5 lbs. Good luck in your search.

wow!!! what action is that built on? And what stock? And does it kick like a mule?!

Catag94 said:

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I only use a 7MM Rem Mag. for any game species in NA.

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It you would consider 7MMWby mag this weighs 7.75 lb and has a 26" barrel. I got one chambered in .270 Win last year and really like it. It's close to a half moa rifle.

Too much emphasis being put on barrel length in this thread. I actually have and actually shoot a 21" 300 WSM. No break as it's gettin a TBAC on at some point hopefully soon. But I worked up a hand load with the large for caliber Berger 215's and was still getting very respectable velo numbers. Would have to look but think the 215's were in the upper 2700's. Also was only losing like 50-70 fps vs what the ammo box said with factory stuff. Not enough change to ballistics to be an issue.

Not the most fun to shoot, but still getting a few 1/2 moa groups at 100 yrds off bags.

If you'll consider a 7mmWby mag then this is weights 7.75 lb. and has a 26" barrel.

https://weatherby.com/store/markv-weathermark/

I got one last year chambered in .270 Win and really like it. It's close to a 0.5 moa rifle.

Chris Kyles preferred cartridge was a .300 Win Mag.

meggy09 said:

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Too much emphasis being put on barrel length in this thread. I actually have and actually shoot a 21" 300 WSM. No break as it's gettin a TBAC on at some point hopefully soon. But I worked up a hand load with the large for caliber Berger 215's and was still getting very respectable velo numbers. Would have to look but think the 215's were in the upper 2700's. Also was only losing like 50-70 fps vs what the ammo box said with factory stuff. Not enough change to ballistics to be an issue.

Not the most fun to shoot, but still getting a few 1/2 moa groups at 100 yrds off bags.

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Thanks for the feedback. The gun I'm looking at is a very high end, well engineered rifle. It's not something some guy built in his garage. The action is Ti and the stock and barrel are carbon fiber. I've read lots of articles about losing velo but I'm not sure it's really going to be enough to make a difference. I don't imagine I would shoot this gun past 500 yards. I'm going to call the manufacturer and ask for some specs

Gunny456 said:

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Chris Kyles preferred cartridge was a .300 Win Mag.

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I love the 300 WM. I have had 2 and will always have one

AggieMPH2005 said:

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I wouldn't want a 20 inch 7 mag. The mv would be in the tank but the muzzle blast would be hellacious.

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Quote:

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A 280 or 7/08 would be my choice for something that short in 7mm caliber. Maybe a 7wsm if you like oddball calibers and reload but even then 22 inches would be better.

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Edited for my 2 cents.

NRD09 said:

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wow!!! what action is that built on? And what stock? And does it kick like a mule?!

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It's built on a Remington 700 ADL. It has a custom stock made by a place in Euless, TX (it was built in 2000) it has a Shilen barrel that is fluted and the receive has metal removed And the bolt is fluted.
Yes, it definitely makes itself known when fired.

Catag94 said:

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I agree with the negatives on the 20" barrel. The short barrel will also cost you velocity and therefore ballistics. I for one also detest breaks and would never have one in a hunting rifle. All that aside, I only use a 7MM Rem Mag. for any game species in NA. I have one that was purpose built as a light weight mountain rifle. I reload for it and have a muzzle velocity of 3250 fps (160 gr. Nosler Accubond). It has a 24" barrel and weighs 5.5 lbs. Good luck in your search.

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Can you provide some details of you load? Brass, COL, primers, powder and charge. I would love to get gain 250 fps on my current rounds.

We're all snipers now. You can't just buy a rifle and scope and some boolits anymore.

Everything needs to be tactical, precision, long range, and perfectly matched gun/scope/ammo (ballistically perfect reloads only!) combos.

Animals don't die with off the shelf 700s, a Leupold VX, and Remington core lokts any more.

FWIW

The rifle in question is a Gunwerks and I was able to call and speak to one of their engineers about the barrel

He told me I would lose 25 feet per second for every inch the barrel is reduced. So if it was a 24 inch barrel and I went to 20, I would lose 100 feet per second. Not that significant in my opinion when you're starting around 3000 feet per second. This is using 168 grain custom loads.

The gun model is the Clymr And it's only available in a 20 or 22 inch barrel.

He said they are making everything shorter and shorter these days

Darby said:

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He said they are making everything shorter and shorter these days

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Can't wait to share this with my wife!

tlfw378 said:

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Catag94 said:

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I agree with the negatives on the 20" barrel. The short barrel will also cost you velocity and therefore ballistics. I for one also detest breaks and would never have one in a hunting rifle. All that aside, I only use a 7MM Rem Mag. for any game species in NA. I have one that was purpose built as a light weight mountain rifle. I reload for it and have a muzzle velocity of 3250 fps (160 gr. Nosler Accubond). It has a 24" barrel and weighs 5.5 lbs. Good luck in your search.

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Can you provide some details of you load? Brass, COL, primers, powder and charge. I would love to get gain 250 fps on my current rounds.

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I use Nosler Accubond Bullets (160gr) for hunting performance. I use IMR 4350 powder at 63.5 gr , Federal brass and CCI mag primers. I have been using. This load for years and have the die set so I don't have the measurement for you on COL. I shoot through a chronograph and zero my rifle at 275 yards (actual distance) This gives me the following trajectory. And I misspoke, my MV is 3178.

OP, the loss of velocity is really not that big a deal. 20 vs 24" like you noted will be 100-150 FPS. Put a can on it and you might get half that back.

The real issue is shootability, it will be loud with the brake, but 7mags are loud anyway. Put a brake on a 24-26" 7mag and tell me how lovely it sounds. Loud is loud. Recoil will be a bit more due to light weight, but the brake is there to aid with that.

Hunting rifles are carried a lot, and shot very little. In the mountains every ounce matters.

I would have no issue buying that rifle. There are other calibers you could use, but look at what you think your max range will be (you said 500, which is very reasonable) and then compare the ballistics you will have to work with from the 7mag vs the other calibers mentioned. You will be ahead of the game with the big 7. I think the real benefit is energy. That 160 class bullet will be carrying the mail compared to the other available options, even in that short(er) barrel.

And for hunting, energy and bullet type are what you want. It's a specialized tool for special application. Go for it.

I will further add that everyone is always concerned with velocity.

That's fine to a point. That point is about 300 yards. Faster equals a more flat usable trajectory at normal hunting distances. I define that as under 300 yards. The faster the bullet the further your Max Point Blank Range extends.

That is all well and good, but past 300 you ain't holding Kentucky windage any more. Those days are over.

You will have a rangefinder, a good set of ballistic tables for your rifle, and a scope that allows you to hold/adjust to place the round on the target at the distance it presents itself.

At that point velocity (in terms of the All You Can Get Theory about longer barrels being better) goes right out the window in terms of importance. Drop is just math. And we now have the tools to easily correct for it.

Wind at 500 might be an issue, but short of you hunting in a hurricane it really won't be to your limit of 500 yards. The bigger bullet, going faster from the 7Mag is your friend here as well.

Darby said:

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FWIW

The rifle in question is a Gunwerks and I was able to call and speak to one of their engineers about the barrel

He told me I would lose 25 feet per second for every inch the barrel is reduced. So if it was a 24 inch barrel and I went to 20, I would lose 100 feet per second. Not that significant in my opinion when you're starting around 3000 feet per second. This is using 168 grain custom loads.

The gun model is the Clymr And it's only available in a 20 or 22 inch barrel.

He said they are making everything shorter and shorter these days

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I'd guess they are going shorter due to the desire for thinner (lighter weight) barrels and the desire to stiffen them up a bit? A long, thin barrel can get whippy and do funny things to accuracy.

Velocity can be a cover for unknown distance. The faster and flatter shooting the less vertical deviation over a given distance which means if you are estimating distance and wrong then you won't be as far off with a faster bullet.

Now with accurate chronographs, laser range finders, dial scopes, ballistics software, etc. available to the consumer you don't need the velocity as much as you did before to hide inaccuracies in distance estimation and how high to aim. It's actually relatively easy to find an accurate load, determine velocity, plug into a calculator and develop dope charts, and then bang away. It has made long range shooting fun!

So, a 20" 7RM that gives up velocity isn't making it harder to hit at distance. I would think it would lose more than 100 fps from 24 to 20" espeically with the heavier bullets and slower powders, but probably not more than 150. So a 168 @ 2850-2900 ish.

I still don't think a 20" 7mm Rem Mag would be fun, but if you're willing to deal with the noise and the blast...

How much does the ClymR weigh?

How much does your 300 WM weigh?

Thanks. I've tried that powder, I'll have to find my data to see the notes. It has been awhile, but I don't recall any powder getting me over 3100. I'll check what the Sendero was able to get.

To me I look at the fact that a 20" barrel probably won't get a 100% burn on the powder. If you don't burn all the powder from the cartridge, then it doesn't make sense to use it if there is one that will duplicate the burned powder performance. As example, of you only burn 90%, that might be the same performance as the 7mm-08, or close. For me if I was even close to a short action cartridge with the desired performance, that is how I would roll. To each their own, at the end of the day, whatever rifle makes you smile is the one you should get.

Disclaimer...I haven't run quick load to see what % powder burn a 20" barrel might get with the various powder options. However, with the 26" Rem 700 Sendero, I didn't always get100%?powder burn with some powders I tried. YMMV.

AggiePetro07 said:

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Darby said:

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FWIW

The rifle in question is a Gunwerks and I was able to call and speak to one of their engineers about the barrel

He told me I would lose 25 feet per second for every inch the barrel is reduced. So if it was a 24 inch barrel and I went to 20, I would lose 100 feet per second. Not that significant in my opinion when you're starting around 3000 feet per second. This is using 168 grain custom loads.

The gun model is the Clymr And it's only available in a 20 or 22 inch barrel.

He said they are making everything shorter and shorter these days

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I'd guess they are going shorter due to the desire for thinner (lighter weight) barrels and the desire to stiffen them up a bit? A long, thin barrel can get whippy and do funny things to accuracy.

Velocity can be a cover for unknown distance. The faster and flatter shooting the less vertical deviation over a given distance which means if you are estimating distance and wrong then you won't be as far off with a faster bullet.

Now with accurate chronographs, laser range finders, dial scopes, ballistics software, etc. available to the consumer you don't need the velocity as much as you did before to hide inaccuracies in distance estimation and how high to aim. It's actually relatively easy to find an accurate load, determine velocity, plug into a calculator and develop dope charts, and then bang away. It has made long range shooting fun!

So, a 20" 7RM that gives up velocity isn't making it harder to hit at distance. I would think it would lose more than 100 fps from 24 to 20" espeically with the heavier bullets and slower powders, but probably not more than 150. So a 168 @ 2850-2900 ish.

I still don't think a 20" 7mm Rem Mag would be fun, but if you're willing to deal with the noise and the blast...

How much does the ClymR weigh?

How much does your 300 WM weigh?

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Good feedback, thanks
This particular Clymr is advertised at 8 lbs 5 oz including the scope, which is a Leupold Mark 5HD 3.6-18x44 FFP

8.5 lbs doesnt strike me as super light weight. My 300 WM is a Browning Hells Canyon, and it's 7 lbs 9 oz including the scope which is a Swaro Z3. It's got a 28 inch barrel (including the break) and I'm currently having it cut down to 24 inches total length, so it's about to be even lighter

sounds like you already have a do-everything mountain rifle. If I were you (and what I'm actually in the middle of doing) I'd complement it with a 6lb-ish sheep style rifle in 7x57, 260, fast twist 243, etc. A lightweight 7mm and your current 300 are going to be so similar you'll end up just taking whichever one you like/shoot best and the other will collect dust or get sent down the road. IMO.

Darby said:

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AggiePetro07 said:

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Darby said:

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FWIW

The rifle in question is a Gunwerks and I was able to call and speak to one of their engineers about the barrel

He told me I would lose 25 feet per second for every inch the barrel is reduced. So if it was a 24 inch barrel and I went to 20, I would lose 100 feet per second. Not that significant in my opinion when you're starting around 3000 feet per second. This is using 168 grain custom loads.

The gun model is the Clymr And it's only available in a 20 or 22 inch barrel.

He said they are making everything shorter and shorter these days

---

I'd guess they are going shorter due to the desire for thinner (lighter weight) barrels and the desire to stiffen them up a bit? A long, thin barrel can get whippy and do funny things to accuracy.

Velocity can be a cover for unknown distance. The faster and flatter shooting the less vertical deviation over a given distance which means if you are estimating distance and wrong then you won't be as far off with a faster bullet.

Now with accurate chronographs, laser range finders, dial scopes, ballistics software, etc. available to the consumer you don't need the velocity as much as you did before to hide inaccuracies in distance estimation and how high to aim. It's actually relatively easy to find an accurate load, determine velocity, plug into a calculator and develop dope charts, and then bang away. It has made long range shooting fun!

So, a 20" 7RM that gives up velocity isn't making it harder to hit at distance. I would think it would lose more than 100 fps from 24 to 20" espeically with the heavier bullets and slower powders, but probably not more than 150. So a 168 @ 2850-2900 ish.

I still don't think a 20" 7mm Rem Mag would be fun, but if you're willing to deal with the noise and the blast...

How much does the ClymR weigh?

How much does your 300 WM weigh?

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Good feedback, thanks
This particular Clymr is advertised at 8 lbs 5 oz including the scope, which is a Leupold Mark 5HD 3.6-18x44 FFP

8.5 lbs doesnt strike me as super light weight. My 300 WM is a Browning Hells Canyon, and it's 7 lbs 9 oz including the scope which is a Swaro Z3. It's got a 28 inch barrel (including the break) and I'm currently having it cut down to 24 inches total length, so it's about to be even lighter

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The ClymR is going to be heavier than your 300 then, and give up performance due to the short barrel.

A relatively light 300 is a perfect all around rifle for out west if you can shoot it well.

If you want something light and more compact, look at a Kimber Mountain Ascent in 7/08 or 308. Not a 7 RM, but not significantly different than a 20" RM in practice.

22" 7mm-08 with 160s is about 2600 fps (what I actually got out of my 7mm-08)
24" 7mm RM with 160s is about 3000 fps
20" 7mm RM with 160s is about 2850 fps

So the 20" 7RM has 250 fps on the 7mm-08.

160 Nosler AB @ 2850 fps at the muzzle will be at 2600 fps at about 80 yards. So the 20" 7RM has about 80 yards of "kill" that the 7mm-08 doesn't.

How far out will the 20" 7RM kill an elk? I bet it's at least 80 yards further than any of us should be shooting at an elk.

NRD09 said:

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sounds like you already have a do-everything mountain rifle. If I were you (and what I'm actually in the middle of doing) I'd complement it with a 6lb-ish sheep style rifle in 7x57, 260, fast twist 243, etc. A lightweight 7mm and your current 300 are going to be so similar you'll end up just taking whichever one you like/shoot best and the other will collect dust or get sent down the road. IMO.

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My 300wsm

I'll try and get all my 260 pieces together and put them on the scale soon

That's exactly what my 300 Win Mag weighs all up.