7mm STW--any thoughts/experience with?

Moly coating was the fad of the day back when I shot Hunter benchrest, I couldn't justify the extra expense at the time, the fad only lasted a few years. The theory at the time was the lubrication on the ojive helped the bullet center itself on the way into the lands.
My personal belief is the bullet ironed moly into the low spots and pores in the metal, it was nearly impossible to remove. I noticed that the zero on my rifle would change slightly as the gun was fired during the course of the day with only light cleanings between relays. When your trying to hit a .0050 dot at 100yds for an X it was maddening.
Moly adds another variable into the equation when your trying to reduce the variables in precision shooting.
 
Interesting discussion. I shoot the parent, 8mm Rem Mag, and my take is it is a luxury to have all that case capacity. Which 7mm is the absolute fastest is not that meaningful; these big case rounds are all very fast, and they will all burn out barrels a lot faster than a 7x57. So, you replace the barrel more often. OK by me. I grew up thinking the whole rifle basically lasts forever, but even the 1917 Danzig Mauser I carried in the '60s was likely rebarreled in 1926 when there was a major refurbishment at Suhl. If you shoot a lot, it's a replacement part.
 
HiBC, where does the force come from to push a 308 bullet ahead of the burning powder's pressure wave?
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I never envisioned the bullet being ahead of the "pressure wave"
The pressure is on the bullet base. Using written words has its problems .
Expansion volume can mitigate pressure increase(the way I envision it)
A large case volume also plays a part in mitigating peak pressure.

But lighting up twice the powder will drastically increase gas production.

An imperfect analogy would be to take an 3 liter engine with 9.8 compression ratio that just runs without pinging on pump gas mid grade. (Like 60,000 psi chamber pressure)
Now we bore it and put in a stroker crank Its now a 3.7 liter engine. But we use the same heads,.
Compression ratio goes up to 12 .5 to 1 . It pings. We can go to higher octane (slower powder) and that will help up to the limits of the powder/fuel we can get.

A previous poster told us about his success with his 7mm Weatherby. About 2750 with a 175 gr bullet? He is happy,I am happy, Enjoy a fine rifle!!

If you go to Hogdon and look up a 280 AI,six loads with a 175 gr bullet exceed 2700 fps and one exceeds 2800 fps. No,I cannot tell you barrel length right now.

My point is,it seems a 280 AI is near an efficiency "Sweet spot" Its diminishing returns to go bigger,

I've owned 3 different 7mm Rems. Its a very good cartridge that I use less now.
Most loads,even the higher perf ones,are around 85% load density.

If I cannot use nearly all the case volume I have,why pursue more?

Its acyually rather miraculous the velocity that can be achieved with RE -15 and RE-19 in a 7-08.

I'll take a heavy for caliber,high BC bullet at 2600 to 3000 fps over a lighter,lower bc bullet at 3400 plus .

I get 2900 with a 200 gr Accubond from my 30-338. That bullet will expand/perform(over 2000 fps) at ranges much farther than I will shoot at a big game animal. Actually,I can say the same about a 30-06 AI launching a 180 gr bullet at 2900.

I'm not making rules for anyone else,but I just do not have a hunting requirement for more.

For long range plinking? I have a target elevation knob when I need it.


And if we run the numbers in ballistic software...If we are still using "Max point blank range" ...relying on velocity to xtend range,run the numbers!!

See just how much a couple hundred fps extends your MPBR. You will be disappointed.
 
Your point blank range increases 10yds per 100fps roughly a poor excuse for magnum cartridges. To me energy on the target is the real reason for the extra velocity along with bullet expansion.
 
Fair enough.
Most folks would agree a 30-40 Krag loaded with a 200 gr bullet will give adequate performance at 100 yds for hunting any North American big game.

The 30-338 launching a 200 gr Accubond at 2900 fps gives that performance at 700 yds.

I do not shoot big game at 700 yds. I don't shoot at 600 yds.

I don't need more than my 30-338.

But I'm not telling you what to do or not do.
 
The 7mm STW was first introducedin 1979 by Layne Simpson of Shooting Times magazine fame, developed from necking down 8mm Rem Mag. In the 40 years since, there were lots of people talking about it but few people really wanted or needed it. Remington chambered the 700 for 7mm STW for a few years, then dropped the chambering when they introduced the 7mm RUM, which is bigger, faster, harder on barrels, and has a sexy middle name. And now we have the 28 Nosler, which is more of everything. The 7mm RUM is faster by about 100 fps, 28 Nosler by about 300 fps. I only ever chambered 1 rifle for 7mm STW, I have chambered several rifles for 7mm Rum for customers, a few of them twice. Barrel life with a 7mm RUM is about 1,200 rounds, so I would expect a 7mm STW to be about the same. Biggest hit against the 7mm STW is non-availability of factory ammunition (Nosler loads for it). Brass can be made from 375 H&H, the parent cartridge for the 8mm Rem Mag.

My first question would be "why?".
 
stagpanther, I'm looking at 1/8 or 1/7 for 28 Nosler and using Berger 195gr. I'll have Manson make reamer. Going to be my 80th birthday present.
 
I have a Remington 700 in 7mmSTW built in the Remington Custom Shop back in 1998. The model is M700AWR, Alaskan Wilderness Rifle. Not to be confused with the 700AWR American Wilderness Rifle that is an off the shelf rifle. Mine is stainless steel coated in matte black Teflon. It can never rust under normal circumstances. Very nice 2.5 pound trigger. I toped it with a 4.5x14x40 Leopold VXIII scope. With my reloads it will shoot just over 0.5 MOA. It will push 100 grain bullets to 4000 FPS, but I don't do that often. I found the best accuracy is 162 grain bullets at 2800 FPS which is below a magnum load, but it should save the barrel for many years of shooting. I did take it Antelope hunting once. Got one at 450 yards with those 162 grain reloads. It hit the Antelope so hard it spun the animal 180 degrees and it crumpled on the spot. Never took even one step.
 
My first question would be "why?".
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Just curious.;)
stagpanther, I'm looking at 1/8 or 1/7 for 28 Nosler and using Berger 195gr. I'll have Manson make reamer. Going to be my 80th birthday present.
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Nice! why the heck not? ;)
I have a Remington 700 in 7mmSTW built in the Remington Custom Shop back in 1998. The model is M700AWR, Alaskan Wilderness Rifle. Not to be confused with the 700AWR American Wilderness Rifle that is an off the shelf rifle. Mine is stainless steel coated in matte black Teflon. It can never rust under normal circumstances. Very nice 2.5 pound trigger. I toped it with a 4.5x14x40 Leopold VXIII scope. With my reloads it will shoot just over 0.5 MOA. It will push 100 grain bullets to 4000 FPS, but I don't do that often. I found the best accuracy is 162 grain bullets at 2800 FPS which is below a magnum load, but it should save the barrel for many years of shooting. I did take it Antelope hunting once. Got one at 450 yards with those 162 grain reloads. It hit the Antelope so hard it spun the animal 180 degrees and it crumpled on the spot. Never took even one step.
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Very cool. That's what I figure--if you take it easy, time your shots and don't go for max loads might help prolong life of the barrel. For a few hundred dollars I don't mind spinning the barrel nut every 2 to 3 years.:)
 
I guess it was 15 years ago or so, I was on a Weatherby site, that many members were talking about the 7mm/300WBY wildcat. Of course there were those that said it had already been done in the form of the 7mmSTW. Others said yeah, but it hasn't been done by Weatherby. There were rumors of a 6.5/300WBY factory offering.

I thought the idea of both of these were interesting. I thought then that the 7/300WBY made as much or more sense as the 6.5/300WBY. Both would be titanic barrel burners.

I own a Cooper MDL22, 6.5/284. If they call these barrel burners, then there should be new terminology for what the uber magnums are, sub 30 cal.

I have read that the best of the barrel on 6.5/284 will be gone by 800 rounds. So, what would the barrel life on STW or 6.5/300WBY be? Maybe 600 rounds.

I, of course don't have to worry about that, because Cooper has a barrel replacement policy. Shoot out one of their barrels and for $125 they will replace and test a new barrel. I love bragging about this. I'm so ashamed.

They started this policy after offering some new rifles in any over the top chambering you can think of. All the WBY's up to 340WBY. 6.5 and 7mmSTW, 7mm and 300RUM, 300 and 338Lapua, and the Noslers. They knew that these customers are going to go through barrels quickly. Being owned by the barrel maker and the fact that these are premium priced rifles, must leave enough wiggle room for a profit.

This policy was greeted with great joy by Cooper's varmint rifle owners. Varmint rifles were what they were for a long time. Varmint rifle owners shoot a lot. So, I'm happy. I may use this policy next year, if I can get in some shooting this year.

I seriously considered having a WBY Vanguard, 300WBY rebarreled to 7mmSTW. It is said that WBY brass can be necked down 7STW. It seems more work than 300HH brass. Not only that, but it would be cool if you could just neck down WBY brass then fire form it. I wanted to try a Lilja barrel. It never happened.

If you are like me and enjoy shooting grossly overpowered firearms then this sounds like fun.
 
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I thought the idea of both of these were interesting. I thought then that the 7/300WBY made as much or more sense as the 6.5/300WBY. Both would be titanic barrel burners.
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Could be--my 300 wby is already showing signs of incipient throat erosion--but it's a vanguard sporter barrel, not as "tough" as the Mark 5's from what I have seen. Also--Roy's "thing," if I understand it correctly, seemed to be making elongated freebore and compensate with longer case necks to enhance concentricity as a means of reducing the higher pressures of his monster capacity cases. I'm very fond of the 300 wby, actually, I just bought some 220 gr partitions just out of curiosity. There's a number of hunters in the area who go after big game around the world who use the 300 wby--I warned them in the summer of 2020 they better stock up on ammo while they can (I'm the only one that reloads in our community).

I've recently heard that a 7mm XC may be in the offing.
 
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The 300 Weatherby Mag has the same 65,000 psi max pressure specs as some other 30 caliber cartridges.

One is the 300 Win Mag with zero freebore. The Weatherby has .34" freebore
 
Cooper has a barrel replacement policy.
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Most hunting rifles in any caliber will never be shot enough to erode the throat, so Cooper can score kudos and bragging points by offering this guarantee. There is nothing "special" about their barrels. I would venture a guess they cost Cooper about $62.50, half of what they ask a customer to pay in their guarantee. Still a great guarantee!
Could be--my 300 wby is already showing signs of incipient throat erosion--but it's a vanguard sporter barrel, not as "tough" as the Mark 5's from what I have seen
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Last week I scoped the bore on a 300 RUM. About 120 rounds down the tube and it is already showing about 1/8" of gas cutting in the throat and leade. Doesn't take much! And Vanguard barrels are no better or worse than Mark V barrels, I bet. Just that most people don't own bore scopes.
 
There is no universal standard for assessing rifle barrel life.

After a friend set a national highpower record at 1000 yards with a borrowed 7mm Rem Mag in 1970, that was the cartridge to use for a few years. Wasn't long before their 700 to 800 round barrel life and iffy bullet quality that 30 caliber magnum's 1100 to 1200 round lives replaced them.

As soon as 26 caliber long, heavy good match bullets were available, the 6.5x284 used them out scoring the bigger caliber magnums.
 
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There are other factors,of course,but one barrel life factor ,for equal steel,bore,twist,etc, might be the number of pounds of powder you can burn through it.
I would guess significantly longer barrels have longer flame duration.

Barrel life is remarkably short if you think in terms of time. Total time a bullet is traveling through the bore...total time the powder is burning.
 
Barrel life is remarkably short if you think in terms of time. Total time a bullet is traveling through the bore...total time the powder is burning.
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True--but add back time accurizing and cleaning and it gets longer again.:D
 
Vanguard barrels are no better or worse than Mark V barrels, I bet.
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Not my experience having shot a few of both models of wby mags, my impression is Weatherby's USA made M5 barrels seem to shoot and last better.
 
At long last, my 28" SS match profile 7mm STW barrel from Shilen arrived today. One quality point I noticed right off the bat--they go to the trouble of packing the barrel in a very sturdy 3/8 ths inch walled cardboard tube with metal end caps fitted and stapled--been a long time since I've received a barrel from anyone that was packed as well to realistically withstand the abuse of shippers these days.

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