4000 fps in a 7mm STW w/140 Bullet?

[FEENIX]

What's the point?

Got you guys excited and going this long ... gun)

[ame]https://youtu.be/3uSTOHa4Im4?t=2[/ame]

 

[longrangebo]

I don,t think you can get 4000 out of an STW, I shot a lot of 7mm,s I still have a 7 mm that sends a 162 hor. at 3550 and have pushed it to 3600 with no preasure! But that is a 7mm416 Rigby! Never tried 140,s I still have the barrel and the bolt and the dies! 7 step,s? I have since made that a switch barrel in 338-408 most likely will not switch the barrel back! It shot great and terminal performance was great. No matter the speed , the wind still has bad effects HaHaHa

 

[J E Custom]

My guess is the 7 STW will have a barrel life of 550 rounds shooting 140's out at 4000 fps. It's bore capacity is 39 grains. 81 grains of powder produces ~ 3400 fps with 140's for about a 700 round barrel life. 90 grains might be needed to get 4000 fps but barrel life would be 500 rounds or so.

If someone has Quickload, an approximate charge weight of RL25 could be produced along with estimated pressure to get 4K fps with a 140.

Unfortunately, you are right. My STW barrel life was shorter with less than 300 rounds through it
@ 3650 and the 140s. The 31" McMillan barrel gave up accuracy before it reached 300 rounds.

That was the last rifle I ever loaded that Hard.

J E CUSTOM

 

[Edd]

.........It's bore capacity is 39 grains. ............

How is bore capacity calculated?

 

[red dawg]

Maybe launched from 747 at 80thousand feet, not very accurate but sure hit the ground fast!

 

[varmintH8R]

Maybe launched from 747 at 80thousand feet, not very accurate but sure hit the ground fast!

That's funny, a 747 at 80000 feet actually is pretty much the equivalent of a 7STW launching 140s at 4000fps.

A debris field.

 

[Jaxdialation]

Agree, the guy is dangerous and untrustworthy.

I've never heard my smith say anything even close to that load of BS

Find a new smith. I personally find guys like that to be untrustworthy and everything they do is questionable. The best smiths I have ever been around keep their mouth shut, their ears open, and never bag on a guy but rather gently educate him. Most good smiths let word of mouth run their business, not running of the mouth.

 

[Bart B]

How is bore capacity calculated?

http://www.longrangehunting.com/forums/f19/bore-capacity-versus-barrel-life-164510/?#post1153103

 

[Lrt307]

Personally the relevance on a hunting rifle shooting 1/4 moa vs 3/8 moa is irrelevant. If you think your barrel is shot after a group on any of the big magnums does this feel free to send me your worn out barrels lol!

 

[Bart B]

I've sold or set back my worn out barrels. They're virtually new when set back one chamber length.

 

[Jaxdialation]

What am I missing? The barrels you have sold are like new?

I've sold or set back my worn out barrels. They're virtually new when set back one chamber length.

 

[Bart B]

What am I missing? The barrels you have sold are like new?

You are forgetting my barrel life point is when test groups open up 50% from when new. That's the same standard Sierra used for barrels testing their QC bullets called "standards" that are 30% more accurate than normal.

Those barrels are not like new. Benchrest barrels are typically replaced at that same point in their lives as they are no longer very competitive as new barrels.

 

[damon spence]

I've seen 7stw's do an honest 3500 fps with a 140, and that was about it with slow burning powders. I was running my sendero with rl25 before data came out using the 140 accubond at 3500 fps. I was also doing load work-ups with my father's 7stw and hit 3500 fps with it using aa8700 and a mild overload. The caliber is really only good for 3400-3450 fps with a 140. That's plenty fast though.

The fastest I've ever pushed a 7mm was the 120 sierra in a 7rum with AA8700 under the hood. I was getting an honest 4000 fps with book loads. I was looking at a deer vaporizing load for it, but the rifle had a bad chamber and never shot well at all so it went to rifle heaven.

 

[damon spence]

I have custom 7mmstw shoot 140 grain nosler accubond at 3600 fps chrony all my loads 88 grains of h1000 fed 215 primer nosler brass col 3.66. Built on Remington sendero consistently shoot less than half inch groups all day long and primers are not flattened or hard to extract when reloading