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

[Rupe]

Now that's, a heavy barrel!

Rupe

 

[Lefty7mmstw]

That's 65,000,000+ psi

Those extra zeros means the barrel's gotta be at least half a mile thick around the chamber.

gotta actually be awake when I post I guess- meant 65 KPSI- good catch.

 

[Lefty7mmstw]

That's 65,000,000+ psi

Those extra zeros means the barrel's gotta be at least half a mile thick around the chamber.

I think a few of our friends here shooting 7 rem's might be over 100 KPSI with some of their stuff. A hammer is not an acceptable tool for opening a bolt even when it says MAG. on the side of the barrel.
I think you would have a tough time getting any lead core bullet to survive 65,000 KPSI; it'd take a low friction monolithic of some sort.

 

[Clovis Man]

Tag -- just in case.

 

[BountyHunter]

Hello,

I recently began shooting long range, and I took my gun to a gunsmith to get a muzzle brake on it. The guy immediately started bragging about his custom made long range rifles. I told him that i would be interested in one in the future.

He then started to say that his guns can reach 4000 fps in a 7mm STW with a 140 grain bullet. Is this possible or is he full of it? he says that his loads are "not in the books."

Thank you

1. He is correct, he can do it ONCE! But I would be standing waaay back when he shows you and have 911 on speed dial.

2. Find another smith immediately, this one is crazier than bat shxxt and you do not want to use to even put on a recoil pad.

 

[thekyrifleman]

4000 fps with a 140 gr????? WHEN HELL FREEZES OVER!!!!!!!!!

 

[headhunter130]

found this accurate reloading.

Wonder how safe and accurate the loads are? fairly quick for an stw, even with a 100 gr bullet.

7MM STW

 

[thekyrifleman]

Headhunter--check the barrel length...29".....pressures over 65K.....sure....

 

[Lrt307]

3650 to 3700 fps is not a stretch for a loaded up STW running a 140. Add some barrel length maybe another 100 fps maybe from a 26" to a 28.5 or 30" tube. 4000 aint happening........

 

[J E Custom]

This is a 3 year old post but it is an interesting read none the less, and should be a warning to those that claim to or load to these levels.

If you read all of the replies the general consensus is it cant or should not be believed or done.

The most I could get with any accuracy was just under 3700 ft/sec with a 31" barrel without loosening the primer pockets with one firing.

My recommendation is to get a bigger cartridge if you cant get the velocity you want without going to excessive pressures. (I like to run around 63,000 psi Max pressures now that I am older and wiser.

J E CUSTOM

 

[Deleted member 46119]

7mm STW: I really don't think you can safely.
28 Nosler: Same
7mm RUM: Maybe with a 32"+ Barrel and 75kPSI load.


I can reach 4000 fps with my 277/26-Nosler and 100s to 115s.

What's the point?

A 30 cal or 338 cal will reach farther with more terminal performance.

 

[Lefty7mmstw]

3650 to 3700 fps is not a stretch for a loaded up STW running a 140. Add some barrel length maybe another 100 fps maybe from a 26" to a 28.5 or 30" tube. 4000 aint happening........

Even 3700 aint happening with my 27" Shilen tube.... I'm at 3350 with my current 140gr accuracy load, and I don't feel like pushing the rifle and destroying a good shooter.

I have done 3500 fps with a 140 in a 24" bbl'd 7stw with rather high pressure and 50 bmg type ball powder though... It ate the brass up after a couple of firings, and really was no better than slightly slower stuff that was more accurate.

 

[Lrt307]

I understand this. I am not arguing the point about safe loads and good shooters. I am here to tell you that I used to run waaaaay high psi and hot hot hot loads in my STW before I even knew much at all about reloading . I am lucky I didn't get blown up! I was running 85.5 grains of RL 25 with fed 215 primer and 160 barnes xlc. My gun actually shot ok and bolt lift was fine. Brass was getting the **** beat out of it. I was young and didnt know any better. I was loading for speed back then. The 160's across my chronograph were running 3450-3473 all day long. I have no doubt at all you can hit 3650 or so with a 140 like I said before "loaded up" now is it safe or a good idea NO!

 

[Bart B]

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.