7mmSTW

[buckenbass]

I have a 7mmstw barrel for my tcr mag  rifle went out and shot it for the first time today..Well shot it four times each time the primer was pressed flat and a hole blown through and open into the firing pin hole ..Had to bang on the gun to get it open..Now if it was a hand load I would say too hot. but it was a factory round..

Is this common with stw like rounds?

Also this barrel was a rechamberd 7mm mag but there is not no markings on it who did the rechamber job Could this problem be a fault in the workmanship?

How will this hurt my gun?

[Iowegan]

Obviously the pressure is too high. It might be the rechambering job or just too hot of a load for the TCR. The breach on a TCR isn't the strongest and will flex a little. The STW is a 65,000 psi round and the barrel and gun were designed for 54,000 psi loads. That extra margin might make the difference between safe and unsafe.  Personally, I wouldn't shoot any more of the factory loads. You can tame down some reloads and try again. Have a good rifle smith take a look at your chamber and have the headspace, throat depth, and free bore measured. There might be a chance a chamber reamer would fix it unless it's already too large.

My guess is the barrel and/or breach is flexing under the added pressure. This is an unsafe condition and could cause the gun to come apart.

[gunnut69]

I'd do a chamber cast and see what the 'smith' did with the chamber.  The TC's that I've seen loaded too hot usually unlock whan fired(makes your hair stand up don't it).  The 7mm STW's are kinda touchy about the chamber.  If the throats a little short or the necks a bit tight you can get into trouble real fast..  This round is treading on the edges of being unsafe, there is little safety margin left...  A chamber cast extending into the throat should tell the tale.  I'ce an STW in the vault on a M700 action that I've still to put together.  The stock is a beautiful piece of English walnut that's light as a feather... Lots of marble cake but the woods likely as brash as elm...  I'd just about as soon  have a 7mmRem mag but it was part of a deal so what I got is what I got...