new gun??? what is it

[yellow dog]

I ended up with a rem 721 bolt action that started life off as a 30 06 and now is a 300 h and h that appears to be blown out and necked down to a 7mm. was built by a gentle man named John Burris I think.


came with 6 bullets and some reloading data

160 speers
80 gr of t570
and mag primer

any ideas on what this is. I got it from a guy who owed me some money and he didn't want it any more.

is it a 300 win /7mm or a .338 win/ 7mm?

 

[Guy Miner]

Did it come with dies?

If not, I'd recommend having a gunsmith cast the chamber, then you'll know exactly what you've got.

Guy

 

[yellow dog]

no dies

think it might be stw?

 

[Silent Sam]

It may be. The 7STW is a necked down 8mm Rem Mag which is a 375 H&H blown out and necked down to 8mm. Get the chamber cast. If the proper caliber is not clearly marked on the barrel you have no idea what it really is. It may be a homespun version of something like the STW, or something completely different...

 

[Elkman]

I will bet its something different. I am still trying to get my mind around an 06 growing to a 300 HH and then an STW. There are/were numerous 7mm Mags, built off of the 300 HH case including the Bee, including some by Ackley, the Sharp and Hart, and my Ackley Manual lists a host of others. Cast the chamber and let us know.

 

[yellow dog]

wouldn't the stw be to long for a 30 06 action?

I will have it cast, and find out but I wish I could find som info on it..

wouldn't one of the already loaded bullets that I have be able to tell me (my smith) what it is?

 

[super-7]

7mm Mashburn is built off the 300 h&h necked down, there is also the 276 rigby which is similar. The shoulder angles and neck length differ if you had some once fired brass you could figure it out.

 

[AzDak42]

I think Super-7 is right.. 7mm Mashburn. But as others have said, any rifle you're not 100% certain of, needs to have the chamber cast.

 

[Elkman]

yellow dog
wouldn't one of the already loaded bullets that I have be able to tell me (my smith) what it is?

Yellow dog, you have a loaded round???? That makes it much easier. A gunsmith should easily tell. He can match it with a known round. If not the chamber will still have to be cast.

 

[yellow dog]

yes I have 7 loaded rounds and 1 that he fired in front of me to be sure.

 

[PJGunner]

"wouldn't the stw be to long for a 30 06 action?"

Nope! The Remingon M700 (721 same thing) will take a .375 H&H length round with ease. I have three Remington long action rifles and the .375 H&H fits in all three. Might have to tinker with the gagzine are definitely replace the bolt but other that that other than a rebarrel or rebored barrel, it's not that hard to do.
Be interesting to find ou exactly what it is chambered to.
Paul B.

 

[SJB358]

The Mashburn would be a cool find. Probably one of the coolest looking 7mm Mags to my eyes. Big long neck for seating them bullets out and plenty of room for them long 7mm bullets.

Looking forward to seeing what it is. Any chance you could take some measurements, at least rough ones with a set of calipers?

 

[elkeater2]

A couple pics of the loaded and fired would help, too! Those can be matched up with others pretty well.

 

[yellow dog]

ill be home in a couple of hours and will try and figure out how to post pics thanks guys for all the help

 

[FOTIS]

Sounds like a 7mm stw.
Cast the chamber

 

[yellow dog]

after a few quick measurements I think it is a stw over all length of case is 2.83

.530 @ belt
.485 @ shoulder
24deg shoulder I think did this with my bow tech angle finder.

the gun smith at my local gun shop says its an STW

also.

 

[FOTIS]

Does he have a headspace gauge?

 

[yellow dog]

im not sure I will ask though

 

[FOTIS]

Cool do that!

 

[filmjunkie4ever]

Not an STW for sure...John Nosler actually talks about a wildcat like this in his book "Going Ballistic." I believe it to maybe be a Mashburn. But all hypothesizing aside, a chamber cast and possibly custom dies will be the correct answer to your question IMHO.