Rechamber from 7 RM to 7 STW?

I have an opportunity to rescue an abused Browning Abolt in 7 rem mag with a 26 inch barrel. The poor rifle stays locked in its safe all year and only comes out to play a couple of days every couple of years and has less than 40 rounds down the tube. Since I already have the same rifle which isn't abused (I feed it lots more than 40 rounds and let it out of the safe a couple of times a month), I was thinking this new gun should have a custom makeover. My thoughts are to have a smith rechamber it to 7 STW, pick up a 375 H&H box mag, and slap a new stock on it.

Will the 9.5 twist give me enough to stabilize the 175 and 180 long range heavies while I burn the barrel up?

Any other ideas?

ksubuck":2eq0lynr said:

Will the 9.5 twist give me enough to stabilize the 175 and 180 long range heavies while I burn the barrel up?

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Short answer--"Yes!" As an aside, the 7 STW will drop moose and elk quite nicely with 160 grain ABs, if the experience of my hunting partner (BlkRam) is any indication.

As I am one of the few here with an STW I would suggest perhaps a 7mm/300 or something that perhaps is inherently more accurate. I have had mine for several years and its been a money pit, that I have never been satisfied with. One of the short wide mags might also work.

I don't really need a new rifle for anything more than a toy to play with. Was thinking a quick and cheap modification or two to make something I haven't played with before. But then I had a better idea. I met a young guy who was struggling with a cheap rifle at the range a few weeks ago. I am going meet him and have him shoot it tomorrow to see if he wants it. No brainer... The current owner is practically giving this gun away and was very interested when I told him my idea to help a noobie get into hunting.

The 7 STW is pretty impressive. Would be a fun project.

JD338

Yup Great cartridge the 7 mm STW - very close to my 7 mm 300 Bee ! get er done - twist is Fine ! RJ

I'd consider leaving it as it is, and rechambering the one that has been shot more. That way you still have a 7 Rem Mag with a fresh throat. Rechambering the rifle that's been shot to STW will clean up the throat a little and you'll be working with a barrel you're familiar with.

JM2C!

ksubuck":16uw70rx said:

I don't really need a new rifle for anything more than a toy to play with. Was thinking a quick and cheap modification or two to make something I haven't played with before. But then I had a better idea. I met a young guy who was struggling with a cheap rifle at the range a few weeks ago. I am going meet him and have him shoot it tomorrow to see if he wants it. No brainer... The current owner is practically giving this gun away and was very interested when I told him my idea to help a noobie get into hunting.

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...I'm cheering for this one!!! :grin: 8) :mrgreen:

As a 7MM STW owner who has been hunting and shooting with it for 16 years, I say "Go for it!!!"

My STW is a custom job that I was able to buy used (for a song!) with a LH Sako AV action, MacLellan Barrel and a Fajen laminated stock, that will shoot sub-MOA groups all day long with factory loads.
1" groups @ 300 yards with Federal Premium 160gr AB loads, and 3" groups @ 400 yards with the old 160 gr Sierra GameKing loads.

It has accounted for numerous moose, elk, deer, bighorn and mountain goat over the years.

I had a 7MM RemMag previously, and was very happy with the Federal Premium 165 gr Sierra GameKing ammo (sub-MOA) that accounted for numerous moose, deer and elk. The only reason I sold it was to replace it with a LH rifle. It was then that I ran across the used LH STW.

I was very happy with the old 7 and did not want to go to the STW (had even turned down the advice to rechamber the 7 to STW when I originally purchased it), as I was completely happy with the 7MMRem Mag and did not want to alter a rifle that would shoot 5/8" groups out of the box with factory ammunition. I have been very happy with the STW since buying it. I would not hesitate to own another 7 Rem Mag, but my favourite cartridge is the 280 Rem and had to have a LH one before considering buying another 7 Rem Mag.

As for rechambering, I do like River Rider's suggestion of rechambering the older Browning to the STW, but only if it has begun to show signs of deteriorating accuracy or throat erosion. And you may not want to mess with an old favourite! Only you can decide that one.

Whichever way you opt to go, have fun and enjoy two different cartridges in similar rifles!

ksubuck":2ygg8w0h said:

I don't really need a new rifle for anything more than a toy to play with. Was thinking a quick and cheap modification or two to make something I haven't played with before. But then I had a better idea. I met a young guy who was struggling with a cheap rifle at the range a few weeks ago. I am going meet him and have him shoot it tomorrow to see if he wants it. No brainer... The current owner is practically giving this gun away and was very interested when I told him my idea to help a noobie get into hunting.

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I hope this works.

Rifle runs good. Put an old Burris Signature 3x9 on it this morning. The kid loved it, of course. He just doesn't have the money right now. So I will buy it and leave it as is. I will work up some reloads for it break the barrel in and let him cut his teeth on it while he saves up to buy it from me. If he changes his mind I will convert it to an STW. I cannot touch my old gun as it is a tack driver as is and I have 20 some animals down with it. It will get rebarreled in 7 RM when the time comes.

Thanks for the replies and ideas. Don't know why I am fixated on an STW now...

There is always the old 7mm Mashburn Super Mag. Easy run of a 300 Win Mag case through a FL die, nick long neck to support 140 thru 175 class bullets... Hard to beat using a 300 Win Mag case since it is usually fairly available.

SJB358":2rkd39nn said:

There is always the old 7mm Mashburn Super Mag. Easy run of a 300 Win Mag case through a FL die, nick long neck to support 140 thru 175 class bullets... Hard to beat using a 300 Win Mag case since it is usually fairly available.

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Or just do it the easier way and go 7-300wm :mrgreen: :lol: . If your running standard magazine lengths of 3.68" or shorter the 7-300wm is less than 50fps behind a STW (and probably closer to 25fps and under). If the STW is throated long and is run in a 26+" barrel then it will be about 75fps faster. Back in the day when the 7STW became quite popular we rechambered a lot of 24" 7RM's and gained next to nothing in velocity. Even though I build my own guns and have 2 STW's, 1000+ rounds of new brass suitable for making 7STW cases (375 H&H and 8RM), and have owned 8-10 STW's, I like the 7-300wm for simplicity. I have 3 of them and it was the second wildcat I ever built, after a 30-338, in '91. Being able to get good quality brass in 300wm makes the decision even easier. Remington 8mm mag or 7STW brass is pretty soft and Winchester is nearly impossible to get. I use to fireform all my stuff from 300 H&H or 375 H&H because it lasted quite a bit longer. I shot a ton of rockchucks and squirrels with a 7STW in the 90's but the 30-8mm Rem. Mag (I have two of those too :grin: . Good calibers I usually build 2+ of for some reason) was just as good or better than the STW.

IdahoCTD":2endvecv said:

SJB358":2endvecv said:

There is always the old 7mm Mashburn Super Mag. Easy run of a 300 Win Mag case through a FL die, nick long neck to support 140 thru 175 class bullets... Hard to beat using a 300 Win Mag case since it is usually fairly available.

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Or just do it the easier way and go 7-300wm :mrgreen: :lol:

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Jeeze man, 7mm Mashburn SUPER Magnum just sounds cooler! Ha

Plus we're paying homage to the old school hunters like Warren Page that killed everything with the big 7 before they were cool!

I'm with you though, I'd imagine there isn't enough difference between the two to matter.

7 mm DAKOTA.

My STW started life as a 7 RM.
It's a WalMart Mdl 70 Black Shadow w a 26 in barrel.
160 Partitions at 3320 are bad news for anything on the receiving end.

Go for it !

...I'm getting older & I can't even remember what I had for breakfast, uh, wait, it's Friday, Friday's R.E.D. shirt, french toast & soft bacon...

...uh, where was I??? Oh yeah, when I first got my 7mm A-Bolt about 20 some odd yrs. ago, I talked to the gunsmith about rechambering it to STW. Seems there was more to it than just a reamer & swapping mags. If I remember correctly the longer mag won't work w/ the floorplate, so you have to cut out the original & rebuild it, but that was a long time ago & it was going to be more than I wanted to spend. I'm not trying to dissuade you, just thought it was a question you might want to ask...

...on the other hand, I'm still rootin' fer the "kid", hoping he can come up w/ the cash, cause it's something he'll be proud to shoot & he'll always remember how a "fellow shooter" helped him out...

Plus, beyond all that, a 7mm Rem Mag can do alot of good things, especially with the newer powders on the market, including the older like RL25 and MRP. Both of those have turned in some really good speeds and accuracy in my old 7..

I hope the young lad is able to take possession of the 7mm from you. Not hardly a better rifle for a new hunter to cover the bases of any hunting he is likely to do.

Making the current 7 mag into a STW is a fine idea. The STW has the velocity to get out for anything and the power behind a large bullet (160-175gn) to take anything in North America. A retired teacher I know took a mulie doe at 625 yards with a 7STW he made.

...well, theoretically speaking, Nosler #7 says 64grs. of 7828 will push a 160gr. AB @ 3015fps from a 7mm RM, the STW uses 75grs. of 7828 for 3123fps. That gives the 7mm RM 2073fps/ 1526ft.lbs./ 61" drop/ 22" wind (10mph FV) @ 600yds. The STW runs 2088fps/ 1549ft.lbs out to 650yds. w/ 56" drop/ 21" wind @ 600yds. 15-17% more powder is gaining you 3-4% more MV & 50yds. more effective range w/ that particular combination of bullet/ powder. Using the max load listed for each you can increase that to 5% more MV w/ the STW & 50-75yds to 1500ft.lbs (650 vs.725)...

...just punching the numbers...