27-7rem mag?

JJMoody

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Any experience around here with a simple neck down on 7 Rem mag brass to 270? A buddy is thinking of a custom reamer running the 170 eol in an 8 twist Proof Research carbon (he has them to build with). Powders, limitations, cool factor etc... I'm sure it's been done a few times and I'd like to hear some thoughts. For some reason he really likes the Howa action. He also does all of his own machine work and is **** good too.
 

JJMoody

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It has already been discussed with a well known reamer maker to run a bore- rider type throat design. They predict +\-3200fps running the 170.
 

Trm82

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Feb 24, 2014
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That would be awesome but it sucks to build a gun entirely around one bullet in case it does not work out.
 

can1010

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Feb 27, 2012
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skip the bore rider and do a 270 weatherby in 28 inch barrel if 3200 is your goal. if want better brass options 270-7mm RM with a long throat should get you to 3050-3100 . the 170s like to jump .090-.150 have not been a problem but they do not like high velocity impacts. I switched my 270-338 RUM IMP to 165 matrix they hold up better
 

johnnyk

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Think that would be a great cartridge. Love the 7RemMag and pretty fond of the .277 caliber.
I run the 170's in my .270 Allen Mag (.010" off) with a mild load of US869 @ 3400fps.
The one deer I shot with it had golf ball sized entry and exit holes in both rib cages. Devasting round.
 

FEENIX

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Dec 20, 2008
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Great Falls, MT
Any experience around here with a simple neck down on 7 Rem mag brass to 270? A buddy is thinking of a custom reamer running the 170 eol in an 8 twist Proof Research carbon (he has them to build with). Powders, limitations, cool factor etc... I'm sure it's been done a few times and I'd like to hear some thoughts. For some reason he really likes the Howa action. He also does all of his own machine work and is **** good too.

For a similar option, check out the .270-.300 Win Mag >>> https://www.longrangehunting.com/threads/270-300-win-mag-now-feasible.155307/
 

JJMoody

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I've been looking at that one since it popped up in 2015! Even referenced it to the guy thinking this stuff up. It's a wealth of great info and I'm back up to page 15 rereading it. Kinda seems like the same thing to me...? Any advantage or disadvantage to using a 7 mag to start?
 

JJMoody

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No kidding right?! Seems like it should have been a popular option for guys. I've often wondered why the 270 wasn't as popular as 26 and 28 Cals For fire breathing hot rods. 270 wby is the only one that comes to mind. I realize that the high bc bullets haven't been readily available til recently.
Just neck it down a tad more to .264 and you'll have a dandy long range rig :)
 

Longtooth32

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Mar 9, 2015
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140SST.jpg
skip the bore rider and do a 270 weatherby in 28 inch barrel if 3200 is your goal. if want better brass options 270-7mm RM with a long throat should get you to 3050-3100 . the 170s like to jump .090-.150 have not been a problem but they do not like high velocity impacts. I switched my 270-338 RUM IMP to 165 matrix they hold up better

This man speaks the truth...I am getting 3225fps (ES 8) out of my 270 Wby with a 28" barrel (shooting the 170 Bergers). Have to use an action longer than the Mark V, 270 Wby action. Need to load more than 3.5" COAL.

Dropped a 6x6 Bull Elk where he stood last year. The 170 did destroy a lot of meat...I still have a bunch of Matrix 165s....

No pressure signs at all with this bullet...I actually think I can get more speed out of this cartridge...

Long case neck and a steep shoulder...may help with barrel life...

Shoots a 140 SST @3630fps...
Shoots a 150 SST @3550fps...

Just used the above loads to fire form the brass and no load development...

ETA...I posted this pic before of the 140 SSTs...
 
Last edited:

Longtooth32

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Mar 9, 2015
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573
Just neck it down a tad more to .264 and you'll have a dandy long range rig :)

I have a ton of 270Wby brass and I am going to do this...necked down to a 6.5mm. Pac-Nor is making my barrel and I already have the dies from Redding...
 

JJMoody

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North Idaho
Man... I look a a little bit of power left on the table and would like to see a 270 wby with a blown out body taper and 35* shoulder kinda like the 338 Baer ( not big Baer). That'd throw some speed out there. I agree that the 270 Roy would be a better option than 270-7mag. I also read you guys' posts on the 270-300 win thread... pretty cool stuff.
 

Longtooth32

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Mar 9, 2015
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Man... I look a a little bit of power left on the table and would like to see a 270 wby with a blown out body taper and 35* shoulder kinda like the 338 Baer ( not big Baer). That'd throw some speed out there. I agree that the 270 Roy would be a better option than 270-7mag. I also read you guys' posts on the 270-300 win thread... pretty cool stuff.

The 270 Roy works well if you do not want a big over bore 270. Brass is everywhere and you do not have to fire form. It has the same case volume as the 7RM and 300WM. If shooting the most efficient bullet for each caliber (195 7mm and 210 30 cal) in this case family...the 270 drops 40" less @ 1000yrds and has the same wind deflection as those two other bullets...and has the same impact energy...

And the 170 jumps .3" (yes .3") in my rifle...

The 170's still rock @ 3225fps...

170bergers.jpg


I can get the 165 Matrix to touch the lands...
 

tbrice23

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Dec 12, 2012
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Location
Indiana
The 270wby has about the same capacity of 7mm RM but not 300WM by about 10 gr.

Man I can't wait for my 270wby barrel to get here.
 

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