270 WSM fast twist build

[OpsMan]

Hey everyone. I am wanting to build a 270 wsm with a fast twist (1:8) barrel. I was looking at purchasing a Bergara Highlander as a donor and buying a prefit from McGowen or Preferred Barrel blanks. Question: Would I be better off building off a 6.5 PRC or 28 Nosler model? Target bullets would be 165 ABLR or 141 Hammer HHT. I understand I could just buy a market 6.8 western but I like the added powder capacity I could get from the WSM case. If I went with a short action, could I seat the bullets out to 2.920ish lengths or would I have to stick with SAMMI lengths around 2.86ish? Any feedback is appreciated!

 

[Lou270]

You will likely want something with at least 3” magazine. A WSM Kimber 8400 or Win 70 works well as both have about a 3.05” Mag. 2.92 may be ok but Shorter and you may run into situation where ogive starts going below case mouth, at least with the higher BC bullets. Anything that is chambered in 6.5 prc should work fine as will have 3”ish mag I had a Kimber Montana 270 wsm rebarreled to 1-8” and very happy. My son uses it so now shoot 6.8W. 270 WSM getting ADG and Peterson brass this year plus nice selection of heavy hunting bullets for 6.8W. Good luck!

Lou

 

[OpsMan]

Awesome. Tks for reply. I bought a Bergara Highlander in 6.5 Creed and put a Hawkins Hunter DBM on it after having stock opened up to an M5. Don’t think that PRC/Saum Hunter mag will hold anything over 2.95 or so. Mainly concerned about chamber being SammI spec and being able to load bullets out to that 2.92-2.95 ish length and not having any chambering issues.

 

[Lou270]

Will need to have bolt face opened if starting with 6.5 creed and going to magnum. 2.92 is on short side. 2.95 is ok I think. Need to do some math. For ex, the berger 170 has nose length of .829 and 270 wsm has case length of 2.1. So 2.929 min length for that bullet. It probably has the longest nose length of any 277 bullet given profile. The standard saami 270 wsm throat should be ok. Actually has a decent freebore of . 15ish I think though may want to check that. I just checked and dont think 165 ablr at 2.92 would be a problem other than little deeper in case.

Lou

 

[OpsMan]

I’m leaving my Bergara 6.5 Creed as is. I’m looking at buying the 6.5 PRC for the donor rifle and changing barrels. Appreciate the info!

 

[khuber84]

If I were doing 270wsm, I'd only build on a medium or long action, run long freebore and send 170 Bergers at 2900-3000fps. That'd be a moderate recoiling rifle and have plenty of juice a long ways out. Since you're limited to a short action, I'd modify the action to accept a wyatts cfe5 mag box, run a m5 oberndorf bottom metal, and chamber it in 65saum or 65prc. This will give you 3.0 coal, utilizing the prc/Saum case to the most of its potential. Easiest would be a Tikka action, and I'd honesty go prc on a Tikka, as it's only a 1" major tenon diameter. The Tikka will let you run what every coal you want with the heaviest for call long sleep bullets.

 

[mcr-85]

If I were doing 270wsm, I'd only build on a medium or long action, run long freebore and send 170 Bergers at 2900-3000fps. That'd be a moderate recoiling rifle and have plenty of juice a long ways out. Since you're limited to a short action, I'd modify the action to accept a wyatts cfe5 mag box, run a m5 oberndorf bottom metal, and chamber it in 65saum or 65prc. This will give you 3.0 coal, utilizing the prc/Saum case to the most of its potential. Easiest would be a Tikka action, and I'd honesty go prc on a Tikka, as it's only a 1" major tenon diameter. The Tikka will let you run what every coal you want with the heaviest for call long sleep bullets.

Mine is a Rem 700 long action. 1-9 twist but I have enough elevation and speed to stabilize the 170 Bergers. I am shooting them at 3050.

Sent from my SM-S908U using Tapatalk

 

[TxLite]

When I looked at buying a prefit for my Bergara a few years back I remember it being a pain due to the conical bolt face. Swaps might be easier or more available nowadays but it’s something I’d check out before buying one specifically to use as a donor action.

 

[khuber84]

Truth of the matter is, pretty much everything 6.5mm 140gr and heavier is gonna have a better BC than anything under 160gr in a 270. Sadly I don't see a resurgence of 277 to bring in a new wave of bullets like the 25 cal did. If it wasn't for the amount of high volume match shooters who showed there was serious demand for high volume sales of high bc heavy 25cal bullets, hunters demands would never been heard.

 

[Lou270]

Truth of the matter is, pretty much everything 6.5mm 140gr and heavier is gonna have a better BC than anything under 160gr in a 270. Sadly I don't see a resurgence of 277 to bring in a new wave of bullets like the 25 cal did. If it wasn't for the amount of high volume match shooters who showed there was serious demand for high volume sales of high bc heavy 25cal bullets, hunters demands would never been heard.

There are more heavy 277 bullets (155+) available than 25. Berger, Barnes, Nosler, Sierra, Hammer all make heavy 277 bullets. The only one that does not is Hornady. These are purely hunting bullets and not match bullets which is driving some 25 cal demand (ie horn/berger). Sierra does offer a 277 170 and 155 matchkings in 6.8W/277 Sig factory ammo as well though have not seen them offer a handloading component. Times a changin…

Lou

 

[OpsMan]

When I looked at buying a prefit for my Bergara a few years back I remember it being a pain due to the conical bolt face. Swaps might be easier or more available nowadays but it’s something I’d check out before buying one specifically to use as a donor

If I were doing 270wsm, I'd only build on a medium or long action, run long freebore and send 170 Bergers at 2900-3000fps. That'd be a moderate recoiling rifle and have plenty of juice a long ways out. Since you're limited to a short action, I'd modify the action to accept a wyatts cfe5 mag box, run a m5 oberndorf bottom metal, and chamber it in 65saum or 65prc. This will give you 3.0 coal, utilizing the prc/Saum case to the most of its potential. Easiest would be a Tikka action, and I'd honesty go prc on a Tikka, as it's only a 1" major tenon diameter.

There are more heavy 277 bullets (155+) available than 25. Berger, Barnes, Nosler, Sierra, Hammer all make heavy 277 bullets. The only one that does not is Hornady. These are purely hunting bullets and not match bullets which is driving some 25 cal demand (ie horn/berger). Sierra does offer a 277 170 and 155 matchkings in 6.8W/277 Sig factory ammo as well though have not seen them offer a handloading component. Times a changin…

Lou

Hornady has been pretty adamant they want the 6.8 Western to die. Make you wonder if they had plans for a short action .277 magnum cartridge of their own. 27 PRC maybe.

 

[Lou270]

Hornady has been pretty adamant they want the 6.8 Western to die. Make you wonder if they had plans for a short action .277 magnum cartridge of their own. 27 PRC maybe.

Not sure. You would think as an ammo maker they would want as much out there as possible so they can make money. They don’t make more money selling PRC ammo than would make selling 6.8W. At some point it just becomes sour grapes which is annoying. Always been a Hornady fan so hope they just support 6.8W customers and not be petty about it.

Lou

 

[wind gypsy]

There are more heavy 277 bullets (155+) available than 25. Berger, Barnes, Nosler, Sierra, Hammer all make heavy 277 bullets. The only one that does not is Hornady. These are purely hunting bullets and not match bullets which is driving some 25 cal demand (ie horn/berger). Sierra does offer a 277 170 and 155 matchkings in 6.8W/277 Sig factory ammo as well though have not seen them offer a handloading component. Times a changin…

Lou

There are heavy options but still not particularly high BC for the weight though. The heavy for caliber 257 bullets actually have a better form factor than many of the 6s or 6.5s and that is not true for 277 options. You can already get 7mm bullets at similar weights with similar BCs to the heavy 277 options.

 

[Lou270]

There are heavy options but still not particularly high BC for the weight though. The heavy for caliber 257 bullets actually have a better form factor than many of the 6s or 6.5s and that is not true for 277 options. You can already get 7mm bullets at similar weights with similar BCs to the heavy 277 options.

The difference is hunting bullets vs match bullets. In a match bullet you have a thin concentric jacket. There is no tapering to halt / slow expansion for ex. So, you can have a thinner ogive as well as a heavier bullet for same length since with a thicker jacket you have less average density (ie more lead). Both promote higher BC at the expense of controlling expansion. So, For hunting bullets you will see heavy 270 bullets are similar BC to anything else for a given sectional density. There are no heavy “match” bullets for 270 yet so there is nothing to compare to say a edlm or tgk except a 277 170 berger. If you look at the berger 170 which also has a thin jacket the 270 BC is right where it should be .. better than all the 7mms until you get 180gr and above.

Lou

 

[wind gypsy]

The difference is hunting bullets vs match bullets. In a match bullet you have a thin concentric jacket. There is no tapering to halt / slow expansion for ex. So, you can have a thinner ogive as well as a heavier bullet for same length since with a thicker jacket you have less average density (ie more lead). Both promote higher BC at the expense of controlling expansion. So, For hunting bullets you will see heavy 270 bullets are similar BC to anything else for a given sectional density. There are no heavy “match” bullets for 270 yet so there is nothing to compare to say a edlm or tgk except a 277 170 berger. If you look at the berger 170 which also has a thin jacket the 270 BC is right where it should be .. better than all the 7mms until you get 180gr and above.

Lou

Ok, lets look at hunting bullets.

Sierra 0.277 175 TGK has a listed G1 BC of 0.560 the 7mm that is 10 grains LIGHTER has a listed G1 of 0.610.

Nosler LRAB - 277 165 - 0.312
Nosler LRAB - 284 168 - 0.310
However, Applied ballistics, who i'd trust over nosler any day, has the 168 7mm @ 0.332 G7 and the 165 270 @ 0.310.

Barnes LRX.. 160 7mm is closest to 155 270 - also higher BC with a lower sectional density.

So in all of the cases above, 284 bullets with lower sectional density still have higher BC than the 277s. Even with the 170 EOL - 6.5 and 7 mm Bergers with the same sectional density as the 170 EOL have higher BCs.

The same game can be played 6.5 hunting bullets but they get better BCs with LIGHTER weight.

I'm not going to pretend these things mean that a guy can kill whatever they want with 270 bore rifles, just that on paper they are snoozers and underperform a bigger bore with the same weight bullets given same case capacities.

 

[mcr-85]

Ok, lets look at hunting bullets.

Sierra 0.277 175 TGK has a listed G1 BC of 0.560 the 7mm that is 10 grains LIGHTER has a listed G1 of 0.610.

Nosler LRAB - 277 165 - 0.312
Nosler LRAB - 284 168 - 0.310
However, Applied ballistics, who i'd trust over nosler any day, has the 168 7mm @ 0.332 G7 and the 165 270 @ 0.310.

Barnes LRX.. 160 7mm is closest to 155 270 - also higher BC with a lower sectional density.

So in all of the cases above, 284 bullets with lower sectional density still have higher BC than the 277s. Even with the 170 EOL - 6.5 and 7 mm Bergers with the same sectional density as the 170 EOL have higher BCs.

The same game can be played 6.5 hunting bullets but they get better BCs with LIGHTER weight.

I'm not going to pretend these things mean that a guy can kill whatever they want with 270 bore rifles, just that on paper they are snoozers and underperform a bigger bore with the same weight bullets given same case capacities.

I'm sure glad everything I've shot with with the measly and inferior 170 Berger didn't read all that. They might have wondered off.

Just giving you shit. There are probably better bullets and options. I built mine for the 165 Matrix that is no longer around. The 170 came along and it works pretty well for me. The new heavy .25 cal stuff is interesting though.

 

[wind gypsy]

I'm sure glad everything I've shot with with the measly and inferior 170 Berger didn't read all that. They might have wondered off.

Just giving you shit. There are probably better bullets and options. I built mine for the 165 Matrix that is no longer around. The 170 came along and it works pretty well for me. The new heavy .25 cal stuff is interesting though.

I'm aware it's all over analytical noise for the most part, but that's largely what cartridge/caliber convos are!

 

[khuber84]

The 170eol is the only thing that keeps the 277 relevant as far as long range wind bucking is concerned. Everything else is mediocre to shit. If I were doing anything 277(almost did 4 years ago, will not now) I'd buy 1500 170eol and pray to Jesus the barrel liked em. You're essentially marrying yourself to one bullet, as the 175tgk is a hard ass bullet that don't expand well, has a mile of bearing surface and poor for weight bc. Sorry, but if you want efficiency, 65 and 7 have it beat in all categories.

 

[Lou270]

Ok, lets look at hunting bullets.

Sierra 0.277 175 TGK has a listed G1 BC of 0.560 the 7mm that is 10 grains LIGHTER has a listed G1 of 0.610.

Nosler LRAB - 277 165 - 0.312
Nosler LRAB - 284 168 - 0.310
However, Applied ballistics, who i'd trust over nosler any day, has the 168 7mm @ 0.332 G7 and the 165 270 @ 0.310.

Barnes LRX.. 160 7mm is closest to 155 270 - also higher BC with a lower sectional density.

So in all of the cases above, 284 bullets with lower sectional density still have higher BC than the 277s. Even with the 170 EOL - 6.5 and 7 mm Bergers with the same sectional density as the 170 EOL have higher BCs.

The same game can be played 6.5 hunting bullets but they get better BCs with LIGHTER weight.

I'm not going to pretend these things mean that a guy can kill whatever they want with 270 bore rifles, just that on paper they are snoozers and underperform a bigger bore with the same weight bullets given same case capacities.

Nope. The 277 175 tgk .56 BC is listed at 1900 fps. The 165 284 higher BC is .6something > 2600 fps and .510 and below 2600. So not higher based on that as not apples. The 277 155 lrx has a higher bc than the 7mm 168 lrx (.54 vs .51). The 160 lrx is new bullet optimized for very long head height of 7mm prc and has higher BC, but Will not work in a lot of saami chambers for other rounds. As for The 165 vs 168 ablr, Nosler revised their BCs and had Doppler testing done at Energetic Materials Research and Testing Center (EMRTC) at the New Mexico Institute of Mining and Technology. Any case My AB book does not have the 165 .277 ablr in it? Which version do you have? AB also shows the 180 eldm bc as ~.7 vs magical .8 that Hornady publishes The 170 Berger EOL is higher BC than 7mm hunting vlds lighter than 180 gr. So like I said there are no surprises

Lou

 

[Lou270]

The 170eol is the only thing that keeps the 277 relevant as far as long range wind bucking is concerned. Everything else is mediocre to shit. If I were doing anything 277(almost did 4 years ago, will not now) I'd buy 1500 170eol and pray to Jesus the barrel liked em. You're essentially marrying yourself to one bullet, as the 175tgk is a hard ass bullet that don't expand well, has a mile of bearing surface and poor for weight bc. Sorry, but if you want efficiency, 65 and 7 have it beat in all categories.

That is not true at all. The 175 tgk expands very well. I have blown multiple coyotes in half with it. The hollow point is very large on this bullet. It does have a thick shank so stays together and penetrates well despite the violent initial expansion. It is quite a good all around hunting bullet if you understand more about bullets than picking which has the highest BC

Lou