270 WBY Mag to ?

[C.O. Shooter]

Hello All,

I am new to the forum, but not to shooting. I have a 270 WBY Mag, Mark V Sporter, sitting in the closet taking up space. I am considering another long range gun and wanted to turn this into a custom. I am looking for something unique, however, easy to convert. I understand for the most part WBY's case are some what similar and would be easy to go up or down in caliber. Not that there is anything wrong with the 270, however, not something I want any more. The rifle means to much to me to get rid of it. I would imagine the .257 would be a nice conversions or go on the high end of a 7mm/300. I currently shoot a .300 Remington Ultra Mag which is very accurate, so I do not know if I want another of that similarity. If I were to go on the larger end of calibers, I am looking at the 338 Laupa! So I don't know, I am just throwing it out there for some other insight!

Thanks for your help!

 

[Outlaw6.0]

You've got a head scratcher there... how about a 6.5/300 WBY??

Ballistically the Lapua isn't WAY better than the 340WBY, the superior brass IMHO, is what makes the difference. (not to mention the beltless case). Heck, if you have the MK5 action, lets go with an allen Mag of some sort!!! might as well let it all hang out.

 

[C.O. Shooter]

I would entertain a 6.5/300! My cousin has a 6.5-284 custom. That thing will shoot! I shot it and obtain a group under a half inch. Funny thing is we talked a load for his last night. He is looking for more speed, however, I told him I would keep the accuracy it produced and forget the FPS! He likes to experiment, nothing wrong with that I guess.

The 6.5/300 could be an interesting round! I may have to see if i can find some ballistics for this animal or some derived from another persons loads. I guess once I find a caliber, I then have to choose a barrel: Lilja, Shilen, Hart, Mcgowan......... O so many choices.

 

[Outlaw6.0]

Yessir! I've been toying with the idea of an uber-velocity 6.5 for some time now.... Look up Sin Arms on here, there is a lot of talk about a 6.5 SIN which in discussion, should equal or even exceed the 6.5 STW in velocity w/o a belted case!!!

the 6.5/300 should be very close to the 6.5 STW as they are close to the same design, plus WBY brass is expensive & kinda soft...

LongTimeLongRanger has experience with the 6.5 STW, hopefully he'll drop in & provide some insight...

keep us postedgun)

 

[C.O. Shooter]

I was just doing some online searching and a lot of people are saying this caliber would be a real barrel burner. I would not be shooting this any crazy amount. Maybe some occasional shooting and during deer season. I would just like to have a back up! Maybe 257 might be my ext best option, however, still open to whatever. Thanks again!

 

[Outlaw6.0]

Make no mistake about it, the BIG 6.5's can torch a bbl VERY quickly if abused (as will any overbore magnum). Treat it right & you might be suprised..... ~1000K Rds would probably be a high maximum rd count before you would have to have it set back, but the ballistics speak for themselves.

There is nothing wrong with the 257 WBY, albeit bullet selection kinda sucks- either the 115 (IIRC) Berger for the longer shots or the 100grn TSX/TTSX for the super high velocity wack'em & stack'em <600yds performance.

 

[Long Time Long Ranger]

With the mk 5 action you can easily convert it to any magnum you want. If you never want to do this again open the bolt face, lengthen the slot on the bottom of the bolt for the 378 case, and get a 378 magazine follower from wby. Then put a 338-378 wby barrel on it. Then you have all you can get well beyond the lapua.

I just got off the range and shot my 338-378 again this morning. It is pushing a 225 grain .65 bc bullet 3530 fps and shot a 1.35" group at 400 yards. This gun has been shooting great for many years. That is why I have seven 338-378 wby's. It has a 28" 1-10 Hart barrel on it. A big rifle like that is just way cool to shoot. It will average 200+ fps over the Lapua and RUM's. It will consistently hold 7-8 inch groups at 1000 yards which is exceptional for a 10 pound scoped out rifle.

 

[backwoods83]

Ltlr has the best idea, 338/378wby but a short/match chambered 257 or 7mm wby would be good as well. The 6.5x300wby is way to hard on barrels and unnessary. Also wby/norma brass is not soft and there is absolutely nothing wrong with a belted cartridge either.

 

[Outlaw6.0]

I agree with the 338/378 for pure horse power.... but kind of curious as i've never encountered a cartridge that was unnecessary?? Overbore to the point of diminishing returns maybe!

I used to use Norma brass in my 6-284, key words being used to... it may not be be "soft" but my experience is it isn't anywhere near Lapua... don't take offense, just my experience.

 

[C.O. Shooter]

I am leaning more to the lower end of the spectrum for calibers. I have my .300 RUM which I have cut holes with at 510 yds! I really want to stretch the legs out on that girl and see what she can do. I think a smaller caliber I would shoot more than a heavy magnum! Decisions decisions decisions!

OK, so the next question would be barrel length and brand. I am a fan of the longer barrels and would not hesitate to put a 30" barrel on this gun! My a Lilja?

 

[bigngreen]

If you load one of the 165+gr 277 bullets in that it will out run the 6.5's and 7mm in just about any form. 338-378 would be a step up and out!

 

[Long Time Long Ranger]

Let Devin put a 6.5 barrel on it and you would have the latest and greatest smaller caliber. I have two 6.5 STW's and both shoot great but are single shots with long bullets. The Sin would feed well with long bullets.

The good thing about going with the 338-378 is the barrels last and last more than the small calibers. I bet you would shoot it a lot more than you think when you found out how much fun it is to easily shoot extreme long range.

 

[C.O. Shooter]

When and if my 300 RUM would ever go out, that might be a good candidate for the 338/378!

 

[Long Time Long Ranger]

Your 300 RUM action will not hold the 338-378. You need your mk 5 action or a really good custom action.

If your looking for a small caliber on your mk 5 action the 270 wby is excellent. I have shot one for over 35 years and own two now along with two 257 wby's and one 7mm wby. The Sin is the same length as these and would do well on your action. In a 6.5 or 7mm that would be a good one for extreme ballistics. Otherwise you have about as good as you can get with your 270 wby.

I have several 7mm STW's and 7mm-300 wby's and they are fun to shoot at long range. You would need to order the 300 wby mag follower from wby and lengthen the slot on the bottom of your bolt to eject the longer cartridge.