270. wsm vs 270 ss

No Sir, I haven't but I have been waiting for years (decades) to see high B.C. 257 and 277 bullets. I studied the barrel life of the 257 Weatherby and 270 Wizzum and I don't think owners lie about barrel life. I have seen shot out 257 Weatherby barrels and they ain't pretty. As I have no experience with the 270 WSM, I reliy on the common honesty of their owners. The 270 EOL 170 gr. Berger appears to be a great bullet (1-8" twist) with a decent form factor and bearing surface. It appears it may be less harmful to a barrel than the 168 gr. 7mm Berger bullets, but that isn't settled law as I have only used 168 JLK's. My only interest is in efficient cases and good bullet design. Anything past reasonable hunting distance is target shooting anyways. The study on .257 131 gr. Blackjack bullets began last June, and I am awaiting information on the 25 SST, 25 Creedmore, 25 XC and 25 SLR. Good Luck with your 270.
More data on the 25 sst this week but so far 3350' has been reached with H1000.
I will post on the 25sst thread when I get it.
Back to 270 thread. Both the 270 SS and 270 wsm are great cartridges and it just depends on what you want. The WSM will have a slight edge in velocity if you run it in over a 3" magazine. Th 270 SS will without a doubt have better barrel life for at least three reasons. Considerably less charge, a longer neck, and a sharper shoulder. We haven't shot the 270 SS enough yet to know exactly but the 7ss will make around 2500 and the 270 is only .007" smaller bore
 
More data on the 25 sst this week but so far 3350' has been reached with H1000.
I will post on the 25sst thread when I get it.
Back to 270 thread. Both the 270 SS and 270 wsm are great cartridges and it just depends on what you want. The WSM will have a slight edge in velocity if you run it in over a 3" magazine. Th 270 SS will without a doubt have better barrel life for at least three reasons. Considerably less charge, a longer neck, and a sharper shoulder. We haven't shot the 270 SS enough yet to know exactly but the 7ss will make around 2500 and the 270 is only .007" smaller bore
The jury is still out on the 270 EOL Berger 170 gr. but for elk and long range, the 7mm Berger 180 gr. Hybrid in a 7mm SS would be hard to beat. You can keep the game on sight with the moderate recoil of the Cartridge, and put more lead on target if it isn't DRT. 28 Nosler doesn't have anything on a 7mm SS if you don't have a one shot kill, and both will do that. The follow up shot is the key, and that is why I don't buy Weatherby's, Ultramags, and 26 or 28 Noslers. If you can keep your game in sight, you will have a GREAT dinner soon.
 
Keep it coming fella's. Thanks everyone that has responded so far. I just see benefits to both cartridges. I love the idea of ADG brass on the ss, but prefer Redding dies and I believe the ss is Forster dies. I like that the wsm has the little extra velocity, ensures me 3050fps+. Every caliber I've owned and shot has always been slower then what everyone else seems to be getting which makes me nervous about the ss. Short action/long action doesn't overly bother me either way. Sure I light the idea of the short action but if I were to do a switch barrel I think I'd prefer a long action as I'm interested in a few long action std. and mag calibers.
 
Every caliber I've owned and shot has always been slower then what everyone else seems to be getting which makes me nervous about the ss.

I've had the exact same luck. My brother built a 6.5-06ai and was getting just over 3200 fps. I built one with a 1" longer barrel and could only get 3150 fps.
Rich was getting 3070 fps with his 7ss with a 180 berger. I have to lean on my 7ss extremely hard to get 3000 fps with a 180 eld'm.

About the barrel life. Its kind of hard to compare barrel life unless the same shooter burned up both barrels. Just cause you read a claim on the internet about getting xxxx rounds down a barrel doesn't mean that shooter shot the same as another shooter getting xxx with a comparable cartridge. If you download the 270wsm to the same velocities as the 270ss it would no doubt improve barrel life.

Also is there any actual evidence of a sharper shoulder and longer neck improving barrel life? Like has someone shot a barrel out in a cartridge with a 35 degree shoulder, chambered another barrel with a 40 degree shoulder in basically the same cartridge and shot the barrel out? Same thing with neck length? Obviously changing the shoulder 5 degrees would change the capacity slightly. But at least it would be a real world test compared to speculation.

Benefits of the SS are possibly better barrel life. Which you lose some of that since you have to fire form. WSM will be less expensive and better velocity.
 
You get a longer barrel life from the longer neck. You get a longer cartridge case life from a sharper shoulder. Though, 30, 35, and 40° shoulders help with barrel longevity somewhat, too. Some barrels are faster than others. I noticed Krieger is one of them in
6.5 mm. Of course, I was running JLK's and Flatlines in a 1/8" rifling so that might have made a difference also.
 
One thing that needs to be clear. When I develope a new cartridge, I ALWAYS, run the pressure (velocity) up higher than I end up shooting it or recommend that other people shoot it. I have reached 3070 with a 180 even with Norma brass and did not loosen the primer pockets. I also measure case heads as I work my way up and use that info. The point is, I've told people that I have run them up that far to show that 3000' with the 180 in the 7ss is a safe place to run it in most rifles, and MANY people run it there. Never have I suggested to anyone that it should be a practice, and I don't think that's what you are saying either. This is just to clarify to others who might read this! If I didn't run the pressures up in testing to above what we end up shooting, people would then say, "how do you know 3000' is safe"? Also, as we all know, every rifle combination is a separate case and barrels can often vary up to 50-75 per second. This is why we always tell people to start low and work up.
As far as barrel life goes, there can be no question that burning more powder down the same bore size, all else being equal, will burn out a barrel quicker. The WSM loses there. The debate goes on as far as neck length and shoulder angle having an affect, but many people far more inowledgable than me agree that it does, and the description of adjusting the flame point on a cutting torch is an example. As I posted earlier, there is no doubt that a wsm will outrun the SS at equal pressure. The problem is, if you load both to say, 2.950" to the lands, I'm betting the WSM will not outrun the SS. The reason is because your useable case capacity in the WSM is likely no more than the SS and it's less efficient to start with. The choice really comes down to what length action and magazine do you want to run and how important is barrel life? As a side note, now that ADG is making brass for the Saum and Sherman, they get the nod there too.
 
Last edited:
I've had the exact same luck. My brother built a 6.5-06ai and was getting just over 3200 fps. I built one with a 1" longer barrel and could only get 3150 fps.
Rich was getting 3070 fps with his 7ss with a 180 berger. I have to lean on my 7ss extremely hard to get 3000 fps with a 180 eld'm.

About the barrel life. Its kind of hard to compare barrel life unless the same shooter burned up both barrels. Just cause you read a claim on the internet about getting xxxx rounds down a barrel doesn't mean that shooter shot the same as another shooter getting xxx with a comparable cartridge. If you download the 270wsm to the same velocities as the 270ss it would no doubt improve barrel life.

Also is there any actual evidence of a sharper shoulder and longer neck improving barrel life? Like has someone shot a barrel out in a cartridge with a 35 degree shoulder, chambered another barrel with a 40 degree shoulder in basically the same cartridge and shot the barrel out? Same thing with neck length? Obviously changing the shoulder 5 degrees would change the capacity slightly. But at least it would be a real world test compared to speculation.

Benefits of the SS are possibly better barrel life. Which you lose some of that since you have to fire form. WSM will be less expensive and better velocity.
Try the Berger 180 over the eldm, has a much shorter bearing surface, giving it more velocity potential. If that's what you're after.
 
Try the Berger 180 over the eldm, has a much shorter bearing surface, giving it more velocity potential. If that's what you're after.

I plan to try other bullets besides the ELD'm. Was even thinking the 195 could be a possibility. I haven't had the best of luck with the ELD'm when it comes to shooting game. I just like the thought of 3000 fps. I don't think most animals care if its going 2950 or 3000 though.

Agree Rich on the speed thing. I wasn't saying you shoot yours all the time at 3070. I just meant I have bad luck like the OP. Seems like my barrels are usually on the slower side not the faster.
 
I plan to try other bullets besides the ELD'm. Was even thinking the 195 could be a possibility. I haven't had the best of luck with the ELD'm when it comes to shooting game. I just like the thought of 3000 fps. I don't think most animals care if its going 2950 or 3000 though.

Agree Rich on the speed thing. I wasn't saying you shoot yours all the time at 3070. I just meant I have bad luck like the OP. Seems like my barrels are usually on the slower side not the faster.

I knew you didn't think that but wanted to make it clear to everyone.
 
This would be a hard one to decide, I think both are excellent but I'd build both different so for me it'd depend on the total build component and the goals.
 
Warning! This thread is more than 4 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Recent Posts

Top