6.5 vs .257 cartridge question

[Bill Norris]

The new 25 bullets have put a low recoiling rifle into almost magnum ballistics. Watching the 25s shoot with the 300s at 1k, they are not that far behind now. Now Im not talking the big 300s, but stuff like the wsm. Its true there's not a lot of bullet options, but when you look at bullets that win matches, there are not a lot of options in any caliber.
For competition, I would say there's not a big difference between a 25 or 6.5. Both are doing well. For hunting I like the 25. I personally don't consider either big enough for elk so if I scratch elk off the table then Im thinking mid range deer and antelope. For that, Id rather have the extra speed of the 25 if we compared say a 25 prc vs a 6.5 prc.

Yea, so far I'm liking the 25 X 47 Lapua. Hoping to get it out to 600 or 700 yds. once this heat backs off somewhat to see how true the ballistics charts are. Sometimes what we see on these programs don't actually paint the true picture that the target does. Me and SVT_Tactical saw a good example of that a few months back when we compared the 115 gr. Tubbs 6mm bullet in 243AI to the 140 gr. 6.5 Berger bullet in 260AI at comparable M V at 700 yds. Ballistics said the 115 gr. was better at maintaining velocity and wind drift but in the real world we did not see that at all in app. 10 to 15 mph winds. I'm hoping the 25 X 47 Lapua will paint a different picture on paper but that remains to be seen.

 

[Bill Norris]

When it became reality there was going to be more then just a couple mid 130's .257 bullets available to us the RSAUM case size seemed like it would be a really good fit for this caliber and weight class. Having a few hundred pieces of new ADG 6.5 RSAUM brass sitting on the shelf I started acquiring parts to have a 25 RSAUM built. Dropped everything off at my smiths and a few months later I had a 25 SAUM that was launching 134 ELD-M's down range at just a tick under 3200 from a 22in Bartlein barrel and I couldn't be happier with how well it shoots. I think once it gets a few more rounds through it it'll likely end up settling in somewhere slightly over 3200.

The 25 WSM's and 25-7PRC's shoot the same bullet/s a little faster but they're also using a fair bit more powder to get there too. I've never been one to be overly concerned about barrel life or "efficiency" but I think the RSAUM case size and .257 caliber makes for a really happy combo without going quite so overbore as the WSM, 7 PRC or even 257 Weatherby.

Yea I feel the SAUM case would be max. if I decided to build one. Barrel life comes into play.

 

[Alex Wheeler]

I like the prc case for the 25 for hunting. Pushes that 130+ class over 3200 in 24" barrels and they hammer. I have a bunch of them out there and I like those cartridges that are easy. And you have Lapua brass. I also like the 25-300 wsm for lapua brass too and 257 Weatherby capacity. I am not a Weatherby guy but I like the 257 W for some reason.

 

[Alex Wheeler]

Yea, so far I'm liking the 25 X 47 Lapua. Hoping to get it out to 600 or 700 yds. once this heat backs off somewhat to see how true the ballistics charts are. Sometimes what we see on these programs don't actually paint the true picture that the target does. Me and SVT_Tactical saw a good example of that a few months back when we compared the 115 gr. Tubbs 6mm bullet in 243AI to the 140 gr. 6.5 Berger bullet in 260AI at comparable M V at 700 yds. Ballistics said the 115 gr. was better at maintaining velocity and wind drift but in the real world we did not see that at all in app. 10 to 15 mph winds. I'm hoping the 25 X 47 Lapua will paint a different picture on paper but that remains to be seen.

I do think theres a little error in our current ballistics calcs. I dont think we give mass enough credit. Then theres also some bullets than just cut wind. We have theories, but BC and velocity are not the be all end all for wind drift IME. Its just a rough estimate.