Looking for thoughts here. Looking at a build. I don't expect there is too big a difference in performance here but still would like to hear if anyone would think one may be marginally "better" than the other.

Perhaps one is a little easier to load or not as quirky with certain bullets? Brass availability an issue with the with '57 (doubtful, just neck up .257 Bob or neck down 7x57, right?)?

Lets hear it...

War Eagle,

I have both and I can't see a hoot's worth of difference in performance between the two. In fact, I often find myself using load data for the 6.5x55 in the '57. Load data for the 6.5x57 is fairly scarce. At one time I dreamed of writing an article comparing the commercial 6.5's. Which is why I purchased the 6.5x57. I also own rifles in 6.5x54 MS and 6.5x64 Brenneke (aka: 6.5x.270 Win.)

For ease of reloading, inherent accuracy, proven performance, and brass availability, one just cannot beat the 6.5x55! IOW: Logic favors the Swede...

However, if one travels to the beat of a different drum.... Then anything goes... ! I rest my case...

Grasshopper

War Eagle,
I think Grasshopper's advice is pretty much on the money. I love the 6.5s - especially the 6.5x54 in the 1903 MS. If you study the published loading data for the 6.5x55 Swede, you will see that it is at very low pressures due to the old rifles that are floating around - like the Krag Jorgenson's, rolling blocks, etc. Even the '96 Mausers are considered weak actions compared to '98s and other modern actions....although I don't really think they are as far behind as some think. The point of this rambling is that if you are willing to go slow and work up, you can beat 6.5x57 performance by a good margin with safe loads in the Swede. The case is fatter and just holds more powder. Loaded at the same pressures, the 6.5x55 is superior. It also has an excellent reputation for accuracy. I have two customs in 6.5x55 and both are very accurate. I would not hesitate to use them on Elk as they have great penetration....for the record I know there are better Elk rifles. Brass and dies for the Swede are also easier to find. I don't think you would be able to tell much difference in the field. You carry a rifle a lot more than you shoot it, so carry the one that makes you feel good.

TexasJohn

Look up Seafire on AR,he has worked a lot with both and has a lot to say. The 6.5x57 is an odd ball 57,more like the 8x57 then the 7x57. The easiest way to get brass is to false shoulder 7x57 and fireform. I think case capacity is a brand question.My 6.5x55 barrel started life as a 6.5x57,just for the ease.

Yep...what he said and what he said...I have both of them as well. I think I buy more for the differences and values in the rifle itself and not so much in caliber. I have a few calibers that are doubles,but the vehicle is completely different.

IF, I was going to build one,I would go with the 6.5x55 due to travel and ammo availability world-wide.My plans are to take it and my 9.3x62 on my next trip to Africa.

Having both, their performance difference ( along with the 260 Rem) is pretty non existent..

My favorite cartridge of all is the 6.5 x 57..mainly because of its being more a rarity.. I also just neck up 257 Roberts brass..
the Swede, if you have a push feed, the rim diameter vary some between manufacturers...

I built my 6.5 x 57 on a long action, and it is throated to where I can seat bullets out to magazine length in the model 70 its on..
in that scenario, one can match 6.5/06 velocities...
the only difference is in the 6.5 /06, the bullet is occupying part of the powder capacity... on the 6.5 x 57, the bullet is not... but you end up with cartridges with the same OACL...

I think the 6.5 x 57 is more practical than the Swede as it can use Roberts and 7mm Mauser brass by just necking up or down as the case may be...

the Swede is more readily available, but has some variation in specs between various manufacturers..

Die costs are a concern also... the 6.5 x 57 is considered a custom... everyone makes the Swede dies..but dies are actually a low cost in the consideration of the life of a rifle..

only go with either if you are doing it on a long action..
if you are doing it on a short action, then I'd do a 260 Rem...

for the 6.5 x 57, as long as 6mm Rem, 257 Roberts and 7 mm Mauser brass are readily available, you never have to worry about brass availability...

Me, I just love having something different than all the other guys...and when you got what they don't know what it is, but they see how accurate it is...then they really want to know all the details and how to get one... then you just smile and be quiet...and let them drive themselves nuts..

( as a side story, some guys who I know that are always shooting the latest greatest and act all snobby with their wildcats... they saw me nailing some targets at 700 yds on our range one day...they wander over and ask me what caliber I am shooting..

since I have seen them act all high and mighty to other folks around there before, when they asked me what I was shooting, I told them I was shooting a Winchester 6mm Medium Length Short Mag..

of course, they admitted they had never heard of it...and asked was it a new cartridge? I told them I wasn't sure how long it was out, but there are rifles available for it...

so these guys leave, and I am sure are going home to either check it out on the Winchester web site, or stop by one of the local gun shops and ask about it..

as they left, my buddy was looking quizically, and asks what the hell is a Winchester 6mm Medium short Mag? I thought you were shooting a 243? My response was " I am, but those pompous bozos don't know that..."

Seafire,

You are my kinda guy! LMAO...