One of our Shooters’ Forum readers, Trent from Louisiana, asked for help deciding between a .260 Remington and a 6.5×55 for his latest gun project. In the Forum thread, respected UK gun writer Laurie Holland provided a good summary of the differences between the two chamberings. Laurie writes:
“The 6.5×55 case has 6 or 7% more capacity than the .260s, even more in practice when both are loaded to standard COALs with heavy bullets, which sees them having to seated very deep in the .260 Rem using up quite a lot of powder capacity. So loaded up for reasonable pressures in modern actions, the 6.5×55 will give a bit more performance.
The issue for many is what action length is available or wanted, the 6.5 requiring a long action. So sniper rifle / tactical rifle competitors will go for the .260 Rem with the option of the many good short-bolt-throw designs around with detachable box magazines. If a bit more performance is needed, the .260AI gives another 100-150 fps depending on bullet weight.
Brass-wise, you’ve got really good Lapua 6.5×55 off the shelf that needs minimum preparation, and it’s strong and long-lived. There is an Ackley version too that was popular in F-Class in Europe for a while that isn’t too far short of 6.5-284 performance. If you go for .260 Rem, the American brass isn’t as good but you can neck-up Lapua or Norma .243 Win and trim them (or neck-down .308 Win or 7mm-08). This has the downside that doing so usually creates a noticeable ‘doughnut’ at the case-shoulder junction, that may cause problems depending on how deep bullets are seated. [Editor's Note: After Laurie wrote this, Lapua began producing high-quality .260 Remington brass.]
For purely target shooting, I think I’d go with 6.5×55 if I was making the choice again today for performance and brass-preparation reasons. In fact, I’ve considered going back to the gunsmith to have the barrel rechambered.
You want a multi-purpose rifle though and that makes things trickier depending on the bullet weight(s) you want to use. The [typical] 6.5×55 and 6.5-08 throats are really designed for 140s, so 90-120s make a long jump into the rifling. If you’re always going to use 130s and up, it’s less of an issue. If you want to use the lighter stuff, I’d say go for .260 Rem and discuss the reamer with the gunsmith to come up with as good a compromise as you can depending on the mix of shooting. 1:8.5″ twist is the norm and handles all the usual sporting and match bullets; you can go for a little slower twist if you won’t use the heavies.
Over here in the UK, in Scotland to be precise, we have a top sporting rifle builder (Callum Ferguson of Precision Rifle Services) who almost specializes in .260 Rem usually built on Borden actions. He throats the barrel ‘short’ so it’s suited to varmint bullets, but will still handle the 100gr Nosler Partition which he says is more than adequate for any British deer species including Scottish red stags.
Accuracy-wise, I don’t think there’s anything between them if everything else is equal. The 6.5 has a reputation for superlative accuracy, but that was high-quality Swedish military rifles and ammunition matched against often not-so-high-quality military stuff from elsewhere. Put the pair in custom rifles and use equally good brass and bullets and you’ll be hard pressed to tell them apart.” – Laurie Holland
After Laurie’s helpful comments, some other Forum members added their insights on the .260 Rem vs. 6.5×55 question:
“To me, the .260 Remington has no advantage over the 6.5×55 if one is going to use a long action. Likewise, the only advantage the .260 has in a modern rifle is it can be used in a short-action. There is more powder capacity in the 6.5×55 so you have the potential to get more velocity plus there is a lot of reloading data available to you for loading at lower velocity/pressure if you choose. The Lapua brass is great and Winchester brass is pretty good at low pressures. Having loaded a good bit for both, the 6.5×55 would always get the nod from me. To me, if someone wants to use a short-action, the 6.5×47 Lapua is even a better option than the .260 for a target rifle.” — Olympian
“There is just one small item that has been missing from this conversation — the 6.5×55 has a non-standard rim diameter of .479″ vs. the standard .473″ of a .308 and all of its variants. Depending on your bolt this may be an issue, or it may not.” — Neil L.