Home Forums Hunting & Shooting Ask The Gunwriters 6.5 Creedmoor,260 Rem Vs 6.5X55 in a modern rifle.

wonder what a 20 inch barreled Creedmoor would give up with 140's? I kind of like the new tikka t3 CTR with 20 inch barrel.

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I can see that potentially working. With 48 grains of Re 26, I clocked some 140 Partitions at 2998 fps from my 24-inch .260. The load was showing some ejector marks, so I started to back off. At 47 grains, I am still at 2924 and accuracy is getting better. Trying 46.5 this morning to see if the group shrinks a bit. Re 26 smokes with heavy 6.5 bullets.

One thing that I notice about 26, is that some of my es is virtually zero.

The 6.5x55 should be able to safely get 2900 or so with a 140 out of a 22-23" barrel with RL-26, since the .270 Winchester easily gets 3000 from a 150 in the same barrel length

I ran some ballistic equations comparing the bore size and powder room of the two rounds. The 6.5x55 should get about 93% of the velocity of the velocity of the .270 with the same bullet weights, and the numbers indicated 2900 from a 140. Am all that surprised, since my custom 6.5x55, built on an FN Mauser action, gets 2825 with the 139 Lapua Scenar from it's 21-inch barrel, using a charge of Vihtavuori N560 two grains below the maximum listed in VV's data. N560 is very good powder, but probably not any better than RL-26.

This is from my last outing with my 22" barreled 6.5 Swede and 140's with RL26 measured with my Magnetospeed.





I believe if I mess with the seating depth a little it'll be pretty decent.

Mine is getting there with R26 with both 140's and 129 grain bullets. It consistently comes within 100 fps of the 270 with similar weight bullets. If you compare same BC to correct for the larger bore advantage it is even closer , like 120s in 6.5 vs 130s in .270.

VV560 seems very close in performance to R-26. When there is no load data for R26 I look at VV560 and MRP data to get a rough idea of charge weight and velocity to be expected with R26. R-26 may split the difference between MRP and MRP2 as those are similar to R22 & R25 all of which are very close in burn rate.