Case capacity for a Creedmoor cartridge is approx 52.5gr water. Some cases are a little more, some a little less depending on manufacturer. I can seat a 139 or 140gr bullet for a full case at around 44.2gr RS62 which generates decent velocities (Lapua brass). The Creedmoor is quite an efficient case as compared with 260 Rem and 6.5 x 55, little of that case capacity is taken up by the bullet as the cartridge is designed with longer, higher BC projectiles in mind and the chambers throated accordingly. My 139 Scenar load is seated to the base of the (long) cartridge neck and I still get a healthy jump to the lands. This is one of the strengths of the design and what makes it so efficient. Whilst 260 Rem has a case capacity of 53.5gr H20, the bullets have to be seated deeper, meaning that the Creedmoor uses it's case volume more efficiently. The 6.5 x 55 holds significantly more powder at 57.5gr H20 but chambers are not designed with the 62,000 SAAMI chamber pressure of the CM. 6.5 x 55 in modern loadings are still a little below this, although well above the older Swedish chamber pressures (51,000PSI).
If you are running out of capacity well short of the desired loading, try another powder. Viht N150 or N160 will work with the 130gr bullet but my recommendation would be RS60 or RS62 which are optimal and should leave you with more than enough capacity. In LRP brass, 42.5 to 44gr RS62 will spit a 130gr bullet out at over 2800fps from a 22 to 24 inch barrel.
