Tinker,
never had heard about a caliber called 6,5x53R jeffery,or do you mean the manufactur of the rifle Jefferey ?
i have found datas at Reloadersnest.com and in Cartridges of the world page 329 10thedition.
First from reloaders nest:
The 6,5x54 Mannlicher-Schoenauer cartridge is a civil version of an old military round. Greece decided in 1903 to use this rimless version of the rimmed 6,5x53R Mannlicher round, used since 1892 with the armies of Netherlands and Romania. The round was used in a bolt-action rifle, constructed by Ritter von Mannlicher, called "Mod. 1903".

The civil version of this rifle was the "Mannlicher-Schoenauer GK", which was produced until the 1970s by Steyr-Daimler-Puch AG in Austria. The Mannlicher Schoenauer GK and the famous Mannlicher-Schoenauer GK carbine with it's 46 cm (18") barrel, often used by hunters in the Alpen mountains in southern Germany (Bavaria) and Austria, were the only civil rifles chambered for the 6,5x54 M.-Sch.

The small but effective round was used by the european hunters even for big game like the european red deer. Karamojo Bell used a 6,5x54 carbine for brain shots on hundrets of elephants.

The traditional bullet for the 6,5 is the 10,3g (160 gr.) round nose soft point. Effective range is approx 160 m with this bullet. All 6,5mm/.264" bullets could be used.

Load 8720 in caliber 6.5mm Mannlicher Schoenauer
LoadID 8720
Bullet Hornady
BulletWeight 160 grs
Powder IMR 4350
PowderWeight 40 grs
Primer CCI
Brass Make Norma
Barrel Length 18 (inches)
C.O.L 3 (inches)
Velocity 2200 fps
Group 1 (inches by 3 shot at 100 yds)
Submitted Date 12/20/2003 10:55:00 AM
Submitted By Hugh Clark
Gun Info
Comment 1" group@ 100 yd. No sign of excessive pressure.

Energy 1716 ft-lbs
TKO 13.28
OGW 409 lbs
IPSC PF 352

The second i have found is allso in 160gn an from the reloadersnest page:
Load 8286 in caliber 6.5mm Mannlicher Schoenauer
LoadID 8286
Bullet Hornady RN
BulletWeight 160 grs
Powder Hodgdon H4831SC
PowderWeight 44.5 grs
Primer Winchester LR
Brass Make Norma
Barrel Length 18 (inches)
C.O.L 3.1 (inches)
Velocity 2340 fps
Group (inches by 3 shot at 100 yds)
Submitted Date 9/5/2003 5:07:00 AM
Submitted By Steve
Gun Info
Comment No press. signs in my MS carbine

Energy 1941 ft-lbs
TKO 14.12
OGW 492 lbs
IPSC PF 374.4

and the third loading data is from the book cartridges of the world:
6.5x53Rmm Mannlicher
bullet:160 gn SP
powder:IMR 3031
Gn:34
velocity 2250
energy 1810
source NA

I hope i was able to help,
Regards,
Swampfox