Here is some info on the 307 Win. from ammo guide
S.A.E. (in.)
Metric (mm.)
SPECIFICATIONS
Bullet Diameter:
.309 in.
Max Overall Length:
2.560 in.
Rifling Twist:
Rifling Lands:
Case Capacity (est):
55 gr. water
Primer Size:
.210
NOMINAL PERFORMANCE
Bullet Weight:
180 gr.
Muzzle Velocity:
2510 f.p.s.
Muzzle Energy:
2519 ft-lbs.
"Easy Link" to this cartridge (copy and paste into emails, forums, etc.):
.307 Winchester -
http://ammoguide.com/?catid=93 --------------------------------------------------------------------------------
The .307 Winchester was developed in conjunction with the .356 Winchester, to provide cartridges suitable for the Model 94 XTR Angle-Eject Carbine. Both cartridges and carbine appeared in 1983.
The Model 94 XTR offered several significant improvements over the standard Model 94, which by then had been in production for 89 years. First, the new model could withstand much higher pressures, permitting more powerful ammunition such as the .307. Secondly, the angle-eject feature meant that spent cases were ejected to the side of the action, rather than staight-up, permitting easier scope-mounting.
Except for the rimmed configuration, the .307 case is externally virtually identical in dimension with the .308 Winchester (7.62mm NATO). As a result, the .307 almost duplicates the ballistics of the military round. The .307 produces slightly less power than the .308, however, as the bullets must be seated slightly deeper in the case to remain compatible with the overall Model 94 action length. This means there is slightly less case volume available for optimal powder capacity. The .307 also suffers from the flat-nose bullet required in tubular-magazine-equipped rifles, yielding more drop and less range than the .308 with conventional pointed bullets.
Externally, the cartridges are so similar, that it is possible to chamber the older rimless .308 ammunition in a .307 carbine, but FIRING SUCH A MISMATCH SHOULD NEVER BE ATTEMPTED, as serious injury or worse could result.
The .307 Winchester can propel a 180 grain bullet at 2510 fps with 2519 ft-lbs of muzzle energy.