All data here is presented for study purposes only.  It was safe in the firearm used by the original author at the time it was used.  Due to lot to lot variation that occurs in all powders but especially in surplus powders, the data presented here may not represent all the lots of that powder.  

 

My observations:

 

 I have had 2 lots of 7383 and they do vary significantly.  One is faster and bulkier, the other is slower and slightly more dense.  Make no mistake, both are bulkier than any other IMR stick powder, but volumetric measurements should only be used within a single lot # as variation between lots is substantial.

 

Both lots share the characteristic of liking pressure to work properly.  Neither makes a good reduced load powder and I would refrain from loading it below 80% load density.  Both lots do their best work at or near 100% load density.  As load density passes 100%, you quickly go from safe to pressure spikes that indicate this powder does not like more than very mild compression.  I would not recommend any load over 105% case fill.  In general, as you work up a load, stop at the first clean burning load.  Going further rarely results in anything good and often results in pressures spikes that can be dangerous.

 

My Data

 

CartridgeBullet in GrainsPowder in GrainsVelocityBarrel LengthFirearm
220 Swift5531250024"Ruger 77
22-2505528235024"Remington 700
257 Roberts (AI)10040232022"Remington 700
300 Wby Mag18065295526"Wby MK5 Accumark
(Overload is possible with this case, use caution)
30-0615054250024"M1 Garand
303 Brit20039195025.2"Enfield # 4
30-3017026150018"Winchester 94
(Very poor load - not enough space for powder to burn clean)
30-4018038216522"1898 Krag Sporter
308 Winchester16540211522"Howa 1500
358 Norma25067260024"P17 Action
(Very poor load - not enough space for powder to burn clean)
357 Maximum18022102014"Contender
(Very poor load - not enough space for powder to burn clean)
458 Lott50068154024"Ruger #1
6.5x5512038290029.1"M/96
7x5712040235023.5"95 Chilean
8x5718542230023.5"98K

 

All velocities are rounded for ease of entry - your results will vary.