10%-20% Higher Performance In A Winchester 73'........

Standard 200 gr bullet:

• Current factory jacketed ammo ............1,190 f.p.s.

• Early 44 WCF / 44-40 factory ammo .....1,301 f.p.s.  (+10%)

• RL-7 powder .......................................1,430 f.p.s.  (+10% / 20% over current)

• RL-7 powder / 240 gr bullet .................1,290 f.p.s.

Back in the mid 1990's Alliant published data for RL-7 powder in the 38-40 & 44-40.

Alliant data taken in a 24" barrel using 2 1/2 Remington primers  

240 gr cast bullet / 23.5 / RL-7 / 1,290 f.p.s. / 12,100 CUP (15% less than 14,000 CUP)

The 20% heavier bullet (240 vs 200) at almost the same ballistics as the early 44-40, delivers 20% more punch. 

Note that Alliant used a heavier than normal 240 gr. bullet since RL-7 is slow burning in the 44-40 and 23.5 grains is almost a capacity load.

I decided to try a similar load of RL-7 under the Lyman 427098 which is 15% lighter (210 grs).  I increased the powder charge slightly due to the lighter bullet and got an average velocity of 1,430 f.p.s. (24" barrel). 

Accuracy was great and due to the slow burning rate of powder, there was some partially burned powder granules in the barrel, but that didn't hurt a thing.    Also, the almost capacity load delivered pretty consistant velocities.   

In a 20" barrel velocity ran about 100 f.p.s. less.