[Peter M. Eick]

Al,

You have a lot of factor's in play here, so when extrapolating it must be done with care. Normally you take the heavier bullet data as a starting point and work up from there. The logic is that given a heavier bullet it should have a lighter charge and working up is safer then working down.

Now when you go from a heavier bullet in 9mm to a lighter bullet, you have changed the COL and the load space for the powder. Thus you need to be careful about COL and bullet seating depth.

With the 135 seated so you have the same shank distance into the brass as the 147, then the 147 data will give you a light load. With the 135 seated deeper, you could get an overpressure load if the bullet shape is significantly different (truncated cone vs. a round nose or JHP).

So rubber meets the road time.

I would make up just a few (say 10) rounds of 147 grn start loads for your 135 and see how you like them. Watch the COL carefully to make sure they feed and function reasonably. If you are happy, keep shooting. If not enough power or too much power adjust accordingly and make 10 more. Repeat till accuracy and power requirements are satisfied.

This is my approach to delving into the brave world of no data handloading.