Dan,
The aluminum inserts with a steel adaptor screwed in is FAR stronger than when used with a aluminum adaptor; but not as strong as a brass insert with a steel adaptor (assuming it's not one of the 'snapping 75 grain ones').
When I was testing the Internal Footings (extreme testing them, I must add), I encountered actual compression of aluminum inserts. These had 125 grain steel adaptors and, of course, the IF behind the insert. This shooting involved direct and angular impacts against 3/4" armor plate, from 20 yards; and was done to evaluate the effect of the IF's. The aluminum inserts began to bulge; bulging the shaft over the insert. Sometimes this occurred after one hit, but always showed up after several hits, soon splitting the shafts.
Is that significant? Don't know. Just know that I would prefer that it not happen. The same testing with hickory shafts: only the filed point were damaged. My goal is to get a carbon Extreme FOC shaft setup that is at least very, very close to the durability of the hardowwd shafts, on heavy and angular impacts.
It sounds like most have worked out how to match field point weight to their BH's. However, rest assured that, if heavier BH's do come on the market, someone, somewhere will come out with field points that can be weight-matched for use.
Ed
TGMM Family of the Bow