It wasn't mentioned in his book but I did read an article he wrote once where him & his dad rode horseback across west Texas when he was quite young. Along the way they bumped into some bad guys that had just robbed a bank & they told the elder Askins that they wanted their horses. Daddy Askins had a shotgun across the front of his saddle & told them they couldn't have the horses, when one of them started to pull a gun he got a face full of lead shot for his trouble.
The younger Charlie (maybe 13-14) thought it was great fun...maybe thats where he got the killer instinct so young
I remember Charlie Jr. saying he got off his horse & took the dead man's gun & still had it after many years.

Dick