Hi all,
Looking for some insight on media size vs intensity for peening 300M. Here's the critical details:

Critical rads = .01''
Part Hardness = 52HRC min
Desired Depth of Compression = max possible

Current Spec = S110H @ .010A to .012A.

In the AMS-S-13165A spec it states in para 3.3.8 the minimum size of media allowed to achieve certain intensities. .012A gives S280. Does anyone know where this comes from? The person that wrote it?

Alternatively, in AMS 2432C it states in Table 4 that you can use S170 or S230 for .008A - .012A

Why so many different limits? According to both specs I'm breaking the rules. Looking for insight into where these limits come from. What are the risks of peening at high intensity with small shot?

Thanks for any help!