Hi, When reloading some .223 cases, my son noticed some bulging at the base of the shoulder where it meets the case body....most common. On some, the shoulder, from base of neck to base of shoulder, has been compressed. On one, the shoulder has almost disappeared. All the above APPLIES ONLY TO THOSE CRIMPED ROUNDS WITH CANNELURES....no issues with non-crimping .223. The rounds in question: shot 1x, trimmed 1x, loaded with 23.3 grains of Benchmark powder, bullet is 55g Hornady..FMJ-BT, OAL: 2.21, case; REM FC, Primer; CCI/BR-4. Somewhat puzzling to me...clearly associated with crimping. Any thoughts as to what might be going-on? Sorry for being so winded...trying to anticipate questions. Gracias por todo!