In my recent accuracy performance tests of 22LR ammo, I mixed ammo makes (ie. CCI Mini-Mags vs Aguila Super Extra vs Federal Auto Match) within the same test session to average out changes in groupings due to barrel heating. But 22LR precision shooters told me my testing method was flawed because I didn’t properly “season” the bore. Seasoning is a process by which the melted wax, from lead-round-nose rounds (LRN), coats the bore and normalizes the performance of that bullet.
So this time, I’ve only tested a single ammo type, Federal Auto Match LRN, in a testing session of 7 targets. I shot 20 rounds of that ammo to season the bore before measuring the groups. I’ve cleaned the bore before changing ammo to CCI Standard LRN and measured those groups.
The results I got were “cleaner” results but those results were surprisingly close to the previous test with mixed ammo types. That leads me to some possibilities or a combination of them:
• Seasoning the barrel doesn’t make a significant difference with factory standard rifles
• Seasoning the barrel doesn’t make a significant difference at 50yrds-100yrds
• My previous mixed ammo tests were valid; one ammo’s fouling residue doesn’t significantly influence a different ammo’s performance.