Really
This is a little over simplified but here's what you do. Research and select 6 different types of carry ammo weighing between 124 and 147 grains. Buy 50-100 rounds of each, take that and your practice ammo to the range and shoot it. POI may vary considerably, but what you are looking for is consistency. When you find one or two you and your gun both like buy more of that and shoot a little of it everytime you go to the range, along with your cheaper practice ammo.
Another method you might try is to buy hardball practice ammo in a similar weight as your carry ammo, again what you are looking for is a consistent POI in relation to your practice ammo. This is what I did in my .223. The really cheap 55 grn ammo was consistently off by 2" from the 69 grn my rifle liked. I got tired of dealing with it so I started buying a cheap (unfortunately not as cheap as the 55 grn) 69 grn practice ammo to shoot and have had very good results with this method.
That may qualify as an understatement.OK - there seems to be a little disagreement as to the more effective bullet weight.
This should be obvious to you by now.If I use 115 gr FMJ as my range ammo, should I expect different performance if I use 147 gr JHP?
This is a little over simplified but here's what you do. Research and select 6 different types of carry ammo weighing between 124 and 147 grains. Buy 50-100 rounds of each, take that and your practice ammo to the range and shoot it. POI may vary considerably, but what you are looking for is consistency. When you find one or two you and your gun both like buy more of that and shoot a little of it everytime you go to the range, along with your cheaper practice ammo.
Another method you might try is to buy hardball practice ammo in a similar weight as your carry ammo, again what you are looking for is a consistent POI in relation to your practice ammo. This is what I did in my .223. The really cheap 55 grn ammo was consistently off by 2" from the 69 grn my rifle liked. I got tired of dealing with it so I started buying a cheap (unfortunately not as cheap as the 55 grn) 69 grn practice ammo to shoot and have had very good results with this method.