124 Grain vs 135 Grain

[Mil-Dot]

So im experimenting with bullet weight for competition for a 2011. Im curious if anyone has noticed a significant difference in 124 grain at 1126 fps which is roughly standard and a tradional 970 fps for 135 grain.

Specifically do you notice any difference in POI with a 25 yard zero. Naturally the heavier projectile will drop faster but I dont think at 25 yards it will make a difference. I think a 25 yard zero would work whether shooting 115, 124 or 135 or even 147 grain?

Looking for feedback for zeroing purposes

Thanks

 

[ikeo1]

So im experimenting with bullet weight for competition for a 2011. Im curious if anyone has noticed a significant difference in 124 grain at 1126 fps which is roughly standard and a tradional 970 fps for 135 grain.

Specifically do you notice any difference in POI with a 25 yard zero. Naturally the heavier projectile will drop faster but I dont think at 25 yards it will make a difference. I think a 25 yard zero would work whether shooting 115, 124 or 135 or even 147 grain?

Looking for feedback for zeroing purposes

Thanks

Like you said, at 25 yards that's not going to really matter. I used to use the brass monkey 135 and then went back to 124 only because I ran out of the 135's. The recoil impulse is a little softer, that's all. I think it helps with follow up shots. Otherwise accuracy stays the same all else being equal. The only real difference is the impulse, higher softer lower snappier.

 

[Shakey]

I had one gun, a CZ, that had a POI shift with 147. Other guns have not shown a meaningful difference between 115, 124, and 147. Shoot it to verify but I wouldn’t expect a shift.

 

[Mil-Dot]

Like you said, at 25 yards that's not going to really matter. I used to use the brass monkey 135 and then went back to 124 only because I ran out of the 135's. The recoil impulse is a little softer, that's all. I think it helps with follow up shots. Otherwise accuracy stays the same all else being equal. The only real difference is the impulse, higher softer lower snappier.

Thank you, thats what I was wondering if didnt want to gave to worry about my zero if I was switching between the 2.

 

[Deleted member 16735]

Incidentally, heavier objects don't drop "faster". It's a function of velocity and subsequently ballistic coefficient which describes the objects ability to keep velocity, so if you have equal velocity the heavier bullet will actually drop less per unit of distance because a heavier bullet has a higher BC. That said, your POI will be different from bullet to bullet even with the same weight and velocity due to the external ballistics of each being different. How much it matters depends on what you are trying to do though obviously.

 

[Mil-Dot]

I had one gun, a CZ, that had a POI shift with 147. Other guns have not shown a meaningful difference between 115, 124, and 147. Shoot it to verify but I wouldn’t expect a shift.

Thanks I generally dont expect a shift in POI unless we are talking 100 yards or more which you would never see in a USPSA match so never concerned. Ive got a 25 yard zero with 124gr but now switching to 135 for a steel match didnt want to have to adjust the zero if I don't have to

 

[AR15barrels]

Heavier bullets land higher out of handguns because the handgun starts rising from the point of aim the moment that the bullet starts moving down the barrel.
At equal amounts of energy, heavier bullets move slower so it takes longer for the bullet to leave the barrel.
The increased amount of time in-barrel causes the heavier bullets to depart at a higher angle from the initial sight alignment when the bullet first started moving.

 

[smoothy8500]

heavier bullets move slower so it takes longer for the bullet to leave the barrel.
The increased amount of time in-barrel causes the heavier bullets to depart at a higher angle from the initial sight alignment when the bullet first started moving.

Thanks for the explanation. I always wondered "why" that phenomenon occurred.

 

[AR15barrels]

Thanks for the explanation. I always wondered "why" that phenomenon occurred.

If you ever lay a straight edge across the top of handgun sights and stick a dowel in the barrel to show the bore angle from the sights, they will be at angles to each other with the bore pointing DOWN from the sights.
This is done on purpose because the bore angle changes before the bullet leaves and that change is what gets the bullet to strike where you were aiming.

This is the opposite of rifle sights/scopes where the rifle is held much more solid so it does not rise like a handgun does.
Rifle sights/scopes aim towards the angle of the bore to get the bullet to rise up through the line of sight before the bullet drops back to the line of sight at the zero distance.