interesting. heavier bullets raise poi

[jkor]

my LCR always shot low with the light bullets I usually carry. tried some 158gr bullets with a mild charge of accurate #2 and it shoots dead on.

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[P7M13]

Getsomeone to video record your shooting.

 

[Knobgoblin]



Lcr is a flinchy lil beast

 

[po18guy]

Let's consider the effects of recoil and bullet path. Guns recoil backward and upward upon firing. Barrel and sights elevate above the original line of sight as this occurs. Slower bullets spend more time accelerating in the bore at lower velocity. This means that the recoil impulse acts for a longer time on the barrel, raising it more. When a slower bullet finally exits, the barrel has recoiled considerably above point of aim. Since the bullet flies in an arc, it first travels above the point of aim/target, reaches the high point of that arc, then begins to drop toward the target, striking it at the point which was aimed at.

Lighter bullets accelerate faster, leaving the barrel at a lower point in the barrel's recoil. If they leave the barrel when it is still at a lower point in its recoil, they will also strike the target at a lower point.

There are innumerable factors which affect this, but these are "generally" speaking. Thus, if you have a fixed sight gun that shoots either high or low, you can alter bullet weight/velocity to bring the hits back to the center of the target.

 

[BillM]

Given roughly the same muzzle energy, a heavier bullet at a lower velocity will
impact higher at close range out of a revolver.

 

[jkor]

Given roughly the same muzzle energy, a heavier bullet at a lower velocity will
impact higher at close range out of a revolver.

I had put my crony away at that point. Surely it was slow as a boat maybe, 700fps

 

[oremike]

This is exactly right. I have a 38 Super that the bullets hit high with the 160gr bullets so the next time I load for it I'm going to use the 130grs to change the poi down a bit.

 

[Spitpatch]

Heavies shooting higher than lightweights in a pistol is one of those hard pieces of information that keeps getting tossed into the dust bin of lost technology.

Similar human behavior might be the reason Captain Kirk had no seatbelts on the Enterprise..

 

[oremike]

I've known this all along just really wanted to shoot the "gong bongers" in the 38 Super but ran out of sight adjustment so on to lighter bullets.

 

[Certaindeaf]

Barrel dwell time.

 

[orygun]

Heavies shooting higher than lightweights in a pistol is one of those hard pieces of information that keeps getting tossed into the dust bin of lost technology.

..

What's old is new again. Handgun shooters, especially reloaders learn this early on.
Jkor is finding that out. Bullet weight selection and velocity is how you tune the load to work with fixed sights.
That's the reason most fixed sight 1911s shoot closest to point of aim with 230gr bullets and 38 Specials do the same with 158gr bullets. Key word is "most".

 

[Hueco]

If it's shooting high, move further away from the target.

/s.

 

[orygun]

If it's shooting high, move further away from the target.

/s.

I laughed, but this is also true. Just how far to back up is the question.

 

[DizzyJ]

The barrel will rise more with a heavier bullet at exit. Therefore POI will rise too.

This has been my experience for many years. Lighter bullet being pushed faster will have a lower POI.

At least with a pistol at common pistol shooting distances.

 

[jkor]

Getsomeone to video record your sho

What's old is new again. Handgun shooters, especially reloaders learn this early on.
Jkor is finding that out. Bullet weight selection and velocity is how you tune the load to work with fixed sights.
That's the reason most fixed sight 1911s shoot closest to point of aim with 230gr bullets and 38 Specials do the same with 158gr bullets. Key word is "most".

Didn't notice this with my 1911 much. revolvers have more muzzle rise I guess, barrel is higher up.

 

[gmerkt]

Add in length of barrel component. The condition described was well-inown with older, long barreled revolvers. Like the police at one time used. The sights on those were regulated for heavy, slow-moving bullets. When people started shooting 125 gr. and even 110 gr., POI was way high. Time in bore was one part, the other was the longer barrel, the front sight on which would pivot even higher under recoil.

 

[po18guy]

Barrel dwell time.

Lighter projectiles do not like to dwell on that subject. So to speak....

 

[ageingstudent]

Add in length of barrel component. The condition described was well-inown with older, long barreled revolvers. Like the police at one time used. The sights on those were regulated for heavy, slow-moving bullets. When people started shooting 125 gr. and even 110 gr., POI was way high. Time in bore was one part, the other was the longer barrel, the front sight on which would pivot even higher under recoil.

Most definitely. You start seeing it even more at~25-50 yds with a .357 carbine with 125gr projectiles vs. 180gr. Even with adjustable sights if you have your carbine sighted in for 125s the 180s tend to print quite a bit higher even though they are going slower. That's been my experience anyway.

 

[Spitpatch]

Add this to the constantly neglected hard information that heavy, large caliber bullets at moderate speeds DO NOT "buck brush" better than sleek fast ones.

It just ain't so.

 

[WillametteWill]

Let's consider the effects of recoil and bullet path. Guns recoil backward and upward upon firing. Barrel and sights elevate above the original line of sight as this occurs. Slower bullets spend more time accelerating in the bore at lower velocity. This means that the recoil impulse acts for a longer time on the barrel, raising it more. When a slower bullet finally exits, the barrel has recoiled considerably above point of aim. Since the bullet flies in an arc, it first travels above the point of aim/target, reaches the high point of that arc, then begins to drop toward the target, striking it at the point which was aimed at.

Lighter bullets accelerate faster, leaving the barrel at a lower point in the barrel's recoil. If they leave the barrel when it is still at a lower point in its recoil, they will also strike the target at a lower point.

There are innumerable factors which affect this, but these are "generally" speaking. Thus, if you have a fixed sight gun that shoots either high or low, you can alter bullet weight/velocity to bring the hits back to the center of the target.

Well stated. Learned this early from an 8 3/8" M29. Slow, heavy bullets shoot way high. Retired Marine pistol team shooter schooled me on this when I was much younger.