Took my 44 Rossi ranch hand with a full length stock out shooting. I put a small reflex sight on it, old people with bad eyes need some help. First, I shot my 240gr hard cast traveling at 900 fps zeroed it at 75 ft. Then I tried shooting some jacketed bullets traveling at 1650 fps and, thay shot 4 in lower? Now I know nothing in shooting and reloading is an exact science but at 75 ft I thought they would be close. But thinking the faster bullet should still be a bit higher, not 4," lower. So just for fun I dialed in the jacketed bullets at 75 ft, then tried the hard cast again, same thing. Slower bullets shoot 4" higher. Did the government repeal the law of gravitys affecting lead? I've heard about this sort of thing but never experienced it in 50 years of reloading and shooting.
Slower bullets shooting higher
- Thread starter MRP
- Start date
saskgunowner101
CGN Ultra frequent flyer
- Location
- near Prince Albert
I recall experimenting with round ball in an inline ml, and slowly dialing back the powder charge, only to be utterly amazed by this fact.
I don’t think it’s the velocity making a 4” difference of impact at 75 feet. One explanation I have heard for this phenomenon that makes sense to me is more along the lines of what EJG said.
Basically the slower bullet remains in the barrel longer allowing the upward recoil of gun and therefore increased barrel angle to drive the point of impact higher. If you held the rifle tighter or strapped it to a sled you would see a reduced effect.
Basically the slower bullet remains in the barrel longer allowing the upward recoil of gun and therefore increased barrel angle to drive the point of impact higher. If you held the rifle tighter or strapped it to a sled you would see a reduced effect.
In working with higher velocity/pressure cartridges, ( 7mm, .30/06, 9.3x62, .308/.307 and probably some I'm forgetting) the lighter/faster bullet has always printed higher than the heavy/slower load. Sometimes substantially so.
Occasionally I'm pleasantly surprised to find a rifle/cartridge combo that groups different bullet weights into roughly the same group. That hasn't happened often.
Occasionally I'm pleasantly surprised to find a rifle/cartridge combo that groups different bullet weights into roughly the same group. That hasn't happened often.
the issue is 75 ft zero the faster bullet has not reached its highest rising point of trajectory you have to compare apple to apple not oranges to apples
the faster bullet has a flatter trajectory
defiantly some interesting theories
the faster bullet has a flatter trajectory
defiantly some interesting theories
kbdplinker
Member
- Location
- Toronto, Ontario
I’ve noticed the same shooting Henry BB 357
Zero for 50y using 158gr 38special, then switch up to 158gr 357mag and the mag hits substantially lower. When used to shooting a lot of 223/5.56, 9mm and 22LR, I haven’t seen this before. I always (wrongfully) assumed shooting higher velocity or lighter grain would make the POI higher. Still trying to understand this. But at least I know it happens now and to compensate for it, even though I don’t quite understand why.
Zero for 50y using 158gr 38special, then switch up to 158gr 357mag and the mag hits substantially lower. When used to shooting a lot of 223/5.56, 9mm and 22LR, I haven’t seen this before. I always (wrongfully) assumed shooting higher velocity or lighter grain would make the POI higher. Still trying to understand this. But at least I know it happens now and to compensate for it, even though I don’t quite understand why.
- Location
- Nova Scotia
My 357 Rossi does that. I shoot 125grn Blazer 38 spl and be POA/POI..
I shoot my 160grn lead SWC with 4grns of W231 and I'm shooting 6" high.
I shoot my 160grn lead SWC with 4grns of W231 and I'm shooting 6" high.
I have noticed this effect when shooting off the bench. It goes away when you shoot offhand. I observed it was with rifles designed for offhand (hunting style) and shot off a frame style rest lead sled etc. The effect seems minimized off bags as well.
My theory was the longer dwell time of the heavier projectile starts the recoil impulse before the bullet exits.
Try again offhand, or switch to a front and rear bag setup, or hold the forend tight then rest your hand
My theory was the longer dwell time of the heavier projectile starts the recoil impulse before the bullet exits.
Try again offhand, or switch to a front and rear bag setup, or hold the forend tight then rest your hand
I was not shooting off a bench, well, a redneck bench. Belly against the fender, elbows on the hood, a semi freehand hold. My old 24" 444 didn't do this going from 2400fps jacked to 1100fps cast bullets. Hope to get out try again soon and try again at 100yds offhand and off some bags.
Lol. No.
I shoot reduced loads in my 1885 45-70 (Malcom 6x scope) off the bench.
15gr Unique with 415gr hits point of aim at 100m.
13gr Unique with 535gr hits at least 6 inches high.
Slower bullet leaves barrel later in recoil pulse.
They both kind of meet up at 125-150m due to heavier slower bullet dropping faster.
15gr Unique with 415gr hits point of aim at 100m.
13gr Unique with 535gr hits at least 6 inches high.
Slower bullet leaves barrel later in recoil pulse.
They both kind of meet up at 125-150m due to heavier slower bullet dropping faster.
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