ive been trying to work up a light load in my 30-30 but am having some trouble. even at fairly short ranges (30 yards) my rounds have been impacting low enough that my limited range of rear sight adjustment just cant compensate for it. any tips or tricks for raising point of impact to come at least close to a hunting load to about 30-40 yards?
changing point of impact to match point of aim
- Thread starter JEB
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ranger335v
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Your POI difference is due to ballistic differences. No simple sight adjustment or trick can negate that.
im still pretty new to this so forgive me if i seem too ignorent. i would think that it should be fairly easy to make a light load that would at least closely mimic the flight of a higher powered load (similar external balistics?) at close range. if i could just get POI high enough that it was in the adjustment range of my rear sight i would be happy.
rcmodel
Member in memoriam
It's due to difference in recoil.
A full power load kicks the gun up before the bullet gets out of the barrel, and your sights are regulated for it.
There is nothing you can do about it except change the load to increase recoil with a heavier bullet going faster.
rc
A full power load kicks the gun up before the bullet gets out of the barrel, and your sights are regulated for it.
There is nothing you can do about it except change the load to increase recoil with a heavier bullet going faster.
rc
CraigC
Sixgun Nut
That's interesting because they should be impacting higher. At any rate, you need a shorter front sight.
Carl N. Brown
Member
Try comparing POI for .38 Special in a .357 carbine at 100 yards versus .357 rounds (I had to get two different step elevators).
Shooting black powder loads in a .30-30 (170 gr at ~1400fps) required about 54 clicks in the scope adjustment for a zero at 100 yards, versus the zero for smokeless factory loads.
Shooting black powder loads in a .30-30 (170 gr at ~1400fps) required about 54 clicks in the scope adjustment for a zero at 100 yards, versus the zero for smokeless factory loads.
qajaq59
Member
What load are you using now?
rcmodel
Member in memoriam
No they should be impacting lower, because the gun isn't kicking up as much while the bullet is still in the barrel.
rc
CraigC
Sixgun Nut
Yes but the faster load will spend less time in the barrel, as it's rising.
IIRC, the general rule of thumb is that for a given velocity, a heavier bullet will impact higher than a lighter one. For a given bullet weight, lower velocity will impact higher. Obviously it is not a hard and fast rule and there are exceptions. Since we don't know the load in question, it may be because it is so light that there is zero recoil.
IIRC, the general rule of thumb is that for a given velocity, a heavier bullet will impact higher than a lighter one. For a given bullet weight, lower velocity will impact higher. Obviously it is not a hard and fast rule and there are exceptions. Since we don't know the load in question, it may be because it is so light that there is zero recoil.
Recoil occurs after the bullet leaves the barrel. If recoil (or the gun "kicking up") had anything to do with where the bullet hits, you couldn't shoot anything accurately. That's like saying that a rifle will have one point of impact for me and a different point of impact for someone else because the rifle will "kick up" different amounts for different shooters.
What is the load that you are trying to mimc the POI of? You could try heavier bullets to bring the POI up or push your existing load a little faster.
What is the load that you are trying to mimc the POI of? You could try heavier bullets to bring the POI up or push your existing load a little faster.
KodiakBeer
member
Are you sure you're moving the rear sight in the correct direction? Are you cranking it up or down?
rcmodel
Member in memoriam
Try shooting a 30-30 carbine off sandbags without holding it down.
Try it again while holding it down hard on the bags.
Then get back to me.
A front sight on a magnum handgun is too high for the sights to be level with the bore axis for the same reason.
A 30-30 carbine ain't too far removed from a magnum handgun when it comes to recoil moving the gun.
rc
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CraigC
Sixgun Nut
Recoil begins upon ignition. Which is why it is so important to interface your firearm consistently shot after shot. If recoil didn't occur until after the bullet left the muzzle then form wouldn't matter much and follow-through would scarcely be necessary.
That's actually 100% true.
ive been using red dot and blue dot for my light loads behind a 135gr LFP bullet (missouri bullet co. #2 whitetail). i have been increasing as well as decreasing my charges and have not been able to match POI at 30 yards even with sight adjustment. firearm in question is a 2002 manufactured marlin 336w in good condition. i am aprehensive to increase too much with these pistol powders because i dont know how much my rifle can handle and i really dont want to find its breaking point (literally). i also have some IMR 3031 and have been thinking about using a reduced charge of that but i dont know how low of a charge would be safe. im using 28.1 grains for my regular deer load, so maybe 20grains would be good with a cast bullet for a reduced load? i have no idea if this would be safe or if it would even work. any ideas?
I guess we'll just have to agree to disagree on the recoil thing. I can say that the point of impact doesn't change at all with my rifle. Whether it's shooting from a sandbag rest, bipod, or using a tree limb for support.
As for the 30-30's POI changing, I'd imagine it would change if you took a rifle with a non free floated barrel and put pressure on it by pusing it down into a rest. You get the same effect when shooting a rifle with a sling attached to the barrel and tighten up on the sling when shooting.
As for the 30-30's POI changing, I'd imagine it would change if you took a rifle with a non free floated barrel and put pressure on it by pusing it down into a rest. You get the same effect when shooting a rifle with a sling attached to the barrel and tighten up on the sling when shooting.
rcmodel
Member in memoriam
O.K.
Why don't you tell him why he doesn't have enough rear sight adjustment to get his light & slow bullets up on target then.
It has been a known problem with lever-actions for over 100 years with non-standard bullet weights and lower or higher then normal velocities.
Gallery loads in military bolt actions were never a problem because the rear sights on them had enough elevation adjustment range to sight in anything.
Not true of lever-action factory barrel mounted sights.
Adding a tang or receiver peep sight would be the only option I can think of.
They would have the necessary adjustment range to make up for lack of recoil shooting light & slow bullets low.
rc
Why don't you tell him why he doesn't have enough rear sight adjustment to get his light & slow bullets up on target then.
It has been a known problem with lever-actions for over 100 years with non-standard bullet weights and lower or higher then normal velocities.
Gallery loads in military bolt actions were never a problem because the rear sights on them had enough elevation adjustment range to sight in anything.
Not true of lever-action factory barrel mounted sights.
Adding a tang or receiver peep sight would be the only option I can think of.
They would have the necessary adjustment range to make up for lack of recoil shooting light & slow bullets low.
rc
RC said:
"A front sight on a magnum handgun is too high for the sights to be level with the bore axis for the same reason"
To expand on this, turn an unloaded revolver over and set on it's sights.
Notice, with the gun upside down setting on the front and rear sight, the barrel bore is pointing up and not parallel to the sights.
So...in the shooting position,with the sights level and on target, if the bullet left the barrel before recoil it would hit the dirt below the target.
It does not, but hits the target, proving that recoil starts at ignition with the gun in upward movement from recoil, when the bullet exits the barrel.
"A front sight on a magnum handgun is too high for the sights to be level with the bore axis for the same reason"
To expand on this, turn an unloaded revolver over and set on it's sights.
Notice, with the gun upside down setting on the front and rear sight, the barrel bore is pointing up and not parallel to the sights.
So...in the shooting position,with the sights level and on target, if the bullet left the barrel before recoil it would hit the dirt below the target.
It does not, but hits the target, proving that recoil starts at ignition with the gun in upward movement from recoil, when the bullet exits the barrel.
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Carl N. Brown
Member
One reason a bull barrel target rifle is so consistent is the mass dampens the effect of recoil before the bullet leaves the barrel.
Effect of recoil does exist and is especially evident with lightweight sporters in deer calibers. I can sight my son's 336C and he still has to fine tune the adjustments for his stance and hold.
Effect of recoil does exist and is especially evident with lightweight sporters in deer calibers. I can sight my son's 336C and he still has to fine tune the adjustments for his stance and hold.
rcmodel
Member in memoriam
Then he wouldn't have enough sight adjustment to get full power loads down low enough.
rc
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