Raising POI

[ConfederateHoosier]

Ok so quick question for you guys, I recently started reloading for 9mm, but I have been loading .38 and .357 for about 2 years (not quite a newbie but have plenty to learn!). Anyway my question: is it possible to raise a bullets POI by using a slower/faster powder? I ask because ANY 115gr factory ammo ive shot shoots low at 10 yards, even lower at longer distance. But Ive shot 2 boxes of WWB 147 gr HP's and they were right on at 25 yards and a bit high at 10. Well I just bought some berrys 124 gr assuming these would kinda meet in the middle (althought locally I couldnt find any 124 gr factory to test) Well went to the range and both loads I made shoot just as low as the 115 gr stuff. I was using 2 diff loads of 3.7 gr of 700x and 5.2 gr of unique with an OAL of 1.130 for both.

Basically what can I do short of buying new bullets or adjusting my sights, to get this to hit POA, even if at only 15 yards or so. Do I need to go slower or faster? Any help is apprciated!

 

[Tilos]

Contrary to what some here had predicted, I used a faster powder to LOWER the POI for a 9mm gun with fixed sights.

I suggest a lighter load of Unique(5.2 is light), or you could look at a burn rate chart and pick something slower than Unique.

I believe you need more "barrel time" before the bullet exits the barrel...a heavier bullet would give you that too.

Another variable is bullet type with lead/plated/jacketed all having different amounts of chamber pressure and friction rates with the barrel.

Sorry I don't have a quick answer and someone else may, only change one thing at a time and you will get there.
YMMV

 

[W.E.G.]

higher velocities usually make handguns shoot lower

 

[twofifty]

I think Tilos is on the right track wrt "barrel time" changing POI.

I have been told by competitive practical shooters that the 147s' lower velocity and slower barrel transit time causes the bullet to leave the barrel a tiny bit later in the recoil cycle. This raises the POI.

You could experiment with slower powders & 124s, or as you found out switch to 147s.

 

[1SOW]

I would recommend using a chrono to 'tune' your bullet and it's speed.

When I got mine, I was really surprised at how far off my 'guess'-by-feel was from the actual speed.

If you get the speed, 'feel' and group consistency you want you may or may not need sight adjustment for that powder.

 

[rg1]

Nothing more aggravating than having a pistol with sights that are not properly calibrated from the factory. I recently bought one that like yours shot so low with all loads that you had to block out the target with the front sight blade by holding several inches high to hit the target. Don't think you'll have much success, maybe a little improvement, with trying to use faster or slower powders. Some difference in raising impact points by using a heavier, slower bullet but to correct the low impacts you'll probably have to change the sights. Most manufacturers have sights of various heights or aftermarket sights which will correct the shooting low problem. That's what I did with my low shooting pistol and now I'm satisfied. Still aggravated at the company though because there was no way the sights that came on the pistol were right with any weight bullet, reload, or factory load. Plus, I used the proper sight alignment and sight picture. If anything a factory sight should shoot slightly higher than point of aim at least for my preference.

 

[ConfederateHoosier]

So slower powders/velocity generally equal higher POI versus faster powders/velocity? I'm going to try and work up some new loads, but I was already using the minimum charge for both powders, so I really dont know if i should back off either of them by too much. I also have a pound of titegroup and a couple lbs of SR4756. I know titegroup is praised in 9mm, but dont know about SR. But basically if I wanna raise it up to shoot POA I need to slow it down?

 

[orrwdd]

I don't think that Titegroup will help you raise the POI. It is a fast, Hot powder. I suggest that you try the starting load of Accurate #7. It is a slower powder.

Bill

 

[twofifty]

Yeah, slow it down by lowering the velocity (within min. safe load parameters) which increases barrel time. Remember also that heavier bullets are designed to be shot at slower speeds, which also increases barrel time.

Like 1SOW suggests, run your various loads over a chronograph and take notes as you go (velocity, accuracy, ease of return to point of aim).

You will eventually find a velocity/powder/bullet weight combo that effortlessly and consistently puts POI on your POA. Without a chrono, you will be guessing and have no sense of which way to go.

Note: loads below min. are not safe either as they can lead to detonation.

 

[Steve C]

To see where a pistol really is shooting to vrs point of aim you need to eliminate as much as possible the human factory which is why the Ransom rest was invented. Sit at a bench and do what you can to immobilize your hands and lock down your sight picture. Concentrate on pressing the trigger directly to the rear along the axis of the barrel. Move the target back to 25 yds and do the same thing. This should show you where the gun is really shoots without much influence by the shooter pulling down, lifting their head and other things that make the rounds shoot low.

Changes in ammunition velocity and load in the 9mm usually make little difference in POI on the target, less at closer range. How the shooter responds to the difference in ammo can make a lot of difference in where it shoots. I've run 9mm ammo from 100gr to 147gr, mild target reloads to +P+ police loads and they all hit in the black at 25 yds if I do my job.

 

[243winxb]

At 10 yards, nothing is going to make a great difference. The sights need adjustment. But as said, this is always worth a try >

you need more "barrel time" before the bullet exits the barrel...a heavier bullet would give you that too.

 

[Walkalong]

More barrel time will bring POI up. Less velocity or slower powders can do that.

More recoil for the same velocity can be had with slower powders. That will bring POI up.

 

[ConfederateHoosier]

Ok so slower powders will bring lower velocity, which brings higher POI. I am thinking about using some loads from my manual designed for 147gr bullets and see how those work. I'm hoping I can fix the problem without changing the front sight (have a 24/7 pro ds and aftermarket sights are hard to find) but if I went that route would I need a taller or shorter sight? If I can't get the 124's to improve ill switch to the 147's and try those before I change my sights.

 

[Walkalong]

Slower powders in and of themselves do not bring lower velocity. The charge weight will determine the velocity. It will take more of a slower powder for the same velocity. That will give a bit more recoil as well as increase barrel dwell time a hair. Both of which raise POI a bit.

 

[Walkalong]

My EMP shot low when new. Springfield replaced the front sight with a taller one for free. If load changes can not cure it, that may be the answer.

 

[243winxb]

Make the handguns front sight shorter/lower, this will make the bullet impact (POI) higher on target.

 

[Walkalong]

That's what I get for going from memory.

Anyway, they replaced the front sight. Problem solved.

 

[twofifty]

Load Options

CH - looking at recipes from Hodgdon, I noticed that both with IMR 700-X and Hodgdon SR-4756 you can develop a load with slower velocities for the 147gr bullets.

For example:

125gr Sierra FMJ: 700-x, velocity spread of 845fps to 1,007fps.
147gr Hdy. XTP: 700-X, spread of 764fps to 836fps = much more barrel time.
147gr Hdy. XTP: SR-4756, spread of 668fps to 834fps = even more brl. time.

 

[1SOW]

It's just 'my' opinion, but I would not tailor my loads based on making the sights work. Won't that leave you 'stuck' with one bullet at one speed? Build the load "you" want or need and fix the sights.

As SteveC said, try shooting from a solid rest. If you are still shooting consistently low at 10 yds, then you neeed a shorter front sight or adjustable rear. If the front is a blade sight, you can file/sand the top down and bring the POI up.