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Discussion Starter #1
My 147gr 9mm loads are shooting high. I've read elsewhere that this happens with heavier bullets. Will increasing the powder charge bring the point of impact down? If not, is there another way to remedy it?
 

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My 147gr 9mm loads are shooting high. I've read elsewhere that this happens with heavier bullets. Will increasing the powder charge bring the point of impact down? If not, is there another way to remedy it?
Nope, the heavy bullets shoot higher because of the recoil impulse. The reverse is true for lighter bullets. You could try reducing powder/vel. it may bring the POI down a bit but short of going to a taller front sight or filing some off the rear sight you are stuck w/ the higher POI.:-(
 

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Point of impact is higher because the slower moving bullet is in the barrel longer. The recoil of the gun has the barrel pointing higher when the bullet leaves the barrel. More velocity will bring the POI down.
 

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Discussion Starter #4
I may try to increase the powder charge, as I'm only running 3.8gr of Unique right now. That's as low as I could get and still be reliable. Don't have a chrono, but it has to be slow.
 

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I would try a faster powder like Tightgroup. That will bring recoil down by making it a bit snappier. Also what spring are you running in the gun? I run a 16 variable in mine for match reloads. Anything heavier will mess with the reloads but too light will cause premature cycling of the gun, causing high POI hits.
 

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Discussion Starter #6
I believe I still have the stock 18# in that gun, I'll have to check my log book.
 

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Discussion Starter #7
I think I'll make up some with 3.9 and 4.0 grains of Unique and see if that pulls it down some. I'll post results.

Thanks everyone for the help.
 

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Point of impact is higher because the slower moving bullet is in the barrel longer. The recoil of the gun has the barrel pointing higher when the bullet leaves the barrel. More velocity will bring the POI down.
Well scooter, at least in large bore handguns, that just doesn't work that way. Barrel time for a short 4" tube is not likely to change POI much, increasing vel. increases muzzle flip, not decreases it. In an 6-8" bbl, w/ certain bullets maybe.
 

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The Speer manual has a minimum of 5.3 or 5.3 gr of Unique for a 124 9mm, I believe. You may want to check the minimum for 147, it can't be that low, can it?

My 124's shot higher than my 115's so I just aimed low! Re-read your reloading material before you go too light of a load and get into trouble. Just my 0.02 grains worth

;)
 

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Well scooter, at least in large bore handguns, that just doesn't work that way. Barrel time for a short 4" tube is not likely to change POI much, increasing vel. increases muzzle flip, not decreases it. In an 6-8" bbl, w/ certain bullets maybe.
I have been shooting competitively and reloading for 20+ years. I have seen what I claimed many times. If you can prove me wrong, please do.
 

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I have been shooting competitively and reloading for 20+ years. I have seen what I claimed many times. If you can prove me wrong, please do.
scooter, I can't "prove" you wrong over the net, just my own exp. from 30+yrs of reloading & shooting.:rolleyes:
 

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Discussion Starter #12
The Speer manual has a minimum of 5.3 or 5.3 gr of Unique for a 124 9mm, I believe. You may want to check the minimum for 147, it can't be that low, can it?

My 124's shot higher than my 115's so I just aimed low! Re-read your reloading material before you go too light of a load and get into trouble. Just my 0.02 grains worth

;)

From Alliant Powder's website:

Bullet: 9mm Hornady 147 gr. XTP
Primer: Winchester Small Primer
Minimum OAL: 1.14
Test Barrel: 4"

Bullseye, 4.2 gr.
Muzzle Velocity (fps) 1,010........Chamber Pressure (psi) 32,900

Red Dot, 3.4 gr.
Muzzle Velocity (fps) 895..........Chamber Pressure (psi) 32,400

American Select, 3.7 gr.
Muzzle Velocity (fps) 890..........Chamber Pressure (psi) 32,700

Green Dot, 3.7 gr.
Muzzle Velocity (fps) 930..........Chamber Pressure (psi) 32,200

Unique, 3.9 gr.
Muzzle Velocity (fps) 912..........Chamber Pressure (psi) 31,885

Power Pistol, 5.7 gr.
Muzzle Velocity (fps) 1,095.......Chamber Pressure (psi) 34,000

Herco, 4.9 gr.
Muzzle Velocity (fps) 1,010.......Chamber Pressure (psi) 30,500

Blue Dot, 6.2 gr.
Muzzle Velocity (fps) 1,050.........Chamber Pressure (psi) 30,200




And my bullets are LRN, so I should load lighter for the lead.
 

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Well this is an interesting problem.

Atmiller I would drop down to a 17lb or 16lb spring in the gun and try a faster powder. I have seen some people have luck with Unique in 9mm but they were using lighter bullets(under 124gr). Slow pistol powders work best with lighter bullets in the small calibers like 32, 380, and 9mm. With heavier bullets these powders are slow to produce velocity at first and that leaves the bullet in the barrel for a longer time period resulting in a higher POI.

I think the 147gr bullet in the XD9tac is just about the best you can get with the stock configuration but if you are not going to load the ammo to factory specs then a lighter spring is needed.

Don't go below a 17lb spring if you are going to continue to use Unique as your powder of choice.

I really feel the Tightgroup/147gr bullet combo is the best for the 9mm platform. So do many other shooters in the competition world.
 

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My 147gr 9mm loads are shooting high. I've read elsewhere that this happens with heavier bullets. Will increasing the powder charge bring the point of impact down? If not, is there another way to remedy it?
AT, I see that you have two 9mm's listed, are you getting the same results with both? Are these results from a bench rest? At what yardage are you noticing this elevation? Have you varied the C.O.L any?
 

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Discussion Starter #15
AT, I see that you have two 9mm's listed, are you getting the same results with both? Are these results from a bench rest? At what yardage are you noticing this elevation? Have you varied the C.O.L any?
These results are from my 5". I'm noticing these as close as 7 yards off hand. OAL has remained at 1.10".

When I run a mag of WWB, the group moves down to point of aim. Group with reloads is tight, but high.
 

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AT, a few more questions; Was that WWB a 147 gr as well? Have you measured one of the bullets (diameter .355 or more) and compare it to a factory round? What brand of bullet are you using? I had a similar problem but I'm not sure about the name brand.

Please keep us informed of what you find. This is making me wish that I would have kept a detailed log book.

I am currently using Montana Gold 147 gr. FMJ, they seem to be a little more to the liking of my barrel. I'm using Universal Clays (H) and it's about the same burn rate as Unique, but I've lowered my "paper load" to 3.2 gr, 1.1" C.O.L. If I don't let the gun get too dirty, she runs just fine. When it starts getting fouled up, it might FTE, her way of talking to me. Then I pamper her a little and ream her and she rewards me over and over.
 

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Discussion Starter #17
Well this is an interesting problem.

Atmiller I would drop down to a 17lb or 16lb spring in the gun and try a faster powder. I have seen some people have luck with Unique in 9mm but they were using lighter bullets(under 124gr). Slow pistol powders work best with lighter bullets in the small calibers like 32, 380, and 9mm. With heavier bullets these powders are slow to produce velocity at first and that leaves the bullet in the barrel for a longer time period resulting in a higher POI.

I think the 147gr bullet in the XD9tac is just about the best you can get with the stock configuration but if you are not going to load the ammo to factory specs then a lighter spring is needed.

Don't go below a 17lb spring if you are going to continue to use Unique as your powder of choice.

I really feel the Tightgroup/147gr bullet combo is the best for the 9mm platform. So do many other shooters in the competition world.
How many grains of Titegroup do you run?
 

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Discussion Starter #18
AT, a few more questions; Was that WWB a 147 gr as well? Have you measured one of the bullets (diameter .355 or more) and compare it to a factory round? What brand of bullet are you using? I had a similar problem but I'm not sure about the name brand.
The WWB was 115 grain.
 

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Discussion Starter #19
I think I'm going to try the two heavier loads of Unique, then switch to Titegroup if that doesn't work. I have a Case Feeder on its way, so I want a good recipe ready to run with it when it arrives.
 
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