M&P CORE Ported Performance Center - terrible accuracy SOLVED page 2

misterzr

misterzr

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First off let me say I have owned several M&P 9mm and have shot thousands of rounds through them so pretty sure it is not me. I bought a new CORE ported when they came out for 3 gun and have a Vortex Venom sight on it. I am shooting reloads with 4.0 grains of Titegroup with Campro 124gun bullets. I have also installed an Apex flat faced forward set set sear trigger. Shot the gun from a rest to try and sight it in with the red dot, and it is shooting 5-6 inch groups at 15 yards. My last CORE was way more accurate than that and I wish I would have kept it.

Any ideas?
 
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My PC M&P 9L shots just fine. Offhand @ 25 yards I can keep them in the black on a B8 target which I believe is 4''? Off the bench it shoots under 2'' no problem. I'm also using a Vortex Venom.

I assume with 4grs of Titegroup your OAL is down around 1.000" - 1.100''?
 
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misterzr said:
My OAL is 1.120 as per Campro load data
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My advice would be to switch powders. Load hotter and take the length out longer. Reason I say switch powder is I personally don't like loading Titegroup hot. If you do, go up to 4.3grs @ 1.160'' and see if the groups shrink. You may also be surprised at the length of the M&P chamber/throat. Drop a bullet into the barrel then drop in a fired case. Tap the case down until it stops. Mine measured around 1.190'' so I set mine @ 1.160''.
 
Jefro said:
My advice would be to switch powders. Load hotter and take the length out longer. Reason I say switch powder is I personally don't like loading Titegroup hot. If you do, go up to 4.3grs @ 1.160'' and see if the groups shrink. You may also be surprised at the length of the M&P chamber/throat. Drop a bullet into the barrel then drop in a fired case. Tap the case down until it stops. Mine measured around 1.190'' so I set mine @ 1.160''.
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Wow! Great idea! I will do this to all my pistols and note the OAL in the logbook.
 
misterzr said:
First off let me say I have owned several M&P 9mm and have shot thousands of rounds through them so pretty sure it is not me. I bought a new CORE ported when they came out for 3 gun and have a Vortex Venom sight on it. I am shooting reloads with 4.0 grains of Titegroup with Campro 124gun bullets. I have also installed an Apex flat faced forward set set sear trigger. Shot the gun from a rest to try and sight it in with the red dot, and it is shooting 5-6 inch groups at 15 yards. My last CORE was way more accurate than that and I wish I would have kept it.

Any ideas?
Click to expand...

I recently switched powders from Titegroup to Ramshot Competition. I wanted a new load for 4 pistols, which included a Glock and a M&P. As per my standard procedure, I loaded a "survey" of loads, from very mild to fairly hot (3.0 to 3.0 gr) and tried 3 different bullets. (This was in 40 S&W, but the procedure would be the same in any calibre.)

I found a good load for all 3 bullets.

Test loads were in 0.3 gr increments. Once again, I found a huge difference in groups with loads only 0.3 gr apart. The point I am making is that when you say you tried 4.0 gr and it shot dinner plate groups, all you are saying is that you found a poor load. Look at my chart. I found poor loads too. And note that in some cases just 0.3 gr more or less powder made a huge difference.

IMG_1780.jpg


I load Titegroup for about 20 different 9mm pistols, including M&Ps. Each of them has at least one load that works well. They all have loads with Titegroup that are poor.

One pistol only works with 3.1 gr. Two require 3.9. And most are best around 3.5gr. Based on that, I suggest you load a survey of 4.0, 3.7, 3.4 and 3,1. 10 of each should tell you if it is a load issue or a pistol issue. Titegroup is a good powder to use for a 9mm.
 
Ganderite said:
I suggest you load a survey of 4.0, 3.7, 3.4 and 3,1.
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From my own experience with a PC Ported M&P. I started @ 4.1 of Titegroup and had constant FTE. I had to shorten them up to 1.090'' and still had about 20% FTE. So I doubt 3.7 or under will cycle due to the ports bleeding off so much velocity/pressure. More so if he takes the length out.
 
I have tried 3.7 as that is what my other M&P non-ported Pro likes, it did not cycle well with the porting as Jefro pointed out, FTE at least half. Shooting an STI 9mm major in IPSC, I have learned that it takes considerably more to make the comp to work properly. As a test tonight I am going to try some factory ammo (yuck) to see if that is any different. Might help point towards either the gun being crap or my load just isn't right for it. The load that I am trying to shoot out of the ported CORE, shoots very accurately out of my non-ported Pro. Also going to try without the optic, the Vortex Venom has never gave me any trouble on the last gun, but who knows if it isn't the problem.
 
For a ported pistol, I suggest switching powder to a slower one, like Power Pistol or 3N37. That will give you more velocity and more muzzle pressure.

Is it possible to run a lighter recoil spring in a M&P? I have not seem them promoted.
 
Ganderite said:
For a ported pistol, I suggest switching powder to a slower one, like Power Pistol or 3N37. That will give you more velocity and more muzzle pressure.

Is it possible to run a lighter recoil spring in a M&P? I have not seem them promoted.
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Even work your way to the slower side... W231/HP38 - Unique - HS6 etc depending on what you have. I went from Titegroup to W231 and am quite pleased.

ISMI does the flat recoil springs for the M&P in 11, 13, 15, 17 & 20. Stock is 16lbs.
 
Jefro said:
My advice would be to switch powders. Load hotter and take the length out longer. Reason I say switch powder is I personally don't like loading Titegroup hot. If you do, go up to 4.3grs @ 1.160'' and see if the groups shrink. You may also be surprised at the length of the M&P chamber/throat. Drop a bullet into the barrel then drop in a fired case. Tap the case down until it stops. Mine measured around 1.190'' so I set mine @ 1.160''.
Click to expand...

What a great tip. I did this for my Glock and M&P (40 S&W).

It looks like the throat is not a factor in picking an OAL. Just a function of what fits the mag and how it feeds.

I will load 20 thou longer than in the past.

DSCN0148.jpg
 
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So here is what I know after testing last night. Bought a box of Winchester 124 target. Both the new CORE and my old PRO shot these with good accuracy. Then tried my reloads, the PRO shot fine with these but the CORE didn't. The reload shots in the CORE were also high for the most part leading me to believe the compensated barrel wasn't working right. Also the reloads in the CORE were ejecting the shells beside me on the bench where the factory loads were slinging them 5 feet away. Pulled a couple bullets on my loads and the charge was a bit shy at 3.9, at 1.120 OAL. Also noticed the factory Winchesters were at 1.160 length, quite a bit longer.

Conclusions - I think I am likely too light a charge for the CORE ported, even though it works fine elsewhere. I don't think there is anything wrong with the gun, even swapped the non ported barrel from my PRO to it and didn't change accuracy. Also likely need to add some length to the reloads. Will load some variations and give it a try
 
misterzr said:
So here is what I know after testing last night. Bought a box of Winchester 124 target. Both the new CORE and my old PRO shot these with good accuracy. Then tried my reloads, the PRO shot fine with these but the CORE didn't. The reload shots in the CORE were also high for the most part leading me to believe the compensated barrel wasn't working right. Also the reloads in the CORE were ejecting the shells beside me on the bench where the factory loads were slinging them 5 feet away. Pulled a couple bullets on my loads and the charge was a bit shy at 3.9, at 1.120 OAL. Also noticed the factory Winchesters were at 1.160 length, quite a bit longer.

Conclusions - I think I am likely too light a charge for the CORE ported, even though it works fine elsewhere. I don't think there is anything wrong with the gun, even swapped the non ported barrel from my PRO to it and didn't change accuracy. Also likely need to add some length to the reloads. Will load some variations and give it a try
Click to expand...

If it was me, given what you just reported, I would try longer and hotter. Longer is not the cause or solution, but hotter is. A chronograph would be a big help.

Do you have a slower powder, like 231 or Power Pistol? better suited to hotter loads.
 
misterzr said:
Conclusions - I think I am likely too light a charge for the CORE ported, even though it works fine elsewhere.
Click to expand...

I found the light loads that gave me FTE issues caused a snappier muzzle flip since the ports weren't working proper. Once I went hotter and hotter with the reload the snappy rise went away and recoil kicked straight back instead.
 
I agree on the hotter, even the Campro load data shows 4.1 to 4.4 Titegroup which I am still below the min. I also have HS6 that I use for my Major rounds in the Grandmaster but I would really like to try to get the Titegroup working as I have lots of it around.
 
It might be the plated bullets stripping.
Are there grey swirls around the holes in the target or tearing around the bullet holes?
 
I think you are right on. you can also try hs-6 which is much slower, but great for 9mm. try 6gr. good for all my 9mm pistols

misterzr said:
So here is what I know after testing last night. Bought a box of Winchester 124 target. Both the new CORE and my old PRO shot these with good accuracy. Then tried my reloads, the PRO shot fine with these but the CORE didn't. The reload shots in the CORE were also high for the most part leading me to believe the compensated barrel wasn't working right. Also the reloads in the CORE were ejecting the shells beside me on the bench where the factory loads were slinging them 5 feet away. Pulled a couple bullets on my loads and the charge was a bit shy at 3.9, at 1.120 OAL. Also noticed the factory Winchesters were at 1.160 length, quite a bit longer.

Conclusions - I think I am likely too light a charge for the CORE ported, even though it works fine elsewhere. I don't think there is anything wrong with the gun, even swapped the non ported barrel from my PRO to it and didn't change accuracy. Also likely need to add some length to the reloads. Will load some variations and give it a try
Click to expand...
 
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