Shooting different ammo back to back

[kibs45]

Had an interesting experience today so I figured I'd run by the people here and see what all y'all had to say. I went to break in a gun ( S&W Shield Performance Center) today so I took a lot of cheap ammo and some defense ammo to verify it would work after running the cheap stuff.

Ran 200 rounds of Tulammo 115 FMJ 9mm and the gun consistently shot low. About 3.5 inches at 10 yards. Move up to five yards and it was about 2 inches low. I figured it was me and my trigger finger but everything was grouping well. So I didn't think too much of it. Perfect practice makes perfect and all.

Switched over to HPR 124 JHP (think it's a Hornady bullet). All of a sudden it was hitting POA, spot on. So either I accidentally fixed the issue for those last 25 rounds or there is a significant enough difference between the ammo to cause a fairly large difference in POI.

So I looked into it a little bit, and was surprised to find that the Tulammo is supposed to be hotter than the self defense stuff. To the tune of 100fps or so. I sure would've guessed it went the other way. The HPR felt much more stout.

Most of all I was just curious to see what everyone else has run into like this. Anyone else end up surprised about things that shouldn't be? By the way, I really like the shield. It generally feels like a much bigger gun than it is.

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[EPS]

I don't know what to say to that I would think like you did bullet weight could be a factor but you said the 115 was hotter that the 124 I know this I target shoot my glock 22 .40 cal with Winchester ammo and I see a big difference between 165 grain and 180 but I am no expert on this stuff

 

[EPS]

OK I thought about it it's got to be the bullet weight lol

 

[kibs45]

I would guess it would be. I'm just so surprised by such a drastic difference.

 

[EPS]

Like I'm no expert but I see big difference in my shooting I shoot better with the 165 and I shoot low with the 180 mmmmmm and like you I tried different yards also from 5 yards out 15 even did some 25 yard stuff

 

[No_Regerts]

Did you notice a difference in ejection?

 

[Certaindeaf]

That's not really that "drastic" of a difference.. at least to me.
The faster, lighter bullet is out of the gun quicker.. it's out of the barrel before the muzzle rises much.. and the converse is true.
It seems your sights are regulated for the 125gr standard velocity stuff.

 

[kibs45]

Did you notice a difference in ejection?

No, not really. Everything was pretty much 3-4 o'clock and consistent distance.

That's not really that "drastic" of a difference.. at least to me.
The faster, lighter bullet is out of the gun quicker.. it's out of the barrel before the muzzle rises much.. and the converse is true.
It seems your sights are regulated for the 125gr standard velocity stuff.

I hadn't considered that it would be more dialed in for a given weight/speed but that would make sense. Guess I'll have to buy some 124 grain FMJ for the next trip and see what happens. In hindsight it maybe isn't "drastic" in a self defense situation where you're aiming center mass, but it seemed really low for such a short distance.

 

[kibs45]

Thanks for all the feedback. It's interesting stuff to think about for sure.

 

[EPS]

Did you notice a difference in ejection?

No but that could be the cheap stuff so far the only target ammo I used is Winchester BLASER and Federal I have shot federal Hydra shock hollow point and Honadey critical defense they all work good it's the heavy stuff that I don't shoot well it could be me too and I just took a dermal to my trigger guard to get rid of the glock nuckle lol that helped

 

[No_Regerts]

I just wondered because I've seen Tula that was really underpowered and ejection is very weak.

 

[EPS]

The only Tula I got is for my AK and I have not gotten a chance to shoot it yet this summer I will I just been goofing around the indoor range this winter

 

[jordanka16]

It does make a difference, my .357 is sighted in for heavy SWC loads, when I shoot .38s in it I have to adjust my poa quite a bit.

 

[Flymph]

I'll test it this week, I'll post a target at 20yards and shoot Blazer Brass 115, and 124... by the end of this I can hopefully blame the Blazer Aluminum for the failures and misses on the first few shots with my MK25...

 

[Alexx1401]

Had an interesting experience today so I figured I'd run by the people here and see what all y'all had to say. I went to break in a gun ( S&W Shield Performance Center) today so I took a lot of cheap ammo and some defense ammo to verify it would work after running the cheap stuff.

Ran 200 rounds of Tulammo 115 FMJ 9mm and the gun consistently shot low. About 3.5 inches at 10 yards. Move up to five yards and it was about 2 inches low. I figured it was me and my trigger finger but everything was grouping well. So I didn't think too much of it. Perfect practice makes perfect and all.

Switched over to HPR 124 JHP (think it's a Hornady bullet). All of a sudden it was hitting POA, spot on. So either I accidentally fixed the issue for those last 25 rounds or there is a significant enough difference between the ammo to cause a fairly large difference in POI.

So I looked into it a little bit, and was surprised to find that the Tulammo is supposed to be hotter than the self defense stuff. To the tune of 100fps or so. I sure would've guessed it went the other way. The HPR felt much more stout.

Most of all I was just curious to see what everyone else has run into like this. Anyone else end up surprised about things that shouldn't be? By the way, I really like the shield. It generally feels like a much bigger gun than it is.

Any time I have run into this the first thing I do is use a good solid rest. At the kind of range I am shooing most hand guns it's me not the ammo. So once I see that it's easy to start getting consistent results.

 

[kibs45]

I would always assume it's me before blaming the firearm. That's why I thought I needed to work on my trigger control. It was interesting though as there was definitely an ammo component to it.

For what it's worth I searched in some of the S&W forums and it seems to be somewhat of a known issue. Apparently some guys have even been told by customer service that the sights are geared around 124 grain loads.

I'll test it this week, I'll post a target at 20yards and shoot Blazer Brass 115, and 124... by the end of this I can hopefully blame the Blazer Aluminum for the failures and misses on the first few shots with my MK25...

That would be cool. I'd love to hear what you and other people find.

 

[Alexx1401]

I would always assume it's me before blaming the firearm. That's why I thought I needed to work on my trigger control. It was interesting though as there was definitely an ammo component to it.

For what it's worth I searched in some of the S&W forums and it seems to be somewhat of a known issue. Apparently some guys have even been told by customer service that the sights are geared around 124 grain loads.



That would be cool. I'd love to hear what you and other people find.

There is of course going to be "some difference" with different weights and even different makers. Just very doubtful it could be a couple inches. I made a real simple rest from an old collapsible camera tripod long ago. It's small and can be tossed in the range bag. Then quickly set up on the bench if I need to see if it's me or a gun. If nothing else you can even just set a range bag up on the bench to rest your forearms on. See if all of a sudden the pistol is hitting where it's pointed. Sadly when I'm having a bad day it's always me not the gun or ammo any more.

 

[Rocklock]

Think you'll find most pistol sights are set up from the factory to be "on" with the heaviest standard bullet weight since lighter ammo tends to hit lower. The end user can always take metal off the front sight to get the lighter stuff "on" but it's kind of tough to do it the other way around.

 

[thorborg]

I would always assume it's me before blaming the firearm. That's why I thought I needed to work on my trigger control. .

A laser, Blue gun or insert if you have a double strike or revolver, is the best way to work on trigger control. I was surprised at how difficult it was to maintain a dot on the wall throughout the trigger pull cycle. Unlike live fire, you can actually and instantly see your short comings to effect improvement. No range time or ammo waste.
You can also seriously improve your point and shoot.
I started with a six inch squiggle and currently averaging a quarter inch or less (most of the time) @ about fifteen feet which is the farthest I can achieve in my home.
I like the blue gun because you can pick it up anytime your bored and practice (it sits by my easy chair)
While the trigger is not the same as my carry piece, if you can maintain a dot through the snap on a blue gun it will be no issue on any real gun with a reasonable trigger.
There is not a dust collector in the house that hasn't been shot a hundred times in effigy.

 

[ORYGUNHolsterCompany]

That's an easy fix, we all know bullets rise when they are shot so your tula must have been in upside down


Just from experience I have seen many claimed velocities on packaging that have no testing standard listed I.e. barrel length, twist rate, gun type (bolt, revolver, auto) gas/piston, all things that will effect the velocity.