9mm HP-38 test results, not what I was expecting

[Shadow9mm]

Ran 2 test loads today both with HP-38. Granted it was a 1 round test, but I was mostly just looking for pressure signs and making sure it cycled. this is the end of a work up so the loads are near or over max, depending on your manual. Follow your manuals.

4in barrel G19

124g XTP
4.4(hodgins max) 1041fps (hodgins says 1037 so not bad)
4.6 1018fps
4.8 (lee max) 1083 (Lee says 1088 so not bad)

115g hornady FMJ
4.7 1042 (Hornady max)
4.9 1110
5.1 (hodgins, and lee max) 1190 (stated 1135-1167, so very good)

Also fired 1 factory ammo for primer and velocity comparison
124g Fed HST 1193


I noticed a LOT of what I would consider primer cratering for all the tests, including the factory ammo. Is this common in the gen 5 glocks? only ones that looked good were the starting loads with 115. Granted it was a sample of 1 round each, but There seemed to be no significant gain from going to 4.4 to 4.8 with the 124g, so I will probably cap it at 4.4.


all columns top to bottom are low to high 124 on left, 115 on right, silver is HST

[pete2]

Be careful, the first pressure signs may be a kaboom. Stay within published loads and you should be okay. All Glocks cause the cratering signs. Gen 5 is different from previous guns.

[Shadow9mm]

Originally Posted by pete2

Be careful, the first pressure signs may be a kaboom. Stay within published loads and you should be okay. All Glocks cause the cratering signs. Gen 5 is different from previous guns.

I'm clear. All the loads I tested were within a published load, however for the XPT, while it was within lee max, at 4.8, it was 0.4 over max for Hodgins at 4.4, and hornady did not have data for HP-38 at 124g.

I generally test from starting load up to max to make sure everything runs ok and no pressure signs. Then I know my max is safe, as well as the minimum to run the gun well.

[Unclenick]

Look at the breech face of the slide to see if the primer "crater" walls aren't simply filling a recess there. Note also that your gun's slide and barrel are starting to unlock before the firing pin has fully retracted, resulting in the smearing of the indentation shape. A lot of Glocks seem to do that.

[rc]

HP38 is a good powder for standard 9 ammo. You are not going to get the top velocity but consistency should be good.

You also need to realize that velocity must be measured as an average. I'm not surprised that with single rounds the amount of powder didn't correlate to the speed. That happens a lot even when you are throwing the same charge over and over. If the charges are close, you are going to get ups and downs where one is faster than the other for individual shots. Even if you measure weight of powder each time there will be velocity variation up and down.

[Average Joe]

I pick up a lot of once fired factory range brass, I have seen a lot of primer hits like yours, I only worry about my primers flattening, yours are ok.

[markr6754]

Originally Posted by Shadow9mm

I noticed a LOT of what I would consider primer cratering for all the tests, including the factory ammo.

I remember posting pics of my cases after my very first reloads, which were too light to cycle my pistol. I received many comments on the "obvious pressure signs" on 100% of my cases, including comparison factory rounds.

One fellow said I'm either loading far too hot, despite my cycling issues, OR I was shooting a Beretta 92FS...bingo. The firing pin hole on Beretta pistols, including my PX4 Storm, is recessed, leaving a perfect primer crater every time.

No I only look for primer flattening no matter what I'm shooting.

My first powder was HP-38, and still a favorite.

[IMtheNRA]

My Beretta 92 guns leave the same marks, except without the firing pin swipe that I saw on one of your primers.

[brasscollector]

Hodgdons also claims the 4.4gr load under a 124gr made 32,000psi. I would definitely tread carefully beyond that point myself.

[Shadow9mm]

Originally Posted by brasscollector

Hodgdons also claims the 4.4gr load under a 124gr made 32,000psi. I would definitely tread carefully beyond that point myself.

always! I like my gun and hands the way they are! I only loaded 1 round to check pressures. It did launch the casing pretty far, recoil seemed normal. There seemed to be a little bit of excessive primer flow compared to the others but no flattening. One of the reasons I felt ok pushing was my OAL was a little longer than the book. This could be why I didn't get where I was trying to go, but I felt with the extra space in the case I had a little cushion to push to the lee manual max.

In short, with no real increase going from 4.4 to 4.8, I am going to stick to 4.4 as the max, no sense in pushing if there is no meaningful gain.