9 mm 147 gr duty load testing

[eb07]

Doc,

Thank you again for all of your work and research.

[snakyjake]

We have always recommended picking loads that tend to penetrate around 15" or so. The 147 gr HST penetrates about 15.5" in the 4LD test--the test that most closely replicates an unobstructed defensive shooting result. Hmmm, based on that it appears that the HST offers nearly ideal terminal performance for urban and suburban defensive use...

Yes, in your test. But NOT Federal's own test in bare gelatin (12.0") or heavy clothing (12.5").

Federal retained weight is 147.0 gr.
Federal bullet is spec.

Your retained weight is 148.4 gr.
Your bullets (assuming 5 bullets) aren't to spec.

Variations...
I haven't seen another test yet where other bullets/tests have shown weight gain. The only variation I've seen is your test. But I haven't seen all the tests, so there might be someone else's out there. I'd like someone to show me a recovered bullet weight gain that has been used for their FBI test results.

Could we see the results of each bullet, instead of the average? That would give us the range (worst-best).

A big deal?
I put a lot more trust on the test with bullets to spec, because that is what is most likely to occur.
And that means HST barely passes; there is a higher chance that it won't perform like your test.

[JBP55]

You may as well do your own test snakyjake because nothing else is going to please you.

[Chuck Haggard]

Yes, in your test. But NOT Federal's own test in bare gelatin (12.0") or heavy clothing (12.5").

Federal retained weight is 147.0 gr.
Federal bullet is spec.

Your retained weight is 148.4 gr.
Your bullets (assuming 5 bullets) aren't to spec.

Variations...
I haven't seen another test yet where other bullets/tests have shown weight gain. The only variation I've seen is your test. But I haven't seen all the tests, so there might be someone else's out there. I'd like someone to show me a recovered bullet weight gain that has been used for their FBI test results.

Could we see the results of each bullet, instead of the average? That would give us the range (worst-best).

A big deal?
I put a lot more trust on the test with bullets to spec, because that is what is most likely to occur.
And that means HST barely passes; there is a higher chance that it won't perform like your test.

My observation of both testing AND real world shootings with this load lead me to believe it's one of the better service pistol loads available.

[DocGKR]

snakyjake,

I have already explained how recovered bullets can gain minute amounts of weight when performing gel testing--did you not pay attention?

I have also discussed why we don't really pay much attention to manufacturer/vendor test results--did you ignore that as well?

I am sorry that you have not seen recovered projectiles gain a small bit of weight; let me think about where I seen recovered bullets gain a grain or two of weight....oh yeah, at LAIR, JSWB-IPT, FBI BRF, CHP, LAPD, SJPD, SCPD, SCSO to name a few places.

My background and experience is pretty well known, heck DOD even put my Bio up on the internet a few years ago when they posted one of the few open source, non-restricted briefings I have given: http://www.dtic.mil/ndia/2008Intl/Roberts.pdf

Why don't you enlighten us about the training you have in this field, because a lot of your comments are causing me to guess you have not done a lot of ballistic testing yourself...

[Jeep]

I have fired the same load, the 124gr +P Gold Dot, just as one example, from the very same gun, running different lots of ammo over the crono. Velocity from 1225 to 1285 was in the ballpark. Running the exact same lot of ammo through two different guns can easily give this amount of variance as well.

Chuck: Might that spread be in whole or part simply measuring error of the chrono? Taking the mean of 1255 fps, the other numbers are +/- 2.4%. I don't know accurate chronographs are, but 2.4% one way or the other doesn't strike me as a huge variation.

[Kyle Reese]

snakyjake,

I have already explained how recovered bullets can gain minute amounts of weight when performing gel testing--did you not pay attention?

I have also discussed why we don't really pay much attention to manufacturer/vendor test results--did you ignore that as well?

I am sorry that you have not seen recovered projectiles gain a small bit of weight; let me think about where I seen recovered bullets gain a grain or two of weight....oh yeah, at LAIR, JSWB-IPT, FBI BRF, CHP, LAPD, SJPD, SCPD, SCSO to name a few places.

My background and experience is pretty well known, heck DOD even put my Bio up on the internet a few years ago when they posted one of the few open source, non-restricted briefings I have given: http://www.dtic.mil/ndia/2008Intl/Roberts.pdf

Why don't you enlighten us about the training you have in this field, because a lot of your comments are causing me to guess you have not done a lot of ballistic testing yourself...

I'm guessing we'll be waiting a long time, Doc.


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[Chuck Haggard]

Chuck: Might that spread be in whole or part simply measuring error of the chrono? Taking the mean of 1255 fps, the other numbers are +/- 2.4%. I don't know accurate chronographs are, but 2.4% one way or the other doesn't strike me as a huge variation.

Sometimes it might be, which adds another bit of variable to what we are looking at, but I rather think not really. If my lot-to-lot average on ten shots, from the same gun, from the same crono, is different, under similar conditions, then I think it's the ammo.

[Tamara]

Chuck: Might that spread be in whole or part simply measuring error of the chrono? Taking the mean of 1255 fps, the other numbers are +/- 2.4%. I don't know accurate chronographs are, but 2.4% one way or the other doesn't strike me as a huge variation.

Have you ever chronographed any ammunition? (Not meant to be snarky, just honestly curious.)

[Hauptmann]

Chuck: Might that spread be in whole or part simply measuring error of the chrono? Taking the mean of 1255 fps, the other numbers are +/- 2.4%. I don't know accurate chronographs are, but 2.4% one way or the other doesn't strike me as a huge variation.

The chronographs that I have used are VERY accurate. When I reload to very precise tolerances and use quality components for match ammo, I will have multiple duplicate velocities from 5 shot groupings. Why not 10 shot?.....because the barrel gets hotter and the properties of the ballistics change. Also, I have run the same ammo load through multiple guns of the same make/model and the velocities are again highly consistent.

In my experience, except for high end match ammo, factory handgun ammo is very inconsistent. Some are better than others. As a reloader, and a guy with borderline OCD, those factory inconsistencies bug me.