Chronograph Report: S&W M&P 40C

[Sparks_1911]

At the range today with a new Shooting Chrony Gamma model, which had some sunscreen issues but still gave some good numbers (I think) before I gave up to do some mods this afternoon (will probably try again tomorrow). Pistol is bone stock S&W M&P 40C (.40 cal, 3.5" bbl), distance from muzzle to chronograph approx 5 yds, 3 rounds fired per string:

M&P 40C
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Hornady 180 gr TAP FPD (#91368) 745/765/677 FPS (yes, that last reading looks odd)

Golden Saber 180 gr JHP (#GS40SWB) xxx/982/983 FPS

Federal 165 gr Tactical Bonded THP (#LE40T3) 958/981 (chrony sunscreen blew off)/xxx FPS
________________________________________________
# in parenthesis is stock/model number of ammo.

xxx = wildly erroneous reading.​

Will update when I get additional info.

 

[Sparks_1911]

Will update when I get additional info.

Chrono appears to have problems, all readings in the 1200 FPS range this morning despite trying all the tricks I know of (sunscreens on/off, tilting towards sun, moving closer, moving farther away, etc), will have to send it off to mfr to be checked out. Sigh.

Again, will update at some point in the future, but probably a month or more. Given the inability to replicate the numbers listed in the previous post, the prudent thing to do would be take them with a grain of salt.

 

[Runningman]

Are you shooting from a rest at a target? For pistols 10 away feet usually works fine. Use a measuring tape to be consistent. Your shooting thru a narrow window of opportunity. Avoid being in the shadows of trees if you are not doing so. On overcast days don't use the diffuser. The diffuser are best on sunny days only.

Your results with Hornady does not surprise me. I have had more than a few different loads from Hornady that checked really low from advertised velocity over the years.

 

[Sparks_1911]

Are you shooting from a rest at a target?

No on the rest. Yesterday I was shooting at a target, today I was just shooting about 6" above the detectors.

I had one of these Shooting Chrony's years ago when I was reloading .38 Super for IPSC Open Class, so I'm thinking the problem is hardware related. However, after scratching my head after this morning, I'm going to try again in the A.M. with some sunscreen mods to shade the device somewhat (the early morning sun today was rather brutal).

I'll bring a rest with me next time, but every shot this morning was a couple hundred FPS high compared to yesterday. Something's up.

On the figures from yesterday, they seem reasonable compared to data supplied by the ammo mfrs:

Hornady TAP FPD 180 gr. 950 FPS (4" bbl)

Golden Saber 180 gr. 1015 FPS (4" bbl)

Federal Tactical Bonded 165 gr 1050 FPS (4" bbl)​

Today I was getting 12xx FPS from all the above, 3 ft to 10 ft.... and this is not even the pistol I was intending to test, it's just a baseline for another project :banghead: