IDPA SSP Power Floor

[IDPA Mike]

Going to the IDPA Indoor nationals in Feb. I am shooting 147 gr. fmj with 3.3 gr. of Tite-Group . OAL of 1.110
Velocity 2,550 Power floor of 374,850 . It is twice as much as I can get away with.
Would I be better off taking the velocity down to get less recoil?
Thanks, Mike

 

[WeedWhacker]

9MM at 2,550 FPS ?????

Velocity 2,550 Power floor of 374,850

 

[IDPA Mike]

9MM at 2,550 FPS ?????

my chrono must be messed up,or I'm reading it wrong?
Average of 10 shots = 2558.09.

I'll try later this week. Acording to Hogdon, I should be getting 1000-1100 fps

 

[IDPA Mike]

,

 

[FSTC]

my chrono must be messed up,or I'm reading it wrong?
Average of 10 shots = 2558.09.

I'll try later this week. Acording to Hogdon, I should be getting 1000-1100 fps

Didn't the thought of 2500 fps for a 9mm raise any flags?

According to hodgon:
147 GR. HDY XTP Hodgdon Titegroup .355" 1.100" 3.2 855 22,500 CUP 3.6 929 27,500 CUP
The minimum load would meet the power factor of 125k.

 

[IDPA Mike]

Didn't the thought of 2500 fps for a 9mm raise any flags?

According to hodgon:
147 GR. HDY XTP Hodgdon Titegroup .355" 1.100" 3.2 855 22,500 CUP 3.6 929 27,500 CUP
The minimum load would meet the power factor of 125k.

That data is for a 4" barrel. My G 34 has a 5 1/4" barrel. May make a slight difference. I will recheck my data later this week.
Thanks, Mike

 

[jasons]

Going to the IDPA Indoor nationals in Feb. I am shooting 147 gr. fmj with 3.3 gr. of Tite-Group . OAL of 1.110
Velocity 2,550 Power floor of 374,850 . It is twice as much as I can get away with.
Would I be better off taking the velocity down to get less recoil?
Thanks, Mike

[STRIKE=3.3 of Titegroup under a 147 and you'd be lucky to see 750 fps.]3.3 of Titegroup under a 147 and you'd be lucky to see 750 fps.[/STRIKE] I had to go to [STRIKE=3.6]3.6[/STRIKE] 3.5 to be safe. (My OAL is a bit longer with fmj though - 1.165.)

EDIT:

I take all that back. According to my notes I saw slightly higher velocities with Titegroup then I remembered:

10 shot groups:
3.3 gr of Titegroup under a Berry's 147 seated to 1.165: Low 805 - High 850 - SD 17.4
3.4 gr of Titegroup under a Berry's 147 seated to 1.165: Low 848 - High 884 - SD 12.2

Ended up loading 3.5 grains just to be safe.​

*(This is from a stock Made in Germany Sig P226)

 

[IDPA Mike]

3.3 of Titegroup under a 147 and you'd be lucky to see 750 fps. I had to got to 3.6 to be safe. (My OAL is a bit longer with fmj though - 1.165.)

*(This is from a stock Made in Germany Sig P226)

How can I check my chrono for accuracy?

 

[jasons]

How can I check my chrono for accuracy?

Shoot something of a known velocity through it? For example, 115 grain Blazer Brass out of my Sig averages just barely 1090 FPS. Or maybe use a second known good chrono as a check... Are you sure you don't have it set for CM per second or something weird like that?

 

[IDPA Mike]

Shoot something of a known velocity through it? For example, 115 grain Blazer Brass out of my Sig averages just barely 1090 FPS. Or maybe use a second known good chrono as a check... Are you sure you don't have it set for CM per second or something weird like that?

I am going to work out the chrono bugs this week. Thanks

 

[WeedWhacker]

Oh and to one original question... Load to pass the chrony.. The PF is 125... I will be loading to a 130PF others will load to a 135... Nothing sucks more than going to a match and being DQ for lack of powder...Or at least the looks on peoples faces tell a long story

Some guys run really close..... I choose to run to pass...

 

[jasons]

Updated my chrono results based on what was in my notes. (My notes are evidently more accurate than my brain.)

 

[IDPA Mike]

I am going to work out the chrono bugs this week. Thanks

From the chrony manual. I was out in bright sunlight.


H) False reading (usually high); can result from very strong light, or by operation near electric motors, radar, powerlines, electric fences, static electricity, radio transmitters, etc. It may also be caused by the Chrony being too close to the gun’s muzzle. Remedy: try using diffuser, moving away from electrical interference, moving unit farther from the muzzle, or all of these.

 

[jasons]

I know being too close will mess up the results. How far back were you?

 

[bpratl]

You can check your chrony by shooting any 22 LR match ammo or any good 22 LR which generally have the FPS on the box. The last time I did this I was amassed on how close the printed data matched my chrony.

 

[IDPA Mike]

I know being too close will mess up the results. How far back were you?

I was 10 ft back. I went as far back as the wire would allow.

 

[jasons]

I was 10 ft back. I went as far back as the wire would allow.

Must have been the light then I guess. I use mine (well, my club's) indoors so I've never had to worry about that.

 

[Timberwolf]

You should be getting about 920fps, which would give you a PF of 135240.

 

[jasons]

You should be getting about 920fps....

With 3.3 grains of titegroup? Unlikely.