Help with chrono data / advice please.

[Len5E1]

I made a post a few weeks ago after my first time using a caldwell G2 chrono (upside down version with LED lights) and got some suggestions that I tried today.

So I tried the chrono set from 9' - 16' today (originally tried it at 5' a few weeks ago) and it didn't seem to make much difference in the readings. What I would like to know is what have people chronod factory 223 or 300blk loads at in terms of spread? I tested some S&B 200 grain subs and was seeing 150 fps spread. I then tested my handloads which were all very well made within .05 grains of each other and was seeing 110-120 fps spread still. Last thing I tested was 9mm but was pretty close (a couple feet) and saw from 1100fps - 1300fps which is very confusing as that means some bullets came out subsonic and some supersonic from factory s&b 9mm. Maybe it's because I was too close? Anyway, my 223 handloads were SUPER accurate, to me, given I was using budget 55 grain hornady fmjs, range brass, and a mediocre faxon pencil barrel. I was getting 1 to 1.1 MOA 10 shot groups which is better than I thought these cheap bullets in a 1:7 twist barrel could do. I still want to know if my chrono is working properly though....

So basically I have a few questions I would really love some advice one.
1) Is it normal for factory ammo to have spreads of 100-200+ fps on various calibers?
2) How picky are these style of chronos for positioning in terms of distance out AND the point that the bullet crosses through?
3) What's your opinion on my details? Am I probably seeing mostly correct fps numbers and need to work on my loading skills or is it probably chrono and/or chrono placement issues?

EDIT: Including some chrono data pics.

 

[straightshooter1]

So basically I have a few questions I would really love some advice one.
1) Is it normal for factory ammo to have spreads of 100-200+ fps on various calibers?

Yes . . . depending on who makes the ammo and the quality control the particular ammo is given. Ammo designated at "match" grade will not have that kind of ES but more like around 30-50. 100 is not good and 200 is awful.

2) How picky are these style of chronos for positioning in terms of distance out AND the point that the bullet crosses through?

Typically, it'll depend on how bright the light source is and how sensitive the sensor is. For a rifle, 10 ft is probably a close as you might want to get so that any smoke coming out of the muzzle doesn't happen to interfere with a reading (which could happen if the light source is weak along with a small bullet and you're close, like 5 ft away).

3) What's your opinion on my details? Am I probably seeing mostly correct fps numbers and need to work on my loading skills or is it probably chrono and/or chrono placement issues?

Yes, I'd say you need to work on your reloading skills as getting an ES of less than 50 really shouldn't be all that difficult.

 

[rockchalk06]

I've placed mine (same model as yours) 5, 7 and 10 feet away. Numbers were pretty consistent at all 3 distances. I did this with my known chrono'd loads. 5 feet just seems to me to be too close, but I have not seen any errors because of it. 10 feet works for me at my range due to the incline.

I bought a portable battery pack for mine. I leave it plugged in with the lights on for better results. I get error 2's and error 3's without it. I just got back from a 6 hour range session and never lost battery.

Work on trying to get everything as consistent as possible. Brass prep, seating depth to powder charge. More consistent you have everything, the lower spreads and lower SD's you will see. I've got several single digit SD loads that printed like shit on paper. But, it was consistent.

 

[straightshooter1]

I've got several single digit SD loads that printed like shit on paper. But, it was consistent.

Same here.

Good results on paper starts with consistent-accurate cartridge prep and the biggest factor with that is consistent-accurate powder loads.