How to Use a Chrono Better

[Wilburt]

I saw a similar thread eailer but had a few differant questions. I am new at chrono's... I chrono'ed a load 10x in a string and 4 strings. I came up with:

ES: 71.9, 112.4, 63.6, and 124.4
SD: 23.9, 19.8, 28.6, and 33.68

This was 40 of the same load. I know it should be better but how do you acheve better results? I was shooting 10 feet away with diffusers on a partly cloudy day using a two hand hold. Does point of aim make a big differance? i didn't get any errors...

Load:
.45 ACP
200 gr Berry's HP
Win Prime
1.200 OAL
Light Taper Crimp
5.1 gr WST (MAX published)

I am trying to make a 165,000 power factor and this load didn't. But I did a differant one that did with results of 800 FPS - 900 FPS (100 ES) with a target of 825 FPS and an AVG of 855 FPS. So would this load work or the very few that droped below 825 disqualify me.

 

[The Bushmaster]

Wilburt...I weigh every powder charge before I drop it in a case and .45 ACP will run all over the place with no rhyme or reason. The 71.9 and 63.6 are pretty good. I try to keep my ES at 50 or below and figure that is damned good for .45 ACP.

Biggest thing...Are they hitting point of aim and are they accurate? If so...Don't put too much worry into it...

A chronograph is a "tool". Not a "God sent"

 

[ReloaderFred]

Many happy reloaders get ulcers within a year of buying a chronograph. I only use mine when I get curious enough to see how fast the bullet is actually going. As long as the load is safe and accurate, I leave the chronograph at home.

Hope this helps.

Fred

 

[SyberShooter]

I use my Pact chrono for several things,
- to check my velocity against the book or factory loads
- to record a history for future developments
- to determine which velocity range is most accurate in each gun
- to monitor when velocity doesn't increase while powder charge does
- to see how consistently I am loading
- add interest to my shooting sessions

I think that each gun has its accuacy 'sweet spot' based on velocity so I try to find that velocity with various bullet/powder combos.

 

[MCMXI]

I'm planning on using a Chrony Beta Master this weekend and the manual mentions that the bullet should pass through the guides about 4" above the sensors. How critical is this? What if the bullet passes 6", 8" or 10" over the sensors? I'll be shooting at a target set at 100 yards so I think it'll be hard to align the chrony with the target if the bullet height (above the sensors) is critical. I'll be shooting a .300 Win Mag so the chrony needs to be 10 to 15 feet away from the muzzle (according to the manual).

 

[The Bushmaster]

1858...Make sure you allow for the rise of the scope above the barrel or you will be too low and shoot your chrony...And please don't embarrass me by askin'...

 

[PCJim]

1858,

I would suggest you place your Chrony as far from the muzzle as the display cable will allow. I found that at appx. 10 feet, I kept getting errors on my Beta Master (late afternoon, no sun, with shades) and could only get 2 readings on 20 rounds from my AR.

If you have a good sunny day and are using the shades, shooting 8" over the sensors should not cause any problems. Of course, the closer you are to the sensors, the more likely you are to get good readings.

I use a camera tripod to set up the Chrony. It really is not that hard to align the adjustable legs with the height of the barrel sitting on the rest. Take your time, don't rush, and you'll be fine.

 

[MCMXI]

1858...Make sure you allow for the rise of the scope above the barrel or you will be too low and shoot your chrony...And please don't embarrass me by askin'...

The Bushmaster, It's not my chrony! I'm borrowing it from a friend and he already put some tape on the rods at 4" and 6" for the very reason you mention. Basically he told me "if you shoot it, you own it!"

So how important is the bullet height above the sensors?

 

[MCMXI]

PCJim, thanks very much for the tips/advice. I've never used a chrony so I really appreciate it. I don't like the idea of shooting A-MAX bullets over the chrony into the ground ... seems like such a waste. I'm going to try to get velocity data while shooting groups on paper.

Thanks.

 

[ReloaderFred]

If you have a laser, that makes setting it up in relation to the target rather easy. One of the cheap laser pointers can be fastened to the barrel with a rubber band as a temporary measure while setting everything up. Just remove it before you start shooting.

Hope this helps.

Fred

 

[MCMXI]

Fred, thanks for the good idea ... and my apologies to the OP for hijacking this thread.

 

[Wilburt]

and my apologies to the OP for hijacking this thread

You're Fine, We are all trying to learn here. I also noticed the chrony needs time in between shoots too. I went to fast a couple times and it didn't read. Also +1 for tripod. It really helped.

 

[Walkalong]

I don't like the idea of shooting A-MAX bullets over the chrony into the ground

I routinely shoot through my chrono on a target with pistols. Setting it up for a rifle would take a little more time.

I weigh every powder charge before I drop it in a case and .45 ACP

After I make sure the measure is dropping the charge I want, I drop every charge from my Redding 10X automatically on my Projector.

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I have found it fairly easy to get ES numbers under 75 and SD numbers under 30 in .45 ACP, and ES &SD numbers under 50 and 15 are attainable.

AA #2 may be the low ES & SD numbers king in .45 ACP, as well as being clean and accurate.

Like Fred posted, some loads with poor numbers still shoot great. If you are loading for PF, then you will want a fairly small ES though.

Some samples


Load # 16
Ranier 200 Gr SWC @ 1.260 O.A.L.
9.0 Grs AA #5 - Start lower!
WLP Primer

Hot summer day - 4" CDP

Hi-929
Lo-865
Avg-897
ES-64
SD-19

Will shoot through one hole.

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Load # 45
Berrys 185 Gr SWC @ 1.190 O.A.L.
6.2 Grs AA #2
WLP Primer

Hot summer day - 4" CDP

Hi-888
Lo-860
Avg-874 - Lost 38 FPS in a 3" CDP
ES-28
SD-10

Will shoot through one hole.

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Load #56 - This one may do it in a 5" gun Wilburt
Berrys 200 Gr HP @ 1.200 O.A.L.
5.8 Grs AA #2
WLP Primer

Hot summer day - 4" CDP

Hi-829
Lo-807
Avg-821 - Lost 37 FPS from a 3" CDP
ES-22
SD-7

Will shoot through one hole.

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Load # 88
Zero 230 Gr JHP @ 1.245 O.A.L.
?,? Grs AA WST - Lost my notes!
WLP Primer

Hot summer day - 5" 1911

Hi-692
Lo-654
Avg-665
ES-38
SD-14
Very low velocity, but the numbers will only get better with more powder

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Load # 103
Berrys 200 HP @ 1.200 O.A.L.
4.4 Grs N310
WLP Primer

Hot summer day - 5" 1911

Hi-846
Lo-768
Avg-820
ES-78
SD-26

Will shoot through one hole.

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Load # 108
Berrys 200 Gr HP @ 1.200 O.A.L.
4.7 Grs Competition
WLP Primer

93 Degrees - 5" 1911

Hi-860
Lo-827
Avg-841
ES-33
SD-12

Will shoot through one hole.

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Load # 120
Berrys 185 Gr SWC @ 1.190 O.A.L.
4.6 Grs N310
WLP Primer

Hot summer day - 2 5" 1911's

Colt
Hi-913
Lo-848
Avg-876
ES-65
SD-21

Will shoot through one hole.

Caspian/STI
Hi-870
Lo-814
Avg-845
ES-56
SD-16

Will shoot through one hole.

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Load # 122
Berrys 185 Gr SWC @ 1.190 O.A.L.
5.7 Grs N320
WLP Primer

Hot summer day - 2 5" 1911's

Colt
Hi-924
Lo-849
Avg-888
ES-75
SD-23

Will shoot through one hole.

Caspian/STI
Hi-873
Lo-793
Avg-839
ES-80
SD-33

Will shoot through one hole.

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Load # 134
Berrys 200 Gr HP @ 1.200 O.A.L.
4.5 Grs N310
WLP Primer

80 Degrees - 2 5" 1911's

Colt
Hi-865
Lo-808
Avg-831
ES-57
SD-18

Will shoot through one hole.

Caspian/STI
Hi-839
Lo-755
Avg-799
ES-84
SD-23

Will shoot through one hole.

These loads appeared safe in my guns using my load procedure. I probably made at least one typo. There is probably one over max that is not a typo. Use at your own risk. Check manuals and start low, working up, as you all know how to do.

 

[Wilburt]

Wow... All kinds of good data. Will make my search for a new powder better.

 

[Slamfire]

I set my up with a laser equipped bubble level. When I shoot on a bench, I plumb the thing and get the laser pointed at the stem of my rest.

With the Chrony Chronograph, it is critically important to not have any off axis error. I have noticed crazy velocity reading, even after plumbing my chronograph, if I am shooting not exactly over the center of the screens. Crazy velocity readings also occur when powder particles cross over the screens.

I had to set my Chrony around 10/15 yards away to get readings when shooting a blackpowder musket. Unburnt blackpowder residue would just cause errant velocities.

 

[ReloaderFred]

The laser bubble level is a great idea. It might even work better than attaching a laser to the firearm, though both could be used for aligning the target with the chronograph.

Hope this helps.

Fred

 

[fecmech]

I don't think I've ever seen a 100 fps es in a 45 acp load! I load mostly cast but all the bullet weights from 164-230 gr plus some jacketed. The biggest es I have is with the 185 Nosler@1050 fps and 8.2 grs of Unique and that is 89 with an sd of 26. Most es are under 50 fps with single or low 2 digit sd's. If you want low sd's and accuracy stick with Bullseye or 231, they made their bones with the .45acp.

Ps. I'm sure different headstamp cases would add to the es-sd spread. My cases are all the same as I purchased 4K of Federals some years ago.

 

[Wilburt]

I deffinatly don't sort my cases. Next time i chrono i'll take alevel with me and see if that helps.