ProChrono Range report

[tbrtt1]

I purchased a Pro Chrono Digital from Shooters Connection (recommendation from some forum members) on Monday and received it on Thursday. Had a chance today to chrono a few of my loads I have been working up of late. I thought I would post the results for giggles.

First off, the Pro Chrono Digital is superb. Put in a battery, turn it on and shoot. Works like a water hose.

All loads tested are with:

Glock34 Gen4 stock barrel

Bayou Bullets 147gr FN 9mm

1.140 OAL

Mixed brass

Shooting from a modified Pistolero (installed some wood beams to stabilize it)

10 feet from the Chrono

Sunny day but Chrono in the shade

15 shots fired for each load

All in FPS

IMR PB 3.5gr-This is a money load IMHO. Soft shooting.

Hi-953

Lo-928

Av-936

ES-25

SD-7

IMR PB 3.8 gr

Hi-977

Lo-940

Av-958

Es-37

SD-11

IMR PB 4.1

Hi- 1051

Lo-986

Av-1012

ES 65

SD-22

Silhouette 3.8

Hi-860

Lo-797

Av-830

Es-63

Sd-17

Silhouette 4.2

Hi-917

Lo-864

Av-889

Es 53

Sd-13

Bullseye 3.0 Another money load-soft

Hi-939

Lo-874

Av-898

Es-65

Sd-17

Bullseye 3.2

Hi-970

Lo-927

Av-945

Es-43

Sd-11

Bullseye 3.5

Hi-1028

Lo-976

Av-998

Es-52

Sd-16

AutoComp 3.8

Hi-923

Lo 878

Av-902

Es-45

Sd-14

AutoComp 4.2

Hi-987

Lo-916

Av-946

Es-71

Sd-19

By all means if this looks out of whack to anyone please let me know. I have other powders I may test at some point.

[Hi-Power Jack]

Your hottest round was PF 155? That a little hot for a standard Glock?

Your lowest power PB (3.5 gr) was PF 140??

What are you doing with these +P+ rounds?

[tbrtt1]

HI-Power,

Just trying to develop a competition load above 125 PF. Please share any and all wisdom.

Here is what I am using for PF from the IDPA 2013 rule book:

8.3.1.6. Calculate the power factor by multiplying the bullet weight in grains by the bullet velocity in feet

per second (fps), divide by 1000, and ignore numbers to the right of the decimal. For example, a 230.1

grain bullet at 794.7 fps: 230.1 x 794.7 / 1000 = 182.86047, or 182 power factor.

I'm getting 137 PF on the 3.5 of PB using the above calculations using the Av velocity. I know in IDPA they take 3 rounds and 2 of em have to meet or exceed the 125 PF. I'll bump the PB down a notch and see what I get but I'd like to keep the PF in the 130-135 range.

The 3.0 BE at 132 PF, 4.2 Silhouette at 130 and 3.8 AC at 132 all seem like winners unless I am seeing something wrong.

I will obviously not use the higher end loads.

BTW, the lower loads I listed, like the 3.5 of PB and the 3.8 of Silhouette won't even cycle the stock recoil spring on my Gen4 G34.

[Justsomeguy]

The comment about not cycling the slide using stock springs is the key here. Most stock guns will not cycle below about 140PF, so it's either going to be a new set of springs or shooting loads at that level. 140PF still feels pretty soft and the stock springs will feed more reliably too, but it's a question of "feel" for most people. Some don't like the "sluggish" feel you get from reduced power springs and others like them. It's all about personal preference when you are developing loads and how well you can quickly and accurately shoot the results.

[Hi-Power Jack]

Bayou Bullets 147gr FN 9mm

1.140 OAL

15 shots fired for each load

IMR PB 3.5gr-This is a money load IMHO. Soft shooting.

Hi-953

Lo-928

Av-936

ES-25

SD-7

TBR, if you're trying to get a PF 130 round, I'd drop the PB down to PF 132 or so,

fire about 30 rounds thru the chrono, and watch that none drop below PF 126. That should

be a real nice round, iff you get lighter springs.

Only other factors to consider are 1. reliability - MUST be reliable, and 2. accuracy.

I'm impressed by your ES:)) 15 shots with a low and high 7 fps apart is Incredible -

just might also be accurate?? I hope. If it is, maybe 3.1 or 3.2 just might be perfect,

if the accuracy holds up, and you get lighter springs.

Good luck in the quest.

[gatnfans]

I'm impressed by your ES:)) 15 shots with a low and high 7 fps apart is Incredible -

I'm a nubie but can you explain where they were only 7 fps apart? I'm just now getting a handle on what the chrono is telling me and this post kind of confused me. Sorry for the dumb question.

Edited February 16, 2014 by gatnfans

[Steve RA]

I think he may have mixed up the extreme spread - which was 25 feet per second and the Standard Deviation which was 7.

Standard Deviation is formula derived and the primary thing to watch is that the lower the number - the better it is.

[Dkrad1935]

If you are asking what the numbers mean? ES is just the highest velocity minus the lowest velocity. It is the extreme spread. Your chrono may or may not eliminate outlier velocities when calculating this.

The sd is a way to describe the variance of velocity from one round to another. In other words if you took the average you have a certain confidence that 68% of your rounds velocities will fall withing the average plus or minus the SD. And 95% withing plus or minus the average plus or minus 2 SD.

So 936 is average. 95% of your rounds will be between 922 and 950 fps. So you will rarely have rounds below 135 PF.

[tbrtt1]

HP, Just,

I sheepishly admit developing loads sans chrono. I used the stock spring as my guide to "ensure" PF. Start low and when the gun starts to cycle consistently ergo I must be making PF knowing the stiffness of the Gen 4 stock recoil spring. Though that theory proved true, I didn't like approaching the upper end of published load data without a Chrono.

I do, and have been using a 14# recoil spring using the lower end of those loads I listed. Now that I have the chrono I can with confidence find a load that works and meets PF. Like everyone on this forum that has a chrono says "can't imagine ever loading without one" now that I have one. Especially considering 9mm is susceptible to pressure spikes.

As for the SD and ES I myself was quite pleasantly surprised. And I am using a Pro1000!!! I am going to chrono a few more rounds in different conditions over the next few weeks/months and see.

[Steve RA]

Most any loading press will generate good ammo if:

It is in correct adjustment - press and dies

The load is a good one

operated uniformly

Primary difference is in speed and ease of operation.

[RDA]

The comment about not cycling the slide using stock springs is the key here. Most stock guns will not cycle below about 140PF, so it's either going to be a new set of springs or shooting loads at that level. 140PF still feels pretty soft and the stock springs will feed more reliably too, but it's a question of "feel" for most people. Some don't like the "sluggish" feel you get from reduced power springs and others like them. It's all about personal preference when you are developing loads and how well you can quickly and accurately shoot the results.

Are you referring to stock Glock? I have had my stock G19 (Gen 3) cycle reliably down to 107PF.

[Sarge]

The comment about not cycling the slide using stock springs is the key here. Most stock guns will not cycle below about 140PF, so it's either going to be a new set of springs or shooting loads at that level. 140PF still feels pretty soft and the stock springs will feed more reliably too, but it's a question of "feel" for most people. Some don't like the "sluggish" feel you get from reduced power springs and others like them. It's all about personal preference when you are developing loads and how well you can quickly and accurately shoot the results.

Are you referring to stock Glock? I have had my stock G19 (Gen 3) cycle reliably down to 107PF.

I don't know if I could run that low but my Glocks would run down to about 115 PF.

[tbrtt1]

The comment about not cycling the slide using stock springs is the key here. Most stock guns will not cycle below about 140PF, so it's either going to be a new set of springs or shooting loads at that level. 140PF still feels pretty soft and the stock springs will feed more reliably too, but it's a question of "feel" for most people. Some don't like the "sluggish" feel you get from reduced power springs and others like them. It's all about personal preference when you are developing loads and how well you can quickly and accurately shoot the results.

Are you referring to stock Glock? I have had my stock G19 (Gen 3) cycle reliably down to 107PF.

I don't know if I could run that low but my Glocks would run down to about 115 PF.

Stock Gen4 G34. Conventional wisdom says that the Gen4 dual spring apparatus is a tad on the stiff side relative to Gen3s. I can't attest to that as this is the only Glock I have owned. I just know with some of the lower loads it won't cycle consistently.

[Sarge]

The comment about not cycling the slide using stock springs is the key here. Most stock guns will not cycle below about 140PF, so it's either going to be a new set of springs or shooting loads at that level. 140PF still feels pretty soft and the stock springs will feed more reliably too, but it's a question of "feel" for most people. Some don't like the "sluggish" feel you get from reduced power springs and others like them. It's all about personal preference when you are developing loads and how well you can quickly and accurately shoot the results.

Are you referring to stock Glock? I have had my stock G19 (Gen 3) cycle reliably down to 107PF.

I don't know if I could run that low but my Glocks would run down to about 115 PF.

Stock Gen4 G34. Conventional wisdom says that the Gen4 dual spring apparatus is a tad on the stiff side relative to Gen3s. I can't attest to that as this is the only Glock I have owned. I just know with some of the lower loads it won't cycle consistently.

Hmm... Blazer ran right at or just under 125PF in my G34 Gen 3. Remington UMC was even weaker. Both ran the gun just fine. I owned a Gen 4 G19 that ran them as well before I traded it for a Gen 3. The Gen 4 should still be reliable with any factory ammo.

[tbrtt1]

Most any loading press will generate good ammo if:

It is in correct adjustment - press and dies

The load is a good one

operated uniformly

Primary difference is in speed and ease of operation.

Agreed, Steve, and I can get 400+ an hour easy from it. A couple of low cost mods (I listed what I did in the Pro1000 thread you started) and she runs great. The only trouble I have is the occasional double feed from the case feeder. This happens sometimes if the press gets a little jerky and causes the case that due to go in the slider creeps forward and lets another one fall. I lube my cases and this helps.

[tbrtt1]

The comment about not cycling the slide using stock springs is the key here. Most stock guns will not cycle below about 140PF, so it's either going to be a new set of springs or shooting loads at that level. 140PF still feels pretty soft and the stock springs will feed more reliably too, but it's a question of "feel" for most people. Some don't like the "sluggish" feel you get from reduced power springs and others like them. It's all about personal preference when you are developing loads and how well you can quickly and accurately shoot the results.

Are you referring to stock Glock? I have had my stock G19 (Gen 3) cycle reliably down to 107PF.

I don't know if I could run that low but my Glocks would run down to about 115 PF.

Stock Gen4 G34. Conventional wisdom says that the Gen4 dual spring apparatus is a tad on the stiff side relative to Gen3s. I can't attest to that as this is the only Glock I have owned. I just know with some of the lower loads it won't cycle consistently.

Hmm... Blazer ran right at or just under 125PF in my G34 Gen 3. Remington UMC was even weaker. Both ran the gun just fine. I owned a Gen 4 G19 that ran them as well before I traded it for a Gen 3. The Gen 4 should still be reliable with any factory ammo.

I never had problems with factory ammo either. But I only shot WWB (never chronoed it) and Geco (chrono at 135 PF). Never ran blazer or Rem UMC. May have to try that for giggles.

[tbrtt1]

Bayou Bullets 147gr FN 9mm

1.140 OAL

15 shots fired for each load

IMR PB 3.5gr-This is a money load IMHO. Soft shooting.

Hi-953

Lo-928

Av-936

ES-25

SD-7

TBR, if you're trying to get a PF 130 round, I'd drop the PB down to PF 132 or so,

fire about 30 rounds thru the chrono, and watch that none drop below PF 126. That should

be a real nice round, iff you get lighter springs.

Only other factors to consider are 1. reliability - MUST be reliable, and 2. accuracy.

I'm impressed by your ES:)) 15 shots with a low and high 7 fps apart is Incredible -

just might also be accurate?? I hope. If it is, maybe 3.1 or 3.2 just might be perfect,

if the accuracy holds up, and you get lighter springs.

Good luck in the quest.

Dropped PB to 3.2 and it chronos 20 rounds as:

Hi-917

Lo-878

Av-898

Es- 39

SD-9

I love this powder and really bummed that it will be discontinued. I'll scavenge and hoard what I can of this stuff. Anyone got any they wanna get rid of?

Hi-P, thanks for the advice (think I did this correct, Sarge) and feedback. Others too.

Edited February 16, 2014 by tbrtt1

[Steve RA]

I wasn't aware I started a Pro 1000 thread, but, I may have slept since then at a Holiday Inn.

[tbrtt1]

I wasn't aware I started a Pro 1000 thread, but, I may have slept since then at a Holiday Inn.

Ha!! My bad. Confused you with someone else.