Seeking help interpreting chrono results...

[Paleoman]

Hi!

I got a chronograph (LabRadar) and did my first measurements (hand recorded, as my SD card was not working). I'd love to hear folks comments on the data collected for the loads I had previously developed...

Setup...

I had my target at about 30-35 feet. I setup the chrono to measure velocity at 0 (default), 5, 10, 15, 20, and 25 feet. I uses a blanket folded into a square, as a bench rest.

Using 230 gr RN plated Berry's bullets, and comparing with Remington 230 gr factory rounds. Used CFE Pistol powder with a recommended range of 5.4-6.4 gr for these bullets. CCI large pistol primers. Fired 8 rounds using a S&W 1911 Govt.

Here are the results:

.45 ACP	fps					Last shot
230 gr	Ave Velocity	Low	High	Extreme spread	Std. Dev	PF	Ke0 ft-lbs	V0	V5	V10	V15	V20	V25	# shots
Factory (Rem)	804	727	871	143	47.1	180	314	785	783	783	783	784	784	6
5.4 gr	679	599	815	216	75.3	137.8	283	599	599	599	599	599	599	6
5.6 gr	690	638	768	131	40.3	143.8	226	625	625	625	625	625	625	8
5.8 gr	752	713	788	75	24.8	173	289	753	752	751	750	749	748	8
6.0 gr	772	736	807	72	24.5	169.1	276	736	735	734	733	732	731	8
6.2 gr	782	757	822	66	22.6	172.5	293	758	750	750	750	750	750	8
6.4 gr	809	771	842	71	24.8	179.2	311	780	779	778	777	776	774	8

Note: On the factory and 5.4 gr I had only gotten 6 shots registered. Didn't get the chrono armed correctly. The chrono aim was off the target by about 6" too. I fixed it for the rest.

Note: The 5.8 gr, 6.0 gr, and 6.4 gr had the most accurate shots. Oddly, the 6.2 shots were the least accurate.

What is the Ke0 (ft-lbs) mean?

Any thoughts as to why the 5.8 gr has a higher PF than the 6.0 and 6.2 gr?

Looks like 6.4 is closest to factory load. Seems like they all have lower standard deviation and spread than the factory load, except for the 5.4 gr.

I do notice that the 5.4 and 5.6 gr have much less recoil.


Any other thoughts, comments, suggestions?

I did 9mm too, but only had one hand load, as I had selected that from the three I created months ago, based on relative accuracy. I'll likely retry the different loads and retest. For giggles, here is the data:

9mm
115gr	fps					Last shot
PPQ 4"	Ave Velocity	Low	High	Extreme spread	Std. Dev	PF	Ke0 ft-lbs	V0	V5	V10	V15	V20	V25	# shots
Factory (Blazer)	1104	1092	1120	28	10.2	126.3	319	1118	1098	1093	1087	1081	1075	8
5.1 gr	1047	992	1047	86	30.6	116.3	262	1013	1011	1008	1006	1003	1001	8

9mm
115 gr	fps					Last shot
P938 3"	Ave Velocity	Low	High	Extreme spread	Std. Dev	PF	Ke0 ft-lbs	V0	V5	V10	V15	V20	V25	# shots
Factory (Blazer)	995	976	1010	34	10.5	113.4	253	995	986	984	982	980	978	7
5.1 gr	891	845	950	106	34.3	108.4	230	950	943	940	937	934	931	7

Note: same distance and setup. Using 115 gr bullets (Blazer Brass for factory, and Berry's RN plated for reloads). Used 5.1gr CFE powder,and Fiocchi primers.

Accuracy was poor on these, so hard to tell. I think switching from .45 to 4" and then 3" barrels and different trigger pulls, exacerbated my trigger control issues (still anticipating a bit, not quite keeping it steady).

Anything of note on these? Pretty limited data.

Thanks in advance!

 

[cockpitbob]

Ke0 ft-lbs: I'm pretty sure that's muzzle energy (kinetic energy at zero distance).

To me it all boils down to accuracy (within safe chamber pressures), which usually means consistency, which standard deviation is usually a good indicator of. I'm surprised with the .45 that the load with the smallest std-dev was also the least accurate. If I recall correctly, 850'/s is at the top end, so I think I would go with the 6.0gr load. It's accurate, tight std-dev and chamber pressures aren't near the redline.

On the 9mm it's fun seeing real data showing how the PPQ's extra inch gets you another 100'/s over the 938. Do you have any idea why the std-dev is 3x worse on your loads vs. the factory? I actually don't think your std-dev numbers are bad. The Blazer looks great.

 

[Paleoman]

Yeah, I was surprised that the 6.2 gr load on the .45 was so poor. This is the second time I shot that load, with rested arms (not in any form of actual holder or "rest"), and both times, it was poor compared to the others.

Here is a link with the pictures of each load level, at around 30 feet.
http://media.michali.net/36/442/

I definitely want to retest the 9mm, and I want to try other loads. Not sure why the std Dev is so much higher. From my notes, possible loads would be 4.9gr, 5.1 (what I have), and 5.3 gr. The max is 5.4 gr according to the Hodgdon info. I'll double check the limits. I wonder if I should create a 5.3 (only) or do a 5.2 and 5.4 gr? Wonder if I should even try a 4.9 gr load.

if I want to use these for USPSA at some point, will I have a concern with the PF? I haven't looked at the rules yet, but I thought it was 120 or so. With a 3" barrel are the limits lower?

I'm having fun with this. I may want to try other brands of factory rounds just for grins.

 

[cockpitbob]

The limits for USPSA are 125K. With factory 115gr ammo in the 3.1" barrel on my little LC9s I get around 115K, just like your P938. Since energy goes as the square of the velocity, but power factor is just linear, by going with a heavier, slower bullet you can get higher power factor for the same energy. These days I'm shooting 147gr bullets. I'm running a mild load and getting 900'/s which is a power factor of 132K. I like how it feels a bit more like the thump of a .45 than the crack of a 9mm in my little gun.

 

[wmccurdy53]

I think you should double check the power factor computation, it seems wrong.
Power Factor is: (Muzzle Velocity X Bullet Weight) / 1000
The rules for USPSA concerning Power Factor are:
Minor >= 125
Major >= 165

 

[cockpitbob]

I think you should double check the power factor computation, it seems wrong.
Power Factor is: (Muzzle Velocity X Bullet Weight) / 1000
The rules for USPSA concerning Power Factor are:
Minor >= 125
Major >= 165

Mine or his? I forgot to divide by 1,000, otherwise all the numbers look OK to me.

 

[Paleoman]

The limits for USPSA are 125K. With factory 115gr ammo in the 3.1" barrel on my little LC9s I get around 115K, just like your P938. Since energy goes as the square of the velocity, but power factor is just linear, by going with a heavier, slower bullet you can get higher power factor for the same energy. These days I'm shooting 147gr bullets. I'm running a mild load and getting 900'/s which is a power factor of 132K. I like how it feels a bit more like the thump of a .45 than the crack of a 9mm in my little gun.

Thanks! I was wondering how to deal with that. I use 147 gr for defensive rounds, so I should used a heavier bullet so that I practice with a similar round.

Do you know what std dev you get on your loads?

What bullet do you use and what COL?

I'm wondering why my std dev is much higher than factory.

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[Paleoman]

Mine or his? I forgot to divide by 1,000, otherwise all the numbers look OK to me.

Yeah I sort of figured you meant 125 and not 12k

Mine are from the chronograph itself.


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[Paleoman]

So, for .45 ACP, I think I'll go with the 6.0 gr load.

For 9mm, I'm wondering what loads to test with 115 gr (as I have 1500 bullets).

I can retest 5.1gr, as I have rounds still. Should I do 5.3gr, 5.2gr and 5.4gr, or all three? Would .1gr changes be noticeable? Should I venture on or above the max given?

Long term, I should go to 147gr bullets for the P938. I can explore for the 4" PPQ too. Would the recoil be better, in that case? Do you folks think I'll need to use two different loads for thesetwo guns?

Would be easier with one load, but I can always do different loads.


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[cockpitbob]

With rifles I'm an accuracy nut, but for pistols I don't pay a lot of attention to std-dev because I'm so much worse than the gun is, especially with that little LC9s. So, I can't really say what a "good" std-dev is, but I think the Blazer ammo is probably very good. I find it curious that the std-dev is a little worse in the P938 with both Blazer and your loads. I suppose it's the barrel length difference.

I've been using cheap cast-coated 147gr bullets for practice. I should probably switch to 147gr for carry to be consistent, but I've been carrying 115gr because that's what I have. Factory 115gr and 147gr ammo will have about the same muzzle energy, but the recoil will feel a bit different, and that's more a matter of personal preference IMHO.

I wouldn't use 2 different loads in the 2 guns. My feeling is that unless it's a target gun that I shoot very well, I'm so much worse than the gun that I'll go with what feels best to me (what I shoot best). I like the thump of 147gr better than the crack of 115gr. I also seem to come back down on target a bit quicker with the 147gr. Now that I think of it, I have never "benched" the LC9s that I've been shooting so much. I'm focused on things like the 5 shots in 10 seconds NRA rapid fire as I chew my way through the NRA Pistol Qualification program.

 

[Paleoman]

Good points. I'm just thinking that I may not hit the required PF, with 115 gr, using the P938.

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[cockpitbob]

There were a couple threads on 9mm loads recently. Here's the one I was able to find. It's all about 147gr 9mm.

 

[Paleoman]

There were a couple threads on 9mm loads recently. Here's the one I was able to find. It's all about 147gr 9mm.

Link?

I talked to some reloaders at a match today. They were all using 124gr bullets. I'll have to decide on 124 or 147 (which would be the same as.my defensive loads). In the meantime I'll try 5.2-5.4gr loads with my 115gr bullets and see if I can get PF and velocity similar to factory (for the 4" barrel).

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[cockpitbob]

I hate it when I forget links and attachments.

https://www.northeastshooters.com/vbulletin/threads/326797-147-grn-9mm-powder-recomendations

 

[84ta406]

I load the same Berry's 230s and CFE powder to 6.3gr and find them to be very accurate in my 45c. So much so that I kept moving the target back 10ft at a time until I saw the spread get bigger. By far my favorite load.

 

[Paleoman]

Thanks!

 

[Paleoman]

Update and some questions for folks...

Since I have over 2000 of the 115 gr bullets, I wanted to try to work on the load more for this bullet. In the future, I'll probably try either 124 gr or 147 gr to see how it fairs.

My primary use is target practice, although I did attend my first USPSA format event. Can't say I really competed... I wasn't prepared mentally, as guys at the event talked me into trying; skill-wise, as I'm still working on accuracy and technique (trying to deal with being left eye dominant and right handed); and equipment-wise, as I only had 3 mags for my Walther PPQ, and my reloads are not with sufficient PF.

In any case, I'd like to compete more. It is a great way to practice what I'm learning, in a more pressure environment that just practicing.

Using the 9mm 115 gr bullets, Fiocchi primers, and CFE Pistol powder, I had created loads of 5.1 gr (already had), 5.2 gr, 5.3 gr, and 5.4 gr (the max in the Hodgdon website for the powder). Yeah, they are really close loads. I couldn't decide between doing 5.3gr, or doing 5.2gr and 5.4gr, so I did all three.

At the indoor range, I setup my target at 30 feet and chrono'ed 10 each of factory (Blazer Brass), and the four loads, in both the 4" Walther PPQ, and 3" Sig P938. Here is a summary of the V0 velocity and PF:

PPQ
Factory v0=1118 pf=128.0
5.1gr v0=1033 pf=117.3
5.2gr v0=1109 pf=126.6
5.3gr v0=1142 pf=130.9
5.4gr v0=1134 pf=129.8

P938
Factory v0=965 pf=109.8
5.1gr v0=897 pf=102.0
5.2gr v0=1002 pf=115.0
5.3gr v0=1026 pf=118.0
5.4gr v0=1062 pf=121.7

It looks like I can use 5.2-5.4 and the PPQ for USPSA minor, and the P938 wouldn't be usable at all (too bad, as I shoot as good as or better with the P938 ).

Any thoughts on why the 5.4gr chronos a bit lower than the 5.3gr, on the Walther PPQ (and not the P938)? When I checked the drop on the Dillon for 4 loads, the 5.1 was 20.3 (-0.1gr), the 5.2 was 20.8 (dead on), the 5.3 was 21.1 (-0.1 gr), and the 5.4 was 21.6 (dead on).

Here are shots of the cases, first just the factory (no marker), 5.1(black), 5.2 (red), 5.3 (blue) and 5.4 (two red lines):


Second, has the same shot, but with all cases:


I think the primers look fine (these are from both guns, whereas the first shot could be from either gun). Seem OK?

 

[cockpitbob]

The primers look nice. Chamber pressures look mild. I've seen some pistol brass where the primer wasn't rounded, but filled the entire pocket out to the edges

I can't pick out anything to comment on in the chrono data other than everything looks good. If it were for a scoped silhouette gun with an 8" barrel I might look at things more carefully with more data, but I don't see anything that says the ammo won't be a lot more accurate than you (or me, at least lol).

 

[Paleoman]

As for accuracy, I was having some problems today. My contacts were sort of dried out, so I was having a hard time getting a good focus on the front sight (I near sighted, but eyes are bad enough that I have to start wearing readers too ). For the PPQ, I tried using a U shaped rest that was at the range and placed the barrel's rail on it. I used the blanket I had from testing the .45 ACPs, to rest my forearms. The gun was a bit higher than before, as was the target I was using. Not sure what I was doing wrong, but all shots were high and to the left (10-12 o'clock) for all ammo.

In any case, I used that as a relative gauge and examined how well groups were shot. I'd say, from best to worst, was the 5.4gr, factory (pretty close, though), 5.3 gr (just a wider spread), 5.2 gr (wider still, little grouping), and 5.1gr (closest to 12 o'clock, but no groupings and wider spread).

For the P938, which has a laser attached (I didn't use it - as never have calibrated it), and a shorter barrel, I was concerned about it staying on the metal rest. I decided to just rest my forearms on the blanket, with no support for the barrel. Gun was lower, but probably more level than with the other setup. This turned out better (closer to bullseye, although some shot variation due to trigger control and somewhat of a freehanded shot.

I'd have to say, best to worst, was 5.3gr (clearly better), 5.4gr, factory (both very similar), 5.1gr, and 5.2gr (both clearly worse).

Thoughts on performance and recordings?

Seems like either 5.3 gr or 5.4 gr would be good to use, forward going (clearly better than the 5.1gr I had been using). I didn't venture to try lower (towards starting load), mostly because of PF.

Comments?

 

[cockpitbob]

You're pickier and looking at things more carefully than me. As an engineer that's often trying to get a pile of data to tell me what's buried in it, I like how hard you're looking at the data That said, with short barreled pistols being shot standing up on your hind legs, I think the human variables overwhelm most of what's going on with the gun and load. A 0.1gr difference is probably "lost in the noise" as electrical engineers say.

Since you're doing IDPA (jealous), one human factor to think about is recoil and time between shots. There's no harm in trying a lighter load. So long as the gun cycles reliably, load her down some more. I developed my light 147g 9mm load with the plan to try IDPA later this summer. With it's 3.1" barrel, my little LC9s can't make the 125 power factor with a 115gr bullet, but if I load the 146gr heavy it will do it. But I plan to shoot the Back Up Gun division and it only requires 95.

 

[Paleoman]

Yeah, I'm anal

by far, I'm the most limiting factor

My thoughts were to try 124gr or 147gr and do the lightest load to get PF that is OK. For USPSA, unless I misread, it seems like they just have major and minor, with the latter requiring PF 125. For the PPQ, that means the 5.2, 5.3, or 5.4gr loads.

I didn't see anything for BUG (if there is, I'd like to shoot that as well, as I want to use the one I EDC the most), so not sure I could use the P938.


For now though, I've got a ton of 115 gr bullets that I want to use. The recoil of the higher loads was noticeable, compared to the 5.1gr I was using, but I do seem to be (subjectively) more accurate slower shooting with the 5.3 and 5.4 gr. Maybe it would be good for me to shoot slower and work on accuracy at this point?

Here are the top 3 shots for the PPQ (using a rest for barrel and blanket for forearms):



and the top 3 shots for the P938 (no rest, just forearms on blanket):


It is about 10-11 yards away, with a 3.5" target.


For the recoil, maybe I should load up a bunch and compare them to the 5.1gr I have - maybe with a more rapid fire to see how it affects accuracy.