An Exercise with P10c, 124gr. FMJ with Sport Pistol powder

[tdogg]

I'll echo what wobbly said earlier in the thread, you can see those thin lines at 25yds?  Give yourself a bigger dot to aim at!  I use a 2 inch dot at 10yds.  That would be better than cross hairs at 25yds.  You may want to reconsider your target distance for load development.

I use the 10108 2 inch black dot target most of the time located here: https://www.targetz.com/targets08.htm

You can almost see an elevation plateau around the 3.9-4.0gr charges.   Might want to investigate that more.   Did you chrono the loads? 

Cheers,
Toby

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[Wobbly]

I'll echo what wobbly said earlier in the thread, you can see those thin lines at 25yds?  Give yourself a bigger dot to aim at!  I use a 2 inch dot at 10yds.  You may want to reconsider your target distance for load development.

• I test at 10yds, which might be on the short side, but that's where I started and (to allow comparison on all my targets) that's what is still used. For targets I go with the National Target Co TQ-2. This has a 2.3" bull on 4x6" target paper. Just right for easy delivery and easy long-term storage.



Apparently, the human eye needs a sharp point to focus on. At 10yds this target looks like a dense black dot that is slightly larger (1.5x ?) than the front sight. Very easy to get a "6 o'clock hold" working.

These people have hundreds of targets. Check them out. They do discounts for clubs, Scouts, almost anything.
https://www.nationaltarget.com/


• On the other hand, is does look like you got something working at 3.8gr. So the mo-jo may be at 3.7/3.8 depending upon components. I'm not discounting any of your work here. There really seems to be something concrete at 3.7/3.8gr.

 

[Duke Nukem]

Thanks, Tdogg!  Thanks, Wobbly!

I'll get some targets like you both described and go through the process again except from 10 yards.  I can see the lines on the target, but they don't appear bold from that distance.  I do find this interesting, and even though my results weren't stellar I think I'm learning something.

 I've only owned a gun for a year, and joined a gun club/range last November, so if it looks like I'm a beginner, you're seeing right.

Question: if I start using a bullet made by another manufacturer, same shape and weight (coated instead of jacketed), do I need to do this again?  I'm down to less than 500 of these bullets and have an order in for something from Missouri bullets.

I've ordered an optic for my pistol, but I'd like to learn how to use iron sights before I start something new.  Lots to learn!   

[Wobbly]

Question: if I start using a bullet made by another manufacturer, same shape and weight (coated instead of jacketed), do I need to do this again?  I'm down to less than 500 of these bullets and have an order in for something from Missouri bullets.

MBC makes lead bullets only, lubed or coated. If you are replacing one lead bullet with another of the same weight and shape, then you might not need to do the entire test set. All bullets are different, but I might step back by 0.1gr and do a test on -0.1gr change, 0.0 change, and a +0.1gr . Meaning if you considered 4.3gr your optimum load with the old bullet, then test with 4.2, 4.3 and 4.4gr.

That help ?

[Duke Nukem]

MBC makes lead bullets only, lubed or coated. If you are replacing one lead bullet with another of the same weight and shape, then you might not need to do the entire test set. All bullets are different, but I might step back by 0.1gr and do a test on -0.1gr change, 0.0 change, and a +0.1gr . Meaning if you considered 4.3gr your optimum load with the old bullet, then test with 4.2, 4.3 and 4.4gr.

That help ?

Yes thanks, that helps a lot.

[Bossgobbler]

if you can get a few sandbags and rest the gun and not your wrist.

[Wobbly]

if you can get a few sandbags and rest the gun and not your wrist.

And get one extra sand bag for your butt to perch on too !!
Some of those targets look like you might have been sitting in your girlfriend's lap, and that is definitely not allowed on this forum.

 

[Duke Nukem]

if you can get a few sandbags and rest the gun and not your wrist.

And get one extra sand bag for your butt to perch on too !!
Some of those targets look like you might have been sitting in your girlfriend's lap, and that is definitely not allowed on this forum.

 

.

Thanks, I've got a pile of sand, I'll look into making a sandbag.  Once I've done that, I'll look into how to use a sandbag!   

Yeah right, Wobbly!  I could say "I wish", but not really . . . I need all the extra cash for shooting!

[Duke Nukem]

Okay, I got serious.  I picked up a chronograph on sale, went to the range without a girlfriend, set up my sandbag, spit out my gum . . and did the best I could do using my ability and technique.  These at 10 yards, target paper was 4-1/4 by 5.5.

This was using Geco brass, Sport Pistol powder, and Armscor 124 grain FMJ round nose bullets, Federal 100 primers.
I did 11 levels of powder, five shots on the target and five over the chronograph:

4.5 gr. avg. 1108 fps, sd 23  spread 58   group size 1.69

4.4 ? I messed up and didn't record this one

4.3   1091 fps    sd 23    spr 61    gr. sz.  1.0

4.2   1063        sd 11     spr 46     gr. sz. 1.81

4.1   1050        sd 17      spr 46   gr. sz.  2.25

4.0    1042       sd 23     spr 62    gr. sz.  1.03

3.9    1024       sd 22     spr 60   gr. sz.  1.62

3.8    1001       sd 6.2     spr 16   gr. sz.  1.50

3.7    982         sd 11      spr 24   gr. sz.  .84

3.6    962        sd 22      spr 57    gr. sz.  1.69

3.5    937        sd 11       spr 28   gr. sz.  1.47






If you look at the SD for the 3.8 load, it's the smallest, but the group at 3.7 is better (again).  Any logical reason for that?  Another area of curiosity is 4.4 & 4.3 shots are somewhat gathered together, but the SD is smaller at 4.2.  I'm guessing there isn't a strict correlation between group size and standard deviation.  Should my takeaway from this be load at 3.7?

Another question- Alliant says max load for this bullet is 4.5 with a fps of 1089 in their test barrel, I'm up at 1108 in my P10-C.  Should I figure I'm overloaded at that amount?  I haven't noticed any signs of over-pressure on the brass, but I don't really want to beat my gun up.

[tdogg]

So to answer your second question first, yes you found max load.  The last three rungs (4.3, 4.4, and 4.5) on the charge ladder are at or above max load.  That is the beauty of using a chrono, you get that information real time and you can stop progressing up the ladder and stay in the safe zone.  Reading pressure signs on pistol brass is not advised, if you can see signs of pressure on a pistol case you are well beyond the safe zone.  There is not really any good reason to load a FMJ at or above Saami pressure specification.

Where you decide to load isn't always cut and dried.  If you plan on shooting competition, you will want to make minor power factor and that means you should look at or around the 4.0 grain load.  If you are only looking for soft shooting accuracy, then the 3.7 load fits (assuming it is clean burning).  If you are trying to best Joe L at long range then you may want to push the velocity toward the top to buck the wind.

In looking at your data, the St Dev and Ranges for the ladder test are not that good/consistent.  I'd wager that you could probably use more practice pulling the handle (consistency is king).  How does your OAL variation look on the finished cartridges?  What are you using to verify the charge weights for each ladder?

Cheers,
Toby

[Duke Nukem]

This last group of 110 cartridges I weighed each charge, I didn't use the powder dispenser.  It's too late to check OAL's, but I'm relying on the Lee seating die which is set at 1.112, I noted it does vary some, but no more than .003 either side when I checked. 

As much as anything, this is a learning opportunity for me; as the expression goes, I don't know what I don't know.  That's why I'm willing to share less than stellar results with the whole world!

[tdogg]

Didn't mean it as a dig!  More of constructive criticism. [emoji16]  There are so many things that go into making consistent rounds, I'm still learning all the time.

Case lube helps
Consistent handle pull
Good metering powder
Case head stamps
Etc...

Also how you shoot through the chrono will also affect the data.   Aligning it with the target and minimizing shooting through it at an angle helps.

Plus or minus 0.003 is pretty good!  I don't think I acheive that with coat lead. 

Regardless of the velocity spread it looks like you found some decent accuracy loads that will shoot nicely.

Cheers,
Toby




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[joejoe05]

Really cool to see the progression. Thanks for sharing! Looks like you have a winner at 3.7gr.

Any idea why all your shots are up and to the right? At 10 yards on a bench I would hope to see more holes in the center bullseye.

Also, might be better to share the data from lowest to highest weight in the future since we should be working up the ladder and read left to right.

Looking forward to seeing more of these from you. Keep it up!

[Joe L]

Duke,

I don't reload, so I can't help you there.  But I shoot a lot of targets, sometimes poorly. 

Here is where I would go from here, where you have made excellent progress.  First, address the SD and spread issues so you know the loads are as consistent as possible.  Then load 50 rounds at 4.0 and 50 at 3.7.  Go shoot and, if possible, chronograph them at the same time.  Same everything else as above--target size, distance, technique.    See if your 10 targets at each load are consistent in group size and then pick the load that gives you the best results, using the 5 best targets at each load, perhaps, to minimize the spread of the shooter.  See if the average is similar to the two targets above from which you picked the 3.7 and 4.0 loads.  If there isn't a clear winner, try 3.9.

Don't release the slide after inserting the magazine with the slide lock.  With the pistol aimed down range, pull the slide back as far as it will go and release the slide so that the first round is pushed in to the chamber and the barrel is seated with the same spring pressure as the second shot will be.  If you "ride the slide" to gently chamber the first round, the barrel will not lock up in the same position relative to the sight as the rest of the shots. 

One shot off in the 4.0 group would most likely be me, not the ammo.  That is no different than one off the paper at 200 like I showed in one of my recent videos.  I know exactly how to deliver a perfect shot from a pistol from a rest, I just can't do it physically and mentally 50 shots in a row.

So now you get to learn two disciplines at the same time, and try to determine cause and effect with a lot of simultaneous variables.  Did I mention I don't reload?   

(You, however, can do it!)

Joe   

[Wobbly]

Man, oh man ! 3.7gr just won't go away, will it ?   

So the black dot seemed to help you. Those targets are much more consistent.

I'll hang with Tdogg. Looks like 3.7gr for plinking and 4.0 for competition.