.45ACP magic load ?

I'm developing a load based on Brazos 180 gr SWC bullets, N310 and Winchester WLP.
I want to use it on both long and short lines.
 
I shot 20-30 rounds groups on 25 yds targets from a sandbag. My pistol is a 1911 with a 5" Bar-Sto match target barrel 1 in 16" twist.
I covered a range from 3.6 to 4.4 gr N310. I loaded 50 or 100 rounds series, and measured the initial, final and halfway through masses, pretty consistent.
 
My chronograph collected some unexpected data.
Here is the graph :
   Blue= Avg
   Red= StdDev
   Green= Spread


Here is the raw data :


What do you think about what is going on between 3.7 and 3.8 grains? Is 3.7 gr a "magic load" for my pistol with an optimum yield from the amount of powder?

Did you sort by case capacity (volume) before loading?

In general the Bar-Sto barrels seem to perform accuracy wise a little better with Jacketed and Karts with lead, but you will find some that go the other way.  

Look at my notes in the favorite loads section.

3.85 grains of VV 310 with 200 gr OT was the best for most of my guns.  the 180 gr SWCs shot almost as well.  If you are using coated bullets you might want to bump that to 3.9 gr.  I used the 200 gr SWC at 50 and simply replaced with 180 gr SWC for 25, no other changes in the loading process. All rounds seated off the shoulder for consistency.  

My SDs were single digit range.  Check your crimp consistency.  Your velocity spreads should be a little less that that, especially at 4.4 (which by the way is THE powder charge for me with 185 JHP Nosler / Star!)

And WLP primers seem to help with consistency as well at lower charges. (They are rated for standard and mag loads.)

CR

I too have been doing a lot of testing over the last week and I am taking a different approach. Like you I am shooting N310 and a SWC but mine is Zeros 185. My old setup was 4.5 N310 with a Zero 185 JHP and 3.8 of N310 with a Zero 185 SWC for the short line.My pistol had a 14 lbs recoil spring. This combo shot good and I thought my testing was over. I was at the range and for some reason I didn’t bring my long line JHP’s so I decided to test the short line SWC’s at 50 yards. I setup my rest and fired 5 and the group was amazing! So I fired 5 more and I was shocked that a quarter could cover the group. I did it 5 more times. I have a nice chrono but I don’t care what the speed is I am just testing group size. I have also lowered my short line charge to 3.2 and now I have to use a 10lbs recoil spring. This is been the best week of shooting my 45 that I have had in along time. Before I left I shot 3 strings for score. 97,96,95. The 97 had a 8 in it and the 96 and 95 just had to many 9’s

Some barrels like lead, some like jacketed, some don't care.

Like I said in another thread, you really need to listen to your gun and see what it wants (accuracy and reliability wise - sometimes stats don't seem to matter much).

Fast powders, like N310, don't burn completely before the bullet leaves the barrel, so more powder doesn't necessarily mean higher velocity. Temperature, case volume, powder position in the case etc. will all affect velocity readings.

One piece of important information is missing in OP pistol description, - sights.  And that would affect load selection.  Open sights or frame mounted optic - 3.7 - 4.0 gr on N310 under projectile would be the range to work with.  Slide mounted optic - 4.2 - 4.5.

I think, data for 4.4 gr test is somewhat skewed and inconsistent with other test batches.  I'd re-test this load.

AP

Where's the chart with the group sizes? Isn't that the thing that matters most?

Thank you all for sharing your experience.
First things first, here are my groups:

In all honesty, they are all the same at 25 yds.
50yds separates the good from the bad, regardless of std deviation!

In reply to CR10X:
I believe I do not shoot well enough to see whether a Bar-Sto or Kart barrel does better with a coated lead bullet. I'll stick to what I have anyway.

I had read your posts, and many others before embarking in this testing process. Not that there were conflicting info, but I wanted to find out what my gun likes best.

I felt that 4.4 was too much. From the very first rounds I knew I didn't like it. The weak 11lbs recoil spring probably had something to do with it. I replaced it with a 13lbs but I don't plan to go back on this load.

I measure the crimp on 10% of my reload. I get consistent results between .463" and .465".

In reply to James Hensler:
It looks like we agree on the fact that there's a sweet spot for lead SWC somewhere around 3.8gr?

In reply to PhotoEscape:
I have a light reflex red dot sight on my slide.

james r chapman wrote:In all honesty, they are all the same at 25 yds.
50yds separates the good from the bad, regardless of std deviation!

I reloaded another batch with 3.7 gr and I will test it on the long line sometime this week.

Hey put the 11lb spring back in and load 20 with 3.4 of N310 and post what happens. You can Chrono if you want but post the group. I think you will be surprised and it’s a 25 yard load

Doing some crimp variations Ransom testing @ 25 yds. 10 rounds per target.
My Caspian really likes the Zero 200 SWC in front of 3.6 Clays with TZZ brass and the .462 crimp. Started at .470 & gradually reduced it.
Now the Springfield doesn't like the Zero's. It likes my H&G 130's @ .465 in front of 3.6 Clays. It just doesn't like the 130's quite as well as the Caspian likes Zero's.

Now if I just had the ability to shoot it without the tremors.
Al

Al wrote:
Doing some crimp variations Ransom testing @ 25 yds. 10 rounds per target.
My Caspian really likes the Zero 200 SWC in front of 3.6 Clays with TZZ brass and the .462 crimp. Started at .470 & gradually reduced it.
Now the Springfield doesn't like the Zero's. It likes my H&G 130's @ .465 in front of 3.6 Clays. It just doesn't like the 130's quite as well as the Caspian likes Zero's.

Now if I just had the ability to shoot it without the tremors.
Al

What brand of barrels are in your guns?

S148 wrote:

Al wrote:
Doing some crimp variations Ransom testing @ 25 yds. 10 rounds per target.
My Caspian really likes the Zero 200 SWC in front of 3.6 Clays with TZZ brass and the .462 crimp. Started at .470 & gradually reduced it.
Now the Springfield doesn't like the Zero's. It likes my H&G 130's @ .465 in front of 3.6 Clays. It just doesn't like the 130's quite as well as the Caspian likes Zero's.

Now if I just had the ability to shoot it without the tremors.
Al

What brand of barrels are in your guns?

 
Everything gets a Kart.

James Hensler wrote:I too have been doing a lot of testing over the last week and I am taking a different approach. Like you I am shooting N310 and a SWC but mine is Zeros 185. My old setup was 4.5 N310 with a Zero 185 JHP and 3.8 of N310 with a Zero 185 SWC for the short line.My pistol had a 14 lbs recoil spring. This combo shot good and I thought my testing was over. I was at the range and for some reason I didn’t bring my long line JHP’s so I decided to test the short line SWC’s at 50 yards. I setup my rest and fired 5 and the group was amazing! So I fired 5 more and I was shocked that a quarter could cover the group. I did it 5 more times. I have a nice chrono but I don’t care what the speed is I am just testing group size. I have also lowered my short line charge to 3.2 and now I have to use a 10lbs recoil spring. This is been the best week of shooting my 45 that I have had in along time. Before I left I shot 3 strings for score. 97,96,95. The 97 had a 8 in it and the 96 and 95 just had to many 9’s

James, how did the 3.2 grains of N310 work out? Did you go further down?

Thanks,

Jason

It would take a real statistician to tell you the right number of rounds it takes to have statistical confidence in your measures of velocity consistency. But I am quite certain, 20 to 30 rounds is not enough.

I am very unhappy with my Chrony chronograph, the on board computer only counts to 32 shots, and I shoot out of 50 round containers. I see weird ES's, SD's all the time due to small sample sizes.

Here is a retest. The flyer was my fault and I knew it was out before I looked through the scope. I have never checked the velocity even though I have a chrony. It feels good in my hand, is enough to work the gun but not overwork it. I think my gun has a 12 lb spring, has a nice snap to the lockup and has a 30mm UltraDot on it.

I also did a lot of testing. Not so much lately. Once you figure out that "magic load" there is not much reason to keep looking for it. I have a non modified Range Officer that shoots good enough at 25 yds to test my loads. Stock barrel and bushing. A little polishing and decent dot is really all it takes at 25. Both of these groups were shot using one hand, sitting and wrist resting on a sandbag. I didn't sort my brass, measure each shot of powder, sort any bullets or do anything except crank the handle and feed it bullets. Once again showing that all of that is not very important to get decent groups at 25yds.

There is an old quote about accuracy. "Even a load with bubble gum and talcum powder will group at 25 yards."

LenV wrote:I didn't sort my brass, measure each shot of powder, sort any bullets or do anything except crank the handle and feed it bullets. Once again showing that all of that is not very important to get decent groups at 25yds.

But, did you clean the primer pockets, wet tumble, or dry tumble? 

I find 3.7 to 3.8 VV310 Starline Brass , shoots best out of MY Springfield Range Officer with a factory barrel. I was a little surprised it shot lead that well. With JHP the barrel seems to be as good as any. 

WST go 3.9.