40 S&W data: 180 gr LFP and Power Pistol

[Shrinkmd]

ABSTRACT:
I managed to get to the range the other day to test my loads, as well as some factory. I was surprised by the velocity, as they were coming out hotter than Lyman predicted. AND it was around 38 to 40 degrees out. So here is the data. I also included the A3 from the chrony, which is the average of the three highest velocities which is useful for maintaining safety, as well as avoiding dragging the average down due to the occasional flyer. The hottest load was the most accurate, with the best numbers as well. But was it "too hot"?

METHODS:
Anyway, here is the info, all shot out of my 4006TSW, measured over CED Millennium 2 chrony, regular light (no infrared for me, yet), N=50. Bullets are Dardascastbullets.com, cases are Federal NT once fired from tjconevera.com, Federal SP primers, Alliant Power Pistol, made on Hornady LNL AP.

DATA:
Wolf 180gr FMJ
High: 902.4
Low: 845
E.S.: 57.4
Ave.: 877.7 A3 898.3
S.D.: 10.7
95%: 3.1

Aguila 180gr FMJ
High: 1068
Low: 981.2
E.S.: 86.8
Ave.: 1030.9 A3 1061
S.D.: 21.5
95%: 6.2

Federal NT 180 gr LFP Federal SP Power Pistol 5.8 gr 1.125"
High: 962.5
Low: 831.4
E.S.: 131.1
Ave.: 937.6 A3 959.5
S.D.: 21.7
95%: 6.5

Federal NT 180 gr LFP Federal SP Power Pistol 6.0 gr 1.125"
High: 991.3
Low: 953.7
E.S.: 37.6
Ave.: 973.3 A3 990
S.D.: 8.5
95%: 2.5

Federal NT 180 gr LFP Federal SP Power Pistol 6.1 gr 1.125"
High: 1005
Low: 926.5
E.S.: 78.5
Ave.: 984.9 A3 1004
S.D.: 14.3
95%: 4.1

Federal NT 180 gr LFP Federal SP Power Pistol 6.2 gr 1.125"
High: 1023
Low: 970.6
E.S.: 52.4
Ave.: 995.6 A3 1015
S.D.: 9.7
95%: 2.8

Federal NT 180 gr LFP Federal SP Power Pistol 6.3 gr 1.125"
High: 1020
Low: 981.5
E.S.: 38.5
Ave.: 1007.3 A3 1019
S.D.: 7.8
95%: 2.3

Federal NT 180 gr LFP Federal SP Power Pistol 6.4 gr 1.125"
High: 1026
Low: 996.1
E.S.: 29.9
Ave.: 1015.9 A3 1025
S.D.: 6.9
95%: 2

DISCUSSION:
Wolf is pretty wimpy for 40 S&W, eh? Aguila was plenty hot. I was expecting my initial load to be around 873 per Lyman 49th ed, but look how fast they were. Each 0.1 gr of Power Pistol bumped the average by about 10 fps (I skipped between 5.8 and 6.0, oh well, but the numbers still work) I felt a little nervous shooting the last box, as they were almost as hot as the Aguila factory. I have not cleaned or resized the brass yet, but I don't see any obvious bulges or smiley face problems (and 4006TSW chamber appears to have full support)

The pistol worked flawlessly, besides one dud primer (I hit it several times, no go...I though that only rimfires had duds!) and one time when it didn't go completely into battery, and needed a slight shove to lock up. Some of the my reloads had a some bullet lube smeared on them, so I'm assuming this was the problem) I was happy, since this pistol had some "slide stop early" issues which S&W took care of (replaced slide stop), but it seems to be running nicely now. Especially with all brand new Wolff recoil, fp, and magazine springs.

So, what should I do to about the velocity? Should I try seating the rounds a little longer? I wonder if the Federal NT cases have less volume, or are Federal SP primers hotter? Lyman says 4" test barrel, and the 4006TSW is a 4". When cooking up to make major power factor, it looks like the 6.0 gr load would be fine, right?

Sorry for the long post, but I hope the data is interesting and useful to others.

 

[WatongaJim]

Great post. I have a .40 but no chrony so I found the data interesting.

 

[Shrinkmd]

Another question: Could my chronograph be off? I was looking at data around the net, and it looks like much higher charges of Power Pistol should yield a lower velocity. For example, loaddata.com says 6.6 gr should equal about 996 fps. My 5.8 gr charge was yielding way higher than the 873 expected.

Or could my scale be off? I frequently check against the 10 gr check weight, as well as weighing multiples of 5 or 10 and weighing together to make sure my weight is exact before loading. The garage was really cold (in the high 40s) when I loaded these. Is it possible the scale wasn't working correctly and the charges were just too high because the scale was off?

I loaded .357 magnum under similar conditions, and those appear to be a little under speed, or about right, and certainly not off the charts like these loads.

What would make the most sense as far as working this load up again?

 

[GooseGestapo]

Your'e comparing apples to oranges.....

The lead bullets have a much lower coefficient of friction going down the bore. With similar pressures, bullet weight, and powder charge, the velocity will be 50-100fps higher.

I'd find the point at which the accuracy is best, and call it good. 25-50fps difference won't be significant in performance. Accuracy is what counts...... (I reread your post and saw it was the highest velocity load... Are bullets .400" 0r .401"? That could also explain the difference...)
Also, did Lyman use a Federal primer? Federals are a bit hotter than either CCI or Winchester primers. I use only Winchester's in Semi-Auto's, and Federals in Revolvers due to greater sensitivity of the Federals. I've had a couple of extruded primers on SA's in big matches that cost me big $$$ due to lost points. Hence, only Win's on 9mm and .40's.

Your S&W has a premium grade barrel, and that alone can account for the exta velocity.

 

[ljnowell]

Looks like you found the ceiling for power pistol with your particular bullet and length. I have done similar testing with 185gr XTPs in my .45s. I found that when I get to 9.4 or so grains I can load all the way up to 10.0(overmax BTW) and see no gain in velocity.

 

[Shrinkmd]

Also, did Lyman use a Federal primer? Federals are a bit hotter than either CCI or Winchester primers. I use only Winchester's in Semi-Auto's, and Federals in Revolvers due to greater sensitivity of the Federals. I've had a couple of extruded primers on SA's in big matches that cost me big $$$ due to lost points. Hence, only Win's on 9mm and .40's.

According to Lyman 49th, they used Winchester Small Pistol. I have some CCI which just arrived, so I can see if that makes a difference in getting the velocity a bit less hot.

Are bullets .400" 0r .401"?

Sized to .401, or at least that is how I ordered them. I should measure and check.

Your S&W has a premium grade barrel, and that alone can account for the exta velocity.

Really? I didn't know that, and I was unaware it could actually make a difference!

The lead bullets have a much lower coefficient of friction going down the bore. With similar pressures, bullet weight, and powder charge, the velocity will be 50-100fps higher.

Well, the numbers from the Lyman manual were for lead, not for jacketed. It looks like 1000-1050 or so is for factory loadings, and all the data for Power Pistol clocks them in a little less.

Thoughts for the future: I will load the same loads in CCI primer and see what happens!

 

[Shrinkmd]

It's all in the size of the primer flash hole!

Duh! I was cleaning some brass, and noticed, hey, the flash holes in the NT brass are way bigger than all the other 40S&W range brass I have. A quick search returned my answer.

The larger flash hole lets more flash in, resulting in higher pressures. I forget where I found this, but they suggested using lower load data, or certainly not going above starting loads using brass with this non-standard flash hole.

I think I will try going a bit below the Lyman manual on my next batch with this brass. I think that the Hornady listed considerably lower Power Pistol loads anyway, as I was hoping to get around 900 fps to practice with before making hotter loads.

Sorry to revive such an old thread, but I figure if anyone else has a similar problem, the solution is now here.

 

[Branden967]

Bumping...very interesting.

 

[LiveLife]

Me too, I am currently testing Unique and got it working quite well and now this thread is making me want to try Power Pistol ... dang, W231/HP38 gonna get jealous!