45 colt chrony #s today 4/22/23

[Deleted]

I took the chrony out. Cheaper Caldwell. It's worked ok for years but midway through my work today, it stopped. But I did get some data that I'm trying to understand. Tested in 3 ruger 45 colt revolvers.

Gun 1. Clements nm blackhawk bisley. 5 1/2" Custom barrel. I think factory cylinder.

Gun 2. Harton old vaquero. 4 5/8" Ruger barrel and cylinder.

Gun 3. Horvath nm blackhawk. S&w barrel 4". Ruger cylinder.

Few constants:
Starline brass-varied times fired

Load #1-
Bullet: mp 270 saa 285g solid PC
Powder: longshot 11.3g
Primer- WLP

Clements BH 5 1/2
Spread 154
Avg fps 1097
SD- 40

Harton vaquero
Spread 50
Avg fps 1080
SD- 15

Horvath bh
Spread 33
Avg 1072
SD 12

Load #2-
Bullet- mp 270 saa 285g PC solid
Powder- longshot 11.3 g
Primer- cci 300

Clements bh
Spread 102
Avg fps 1080
SD 35

Harton vaquero
Spread 36
Avg fps 1073
SD 10

Horvath bh
Spread 35
Avg fps 1063
SD 13

Load #3
Bullet- MP-45 carbine.270g NLG PC penta
Powder- longshot 11.3g
Primer- cci 300

Clements bh
Spread 124
Avg fps 1122
SD 36

Harton vaquero
Spread 58
Avg fps 1095
SD 17

Horvath bh
Spread 55
Avg fps 1104
SD 15

Looking at this info I see each Gun having a SD trend. The Clements gun is high and the Horvath consistently lowest. With the Harton Gun trending consistently lower as well. I guess it's variations in the guns themselves? Barrel cylinder gap, forcing cone, alignment that adds much to the variables? The Clements bh has been exceptionally accurate for me but it always trends higher SD and avg fps Spread.
My avg fps align reasonably with Brian Pearces Load data for the 270saa bullet published in Handloader last year.

The 45 carbine bullet is no lube groove and I suspect it runs at higher pressure but the cci 300 Primer didn't show any signs. I was interested to see how the 270saa Load was affected by trying WLP and cci300 primers. The results were similar and accuracy appears the same. I've found the 270saa bullet very accurate in just about every 45 colt I've tried, but the carbine bullet is inconsistent. I think the lube groove version would show more potential.
Looks like SD and avg fps are lesser problems at revolver ranges? I just think it's weird that the Clements gun shoots such high spreads and SDs but is also my favorite accuracy revolver? The best SDs I ever got in this gun was with unique and the worst was 2400. I have not shot either of those powders in either of today's other 2 test guns.

Looks like I'm in the chronograph market and bummed I didn't get to test my other loads. I think that each gun showing similar SD numbers in each of the three loads proves that much of the variable lies in the guns themselves. I appreciate you reading this. Maybe it helps you or you can help me get better results.

[Deleted]

L to r. 
Clements, Harton, Horvath

[edk]

Interesting there is little-to-no velocity advantage firing the Clements with its' 5-1/2" barrel.

[lar4570]

That's a bummer about your chrony. I read somewhere that they are out of business. I've had the Beta Pro? for several years and like it.
I've had Chrony's since the F1 came out and the only problems I've ever had with them was when friends would end up shooting it.
My standard disclaimer was you shoot it you bought it.

[Deleted]

Apr 22, 2023 15:05:03 GMT -5 edk said:

Interesting there is little-to-no velocity advantage firing the Clements with its' 5-1/2" barrel.

I'm a bit surprised about the barrel length changes also. I usually take a couple guns with the same barrel length but even then there is variance.

I don't really need a chrony with all the data that's out there but I like having my own notebook of personal load data to compare.

[bigbrowndog]

A chronograph provides so much more info than just velocity related, it is a must have for me. However it also allows no conclusions to be drawn about velocity and barrel length. There are too many variables to unequivocally say there is no advantage to the 5.5” barrel over the shorter. Powder, barrel constriction, etc are just some of the variables. For me the biggest help a chrono gives is actual data for a given load from my guns at various temps, humidity, and elevations. I’ve met a few folks who prefer to guess or not know what their velocities actually are, to me that is like driving a car with an inoperable fuel gauge, or one that gives random levels and not know if they are correct.

Several times I’ve been able to chrono and place data into a ballistic program and then go in to make accurate hits on targets beyond 100 yards just by knowing velocity and trajectory. I carry mine in my vehicle at all times so I can chrono whenever the urge or need arises.

Trapr

[edk]

Apr 22, 2023 18:47:18 GMT -5 bigbrowndog said:

There are too many variables to unequivocally say there is no advantage to the 5.5” barrel over the shorter. Powder, barrel constriction, etc are just some of the variables.

Completely agree. All things being equal: barrel dims, gap, on and on, there absolutely would be a velocity difference. I guess the essence of my post might be expressed in a different way: Note how all the variables in several revolvers can stack in a way that the differences in their barrel lengths is not apparent when chronographed.

[bigbrowndog]

EDK, I’d be curious to see if the lack of difference carries over for other loads, bullets and powders, perhaps it’s just Longshot or that load that delivers those consistent velocities over the spectrum of barrel lengths
It is an interesting anamoly.
Trapr

[Deleted]

The chrony is a useful tool but I've done a lot of testing the past few years and have notebook full of load results. I don't have to be in a hurry. I don't hunt. I really only shoot my guns at one location. The range here only offers 40 yds or so in the handgun area. The rifle range allows handguns but it's not set up for anything other than strictly paper punching and ive had guys complain about my revolver on the line. The other local ranges are even shorter range for handgun and more limited for handguns on the rifle. East TX is not shooter friendly.

[rufus]

I have had several “inexpensive” chrony I think they were. Last year my wife bought me an Ohler I think is the name with a printout and I will say while expensive it’s worth every penny.

[contender]

Interesting results. I use my crono as a way to gauge what MY guns do with MY loads.

I bought an Ohler 35P long ago and have never regretted it. As noted,, not cheap, but worth it in the long run. I am hearing good reports about the "Lab Radar" units as well. I haven't tried one yet.

[bradshaw]

Professor.... fine report, thank you.
Perhaps because I disincline to mathematics, velocity Extreme Spread means more than the statistical Standard Deviation. Standard deviation doesn’t register in my pea brain until 10 or more rounds are fired. Nevertheless, your data is most interesting. My SWAG speculates the negligible velocity gain of the 1” to 1-1/2” longer David Clements sixgun may have a wider gap. As your report its superior accuracy, I would not assign its lack of velocity gain to an excessive forcing cone.... Unless, the Clements revolver sports FREEBORE with short forcing cone. Freebore usually reduces velocity around 50 fps, or so.

FREEBORE can be an emotion-laden subject. In general, freebore contributes nothing the rifle accuracy and is usually detrimental. Whereas, in presence of chamber-to-bore misalignment (runout), it may smooth the transition of a revolver bullet from CHAMBER EXIT HOLE to RIFLING. Anything that preserves DYNAMIC BALANCE aids accuracy.

There may be other reasons the Clements gun looks slower relative to barrel length. As various students of the revolver demonstrated years ago, CYLINDER GAP relates directly to velocity, especially at high chamber pressures. Some shooters made the same correlation to accuracy. As the main instigator in discerning barrel/cylinder gap plays only a bit part in accuracy, I have found 50 to 150 fps velocity difference far lest consequential at the target than ACCURACY.

Accuracy is a potent elixir.
David Bradshaw

[lar4570]

A few decades ago when I bought my first F1 Chrony, a friend and I were at the range shooting various loads across it. An older gentleman said to us that we were just wasting our time with that piece of junk. He said that there was no way it could be as accurate as his chronograph. I think it was an Ohler???
So I suggested that we stack them front to back and see what they read. I placed the F1 right behind his and we shot everything from a pellet pistol, 22lr, 357, 44, 45 colt and I belive he has a couple of rifles that we shot as well.
Both chronographs gave the same exact readings for every shot except once where it was off by only 1fps.
He was not happy at all and said that it didn't prove anything.
I think a chronograph is a very valuable tool, especially when working up a load for which there's not any published data.
I would really like to get something to measure pressures.

[pete]

Professor,
That Horvath Blackhawk is sweet. It's impressive how it keeps up speedwise with the longer guns. I'm thinking it just might have the tightest barrel/cylinder gap. When I rebuilt my super Blackhawk I shortened the barrel from 6" to 4⅝", and set the gap at .002". I also firelapped out a tiny bit of thread choke and polished the bore. The result was that I picked up 100fps with my hunting load, and the before and after readings were with ammo from the same box.
So what does it mean? Nothing, it's just interesting to the ballistic minded!

[Deleted]

Apr 23, 2023 23:11:31 GMT -5 pete said:

Professor,
That Horvath Blackhawk is sweet. It's impressive how it keeps up speedwise with the longer guns. I'm thinking it just might have the tightest barrel/cylinder gap. When I rebuilt my super Blackhawk I shortened the barrel from 6" to 4⅝", and set the gap at .002". I also firelapped out a tiny bit of thread choke and polished the bore. The result was that I picked up 100fps with my hunting load, and the before and after readings were with ammo from the same box.
So what does it mean? Nothing, it's just interesting to the ballistic minded!

That Horvath gun is probably my slickest ruger custom overall. I think he is seriously underrated in the sixgun world. My two Clements guns are set up like factory guns. They work awesome. The tighter guns I've had develop problems when shooting them as much as I do.