Help with some weird 44 spcl Chrono results

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Typetwelve

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Quick facts:
Loading for 44 special, all using CCI non magnum large primers.
-Ran some Missouri 240g lead over 6g Unique (my control)
-Ran some Hornady 200g XTP over 9g Unique, 13.5g 2400, and 18g 2400
-Ran some Hornady 180g XTP over 8.5g Unique, 14g 2400, and 16g 2400

All rounds were through my S&W 629 4".

I started with my 240g lead "control", chrono was a-ok, showing very predictable results in the high 700 fps range.

I started with the 200g XTP over 9g Unique, not sure what the deal was, the fps was coming in at high 300 fps range, not possible. I moved to 13.5g of 2400, it was reading mid 500 fps range, again, not possible with that load. When I moved to the 18g 2400 load, the wheels fell off, FPS on the first 2 shots was in the 8000 fps range. I immediately stopped, popped in a control round, and it was a-ok, showing fps in the high 700's. I ran 3 more of those 18g loads, 2 of which were again way over and one read 812 fps. With the recoil (and flame) of those 18g loads, there's no way they were moving in the 800 fps range. I know that's a hand-dyno assumption, but I know what a 1000 fps load feel like in that 629.

At this point, I ran another cylinder of my control and once again, A-ok.

I moved on to my 180g loads and all of them chrono'd just like I expected them to; 8.5 unq in the mid 900 fps, 14g 2400 in the mid 700 fps range, 16g 2400 in the mid 900 fps range.

I never moved the chrono during this session.

So, I have two questions:

-For the life of me, every 200g XTP load I made caused problems, I have no idea why.
-Every 2400 load I made thew unburnt powder everywhere.

Any help on this one?
 
What chrono? If it uses sky screens, how far away were they?

It's a Prochrono DLX. The skyscreens are the ones it comes with.

I would have really focused on the chrono, but it was running fine all day with everything except those 200gr XTP loads, which is really strange.
 
Did they feel any different?
Less recoil or quieter report?

They all felt like some pretty stout loads, more umph than my 6g Unique 240g loads I use for basic target practice. The 18g 2400 loads were down right hot, not magnum hot, but hot enough.

I made a chart before making all of these loads and give or take, I'm not too far off on my estimations. With the 180g loads, I was within 100fps (or less) of all of my estimates.

I estimated the following with those 200g XTP projectiles:
9g Unique- 1000 fps
13.5g 2400- 900 fps
18g 2400- 1100 fps

I knew those 18g loads were going to be screamers...and they didn't disappoint. Plenty of recoil and a nice flame out the end of the barrel (again, running these through a 44 magnum revolver). I have an old article where they review all kinds of hot 44 special loads. They listed a 200g XTP over 19g of 2400 in the 1263 fps range at under 25,000 PSI.
 
-Every 2400 load I made thew unburnt powder everywhere.

Any help on this one?

In my experience, 2400 is the messiest powder I've worked with. It leaves a stuff everywhere. It might produce high velocity and it might produce good accuracy, but gawd the mess . . .
 
In my experience, 2400 is the messiest powder I've worked with. It leaves a stuff everywhere. It might produce high velocity and it might produce good accuracy, but gawd the mess . . .

Yup...a mess it made. It didn't leave the revolver looking like a coal miner, but it chucked powder everywhere and on everything.
 
-Every 2400 load I made thew unburnt powder everywhere.
It is too slow for .44 Spl pressures. Not even "hot" .44 Spl loads, which I recommend you do in magnum cases. It will not burn completely as you found out.

What fast to medium speed handgun powders do you have?
 
Chronograph may be too close and is being triggered by powder/blast. I have the DLX and I typically place mine 15 feet from the muzzle and have used it with 9mm, .45acp, .44mag, and .22TCM (the fireball generator!). No issues with any of these.

Try backing it up to 15 ft and see if you get more reasonable results.
 
It is too slow for .44 Spl pressures. Not even "hot" .44 Spl loads, which I recommend you do in magnum cases. It will not burn completely as you found out.

What fast to medium speed handgun powders do you have?

Faster than 2400? Bullseye, Titegroup, HP-38, Win 231, Unique, Sport Pistol, I even have some N0 7, but that's not much faster burning than 2400.

Should I regulate the 2400 to magnum loads? I really bought it because that's what was used often way back when with hotter 44 spcl loads and wanted to play with it a bit.
 
As has already been said, 2400 leaves unburned powder when not loaded at the top of the range.

I have loaded some of the Keith loads for .44 Special (18.5 grains of 2400 and a 245 grain Keith bullet) and it was much better. However that load is stout and not recommended for a lot of factory .44 specials, so I'm not advocating it.

For stout (but not too stout) .44 Special loads, I like 7.5 grains of Unique or 7 grains of 700X. Neither are considered clean powders, but I shoot cast bullets almost exclusively in .44 Special and Magnum, so anything is dirty.
 
I had erratic readings once and having the screens to close was why.
Yeppers, I've gotten some pretty wild readings (and a lot of "Err" readings) on my Chrony F-1 by being too close to it. It works fine though if it's 6 or 8 feet from the muzzle of my Sheridan Blue Streak pump-up pellet rifle.:D Other than that, I place my chronograph 6 or 8 yards from the muzzle of the gun I'm going to shoot over it.:)
 
Over the decades I have had a lot of strange velocity readings from my Chrony Chronographs and these are the things that I have done to reduce errant readings.

I plumb the chronograph so it is level front and back, and side to side.

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I line it up so my bullets are going directly over the center of the sensors. Off axis shots create strange and wondrous velocities. If the sun shines on a sensor, the chronograph gets all confused. I try to set the thing up in a shaded area.

YQbTw6y.jpg


I shoot a "reference" load. This load is well characterized over the chronograph. When I am shooting pistols, this is typically a 38 Special load of 158 L 3.5 grains Bullseye. With a rifle, I have shot thousands of rounds out of a case of CMP Remington Target Match. Awful stuff, I get lots of misfires, it is not that accurate, so blowing the stuff over the screens is a good way to get rid of the stuff. Wish I had never bought the stuff, there was a reason the Army disposed this ammunition.

And I move the chronograph out. I may have had the thing 20 yards out when testing my 58 caliber musket. That smoke pole blew powder residue way, way, out. And all that residue confuses the sensors. I remember shooting my M1911 and seeing the screens rock. I had supernatural velocities. That long barrel, with a load of ball powder, was confusing the heck out of the sensors.

L0pUzCw.jpg a

The only real cure was to move the chronograph out. Ball powders in my pistols cause similar problems, 2400, AA#9, H110 in the 357 Magnum all require the chronograph to be moved out. These powders put out too much residue and confuse the sensor.

I recommend writing down the temperature and comparing in colder/hotter weather. You will be surprised how temperature affects velocity.
 
Sometimes if the chrono has problems reading the bullet coloring he bullet black with a sharpie helps.

Might or might not help cheap and easy to try.
 
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