I recently loaded and tested some .44 special loads but my velocities are A LOT higher then the data calls for? Data was from the bullet manufacturer tested in a S&W 6" barrel

The load was WIN .44 spedial cases, WLP primers, Lasercast 240gr SWC bullets .431 dia

all fired in a S&W 629 revolver with 6" barrel

6.0gr unique data predicts 660fps
observed 896.3/878.9/828.5

6.4grs unique predicts 720fps
observed 897.5/916.2/916.0

6.8grs unique predicts 780fps
observed 970.8/977.5/961.1

There were no signs of pressure, cases easily removed from cylinder and were very mild shooting. Chronograph was a Shooting Chrono Beta Master at 10' from muzzel.

Thoughts, suggestions, concerns?

Big Bird, your velocities seem a little bit high but you never know, there are a lot of things involved, a big one is barrel/cylinder gap, this can change things quite a bit. Also I have the same chronograph you have & mine has always been quite a bit faster when checked against my friends CED chrono. Mine is consistent but always reads too fast. My normal load in 44 special brass is 7.5 grs of Unique with a 240-250 gr slug, these usually clock about 925 fps to 975 fps, depending on gun & barrel length. Its a very good load & your 629 will handle many, many thousands of them & never break a sweat, its pretty mild in a magnum gun.

Dick

My old Speer manual had an interesting test .They took a bunch of 357 , 4" revolvers and tested them with 125 gr ammo all from the same lot. The velocities ranged from 1200-1600 fps !!!
So that's why you have to handload carefully considering more than one book, +chrono + checking for pressure signs .For the 44 special the 200 gr at 900 makes a dandy defense load and a 240 at 950 makes a good short range deer load.

I would suspect some hoakie chronograph readings, I would retest and shoot another load in a different gun at the same time as a point of reference.

You are shooting a .431" bullet, too. That extra .001" allows for very good gas sealing. That factors into what you are seeing as well.

Dick is the authority here, having probably shot several hundred thousand more cast bullets than myself, but in 30 years of casting, I have observed higher velocities and lower pressures with cast than jacketed, in almost all cases. I typically use jacketed data for my own cast bullets, and usually find numbers roughly 100 fps higher with cast than with jacketed, sometimes higher than that. I just chalk it up to larger diameter bullets sealing in the bore, and the fact that lead is somewhat self lubricating, which leads to lower pressure.

But maybe I am nuts./

Thanks for the insights guy's, Swampbuster I had shot 3,...243 loads and 2 7-08 loads over it that same range session and the velocities were close a little lower than the load data predicted for those loads.

Second the similiar readings with low SD would lend me to think it was something other than the chronograph but it is entirely possible.

My main concern was the 200fps velocity increase over predicted. This is technically a good thing,...if I get higher velocities with a lower charge in this firearm correct?

Dick if I'm getting 970fps with 240gr SWC and 6.8grs of Unique what is gained by slowly working up to 7.5 grains? I would think I would be in the 1100fps if everything held true to my observations.

What was the temperature out?
Higher temperature = higher velocity
Was your chronograph opened perfectly flat??
If the chrony's are slightly closed, they give high readings.

AS: Temp was 78 degrees and over cast with a 2mph wind quartering off my left shoulder.

It is possible the unit was not opened completely flat. I have it mounted on a removable tripod base, and just use the quick disconnect on it, once I level the tripod.

I will have to reload the 3 charges and see what I get for velocities, I'll have to watch that in the future.

Big Bird, sorry for the late reply, I"ve been moose hunting.
Its possible the high velocity readings are correct but I doubt it & its very possible as Sniper suggested that your Chrony wasn't all the way open, this is quite common when using them.
If you have access to another chrono you can double check the readings against yours.
Most 44's, depending on barrel length will clock right around 925-975 with 7.5grs of Unique & the 240-250 gr slugs...but some will go faster, you'll just have to double check your Chrony, I'm betting its reading too fast.

Dick

I had a pair of cheap chrony's after erratic readings, sent the 1st IN and it was replaced. The replacement seemd to give me accurate readings, but maube 10% of the time it gave me ERROR or no reading at all.

Gave it away...bought an OEHLER. I'd say if you have a cheap chrony...you got what you paid for.

Was at the range the other day testing .243 loads and was getting consistent readings, over the chrony. I suspect now that the high readings were from the unit not being fully open.

Thanks for all the input,....I'll have to work up the .44 specials again and take another go at it.

I was just nervous,...when the velocity was so different (higher) then what was expected in the loading book.