Does this .44MAG data make sense?

[Zak Smith]

I am trying to work up a load approximating factory hunting loads using Alliant 2400 with a 240gr Laser-cast SWC or XTP. I'm starting with the SWC's 'cause they're cheaper. I'm shooting a 6.5" model 629, using Starline cases and WLP primers.

Last week, I took the following data:

gr    fps  sd
12    890   53
13    938   21
14   1068   30
15   1134    5.5
16   1172   22
17   1236   28

Since that didn't really get fast enough, I did the following today:

gr       fps       sd
17.0   1205    27
17.5   1216    20
18.0   1218    22
18.5   1235    19
19.0   1280    19
19.5   1304    24

What's up with that? When I extrapolated from the first set of data, 18gr should have yielded a velocity of around 1300fps, but you can see the second set of data is requiring more additional powder for the same velocity increment vs. the first set of data. I am also somewhat confused because some of my loading manuals list MAX for this load around 22, and some list it around 19-19.8. Some of the books I have say that 19gr should be much faster than 1300fps.

Do these numbers seem in-line with your data for this load?

The primers are still rounded, and these loads don't "feel" very hot. Is the answer to keep going?

Does anyone else have a recipe for this type of load?

thanks
Zak

[sricciardelli]

My first impression is to doubt the validity of your tables...

[KP95DAO]

smithz,

It is not uncommon to hit a plateau when working up a load. You either decide to go through it or stay there. Depending on how close I am to the desired pressure and velocity levels I make that decision.

Wait until you get a load that reaches a plateau and then starts going downhill as you add more powder. This being the result of under ignition due to a slow powder and compression.

Another phenomenon is the tendency of Blue Dot to have pressure spikes when used below 32 degrees F. I witnessed this myself and thought it a fluke until I reproduced the results a second time. This had been reported; but, I thought it unlikely. Nothing like seeing something yourself.

[stans]

Perhaps you are encountering the Law of Diminishing Returns or the two sets of data have some problems. What were the weather conditions like on the two days at the range. Since the first set of loads stopped at 17.0 gr and the second set started at 17.0 gr, the velocities should be nearly identical if none of the components were changed, including lot numbers of the powder and primers. Did you disturb or find it necessary to change the powder measure's adjustments between the two sets of loadings at 17.0 gr?

[Mal H]

A couple of points to consider:

No doubt Your gun was warmer and therefore the cartridges in the cylinder were warmer when shooting the first 17 gr loads than when shooting the second set. It would be interesting to see what the 12 gr loads would produce if you shot them last instead of first. Or you could reverse the order of firing and see if there is a drastic difference in either list.

There is a point at which some of the extra powder is starting to burn outside the barrel instead of entirely inside it.

The data in reloading manuals is for "display purposes only", i.e., it is a good guideline. But don't expect their results in your gun, it usually doesn't work out that way - too many variables.


And a question: How many rounds were in each group?

[WESHOOT2]

In your gun...............

You may NOT extrapolate data ever ever ever; you must test.

Highly recommend W296, H110, or N110 for 44 Mag.

Do not recommend non-sense loads through S&W.

Based on your chart I'd stop at 19.5g 2400. Do NOT ASSUME that the XTP will perform the same as lead; you'll need to work UP again.

[C.R.Sam]

Mal and WS2 pretty well diagnosed it.

In my opinion, 6½" barrel 629, 240gr, 1300fps pretty well out there. I would back it off to 19gr for your gun. Test for accuracy. If accuracy not satisfactory I would back it down till it became satisfactory.

Like Tim said......when you switch bullets, start over and work up again.

Sam

[Zak Smith]

Here are a bunch of answers:

0. The cases, primers, and powder all came from the same physical containers for both batches.

1. Set 1 was done on a 95-100F day. Set 2 was done on an 80-85F day.

2. I make sure my chronograph is generating good data each time by running some mini-mags from my 22 pistol through it. For the first batch, this "control" group gave an average of 1017 FPS for 5 shots. For the second, it gave 1010 fps.

3. The gun was likely hotter as the first batch went through, since I had already run the same powder-points (12-17gr) through it with 180gr bullets.

4. 5 rounds per datapoint.

5. The powder measure had been recalibrated in between the two different 17.0 gr loadings. The way I load these test rounds is to use the powder measure to get just under, and the dribble the last few tenths of a grain into the scale. Before each set, I make sure the scale is zeroed.

6. I intend to re-do this experiment with XTP's, if I decide to figure out that load.

7. Factory Federal American Eagle 240gr loads clock in at 1419fps in this gun, on the 95F day. (sd = 13). On the cold day, around 1345FPS (sd=26).

8. For comparison, here's some H110 data, though using 240gr XTP's:

22.0gr   1262   17
22.1gr   1279   28
23.5gr   1332   17
24.2gr   1339   21

I started on the whole 2400 experiment because I wanted to see if I could avoid the huge fireball from H110, and get more rounds per pound of powder...


thanks
Zak

[C.R.Sam]

BUT.....
The H110 should be giving you quite a bit lower PEAK pressure than the 2400 for a given bullet wt and velocity.

Same with W296.

Sam

[Pappy John]

I've been loading the 240 XTP with 2400 powder for a year now and your numbers sound real close to mine. Through a 7.5 Redhawk I'm getting 1300 fps with 19.6 gr. Remember that 2400 is a slow burner and through your shorter barrel the more you stuff in, the more you're burning post-muzzle. The fireball probably looks damned impressive at night but you're not gonna get much faster than that with your current powder selection.

[Zak Smith]

I appreciate all the advice given here. I have reloaded lots and lots of rifle rounds (243, 8x57JS, .308), but am somewhat new to pistol rounds.

I loaded up a batch of 19gr(#2400)-1300fps loads, and my next batch will be 17gr(#2400)-1200fps, just to make things a little easier. This load is also just about the same as Keith's heavy 44spl load.

thamks
Zak

[sricciardelli]

"4. 5 rounds per datapoint. "

Are you using the same 5 chambers in the cylinder for each and every load?

[Zak Smith]

Nope, not the same chambers. Although, I have seen very consistent shot-to-shot accuracy with the 15gr #2400 load. (5.5fps SD)

[MADISON]

I killed a 3 inch 629 with 21.0 grains of 2400.
You should be aware that a S&W 29/629 is a much weaker gun than a Ruger.
My favorate load for my Ruger:
19.0 grains of 2400
I use 12.4 grains of UNIQUE in my Redhawk. Pleople tell me it is tooo hot but the Ruger Redhawk loves it.
Be careful; take notes and; work up slowly.
MADISON

[Southla1]

DO NOT START WITH THIS LOAD!!!!


For years the standard load for a .44 Mag was a 240 grain cast bullet and 22 grains of #2400. I can even show you load books (they are old as dirt like me) that show this as a MEDIUM load.

OK since then we know more and have backed off some, the lawyers got involved, and the powder may be of a different burning rate than the older powders even though they have the same designation, plus each gun is a law unto itself.

I have used loads that equal some of the old data in my .44 magnum...........do I still use it? NO!

I will admit that my "standard" 44 Mag load is 20 grains of #2400 over a cast bullet of 230 grains (linotype is light) and a regular LP primer. It's as hot as I want to shoot consistantly.

I finally got old enough (or got enough sense) to like moderate to light loads.

If you have no pressure signs I would stick with 18 or 19 grains. Over the long run it's easier on you and your gun and whatever you hit with it will never know the difference between a medium load and a hot one.

[C.R.Sam]

The LOWEST load that will give you the desired bullet performance and accuracy at the desired range will be the easiest to shoot accurately and render the greatest longevity of the gun.

If you have to push the limits of the gun to get the desired effect, you are using the wrong gun.

Sam

[stans]

Well said C.R. That is why I quit trying to find ultra 357 Magnum loads and just bought a Super Redhawk in 44 Magnum. No more 357 loads that rock the whole range and start brush fires 1/4 mile from the muzzle.

[WESHOOT2]

I, instead, acquired a 357 Redhawk.

Now I can blow primers safely LOL.

DO NOT TRY THIS AT HOME

[C.R.Sam]

Not fair Tim.
Not enough .357 Redhawks to go around.

Sam

[WESHOOT2]

Not enough.
Had to settle for 7.5" version.
Good thing it fits my Sparks HSR (for IPSC, natch).
(That 'hair-provin' picture )