Crimping the .44Mag

[7075-T7]

Is there such a thing as too much crimp with the .44Magnum? Or will you just wear brass out faster? (With jacketed bullets)

Thanks in advance.

[MoJo]

You can apply so much crimp that you will buckle the brass. Apply enough crimp to keep the bullet from moving during recoil.

[Jumping Frog]

Heavier loads need a heavier crimp. Also, slower powders need a heavier crimp.

Here is my crimp on some max loads using H110 with my cast bullets:

[Houston1944]

The only sure way I know to confirm I have enough crimp on my heavy loads in 44 mag and 454 Casull is to test them. I will load up 5 rounds and take them to the range with my calipers. I select one for the test round, measure the OAL and load it in the cylinder along with one of the other rounds. After firing I check the OAL of the test load, and if no bullet movement I will continue this process until all four have been fired or the bullet has started creeping out on my test round. I consider it acceptable if I complete 3 firings and the movement is less than .005.

[7075-T7]

Heavier loads need a heavier crimp. Also, slower powders need a heavier crimp.

Here is my crimp on some max loads using H110 with my cast bullets:

Thanks for the picture! Mine are a little less than that with a med-med-high load of Blue dot. I my brass ends about halfway up the canurlle (spelling ) and seems to roll in about 1/2 of what your picture shows.

On H110, how do you get that powder to meter well? it seems to be all over the place with my dropper.

[Jumping Frog]

On H110, how do you get that powder to meter well? it seems to be all over the place with my dropper.

Meters just fine for me. I use the Lee Pro-Auto Disk powder measure.

When I am using a new powder, or a powder charge that is substantially different than previously used, I'll make 30 powder drops and weigh each one to see the mean and the variance to have confidence a given powder/charge combo is reliable. I throw 30 charges because n=30 will provide statistically significant results.

These were some H110 test results I posted over on the LoadmasterVideos forums a couple of years ago to demonstrate the approach I use. I wanted to verify if H110 with the Lee Pro-Auto Disk and Double Disk kit would provide reliable results. I expected H110 to meter well since it is a very fine ball powder. In contrast, Clays is a fluffy powder that does not meter as well. In the same series of posts, I showed where dropping 3.7 grains of Clays with the adjustable charge bar was entirely unreliable because I had powder bridging cause 3 samples in the 0.3 to 0.8 grains range! The double disk kit with Clays was also dangerously unreliable in the 4-5 grain range, but 8 grains was exceptionally accurate.

In this case, I used H110 as the powder because it is a very fine ball powder that meters quite consistently. I wanted to see if I could rely upon the Double Disk kit to provide reliable results when loading .44 Mag loads.

I used the used 0.76 cc disk bottom + 0.71 cc disk top for 1.47 cc total. Results were:

mean 22.8
stdev 0.0548
range 0.2
% stddev 0.2%
3 sigma 0.7%

Using the larger volume with a better metering powder produced terrific results, with a 3 sigma result, stating the 95% of cases would be +/- 0.7% of the mean for 22.8 grains of H110.

The raw data (in grains) was:
22.8
22.7
22.9
22.7
22.8
22.8
22.8
22.8
22.7
22.8
22.8
22.8
22.8
22.8
22.8
22.8
22.9
22.8
22.8
22.7
22.8
22.8
22.8
22.8
22.8
22.8
22.9
22.7
22.7
22.8

My bottom line is that I think every time I am going to use a new powder, or an existing powder with a substantial weight change, I will measure at least 30 powder drops to evaluate consistency. When using powders that are known to meter inconsistently, such as Clays (to a lesser extent) or Unique (to a larger extent), it is critical to understand how well your process is in control.

[7075-T7]

Thanks for the help!

I got some 2400 this weekend and it meters perfectly for me. So I'm thinking that my H110 troubles might have been user error.

What weight bullet are you using for 22.8gr of H110?