R44MBS Single Shot Range Day

[Ranch Dog]

I've been pretty busy with ranch work but promised myself that I would use the morning of the 4th to work out a safe max load of H4227 that would rival the velocity that Lil' Gun could produce. In that I use QuickLoad, I generally limit my calculated loads to 105% case density as I've seen some strange things happen to pressure as compression takes place. The slightly compressed load of H4227, 105%, just doesn't offer much. Less that 1500 FPS.

Early in the week, I attached a strain gauge to the barrel so it would be cured by the time the weekend rolled around. The Single Shot and short cartridge does not really lend itself to the gauge. The lead connector ends up being unsupported and caused me to worry about the delicate instrument making it through the range session.



Out at the range I put a lot of electrical tape on the gauge and it's lead. If it starts to bounce with recoil, it won't last very long.



Also trying out a new chronograph today. My CED had been giving me fits and I finally was tired of replacing parts. I ordered and received a Calwell Premium Kit from MIdwayUSA.

The yellow box is the pressure trace equipment which is bluetoothed to the laptop. The Caldwell chronograph is connected to my Galaxy phone via a cable, using the Caldwell Ballistic app, and the data from that app is being bluetoothed to my laptop as well.



I only shot at 25 yards because I was only interested in collecting the pressure data at today for two compressed loads of H4227. 23.0-grain which sits at 114% case density and 24.0-grains at 119%.



The left target is the 23.0-grain of H4227 and the middle is 24.0-grains. Both of these targets received 5 shots. The target on the right is three shot of H110, 21.0-grains. I use this a verification load to calibrate the test equipment. I extensively compared it against a factory load for this purpose. When I need verification ammo I like to buy Hornady because they are very free with the pressure data for the given lot. It takes about three minutes to get it from them. I have a verification load for every cartridge I shoot. With the comparison drawn years ago, I can load the verification loads rather than buy ammo.



There was no difference of the primers within the three traces.



A screenshot of the 23.0 grain load of H4227.



Same with 24.0 grains of H4277.



The load record for 23.0 grains of H4227. Muzzle velocity of 1689 FPS at 39,066 PSI.



24.0 grains of H4227. Muzzle velocity of 1788 FPS at 42,047 PSI. Both of the loads have a very stable pressure SD though both of these loads are exceeding the 36.0 KPSI MAP for the 44 Mag.

These are not revolver loads and to use them as such would be foolish and at your own risk. The Rossi Single Shot does have a .065" chamber wall and the rifle is chambered in 308 Win which is a 62.0 KPSI MAP cartridge.

What I've been looking for is a viable arm to shoot up 4 lbs of H4227. I've tried it in a number of cartridges and the velocity is disappointing all around. A full case does not generate a lot of pressure so I thought the compression might increase the velocity, making it comparable to H110 or even Lil'Gun, which it did. The Single Shot is going to be a back door hog killer. The rifle that I grab or carry on my evening walks. The sub 1500 FPS at the max for the bullet and cartridge combo was useless of my purposes and this looks like a great alternative given the firearm and will prevent the powder from becoming flower food.

Now that I've explored the potential, I will use the 23.0-grain load as the velocity sits between what H110 and Lil Gun produces.

[klr]

Nice work, and thanks for sharing your results. I'm impressed with the science you apply to your reloading.

[Zippidydoodah]

Looking at the graphs, is it safe to assume the bulletsbullet left the barrel by the end of the 1.5 milliseconds and roughly 20,000 exit pressure. Thanks for all your work. It is nice to see actual pressure trace and see how violent the acceleration must be.

[Ranch Dog]

Looking at the graphs, is it safe to assume the bullets/bullet left the barrel by the end of the 1.5 milliseconds and roughly 20,000 exit pressure. Thanks for all your work. It is nice to see actual pressure trace and see how violent the acceleration must be.

My bad on the images, you might need to refresh your browser (Ctrl +F5) but I've uploaded new images at a greater resolution that show the exit point (+) and optimum barrel timing markers (Δ).

If I was really into a precision load, I would pay a lot of attention to the details in putting the handload together and then try this again to see if I could eliminate the delayed ignition or at least see what the occurrence of the same is over a ten shot string. Once this was resolved, the exit points would become tighter and then I would decelerate or accelerate the load to bring it to the closest timing mark. With the shock of the shot, any barrel has a vertical oscillation, the timing marks show the point that the barrel is passing through the null. This is the load development part of this pressure trace equipment and it can be very useful and exact.

The slower ignition, two shots in each group, could be loose primer pockets. This lot of WWS has five previous reloads on it and I would not expect that yet. The pockets & flash holes are uniformed on each cycle, not so much for correction as that was done on the first cycle, but just to feel for such an issue. The other possibility is that the Large Pistol primer is not consistently igniting the compressed load of powder. I've never bought Magnum primers and I'm not going to start now. I might try a Large Rifle primer though.

It is weird how both strings had two occurrences of the delayed ignition and that causes me not to overthink it. I didn't post the stats so here they are. In that these were short strings the 95% probability is what I tend to compare.





The next step will be to shoot a 23.0-grain 10 shot string across the chronograph at 50 yards and then some shooting at 100 yards to see how the rifle does. When I was unplugging the cable from the strain gauge, one of the gauge's leads broke. I thought that might happen as the plug was not secured to the barrel. That kind of blows as the are about $30 each.

[Zippidydoodah]

Watched some pressure trace on a press air clutch and brake to get them timed properly. It was interesting as we could accept a 10% overlap between clutch and brake start-stop times. Your 1-1.5 M-sec are critical in the barrel as the bullet has probably exited the barrel by that time. It would be nice to expand the curve while inside the barrel to see the area under the curve. That would really show how efficient the powder is for the application.

[Ranch Dog]

Watched some pressure trace on a press air clutch and brake to get them timed properly. It was interesting as we could accept a 10% overlap between clutch and brake start-stop times. Your 1-1.5 M-sec are critical in the barrel as the bullet has probably exited the barrel by that time. It would be nice to expand the curve while inside the barrel to see the area under the curve. That would really show how efficient the powder is for the application.

You can do that and number of other things. Of course, these are just screen shots.

[Missionary]

Good morning
Thank you Mr. Mike for taking the time and energy to place these graphics and info here to ponder. That is very educational. That batch of 4227 powder looks stable under those compression parameters in that rifle/ cartridge combination.
Never had thought to compress 4227 that much as so far have not seen any good pressure information this well documented. Looks like a well thought out and "safe for that rifle" way to expend 4 pounds of powder.
Piggy's you have been notified !
Mike in Peru

[Moon Tree]

RD, this post is sooo far above my learning curve that it's not funny. I first pulled the post up at work on a break. I quickly realized that I need to wait until I got home to actually "read" this one. Surprisingly, I understood what you were doing and most of the results.

I feel blessed to be a part of this community, where folks like you take us newbies by the hand and lead us through such processes. I look forward to see some dead "back door" hog pictures.

[Ranch Dog]

The next step will be to shoot a 23.0-grain 10 shot string across the chronograph at 50 yards and then some shooting at 100 yards to see how the rifle does.

What I ended up doing was loading 15 cartridges with 23.5-grains of H4227 but because of the ranch work I have going on, I didn't shoot them until two days ago, they just sat on the bench.

What caused me to end up shooting them is two boar hogs chasing my three legged dog. I had let her out to take a pee before we went to bed and I heard a distressed bark so I went out the door. I heard hooves hitting the ground and though the horses that my neighbor puts in my pasture were chasing her. When they came into the view of the yard lights, two boars were hot on my dog's tail. I hit them with a spotlight and they slowed, became disoriented, and left. The next day I shot the test loads at 100 yards, rather than 25-yards, across the chronograph and sighted it in. Here is the load and what the 44 Mag Single Shot is doing with that load.









Overall, I like the velocity and the terminal effect it is producing with the heavy lead bullet. I am not happy at all with the accuracy as the MOA is almost twice what I need to see from a hunting rifle load. This simply may be a product of H4227 but I will take some more time evaluating loads from 23.0-grains through 24.0-grains. I'm also going to size the bullet to .430" on the next batch. From my slug, I have a .4285" groove so a .432" bullet going down the pipe might actually be crushing the projectile too much.

Still a couple of boar hogs chased my dog so I shot one bullet at the 6" gong hanging from my 100 yard berm and the ringing stated good enough!

I guess it was good enough as I killed a hog at about 55 yards last night!
R44MBS Single Shot vs. Feral Hog