M29-2 Displaying Exceesive Pressures With Light Loads

[semperfi71]

Hallealoooyayy...I think I solved it. And am I glad as I was losing sleep over maybe having to get rid of "Ole Boomer" and having to try to buy another M29.

The Speer 240 grain/H110 loads showed pressure signs in the M29-2 only at the maximum load of 24.0 grains. Which is maximum in most reloading manuals. And even then, out of five shots, I only had two sticking cases; and the primers were not as flattened as in the Remington 240 grain load.

I shot the Remington loads (both the 2400 and AA#9) in my Ruger Vaquero .44 Magnum. At 18.5 and 19.0 grains respectively I started getting sure pressure signs of very flat primers and sticking cases. Still below supposedly maximum for this bullet and these powders.

I miked the Remington and Speer bullets and they came out to approximately .430 (R) and .429 (S). I was using my RCBS plastic micrometer setup which may not be as accurate as a metal one.

The Remington bullets, in exterior texture, were rougher than the Speer.

Evidentally the S&W has a bit of a tighter bore over the Ruger, but both handguns will not reach anywhere near "book" maximum with the Remington load.

I chronoed the shots. With the two 2400 loads and AA#9 loads at about 18.0 grains the S&W would chrono 1120 to 1170 fps. With the Ruger they would chrono 1230 to 1300 fps. The S&W has a 6 inch barrel and the Ruger a 7 1/2 inch barrel.

With the S&W and the Speer load at anywhere from 22.0 to 24.0 grains I was getting only 1150 to 1200 fps.

I may be getting rid of this chronograph someday though. At all loads chronoed I'd get several at 1100 to 1200 fps and with each five shot group I would get at least one and sometime two loads that chronoed 950 fps!!

I know that sometimes chronos might "print" a bit off but that is pretty suspect to me.

It's a Pact and maybe I should spend the bucks for an Oehler.

Yes, the older Remington 240 Grain loads were shot with an older, long shot away lot of powder.

Thanks for all the input.

I haven't shot any fullhouse .44 Magnum loads in a long time. I loved it!!

 

[tomcatt51]

I may be getting rid of this chronograph someday though. At all loads chronoed I'd get several at 1100 to 1200 fps and with each five shot group I would get at least one and sometime two loads that chronoed 950 fps!!

Makes me wonder if maybe you were too close to the chronograph and muzzle blast was messing with your reads.

 

[semperfi71]

Chrono was 10 feet away. A long time ago considered a safe distance. BUT, maybe I should have had it out further? Next time I take it I will experiment.

 

[tomcatt51]

Chrono was 10 feet away. A long time ago considered a safe distance. BUT, maybe I should have had it out further? Next time I take it I will experiment.

I'd definitely try it out a bit farther. See if having it out 15 ft makes a difference.

 

[WR Moore]

A few comments:
1. Don't test scales with bullets. RCBS makes sets of test weights so that you can zero your scale at your chosen load with weights of known accuracy. These sets are very reasonable in price and much cheaper than new guns or hospital visits. BTW- don't handle the weights with your hands, the sets come with tweezers. Use the tweezers.

2. I don't use 296 but the WW load data states in no uncertain terms NOT TO REDUCE THE POWDER CHARGES FROM THOSE LISTED! You can check their load data on the Hogdon website.

3. Just because the test weapons used to develop load data allow a given powder charge with acceptable pressures doesn't mean your personal weapon will.

4. 15 feet is the standard distance for clocking pistol ammo with a chronograph.

5. The gent who described the cause of false high pressure primer signs with reduced loads was spot on. The primer creates a high pressure within the primer pocket and expands/protrudes before the case moves back against the recoil shield. This squashes the primer.

 

[semperfi71]

Yes sir, Winchester in some of their manuals stated do not reduce the loads, I have an older one that said reduce no more than 6%.

Many reloading manual did, and still do, show reduced loads to work up to the maximum.

BUT, I have chronoed reduced loads in W296 and H110 and got very erratic velocitys, like 400 fps followed by 900 fps. I have become a bit more careful with W296 and H110.

I have known since my first reloading manual that my guns and anybody else's can differ, so caution is called for.

In wax bullet loads, blanks, and such reduced loads the primer will indeed back out and tie up the revolver. They always suggest opening up the primer pockets to avoid this.

I have never had this happen in any reduced powder load that I worked with. But with the exception of W296 and H110 I never reduced loads that much. But it could happen I reckon.

I will be moving the chrono out to 15 feet.

Thanks for the input.