Is H110 a Viable Propellant in Small Cartridges?

[Chev. William]

Notes on my Projects:
- .25ACP Ruger Single Eight is back in my hands with three *-shot cylinders ready for Test firing; .25ALRM, .25ALS, and .25MACP all with parallel wall chambers of .2795" diameter.

- .25ACP Ruger Standard Auto Pistol with 8-1/8" barrel is working as a "Single Shot Auto Eject" until I can fabricate magazine(s) to feed it.

- .25ACP converted Stevens Favorite rifle is Still awaiting my gunsmith's ministrations.

- .25ACP conversion of a n 1890 Winchester is waiting for my gunsmith to permit me to submit it for final fitting of parts.

- .25ACP conversion of a Stevens 44 action; most parts gathered, including a barrel blank, to be machined and assembled.

-25ACP conversion of a Marlin 'Levermatic'; waiting fo rmy gunsmith to give me permission to submit the donor gun and parts for the Conversion.

Current winter Weather is wet, cold, and Breezy precluding any activity in my outdoor reloading shop.

I did get a "Range day" Thursday Feb. 14th afternoon to shoot my .25ACP converted Ruger Standard auto MKII pistol at my local outdoor commercial range. fired about 150 rounds in single shot mode.

Chev. William

[ahall]

be careful with your assumptions - its rolled bar and typically the specks are from a tensile test specimen pulled in the axial direction. The ability to withstand hoop stresses can bu much lower, especially if the alloy has any free machining additives. The additives tend to form stringers as the bars are rolled. Its the stringers that cause a local weakness that breaks the chips and makes it free machining.

from the ASM International heat Treaters guide - 1144 - special-purpose grade. Very high sulfur content, equal to free machining 1213, High sulfur reduces transverse impact and ductility.

When I saw the 1144 it reminded me of an experience with 1187 gears. Our supplier switched from flame cut plates to round bar, and the teeth began coming off in service. Sulfur stringers at the root of a tooth are a great place to start a fatigue crack.

Second, the test bar is pulled at mid radius for the bar, prior to any pealing or other final finishing. Heat treating and cold working are not always effective at raising the tensile strength of the core of the bar.

I speak from experience in another industry and have sent a few truck loads of steel back to the supplier over these issues.
Reject a few loads and they get your stuff right, and push the junk on someone else (like the little guys).

"stress proof" and "fatigue proof" are just marketing terms applied to high strength alloys. No magic.

[Chev. William]

Thank you, more information is always welcome.

My Aftermarket 1144 alloy Cylinders have withstood "Proof" testing to date: I used 3.1 grains of BE-86 propellant behind a 50 grain FMJ projectile fired with WSP primers in all Eight chambers of my first converted, .22MAg to .25ACP, cylinder two full sequences with no indication of overstress in the cylinder.
My new Cylinders are cut with smaller diameter Chambers; .2795" diameter Parallel walls versus the older one of .280"-.283" diameter Tapered chambers.

Another person did some calculations and figured I was probably running about 30,000psi Pmax MAP with my load and also calculated a yield strength of the cylinder walls of about 47,000psi at the thinnest section.
Since Factory loads are rated at 25,000psi Pmax MAP or Less I believe I have a Safe revolver.
My Pistol has a Cr-Mo Alloy barrel with the cartridge body fully enclosed by Barrel metal and the rim surrounded by the Bolt, which is some hard Alloy steel. I do not believe I will have any failures in the pistol either.

Chev. William

[GONRA]

GONRA's usual half *** answer:
When WW / Olin sold 630P powder (relatively slow, "not-so-small HARD BALLS" - NOT "flattened ball powder")
their SUGGESTED LOAD (not some GONRA Crapola) as I loaded quantities:
50.2 gn. cast lead Ideal 252435 bullet, .252 inch diameter, 3.0 grains 630P Powder, CCI #500 Primers.

So - wots "so special". Seated bullet is PHYSICALLY supported on the HARD 630P Powder Balls...