Is H110 a Viable Propellant in Small Cartridges?

[Chev. William]

The Loads Contained Herein are NOT TESTED! They are Calculated for DiSCUSSION purposes ONLY!

Using “QuickLOAD” software on the ,25ALS cartridge design (Ammoguide Cartridge file #958) and a Hornady #2510 Bullet in the calculations to develop a Charge Variables table.
Cartridge Data entered:
Bullet = .250” sized dia. 60 grain Hornady 2510 semi jacketed Soft Flat Point.
Cartridge = .25 Automatic Long Stevens of 1.125” case Length. H2O cap. = 12.11 est.
OAL = 1.395”; Bullet Length = 0.544”; Shank Seating Depth = 0.274”;
Barrel Groove diameter = 0.251”; Barrel length (breech face to muzzle) = 12”;
Bullet Travel = 11.149”.
Pmax (MAP) = 25000psi; Measure method =piezo CIP;
Cross Sectional Bore Area = .048267 Sq. In.; Volume Occupied by Seated Bullet = 3.439 grains H2O; Usable case Capacity 8.667 Grains; weighting Factor = 0.75.

Propellant data Entered (other than supplied by QuickLOAD file)
Hodgdon H110 Propellant; Shot start Pressure = 2900psi; Charge weight = 8.0 grains; 93.2 % fill.

Step% Fill% Charge(grains) Vel(fps) Energy (ft.lbs) Pmax(psi) Pmaz(psi)
-10 84 7.20 1425 270 16132 2703
-08 86 7.36 1459 284 17083 2805
-06 88 7.52 1494 297 18091 2707
-04 90 7.68 1530 312 19170 3010
-02 91 7.84 1565 326 20325 3114
Nom. 93 8.00 1601 342 21562 3217
+02 95 8.16 1638 357 22888 3320
+04 97 8.32 1675 374 24312 3423
+06 99 8.48 1712 390 25831 3526

The Calculated steps below -10% and above +06% are deleted from consideration.

Questions for consideration:
1. Is this Propellant within its SAFE working area in this application?
2. Would the low end Weight be a SAFE Starting Charge for this Propellant?
3. Is this Bullet Heavy enough for caliber to ‘work’ with this propellant successfully?

From past testing, I have found that the Revolver that I use performs about 2.1 percent BELOW Specified Muzzle Velocity when measured about 5 yards from the muzzle, using CIP Standard Controlled commercial Ammo as a reference Cartridge.

Best Regards,
Chev. William

[dragon813gt]

I'm assuming the cartridge is straight walled like the 25 ACP. Quickload gives erratic predictions w/ straight wall cases. I do not play w/ H110 loads. There are less erratic, and that's an understatement, powders available.

[DougGuy]

Why would you choose such a slow burning powder for a 60gr boolit?

[Chev. William]

Why would you choose such a slow burning powder for a 60gr boolit?

DougGuy,

Potential case Fill of the cartridge Volume is one reason for considering this Propellant.

Another is also thinking of this cartridge in a Rifle with a 22" to 24", or even 26" barrel.

The Revolver with a 12" Breech Face to Muzzle Distance is a Compromise that is also an easy one to Try IF, and only IF, it seems This propellant has possibilities. It only takes a reamer and a replacement cylinder to change cartridge Length in this particular custom built revolver, up to a maximum cartridge length of 1.400" inches.

THEORETICALLY, a Rifle, such as a turn bolt, or even a Rolling Block Single Shot, would allow longer Cartridge lengths and Bullet weights such as a 120 grain spitzer point, still with around only one bore diameter, or slightly less, of seated bullet in the case.

There is also the Crimp used on the cartridge to increase Starting pressure, which has not been included yet in the questions or Conditions under considerations. the postulated 60 grain bullet DOES have a cannelure/crimp groove in its design, and the jacket would be better retained than a typical Lead Cast Bullet.

Best Regards,
Chev. William

[DougGuy]

I noticed the % of fill as being correct for H110, I just question how much of it can be burned before the boolit leaves the muzzle. A boolit that light would seem as if it would move too fast for much of the powder to burn.

I use a modded collet crimp on my straight walled cases that increases time before boolit pulls crimp which cuts down on SD quite a bit.

[flint45]

It works well in .22 hornet with 45 grain bullets.

[earlmck]

H110 is my powder of choice for my hornet and k-hornet with similar case capacities and even lower sectional-density bullets. I'd think it would be a natural in your proposed application, though I have no direct experience.

[Kosh75287]

I have an aversion to H110 for anything except .30 Carbine, so I want my inherent bias to be clear from the outset. I'D be inclined to try a work-up with Alliant 2400. It's faster burning, which may help with the 60 gr. projectiles, and you can reduce the "maximum" load by more than 3%, without inviting erratic ignition, a la H110.

[Chev. William]

I have an aversion to H110 for anything except .30 Carbine, so I want my inherent bias to be clear from the outset. I'D be inclined to try a work-up with Alliant 2400. It's faster burning, which may help with the 60 gr. projectiles, and you can reduce the "maximum" load by more than 3%, without inviting erratic ignition, a la H110.

That "3%" limit seems to be 'Breached' by some published .30 carbine loads which recommend STARTING charges about 80% of the Maximum charge stated.

Something is not being stated somewhere. Perhaps Ambient temperature have some effect on H110's "Temperament"?

Chev. William

[lar45]

If it's going to be around 25k psi, then H110 may not be the best option as it burns best at higher pressures and 100% load density.
If you want that burn rate, then maybe look at 4227. It has about the same burn rate, is a little more bulky and can operate at lower pressures. 2400 is another powder that can operate at lower pressures and doesn't need to be at high load densities.

[lotech]

Using an appropriate powder for the cartridge is always best. QuickLoad may provide guidance, but traditional and proven load development still works very well.

[Leadmelter]

H110/WW296 must be loaded to a min 90% density with a magnum primer for success.
Leadmelter

[Chev. William]

H110/WW296 must be loaded to a min 90% density with a magnum primer for success.
Leadmelter

It seems several Published .30 Carbine load recipes for H110 may have different views and they indicated they were Chronographed Recipes to boot, Curious and Strange.

Chev. William

[DougGuy]

Most sources I have read over the years say it does not like less than about 78% density, some even say 75% but I have never read where 90% minimum is recommended and I been reloading a good long time now.

The last few years I have been wanting to step back away from the 30kpsi power band and heavy boolits, and I got away from H110 simply because a few loads went slightly below recommended starting weights. I looked to 2400 and LilGun for these loads in the 75% - 90% power band for the Ruger Only 45 Colt in a full size Vaquero. I had very good luck with both these powders in this slightly reduced application.

I guess H110 would work, it just doesn't hit home as the ideal choice in the application OP is using it for or wanting to use it for. I don't have QL loaded on this machine or I could go looking myself since this is a HYPOTHETICAL load and being worked up in QL. I would be looking at the % of powder burned, I think it may be pretty low, but I could be wrong..

[P Flados]

I use a lot of 296/H110.

I have used it for both typical uses and a few examples that most would consider off the wall stuff. I have experienced the erratic performance that comes with inadequate load densities. Unless you have lots of "excess" strength in your gun, you really really really do not want to think about taking chances with low load density stuff.

Having said the above, now for the other side of the coin.

I would expect it to produce near maximum achievable velocities for medium to heavy boolits in any straight wall case with at least the length to diameter ratio of 357 magnum as long as your gun can tolerate 35,000 - 50,000 psi. I fired off a bunch of 100 gr boolits over 13.2 grs of H110 in my 327 today and am confident that I got about the best velocity I could get. And by the way, it was also produced the biggest flash/bang of anything resembling a cary gun load fired at the range while I was there.

I have found it to be most reliable with a high (but not 100%) load density. A 1/16" gap between base of boolit and powder seems to work real good.

With a gun that could handle a 357 mag, reducing the diameter to 25 cal would give you a gun able to handle pressures higher than the cases can take (this is a comfortable situation).

With a gun that started out as a 32, a 22 mag or something similar, I am not sure it would be a good idea to play with a powder that prefers greater than 30,000 psi, and can get "erratic" as you reduce charges.

[Chev. William]

P Flados,
Re: your Comment: "With a gun that started out as a 32, a 22 mag or something similar, I am not sure it would be a good idea to play with a powder that prefers greater than 30,000 psi, and can get "erratic" as you reduce charges."

The Ruger revolver I am using in my Experiments as a Test Gun started out its life as a "Convertible Single Six, New Model, in .22CAL". I bought it Used from the Gun shop that then did the conversion from RF to CF, from 6-shot to 8-shot, and made and fitted the 10-5/8" long, one turn in 9.8 inch twist Barrel for it from a Lothar Walther .25 Auto/ 6,35 Browning Cr-Mo Alloy steel Barrel Blank.
The Ruger Single Six new Model has been marketed by Ruger in calibers up to .327 Federal Magnum as far as I know in the blued frame type similar to mine.

I have NOT YET fired it with ANY H110 load but Have fired it with 3.0 grains of BE-86 Powder in a .25ACP case behind a 63 grain Lead bullet several times. As "QuickLOAD does NOT include BE-86 in its libraries of propellants, I have no idea what pressures are being developed by this load; although my Primers showed no excess pressure signs (both the primer edge and firing pin indent edges were still rounded, not flattened nor blown to sharp corners). The cases expanded the Same as Standard Factory loads fired in the same chambers and cylinder, which was made with a Standard SAAMI .25ACP Tapered Chamber Finish reamer.

My gun shop is now in the Process of working up a new Replacement 8-shot cylinder that will have straight parallel walled Cylindrical Chambers of .2795" nominal diameter. I am thinking the new Cylinder will better support the Cases and reduce the case expansion I have seen to date in all my fired .25ACP cases.

Also currently I have on Order from JGS Precision, another similar Diameters reamer for a longer "Mildcat" .25 Auto. Long Rifle cartridge of .960" Case length.

After that one is finished and received, I plan to order one made for a ".25 Magnum Auto. "Mildcat of 1.055" case Length.

Longer term plans are also in place for new cylindrical chamber reamers for case lengths of 1.125" and 1.250" for my other published "Mildcats" of the same diameters.

Best Regards,
Chev. Wiliam

[jonp]

Tried it along with Blue Dot in a 38sp. Both were very dirty and I saw no point to it.

[P Flados]

Chev,

I found SAMMI numbers for chamber bore of 0.2828" for the 25 ACP and 0.3412" for the 327. SAMMI max pressure for the 22 mag is 24,000 psi and for the 327 it is 45,000 psi.

Lets "do the math" on comparing 25 acp allowed pressure to a 327 based on maximum expected breech forces. For the 327, the pressure times area = 45000 psi x 0.0914 in^2 = 4114 lbs. To generate this much breech pressure, the 25 ACP pressure would need to be 4114 lbs / 0.0628 in^2 = 65,500 psi. This should provide you with ample confidence for basic frame stresses at expected pressures.

Next is a discussion of cylinder strength. Softer steels can have a yield strength as low as 36 ksi. What I call strong steel will have a yield over 100 ksi. When I look at my SP-101 327 revolver, I see chamber walls that look like they would deserve a very strong steel. Very strong cylinders cost a lot more to make. In 22 LR/magnum, your gun had thicker cylinder walls than the same gun in 327 Fed and a much lower working pressure. Also, with the smaller chamber the same internal pressure gives a lower primary stress in the cylinder (called hoop stress). Therefore, there is every reason for Ruger to use a steel that is much less strong in their 22s than for their 327s. There is also the location of the notches. The Single seven has them located where they do not reduce wall thickness at the high stress region. A Single Six has the notches such that material is removed at the location of maximum stress.

With any load above normal 25 ACP pressure, you will using be some of the legendary Ruger "built tough" margin. However, the challenge is that you do not know how big the margins are.

I seem to recall that you have a defective cylinder that will fit your gun. If you were to have one of the good chambers reamed for 25, you could use the cylinder for proof testing under controlled conditions (most notably, no body parts anywhere near the gun).

[Chev. William]

P Flados,
According to the Distributor of my 'replacement' aftermarket Cylinders, they are made from 1144 Alloy Steel; which I understand from Materials Dealers is a Carpenter Steel called, by them, "Stressproof" with a design Strength of about 100,000 psi yield as manufactured.

If a Post Machining Heat treatment was used, I have no Information on that.

My Gunsmith has commented that he uses a Lot of Lubrication and Very slow cutting for reaming my cylinder as they Are Harder than the normal Run of Materials he is used to.

The cylinders are first bored And reamed to a good .2510" diameter finish; THEN rough chamber reamed followed by Finish Chamber reamer.

My current choice of Parent Brass is 5.7x28mm, I believe, is Specified for 50,000psi MAP equivalent in the European Regulatory environment. I would gather that that pressure limit is not reduced by my Swaging DOWN the case body diameter, as I have found the Wall thickness to Increase on my sectioned cases.

Would you agree with my estimates?

Yes, I posed the Questions for a MAP of 25,000psi so i could stay within the Known area UNTIL I can Prove to myself that a higher MAP may be safe.

My personal limits on my Other Test Actions are Lower; as to date I limit them to about 1124fps muzzle velocity out of difference to their age and designs.

I hope sometime in the future to afford the buildup of a Rifle that is capable of testing loads to the 40,000psi or 50,000psi MAP range. But that is not now.

Best Regards,
Chev. William

PS: My longest chambered ".25 Mildcat" using a new Lyman Dial caliper measures .285" at the rear of chamber; .100" wall from chamber to outside cylinder diameter; .075" chamber to chamber wall thickness; 1.405" chamber length from rear face of Cylinder to front face of Cylinder. the rims sit in a rebate so The rear cylinder face is roughly the base datum. The Ratchet extends about .084" behind the rear face and the overall length of the cylinder, at center line, is about 1.623". Chev. William

[P Flados]

I found the following:

1144 also sometimes referred to as Stressproof ®, is a carbon-manganese grade which is severely cold worked to produce high tensile properties. The bars are specially treated to relieve the stresses set up by the cold drawing, thus minimizing the tendency to warp after machining which is common in ordinary steels. 1144 cold roll bars have high strength hardness, without the need of heat treatment.

This material get its strength from cold working. As such, it would probably get softer with any attempt at heat treating.

I pulled up an online tool to run the numbers:

https://www.engineersedge.com/calcul...oop-stress.htm

Assuming a thin wall cylinder with a 0.075" wall thickness (the limiting number from the info you gave) and a mean diameter of 0.285 + 0.075 = 0.36", I get 98,400 psi of stress at 41,000 psi chamber pressure. This does not include any strength reduction due to material removal at the notches. It would be a challenge to figure the numbers if the notches reduce wall thickness to below 0.075". SAAMI gives a 140% multiplier for proof loads. This leaves you with a working pressure of 29,290 psi.

Using hoop stress for strength is probably conservative. The actual strength at the thinnest location is probably re-enforced some by the adjacent thicker material. However, the "extra" is probably not that much.

Neglecting the brass is also conservative. The brass adds strength and it reduces the effective mean diameter. Lets run the numbers on just the diameter part. The effective OD will be the chamber ID plus 2 x wall or 0.435. Lets call the new ID as 0.257. That drops the mean diameter to 0.346". This increases chamber pressure at yield to 43,300 psi. Working pressure goes up to 30,900 psi. I may be playing a little fast & loose by reducing mean diameter the way I did, but I am pretty sure this pushes your working pressure to over 30,000.

If you had gone with less chambers in your cylinder, you may have been able to increase the min wall to 0.10". Using this value would push the chamber pressure at yield to 53,900 psi for a working pressure of 38,500 psi.

Note that choice of steel and heat treat really does matter. I have dealt with staineless (17-4 ph) valve shafts that ran 125,000 psi for yield. I am sure that my Ruger SP 101 cylinder has a yield well above the 100,000 psi of your aftermarket cylinder.