I asked a while back and didn't get information on a load, so I'm asking again.

Do any of you know what the maximum load for a .32-40 in an original '94 Winchester, using H4895 and a 170 grain gas checked lead bullet? I don't want to hurt the rifle or myself.

I've tried 16 to 22 grains, and plan on trying 22 1/2 to 25. Ken Waters had a load of 24 grains that shot well.

FACTS?
OPINIONS?

Do any of you know what the maximum load for a .32-40 in an original '94 Winchester, using H4895 and a 170 grain gas checked lead bullet? I don't want to hurt the rifle or myself.
OPINIONS?

The Lyman #46 manual puts 30 grains as a maximum for IMR4895 under a jacketed 170 grain bullet. H4895 is close, but not identical, and your bullet is longer with lube grooves so try starting with 23 grains and work up watching for pressure signs.

Nick

Thanks Uncle,

I know to watch for primers backing/flattening out. Cracks in cases too.

Are there other signs?

Watch for growth in the case head immediately ahead of the rim. It should never exceed 0.002" in a high power load and probably not even half that in an old low pressure cartridge. If you have primer pockets getting loose, that is another excess pressure sign (caused by the case head widening). Increased difficulty in extracting the case after firing is another. The primers may not only flatten, but start to flow into the small gap between the firing pin and its hole in the breech face. This is called cratering, since the firing pin indentation starts to resemble a lunar crater with the gap flow countour being the crater wall.

Most often you see the primer start to flatten out first, but there is no sure sign, so you have to be aware of all these things. The most extreme thing you can do is buy a strain gauge pressure instrument like the RSI Pressure Trace (which has gauges you can remove without blemishing the gun's finish). If you first get a pressure reading from a known safe factory load, you can then work yours up to match that same reading. There have been arguments about the absolute accuracy of pressure measured this way, but the gauges and their measuring instruments have advanced since the HP White lab comparisons were done, and, properly installed, will certainly tell you what the steel is feeling, regardless of the absolute pressure values inside. I don't have a clue what factory .32-40 ammunition might be available to compare to, however?

The only other tool at my disposal is internal ballistics software. It can estimate pressures, but because of differences in powder lots, etcetera, you have to take it all with a grain of salt. Nonetheless, it doesn't usually do too badly, and for relative comparisons it is fine. If you can give me the length of your bullet and your overall length after seating, I can give you a ratio, based on the Lyman load, for what powder charge will give the same pressure as the Lyman load. Lyman doesn't list a pressure for it, so their load was a firearm workup. Probably less a safety factor they don't mention. If, in addition, you can give me the water capacity and trim length of your case, I can give you the software's estimate based on that and see how well it agrees with the Lyman number? Having played with it a little, I can guarantee it will be lower than Lyman's 30 grain number by 5-10%.

If you've never measured case water capacity, you should start with a new case, be sure it is trimmed to your trim length and put a spent primer in it. Weigh this, and record it as your tare weight. Now fill it with water nearly to the top. Tap it on a hard surface to knock any bubbles loose. Use an eye dropper to bring the water exactly level with the case mouth and weigh it again. Subtract the tare weight from the result. This is your water case capacity.

Also, just to be sure, you are shooting .32-40 Winchester and not .32-40 Bullard or .32-40 Remington-Hepburn? The latter two use 0.309" and 0.315" bullets, respectively, and are really only suitable for black powder loads. .32-40 Winchester has a real 0.320" groove diameter, so 0.321" cast bullets are usually used with it. If you are uncertain, measure your groove diameter by slugging the barrel with a pure lead bullet or fishing sinker and applying the micrometer.

Nick

Nick,

If you'll give me a couple days, I will get some numbers to you.

Yes, it's all Winchester .32-40.

Thank you for your time and expertise relating those pressure signs. The boys and I shoot several rifles and handguns, so that is valuable information.

I was just rereading your first post and taking note that the gun is an "original" '94. Do you know what year it was made? The serial number can probably be looked up or queried about on the Winchester Collectors web site (http://www.winchestercollector.org/guns/1894.shtml) (see FAQ from there). The Lyman load was developed in a '94, but it was likely a modern gun. The concern with older guns is they have been fired with mercuric and chlorate primers, and these may have caused steel weakening corrosion if the cleaning wasn't right. If you know someone with a bore scope, have them take a look from the breech end. Also inspect the inside of the reciever and the bolt under magnification, making very sure there are no cracks or serious pits anywhere.

Nick

The rifle was made in 1904. Seems well taken care of, except the rifling is getting quite worn.

Has either been shot a few times or cleaned a lot. But if the metal is in good shape, it should hold up to load specs (about 36,000 PSI). If you measure the other parameters, I will tell you what the computer thinks of it all.

Nick

I have used both 24 and 29 grains in a model 93 marlin with jacketed bullets and cast ! With 24 grains you will get about 1450fps and with 29 grains you will get about 1900 to 2000fps ! JAGG

I haven't forgotten--been very busy these days. I'll try to get the specs by the weekend.

You fellows' help is appreciated.

One more pressure sign I forgot to mention that applies only to guns with their bolt lugs at the rear of the bolt, like a lever gun. Measure the length of the cases after firing. If they suddenly start to get longer it is a sign of the reciever being stretched by rearward bolt thrust. This can be confusing because there is a threshold in the 20,000-25,000 PSI range where cases stick to the chamber wall and grow becuase the head stretches the brass to the rear of the headspace excess when the sides are stuck to the chamber like that, instead of the whole case moving to the rear.

As a result, low pressure loads won't grow the cases at all. When it gets high enough, they will grow, but by a fixed amount per firiing. Then, when pressures get too high, the cases will start to grow even longer.

Nick

Wow! Talk about knowing what you're talking about!

I'll watch for this--in my other rifles too.

I've copied your posts, and hope to go out to the shop tonight to get you the specs.