There were no 44-40 +P factory loads...well sort of!
Let me start at the beginning...sort of!
I'll cut it very short but it's complicated!
SAAMI max pressures for the 44-40 is 13,000cup set in stone by the 1970's...yes, 1970's. By 2015 SAAMI added 11,000psi MAP. So we have both 13,000cup (copper crusher) and 11,000psi (piezoelectric) as guidelines. There is actually a third testing method, CIP which is 15,954psi. Basically the the same peizo test with the "transducer pressure sensor" located in a different location that gives slightly different readings. Details here:
sites.google.com/view/44winchester/handloading/ansisaami-specs+P and +P+ Loads
Wikipidea says
"...commonly designated as +P or +P+, is small arms ammunition that has been loaded to a higher internal pressure than is standard for ammunition of its caliber (see internal ballistics), but less than the pressures generated by a proof round." When "proof" pressures are surpassed, generally a new name and design is created like the Magnums. Today they are called "Wildcats".
The 44-40, from it's creation, was basically a 1,325fps cartridge that produced somewhere between 11,000psi and 14,000psi (13,000ish cup to 15,000ish cup) with a 200gr to 217gr lead bullet respectively with black powder and early smokeless powder.
Here is where it gets good!
By 1903 Winchester offered the 200gr JSP and full metal jacket 1,500fps 44-40 High Velocity "Low Pressure" loads (actual pressures unknown to me). By 1910, Winchester offered the 200gr JSP 1,570fps High Velocity higher pressure loads of which are reported to be 22,000cup...nearly double in pressures. Both loads were developed specifically for the Winchester 92 and were so labeled as such as well as labeled with Yellow (JSP), Pink (Full Patch)and Lavender (full patch) colored labels.
It is knot known to me the pressures that the early "low pressure" H.V. loads produced but 1930's handload data by Sharpe shows 14,000cup for loads in the 1,500fps range. To continue the confusion, higher velocity loads exceed 2,000fps at 33,000cup. Although those pressures exceed the factory HV loads, so does the velocities.
By today's standards those factory loads should have been a new design as to not fit in weaker action rifles or revolvers. They far exceeded +P and +P+ loads if the pressures exceeded proof loads. More on +P and +P+ loads here:
sites.google.com/view/44winchester/handloading/p-p-vs-magnumsTo make it more interesting, Sharpe's 1930's load data for revolvers calls for 15,000cup max...exceeding what my theory is on the early HV low pressure loads (again only for the Winchester 92'). They also list 250gr bullets for the 44-40 revolver loads.
The 44-40 should never be compared to the 44 Magnum, they are two different animals, one with 200gr-220gr bullets and one with 240gr or heavier bullets....unless you go to the extreme "Wildcat" load of which then yes, get a 44 Magnum!!!
Replicating Winchester factory loads is not trying to make a 44-40 into a 44 Magnum.
1873 Black Powder - 1,325fps (Winchester 73', Revolvers by 1876)
1895 Early Smokeless Powder - 1,300fps (Winchester 73' and Winchester 92') Okay for revolvers by 1909.
1903 Low Pressure HV loads - 1,500fps (Winchester 92 ONLY)
1910 High Pressure HV loads - 1,570fps (Winchester 92' ONLY)
It is reported the the HV loads stopped in 1938 but after WWII they were still offered but by the 1960's the HV loads were noted as being for ALL FIREARMS thus also a lot slower in velocity (~John Kort tests results)
Lyman's 49th handloading manual lists NINETEEN rifles chambered for the 44-40. Lyman divides them into two categories, Group I (Weak Action) and Group II (Strong Action) link:
sites.google.com/view/44winchester/handloading/ansisaami-specsJohn Taffin lists some very nice loads in the November 2003 edition of Guns Magazine. John warns against using old data which a very wise thing to do. Most powders are replaced by improved powders for a reason. Make sure you are using the correct firearm with the correct loads.
Before I go any further, the 44-40 should never be loaded for velocity (unpublished loads) because the loader/shooter will exceed max pressures long before high pressures signs are evident. In excess of nearly 25,000cup or maybe close to 30,000psi....ask me how I know!!!!
I had the privilage of being able to do some pressure testing as an amateur using the PressuretraceII system. All of my results are extremely consistent but that doesn't make them correct. Using Buffalo Bore "Heavy" 44-40 commercial loads as my "Control", I concluded the following;
Early black powder replications with pre-1884 original cases - Swiss FFG, 40gr/w equaled 40gr/v and required .17" compression. 1,373fps @ 14,285psi. 40gr/w Swiss FFFg in post-1884 cases using both large and small primers, less volume required approx. .19" compression of the powder...all using the 427098 lead bullet. This load produced 1,276fps @ 12,755psi. 40gr/w of Swiss FFFg in the pre-1884 cases produced 1,356fps @ 12,648psi. By the early 1900's, those loads used in REM-UMC cases produced 1,248fps (consistent with velocities at that time)@ 10,037psi. Those same loads in modern Starline brass produced 1,226fps @ 8,953psi.
Thus early Sporting Black powder loads probably produced between 12,500psi and 14,200psi pending components. Approx. 13,000cup to 15,000cup in line with 1930's manuals over-all pressures.
Thus modern black powder loads only produce about 9,000psi (full loads)
Smokeless powder gets complicated because I don't have any original powders to test. Swiss black powder is the best we have today and was a good comparison.
Dupont #2 was used as the early smokeless powder and it was a bulk direct replacement for black powder. Some early smokeless powder was said to create less pressures than black but again, I don't have any to test. It was also warned by Sharpe the the "dust" in the Dupont #2 could settle in the primer pocket and create higher pressures. By the 1930's (the last years of the HV loads), the popular handloading powders for the 44-40 was mid-range rifle powders. Sharpshooter was designed (as most were) for .30 cal cartridges but worked well in the large black powder cases. Sharpshooter was a "bulky" powder but not a BULK powder like black powder. It is designated on the powder can "For Use In Black Powder Rifles". Sharpshooter, Lightning, 2400, 1204, 4227 and SR80 were all "rifle" powders. 4227 directly replaced 1204 and is still in use today. IMR-4227 is IMR's Magnum powder. It was a mid-range rifle powder before the advent of the Magnums. 2400 is also considered a Magnum powder long after it's intended use as a rifle powder for small caliber rifles.
My best replications using smokeless powders is done with Reloder 7 and IMR-4227.
(MY PREFERRED LOADS)
Reloder 7 - 1,361fps @ 12,000psi (220gr 43-215C) 40 consecutive shots at 100 yards at 3.30 inch group with a scoped Winchester 73' (Weak Action) and is close to 14,000cup
IMR-4227 - 1,590fps @ 18,000psi (Winchester 200gr JSP) 2 1/8" groups at 50 yards with scoped Marlin 1894CB (Strong Action). 18,000psi seems to be close to 22,000cup
My last load that is unpleasant to shoot I used to hit golf balls at 265 yards. Test loads came in at nearly 1,700fps @ 20,000psi but actual load used was 1,600fps @ estimated 19,000psi in the Marlin 1894CB. In excess of 22,000cup.
The danger with all of this is multifaceted, large diameter bullets, magnum primers, tight chambers and small bores can be disastrous. STAY WITH LYMAN'S MANUAL for Group II high velocity high pressure loads.
For tons of 44-40 information check here:
sites.google.com/view/44winchester/One thing I forgot to add. I also tested an "accidental" double charge of 6gr of Unique which would be 12gr. Using standard load components, Starline, 200gr lead and an over charge of 12gr of Unique, I recorded 1,635fps @ 21,786psi well in excess of 25,000cup if not 30,000cup. The highest recording I had during my some nearly 900 rounds of presure tests conducted.
Taffin's 2005 10gr of Unique with an Oregon Trail 200gr lead bullet (1,390fps) gave me 1,419fps @ 14,000psi which would be close to 15,000cup to 15,500cup
Sharpe's 1937 9gr with a 200gr lead bullet is reported to be 1,305fps @ 10,200cup and 11.3gr to 1,530fps @ 16,000cup
THUS stay away from UNPUBLISHED LOADS unless you are using a strong action firearm or test equipment and you are will to break something or lose a finger or more.