Where do you find this information? Trials were being conducted on the M44 in 1943, so why would they started using a "trial" designed stock on a production gun that is not the same model and the trial M44 is not even approved yet?
http://www.mosinnagant.net/ussr/russian-m44-carbine.asp
The Model 1944 Carbine was designed with the earlier Russian Model 1938 Carbine as an official blueprint, with the only major deviation in overall design being the addition of some form of bayonet. Bayonet testing was undertaken in 1943, with a specimen designed by N.S. Semin becoming design of choice. The selected bayonet was a permanent side folder and seemed the perfect solution to the Soviet dilemma. The short length of the carbine would not be affected in normal use and the side- folding bayonet could smoothly be extended when necessity arose. The added convenience of a permanently attached 15.1 inch crucifix bayonet was that this was one less item the Red Army soldier would be forced to carry, or lose for that matter. The carbine can be fired with the bayonet folded in place or extended, but it is important to note that the M44 was designed to be fired with the bayonet in the extended position. This design fact means when the bayonet is not extended, the point of aim/impact changes. A small slot, or channel, was carved into the right side of the stock that allowed the tip of the bayonet to rest when not extended. This added groove is the only major stock modification that separates the M44 carbine stock from the earlier M38 carbine stock. Although one source states differently there were indeed "dimples" cut into both M91/30 and M38 stocks. These dimples are located behind the rear barrel band. M38 carbines can also be found in M44 stocks. As the M44 stock will fit both models production of the M38 stock was halted once M44 production was underway, since there was no real reason to produce two stock types when one would do. So M38 carbines made from 1943--1945 might well have been fitted with M44 stocks at the factory.
There was also a limited use of a laminated stock for the M44 during the war years, as it seem that in 1943 the Soviets were producing a version of laminate stock for the Mosin Nagant- the first production of laminates being for the M38 carbine. The wartime use of laminate stocks was by no means common as most laminate stocks are post war manufactured. Almost allt of the M44 laminate stocks have a reinforcing bar/screw in the rear of the stock behind the trigger housing to add strength as it was found these stocks could crack during firing. There are at least two distinct color variations of these laminate stocks that collectors have observed. The first variations have a blonde hue while the second specimens are more red in color. It has been suggested the blonde stock is the original color while the red is the result of the shellac added later. This does indeed seem to be the case in examples that I have examined, as the Soviet use of shellac seems to have been dropped or scaled back as standard practice during the War years. It is assumed this was done to ease in production time as anything that saved production time would have been implemented. While laminate M44 stocks seem to have captured the interest of collectors the fact is these are not rare nor uncommon. It is rather rare to locate a true laminate M38 stock or a laminate M91/30 stock but this is not the case with the M44 carbine. Laminate M44 stocks are pretty commonplace with most being fitted post war.