FYI, the Russian RP46 parts kit shown in this video is currently selling on GunBroker, with no reserve and a penny start: https://www.gunbroker.com/item/778500561
The RP-46 was the final iteration of the Degtyarev DP27/DPM light machine gun, modified to feed from Maxim/SG43/PK belts instead of pan magazines. As such, it was able to serve the role of a universal machine gun like the MG34 and MG42 until the Soviet Union was able to develop a true purpose-built GPMG in the PK.
Because the RP-46 is a very rare firearm in collectors’ hands today, it is not well understood by most. While the top feed adapter is known, many people do not realize that several other elements of the weapon were changed at the same time, including a complete redesign of the gas block. Today we are looking at a Russian-made set of RP-46 parts and also a North Korean set (North Korea adopted the design as the Type 64, with several changes form the Soviet pattern). We will also look at the American-made reproduction RP46 top cover made by SMG Guns of Texas.
The reproduction adapter has several improvements over the originals, while maintaining a very authentic look. Most significantly, it can be used without any permanent modification to a semiautomatic or fully automatic DP/DPM.
Very nice presentation in traditional Ian-like fashion; particular and systemic.
I must say that I was not prior to this and preceding presentations that familiar with DP guns, in fact I considered them kind of low-grade war-time expediency fill. This part however convinces me of the opposite; especially with this belt-fed conversion. It somewhat resembles DShk design.
“DP guns, in fact I considered them kind of low-grade war-time expediency fill”
You probably confused DP with one of machine gun created starting in 1942 with fast production in mind, which are described here: https://www.kalashnikov.ru/pulemyotnaya-drama-krasnoj-armii-2/
What is important here was that according to Technical Tactical Requirements No. 2202 (ТТТ № 2202) they need DP replacement, which would have 1,5-2 times smaller technological volume – or in simple words, would need 1,5-2x less time to make 1 example.
Actual time needed to craft one example (without magazine):
DP [series production = control sample] – 24 machine hours
КБП-180 (Degtyarev) – 21
КБП-260 (Degtyarev) – 27
64-П (Savin) – 23
РПС-3 (Simonov) – 18
ТКБ-335 (Bulkin) – 24
ТКБ-336 (Akulin) – 27
All machine guns feed from box magazines, except КБП-260 (belt)
None full-filled reliability condition, it was noted that for most failures to fed magazines were guilty (excluding КБП-260). Acceptable failure rate was 0,15 %.
“It somewhat resembles DShk design.”
Indeed, Degtyaryov himself want to make whole system of similar machine gun, which would allow easier machine guns and armorers training than in case when each machine gun would be totally different design from all others.
Thus he designed trio of similar machine guns (DP – infantry, DT – tank, DA – aviation) and also high-caliber machine gun (DK, which will evolve into DShK).
DA will be replaced fast, by ShKAS, however it is note-worthy that Degtyaryov also designed belt-fed aviation machine gun, which is described in English (among other Soviet aviation armament system from 1930s) here: http://www.quarryhs.co.uk/Degtyarev.pdf
(I think it will be interesting read to anyone interested in 1930s aviation machine guns of Soviet Union), but as already said ultimately lost to ShKAS. It must be noted that this fact is rather testimony of rapid progress in aviation in 1930s rather than machine gun design shortcomings.
DP and DT evolve simultaneously into DPM and DTM respectively.
Low point in Degtyaryov machine gun line is DS-39, supposed to replace aging Maxim 1910 machine gun, but proving unreliable (especially with certain types of cartridges cases), despite long development time (some source mention as early as year 1932), though in defense of Degtyaryov it must be noted that requirements were ambitious and many others also failed before finally Goryunov design was found good enough (become SG-43).
Interestingly DS-39 spawned tank machine gun – namely 56-П-423Т, see photos (all but last): https://warspot.ru/8159-drugoy-degtyaryov
Though, it (according to knowledge available now) was made only in prototype form.
I forget about RPD, that is 7,62×39 machine gun. While mechanically there was nothing new it was first Soviet mass-produced machine gun for intermediate cartridge (or SAW as it would be called in today U.S. parlance), thus being one of first such weapon adopted and if I am not mistaken, first such weapon adopted by major power.
And there was also PPD (sub-machine gun), while maybe not innovative it was first sub-machine gun widely (by 1930s standards) deployed by Red Army, allowing getting experience with such kind of weapon.
“somewhat resembles DShk design.”
Degtyaryov will also attempt to created 14,5-mm machine gun (14,5×114 cartridge, “AT rifle cartridge”), for which main purpose would be AA defense, see 4th image from top:
it failed, proving ground staff examined and concluded that it was due to machine guns being so poorly made, that only one flap (left one) was actually transmitting forces (according to design 2 flaps should do it, like in DShK), but anyway before that despite all mechanical adjusting, spring changing and so on, there was no way to fire more than 105-110 shots without malfunction. Additionally most severe problems of AA defense were solved by M16 MGMC delivered under Lend-Lease act (hence photo of M16 MGMC in this article).
Others also attempted to design 14,5-mm machine gun, 14,5×114 machine gun by Degtyarov (DShK-14,5) and by Simonov were tested already in 1939. It was decided to do not further works on first and to further develop second one. However problem with belt-fed proved by unsolvable, by 1942 it was abandoned in favor of 10 round clip.
“RP-46 was the final iteration of the Degtyarev DP27/DPM light machine gun, modified to feed from Maxim/SG43/PK belts instead of pan magazines.”
Also it was cumulation of experiences gained from Great Patriotic War, you can read (in Russian) users remarks about weapon they used:
Generally, disk magazine was criticized rather than machine gun itself.
Chosen users remarks:
We want hand-held machine gun modeled after MG-42
It is purposeful to redesign DP machine gun after MG-42 pattern and replace disk with box magazines [yes, box not belt, thus possibly that “after MG-42” means “implement better barrel change”]
In battles of Great Patriotic War, it did not prove as automatic weapon of riflemen unit. It is necessary to rework it to fed from metallic belt and alter bi-pod, lighten and make it construction closer to Czechoslovak machine gun ZB
That all being said, it must noted that it was measured against MG 34, then top of development in infantry machine guns.
Very nice review of Degtyarov’s work. He was truly one of Soviet best designers. Otlychnik!
North Korea has a “shoulder thing that goes up” oO
Wouldn’t SMG’s short-stroke tappet gas block preclude the use of corrosive ammo? Or has the supply of cheap surplus corrosive ammo dried up?
The RP1946’s side-loading belt system replaces the top-mounted pan magazine as part of the move to upgrade the DP1927 with a higher rate-of-fire.