Originally posted by MiloMorai
WRONG
It was MG151/20s. The MG151s were out of production.
The Do 335V1 W.Nr. 230001, CP+UA, made its maiden flight on Oct 26 1943
You should by this book.

Author: By J. Richard Smith, Eddie J. Creek & Thomas H. Hitchcock
ISBN#: 0-914144-52-9
Summary: 184 printed page hardcover
Price: US$ 49.95
Role : Fighter
In-Service Date : November 1944
Manufacturer : Dornier-Werke G.m.b.H.
Number Produced : Unknown
Crew : 1
Length : 13.85 meters
Height : 5.00 meters
Empty Weight : 7400 kilograms
Operational Weight : 9600 kilograms
Wing Span : 13.80 meters
Wing Aspect Ratio : Unknown
Wing Area : 38.50 square meters
Engine : 2x Damlier-Benz DB 603A-2 (1750 hp)
Max Speed : 770 kph @ 6400 meters
Cruising Speed : 685 kph @ 7100 meters
Climb : 552m per minute
Service Ceiling : 11400 meters
Range : 1380 kilometers
Fuel Capacity : Unknown liters
Machinegun Armament : None
Cannon Armament : 1x 30mm MK 103 (Propeller Hub - 70 rounds)
2x 15mm MG 151/15 (Nose - 200 rounds each) Payload : 500kg (Internal)
Gunsight : Revi C/120
Avionics : Fug 25a IFF
Pilot Armor : Yes
Self-Sealing Fuel Tanks : Yes
Armored Windscreen : Yes