“Keep Your Powder Dry” is a 1945 drama film starring Lana Turner, Susan Peters, and Laraine Day as women who join the Women’s Army Corps during World War II.
The only way for Valerie Parks (Lana Turner) to earn her inheritance is to prove to the trustees of her family estate that she’s more than a playgirl. The best way to prove herself worthy, she decides, to join the war effort by becoming a WAC  (Woman’s Army Corps). During training, Val clashes with a more serious daughter of the military, Leigh Rand (Laraine Day) and befriends the earnest Ann Darrison (Susan Peters) among a varied group of women. Her experiences in training begin to show Valerie there may be more to life than the hollow existenece she’d been leading with her headless, or rather, mindless, society friends.

Lana Turner plays Valerie “Val” Parks.

Here was a distinct novelty: a Lana Turner feature in which the romantic element was virtually nonexistent.
“You’ll be fascinated with the way the inner workings of the WAC are shown in this picture, ” wrote Virginia Wilson in Modern Screen. “And when you see Lana in her uniform, you’ll probably rush right out and join up yourself. ” Which may have been the reason why MGM and the WAC joined forces to make this film in the first place.

It’s interesting to watch Lana’s character grow in the story from social butterfly, with little more on her mind than highballs and high heels, to a responsible woman. She becomes able to shed her self-interest and devote herself to a cause and to friendship with women very different from herself.

Trailer:

You can watch the film here.

Lana Turner did a lot of movies. She really loved being a moviestar.
Here are the most important films in which she starred. Just click the links for more info, photos and videos.

20 April 1937: A Star Is Born
9 Oct. 1937: They Won’t Forget
24 Oct. 1937: The Great Garrick
1 Jan. 1938: The Adventures of Marco Polo
22 July 1938: Love Finds Andy Hardy
12 Aug. 1938: Rich Man, Poor Girl
9 Dec. 1938: Dramatic School
28 April 1939: Calling Dr. Kildare
18 Aug. 1939: These Glamour Girls
29 Sept. 1939: Dancing Co-Ed
19 April 1940: Two Girls on Broadway
19 July 1940: We Who Are Young
25 April 1941: Ziegfeld Girl
12 Aug. 1941: Dr. Jekyll and Mr. Hyde
2 Oct. 1941: Honky Tonk
18 Febr. 1942: Johnny Eager
27 Aug. 1942: Somewhere I’ll Find You
1 April 1943: Slightly Dangerous
19 Aug. 1943: Du Barry Was A Lady
13 Nov. 1943: The Youngest Profession
23 Aug. 1944: Marriage Is a Private Affair
8 March 1945: Keep Your Powder Dry
1 Oct. 1945: Week-End At The Waldorf
2 May 1946: The Postman Always Rings Twice
5 Nov. 1947 : Green Dolphin Street
1 Nov. 1947: Cass Timberlane
29 April 1948: Homecoming
20 Oct. 1948: The Three Musketeers
1 Sept. 1950: A Life Of Her Own
2 March 1951: Mr. Imperium
5 Sept. 1952: The Merry Widow
25 Dec. 1952: The Bad And The Beautiful
25 Aug. 1953: Latin Lovers
1 May 1954: Flame And The Flesh
7 Sept. 1954: Betrayed
13 May 1955: The Prodigal
4 June 1955: Sea Chase
14 Dec. 1955: The Rains Of Ranchipur
12 Jan. 1956: Diane
13 Dec. 1957: Peyton Place
30 Jan. 1958: The Lady Takes A Flyer
2 May 1958: Another Time, Another Place
30 April 1959: Imitation Of Life
23 June 1960: Portrait In Black
19 July 1961: By Love Possessed
2 Nov. 1961: Bachelor In Paradise
25 Dec. 1962: Who’s Got The Action?
24 Febr. 1965: Love Has Many Faces
27 April 1966: Madame X
30 April 1969: The Big Cube
7 Nov. 1974: Persecution
27 Oct. 1976: Bittersweet Love
31 Oct. 1980: Witches Brew
21 May 1982: Dead Men Don’t Wear Plaid

Sources: Wikipedia, IMDB, Rotten Tomatoes, Lana’s biography “Lana, the Lady, The Legend, The Truth“, “The Films Of Lana Turner” by Lou Valentino and “Lana Turner, The Memories, The Myths and The Movies” by Cheryl Crane.