The 37th Mississippi reported none killed, but 3 wounded in the explosion of the crater June 25. [The Vicksburg Campaign, Vol. III, Unvexed to the Sea, E. C. Bearss, Morningside Books, 1986, p. 925]

Misspelling like this are commonplace as is the transposition in old documents, E to F, etc.

I suggest you obtain his Compiled Service Records through the service noted in the Red enclosed box above. The handwritten affidavits of his father regarding claim to his son's effects are difficult to read on line. Many of these men were originally buried in other locations, and only later were reburied in the Soldiers Rest Area of the Vicksburg City Cemetery, Cedar Hill.

J. M. Bergis, Private, Company E, 37th Mississippi, died July 2, 1863, buried Cedar Hill, Cemetery, grave no. 128**
[Confederate Roll of Honor, Known Confederate Dead, Vicksburg Campaign, Jan. 1862-July 1863, Gary W. Webster, "Ole Sow" Publications, 1998

** Note, the original cyprus head boards were long ago disintegrated and the original burial locations no longer known.
Tomb stones were placed in the late 1970s in sections by state of unit.

....

J. M. Burgess, age 29, Private, Company F, 37th Regiment Mississippi Volunteers, enlisted March 12, 1862 at De Soto for 3 years or the war, died July 1, 1863 [in hospital*] from wounds, killed in trenches [Jn. Burgiss], left neither a wife nor children

* A printed form letter from the Treasury Dept., Second Auditor's Office, Chairman Div. of Deceased Soldiers. in a printed Section, "Alleged, died in Hospital," and written in long hand "on 1st Jul 1863"

Company F Record of Events

Stationed at Columbus, Mississippi, March 12-June 30, 1862.
Stationed at Saltillo, Mississippi, July August 1862.

Stationed near Lumpkin's Mill, September-October 1862.
Stationed in bivouac, Yazoo County, Mississippi, November-
December 1862.
[For record of events, see Company A.]
Stationed at Snyder's Mill, Mississippi, January-February 1863.
Stationed at Enterprise, Mississippi, April 30-October 31, 1863.
Last mustered under fire of the enemy's gunboats at Snyder's
Bluff.
March 17-18.— On the night of May 17 marched into Vicksburg
and early on May 18 took position between the Jackson and
Graveyard Roads. Was not relieved during the siege of forty-one
days.
July 4.— Was surrendered to the United States forces under Gen-
eral [Ulysses Simpson] Grant.

M269: Compiled Service Records of Confederate Soldiers Who Served in Organizations from the State of Mississippi