Updated: Apr 2
Photo Credit: Bob Rowen
"General Walker receiving his 2nd Star in 1957"
"It is requested you that you withdraw this substituted bullet from all records and files pertaining to the assassination of John F. Kennedy and the attempted assassination of Walker, and that you assure the security of the withdrawn bullet for future comparisons" - Edwin A. Walker
The above quotation was from a letter from former Army Major General Edwin A. Walker to the U.S. Attorney General on February 12, 1979.
There's been a lot of confusion regarding this comment by former Major General Edwin Walker in the JFK Assassination community, particularly by some (not all) conspiracy advocates that claim the Walker bullet was faked.
However, in fairness, to anyone that expresses an interest in the Walker case, it can be confusing, and this article will hopefully increase your knowledge and awareness of the true facts.
An attempted murder of General Walker occurred on the night of April 10, 1963. While he sat at his desk at his fashionable Turtle Creek Blvd home in the Highland Park area of Dallas, one single rifle shot rang out. While preparing his 1962 Tax Returns (due on April 15th), a bullet crashed through the lower window sash, just missing his head (inches) and plummeted through his lathe/plaster office wall and exited out the other side in an adjacent room. The slug was found by Dallas Police officers who responded to the scene. It was badly mangled due to the dual window and wall impacts. (See photos CE 573)
A video of General Walker on the next day (April 11, 1963) can be viewed here. https://www.youtube.com/watch?v=yCjahRnkQfk
Photo Credit: National Archives
"CE 573 Walker bullet recovered"
Photo Credit: National Archives
"CE 573 Walker bullet recovered (reverse side)"
As you can clearly see, the bullet slug was in bad shape, with lead exposed through the remaining copper jacket. The initial Dallas Police Offense Report described the slug as "bullet of unknown caliber, steel jacket".
Excerpt from the Edwin Walker Case File, Dallas Municipal Archives
You can view the entire Case File here.
Now this adds to more confusion, as the bullet slug was defined as a "Steel Jacket", not a "Copper Jacket" like the one in evidence. Along with the Walker letter to the Attorney General, suspicions arise to the authenticity of that bullet, that it was substituted to frame Lee Harvey Oswald in the Walker shooting.
This author has no reasonable answer why it was described as a "Steel Jacket" bullet; however, I've seen accounts where jacketed bullets were characterized that way back in the day to rifle bullets.
Be that as it may, we dig further to investigate what happened to that bullet and its provenance to clear up this confusion.
In early December 1963, an interesting twist in the Kennedy Assassination happened. Ruth Paine, who had invited Marina Oswald to live with her in Irving, Texas, found a Russian language "Home-Maker" book that she wanted to return to Marina, who was sequestered under Secret Service guard, by orders of President Johnson. She gave the book to an Irving Police Officer who in turn delivered it personally to the Secret Service protection detail. Naturally the Secret Service agents inspected the book and found a letter inside the Russian book.
The letter was written in Russian. Marina was questioned on this letter, and it was translated. Only at that time did Marina disclose that her husband had attempted to kill General Walker. With that occurrence, the FBI contacted the Dallas Police Department about the bullet that was still in their possession. Lt. Carl Day retrieved the bullet from the City-County Criminal Investigation Lab at Parkland Hospital.
The FBI determined it was a 6.5 mm bullet, however due to its distortion, they were unable to conclude it was fired by Oswald's Mannlicher-Carcano Carbine to the exclusion of all other rifles.
The rifling marks on the bullet were consistent with Oswald's weapon. 
Walker's Objection to the bullet in the televised HSCA Hearings
Walker began a series of letters complaining that the bullet depicted in the HSCA televised hearings of the 1970's was not the actual bullet.
It should be noted here that the HSCA concluded their televised hearings in September 1978.
On September 12, 1978, Walker sent a "Mailgram" off to Robert Blakey of the HSCA. Clearly Walker was watching the televised proceedings as it happened. He admonished Blakey for using a bullet that was not the Walker bullet.
Receiving no response, Walker wrote a personal letter to the Attorney General on February 12, 1979. Again the content of the letter was complaining about the bullet and it was not representative of the actual mangled bullet recovered at his Turtle Creek home.
On February 15, 1979, Walker decided to write a letter to Don Byrd, Dallas Police Chief asking his assistance to get that substitute bullet out of the record. Walker stated he still hadn't received any replies.
Frustrated, Walker clearly felt he was being ignored. On April 24, 1979, he fired off another letter to Griffin Bell, the Attorney General. This time he enclosed a copy of the Blakey Mailgram and his copy of the letter to Dallas Police Chief Don Byrd. He mentioned there were no replies.
By June 1979, Walker is frustrated again. General Walker hired a Washington D.C. attorney, Joseph Dinsmore Murphy, to write a letter dated June 7, 1979. It was addressed to the Deputy Attorney General, Robert Keuch. The letter states that Walker wanted to correct an error using a substituted bullet instead of the actual bullet. Keuch acknowledged receipt of the letter. 
By this time, Walker finally got some attention and Deputy Attorney General, Robert L. Keuch got the ball moving.
Provenance of CE 573 (Walker Bullet) established
Special Counsel to the Attorney General, Robert L. Keuch addressed this complaint of Walker's "substituted bullet". He reviewed the FBI files of their investigation. After that, he contacted the National Archives to deliver CE 573 to the FBI Laboratory for physical examination on June 29, 1979.
As per protocol, a National Archives representative delivered CE 573 to the FBI lab and remained in complete control and custody at all times during the examination. The bullet was still in the Dallas Police (DPD) Evidence Box and removed and placed under a microscope. Here's what they observed.
The DPD Evidence Box top had the markings of "4-10-63 Turtle Ck Burg by F.A., BGB, RF, JH, Q188" (FBI evidence designation)
Inside bottom of the DPD Evidence Box had the markings of "Day 7640"
The outside bottom of the DPD Evidence Box had the markings of "7640 Day, Q188 and Rm"
On the bullet itself, the following discernable inscriptions were observed; "Q188, N, B, J, O (or D), JH, and RF
Therefore of the DPD, "N" referred to Billy G. Norvell (Police Officer at the Walker scene, "B" would be B.G. Brown (Crime Scene Search Section who received the bullet from Office Norvell), "D" would be Lt. Carl Day of the DPD Crime Lab. The "A" could have been either Louie Anderson or F.T. Alexander of the City-County Criminal Investigation Lab at Parkland Hospital
The "JH" and "RF" were the FBI Lab examiners in December 1963 
There can be no doubt that CE 573 (Walker Bullet) at the National Archives is the original 6.5 mm Copper Jacket bullet recovered at the Walker home.
Walker was objecting to a "pristine bullet" shown in the televised hearings as not the bullet that was recovered in mangled condition. For some reason, he was upset that they didn't use CE 573, which has an undeniable evidence chain.
Speculation that the bullet was a 30.06 instead of a 6.5 mm bullet is unfounded, according to the evidence. Although this author has seen a couple of newspaper reports on the Walker shooting saying it was a 30.06 (common hunting round), the evidence and the DPD crime report stating "unknown caliber" negate this rumor. It is reasonable to assume that perhaps there was some speculation that it was a 30.06 at the Walker scene, which got passed down to a newspaper reporter.
For more on the Walker Shooting, please consider the book "Pieces of the Puzzle - An Anthology" by Gayle Nix Jackson. Available on Amazon https://www.amazon.com/Pieces-Puzzle-Gayle-Nix-Jackson/dp/B077RXGPJV
1 - Edwin A. Walker Papers, Briscoe Library (page 6 of link) https://archive.org/details/19790202WalkerBlakeyTV/mode/2up
2 - FBI Internal Report of the attempted Walker Assassination https://www.maryferrell.org/showDoc.html?docId=96433#relPageId=11&search=Walker_bullet
3 - FBI Teletype December 4, 1963, showDoc.html (maryferrell.org)
4 - Letter from Robert L. Keuch (Special Counsel to the Attorney General) to the FBI, July 3, 1979, showDoc.html (maryferrell.org)
5 - Edwin A. Walker Papers, Briscoe Library (pages 1-6 of link) https://archive.org/details/19790202WalkerBlakeyTV/mode/1up