Curious About the .458 Winchester Magnum M1 Garand

General
1

Seeking Advice on the .458 Win Mag M1 Garand

I’m really interested in the idea of customizing an M1 Garand to shoot .458 Winchester Magnum. I’ve been doing some research, but I still have a few questions.

  • Functionality: How well does the M1 Garand perform with the .458 Win Mag? Are there any specific issues I should be aware of?
  • Modifications: What kind of modifications might be necessary to make this conversion successful? Are there specific parts that need to be changed?
  • Performance: What are the experiences of others who have done this? Is it worth it, or are there better options out there?
  • Hunting and Shooting: For those who hunt, how does the M1 Garand in this caliber perform on game? I’d love to hear about your experiences.

Any insights or advice would be greatly appreciated! Looking forward to the community’s thoughts on this unique firearm combination.

8 Likes
2

I’ve been researching the .458 Winchester Magnum for a while. When loading for the M1 Garand, I recommend using slower-burning powders like H4895 or IMR 4350 to ensure proper function.

3

That’s great advice! I’ve also seen people recommending RL-19 for this type of loading. It really seems versatile for heavier bullets.

4

Just be careful with your bullet selection. For the M1, you want bullets that are not too long since they can affect cycling. Stick with flat bases, and you’ll be fine.

5 Likes
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That makes sense! Any specific weights you recommend? I’ve seen options ranging from 300 to 500 grains.

6

For the M1 Garand, I’d suggest sticking with 400-450 grain bullets. They provide a good balance of performance without over-stressing the operating system.

7

You could also consider using a muzzle brake if you’re worried about recoil, as the .458 kicks like a mule!

8

Good point! A muzzle brake would definitely help. But does anyone know how it might affect accuracy?

9

Generally, it shouldn’t affect accuracy too much if properly fitted. Just make sure to test it out beforehand at the range.

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I’ve seen mixed results about accuracy with a muzzle brake. Sometimes it can throw off the harmonics of the barrel.

11

That’s interesting. Sounds like more testing is needed. Has anyone tried Varget powder for this setup?

12

Varget can work, but you may get better results with a stick powder like IMR 4064 which has a reputation for consistent loads in heavier calibers.

13

I’m still out here trying different combinations. So far, the IMR 4831 has shown promise for me.

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That’s encouraging! Just remember to keep an eye on your OAL. The M1 can get finicky with longer rounds.

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Absolutely! Safety first, right? I wonder how much of a difference adjusting the seating depth makes in the overall performance.

16

Great point! It’s all about finding that sweet spot. Are there specifics on how much to adjust?

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Typically, adjustments of 0.020 to 0.050 inches can provide noticeable changes, but it’s all about trial and error.

18

I’ve been exploring the idea of converting my M1 Garand to chamber .458 Winchester Magnum. The modification involves altering the block and possibly the gas system, which can be quite the task! Anyone here done this? What challenges did you face?

4 Likes
19

The .458 is a beast of a round! Be sure to consult a competent gunsmith. It’s crucial to consider the M1’s gas system—adjustments will likely be needed to handle the higher pressure.

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I haven’t tried this conversion yet, but I wonder about the reliability after such extensive modifications. Will it still cycle properly? Anyone have experience?