Question about the MP 413-640 and MP 41 Hammer

[freeze]

I'm in need of some information, and can't think of a more informed group of shooters to ask.

I am considering the MP 413-640 as a solid or the 41 Hammer, and was hoping that if someone here cast or uses this bullet they could measure the meplat for me.

I am considering these as solids because I don't feel I have the experience to determine an alloy that would perform as cast HP in the velocity range I would like to achieve.

Along that same though process, anyone have experience with these specific bullets on whitetails? If so are you using it as a HP (if so which pin do you use) or solid, and how has the terminal performance been?

I have no question on the quality of MP molds, as I have several and love them.

I currently shoot the xxx-640 profile in other calibers, but always as a HP; as well as the 432 Hammer that I shoot with the Penta HP.


Thanks,
Freeze

[bigbore5]

I really like the 640 designs. I currently don't have a 41mag except for a Desert Eagle, which is a jacketed bullet only gun as cast will ruin it.

What velocity and pressures are you looking to load for? Do you powder coat? Are you wanting plain base or gas check? Are you a hunter? All of these determines the alloy hardness you need.

I powder coat 14bhn heat treated MP359-640 large hp bullets plain based for the 357 Max and shoot them at 1700fps and 43,960psi with no leading and amazing performance cast from a foundry source 96/2/2 alloy. Really screws up a groundhog's day as far out as I can hit them.

[freeze]

Mar 31, 2024 18:25:22 GMT -5 bigbore5 said:

What velocity and pressures are you looking to load for? Do you powder coat? Are you wanting plain base or gas check? Are you a hunter? All of these determines the alloy hardness you need.

I powder coat 14bhn heat treated MP359-640 large hp bullets plain based for the 357 Max and shoot them at 1700fps and 43,960psi with no leading and amazing performance cast from a foundry source 96/2/2 alloy. Really screws up a groundhog's day as far out as I can hit them.

I am planning to run them 1500-1600 FPS.
I PC all my cast, and would want a plain base bullet.

I have successfully driven PC bullets over 1600. Specifically the 359-640 in a 353 Casull.
I use an alloy of WW mixed with pure lead and have had great success with large HP versions of the 640 profile but those velocities are always around 1050-1250 fps.

My concern is nose integrity (after expansion) as velocity increases to 1500+ fps.

Thanks for the response,
Freeze

[revolvercranker]

Mar 31, 2024 18:54:24 GMT -5 freeze said:

Mar 31, 2024 18:25:22 GMT -5 bigbore5 said:

What velocity and pressures are you looking to load for? Do you powder coat? Are you wanting plain base or gas check? Are you a hunter? All of these determines the alloy hardness you need.

I powder coat 14bhn heat treated MP359-640 large hp bullets plain based for the 357 Max and shoot them at 1700fps and 43,960psi with no leading and amazing performance cast from a foundry source 96/2/2 alloy. Really screws up a groundhog's day as far out as I can hit them.

I am planning to run them 1500-1600 FPS.
I PC all my cast, and would want a plain base bullet.

I have successfully driven PC bullets over 1600. Specifically the 359-640 in a 353 Casull.
I use an alloy of WW mixed with pure lead and have had great success with large HP versions of the 640 profile but those velocities are always around 1050-1250 fps.

My concern is nose integrity (after expansion) as velocity increases to 1500+ fps.

Thanks for the response,
Freeze

Boolistdesigner, a member here, designs most if not all of MP's hollowpoint molds. I know with speaking to him he designs them to act like the Nosler Partition bullets. That is they front expands and might shear pedals off, but the botton remainder of the bullet pushes on through and out the deer or what animal you are hunting. His hollowpoints expand after entering the animal and give that terminal shock and large cavity, then the pedals may shear off, but no problem as the base continues on through like a Nosler Partition.  Don't worry about the losing pedals. I'll tell him to look in on this thread and you can get it from the horses mouth. 

[bigbore5]

That's exactly how they have worked for me. I haven't used the penta pin on big game yet, but the two hogs I shot with it had very good damage for about the first 8 inches, then the petals came off shredding the lungs while the base drove on very straight to exit. This is from the 357max, @1650fps mv,at 37 and 74 yards broadside. Both pigs were over 200 pounds.

[contender]

I have that mold,, (413-640) but haven't taken any game with the bullets,, so I'm no help there. But so far,, the accuracy has been as expected. I'll have to dig around & get some out to measure the meplat. But if I were to go after whitetails,, I'd use either of the HP designs w/o worry.

[foxtrapper]

I get .368 meplat on the solid mp mold

[boolitdesigner]

You got good information from the others here. These bullets with the larger hollow points are Nosler partitions in performance. They kill very fast. FORGET any fears that they don’t work. Ask sixshot what he thinks.
I have killed a lot of deer with these and other bullets of my design. No need to ask if they perform because they do. All you have to do is your part.

[freeze]

Apr 1, 2024 9:53:59 GMT -5 foxtrapper said:

I get .368 meplat on the solid mp mold

Thanks Fox trapper .... Is that the 411 Hammer or the 413-640 that you measured the meplat at .368"


-Freeze

[freeze]

Apr 1, 2024 10:08:34 GMT -5 boolitdesigner said:

You got good information from the others here. These bullets with the larger hollow points are Nosler partitions in performance. They kill very fast. FORGET any fears that they don’t work. Ask sixshot what he thinks.
I have killed a lot of deer with these and other bullets of my design. No need to ask if they perform because they do. All you have to do is your part.

I appreciate all the good info.
I have killed several deer with various versions of the xxx-640 and have always had good performance. Based on wound cavity I would say that at my velocities the petals are not coming off, but I can't be sure because I certainly have never recovered one from game (and I consider that a VERY good attribute).

While I don't doubt the effectiveness of the partition style, even of the petals shear off; as that seems to be the consensus of the replies so far. However my personal gut reaction would be to not have the petals sheer off, which seems to be the case with my alloy at velocities below 1250.

My current thinking is if I'm going to lose the nose due to alloy limitations then I think I would prefer to shoot the bullet as a solid. I could be wrong and want to hear more.

Thanks again to all who responded, I appreciate your time and experience.


-Freeze

[foxtrapper]

Apr 1, 2024 17:54:58 GMT -5 freeze said:

Apr 1, 2024 9:53:59 GMT -5 foxtrapper said:

I get .368 meplat on the solid mp mold

Thanks Fox trapper .... Is that the 411 Hammer or the 413-640 that you measured the meplat at .368"


-Freeze

It’s th 41 hammer

[freeze]

Apr 1, 2024 19:34:58 GMT -5 foxtrapper said:

Apr 1, 2024 17:54:58 GMT -5 freeze said:

Thanks Fox trapper .... Is that the 411 Hammer or the 413-640 that you measured the meplat at .368"


-Freeze

It’s th 41 hammer

Thank you for taking the time to not just measure, but the additional time to follow up.

Much appreciated.

Thanks,
Freeze

[bigbore5]

If you don't trust the petals shearing off in game (I don't trust it yet either), use the round pins. I've never had a problem with them.

[freeze]

Apr 2, 2024 4:34:40 GMT -5 bigbore5 said:

If you don't trust the petals shearing off in game (I don't trust it yet either), use the round pins. I've never had a problem with them.

Thanks for responding big more.

Are you referring to the pins that result in a typical flat point or the really small ones that result in the "cup point"?

I am pushing the 359-640 to around 1600 fps and have opted for the small cup point in an attempt to ensure nose integrity, yet encourage a little expansion. Unfortunately I haven't had a chance to test this theory on whitetails yet!

At velocities of 1250 and below I have had no indication that the petals shear off while passing through game (using large or small HP pins) with the 454-640, the 477-640 and the 477-640_Light.

I'd like to know meplat of the 413-640 before I decide that would be my mold choice. I want a very effective flat point as a fall back plan if I never learn to trust the petals shearing off.


-Freeze

[contender]

I dug out my mold & all. The 413-640 has a meplat of .285.