250 grain .458 Hornady MonoFlex

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BuckDoeHunter

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Beautiful morning for some bullet testing, light winds and temp around 65*F.

The .458 250 grain MonoFlex is a copper alloy material and is harder than solid copper. I had to anneal these bullets in order to get them thru my Full Form Brux die.

Before and after annealing, the tip is removed before the bullet is heated, I wonder if there are any aftermarket tips that would work for this bullet?


My annealing station


When the bullet is cherry red, I push it into the can filled with water.


100yd 3 shot group with my heavy contour RemBrux 700ML, 10gr N110 with 57gr H4198, veggie wad, I was pleased :dance2:
 
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bamawoodsman

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Good work and Great shooting! I’m very pleased with the monoflex also. My gun doesn’t shoot as tight as yours but it will put them in 1 inch at 100. They also performed well when I shot one thru 5 water jugs at 110 yards. In my opinion a great hunting bullet and very accurate.
 

BuckDoeHunter

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I tried using a cheater bar on my press to see if I could get a MonoFlex that wasn't annealed through my die, nope! I removed the tip while the bullet was in the press, I then used a small punch to tap the bullet back out of the die. Maybe if I had an arbor press, I could get it to go through but no harm done, it's fun to experiment :cool:
 

D55

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Do you like the monoflex better than say a 275 Barnes xpb or is it just another option/tool in the box?
I tried using a cheater bar on my press to see if I could get a MonoFlex that wasn't annealed through my die, nope! I removed the tip while the bullet was in the press, I then used a small punch to tap the bullet back out of the die. Maybe if I had an arbor press, I could get it to go through but no harm done, it's fun to experiment :cool:
 

bamawoodsman

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The monoflex is 2nd from the left. The 275 xpb is 3rd from the left next to the monoflex
 

BuckDoeHunter

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Do you like the monoflex better than say a 275 Barnes xpb or is it just another option/tool in the box?
Most likely just another option. I like the XPB but when I see it fail expansion tests, it makes me leery to use it hunting. But on the other hand, I read your posts on successful deer hunts so it makes me think the bullet is working as it should.
 

BuckDoeHunter

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I’m surprised a bullet that hard expands as well as it does.
I don't think it's super hard, I think trying to smear the entire bearing surface through the die is too much for my press/die combo. You can see the shiny smear marks next to the engraved rifling marks on the un-annealed bullet. I'm not sure how much force the die can take before it may get damaged. I do wonder if I'm making the bullet too soft by annealing it and what that would do to it's performance on game.
 

ronlaughlin

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This bullet works good for me. It is accurate. It seems to be more reliable than the TEZ. Never was lucky enough to kill a deer with this bullet, but did use it on a coyote. This bullet was devastating on the coyote. Used in a sabot in a 50 rifle it, in my opinion, is an excellent choice.

However, it is too hard for me to enjoy sizing it to fit a 45 rifle. When it was run through the smooth die, and brought down only 0.0025", it was far more strenuous than desired. Other bullets used in my 45 rifles, are easily sized from 0.453" to 0.4502" using just one set.

Seems unlikely this bullet will ever go hunting again. Why fight it?
 

BuckDoeHunter

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This bullet works good for me. It is accurate. It seems to be more reliable than the TEZ. Never was lucky enough to kill a deer with this bullet, but did use it on a coyote. This bullet was devastating on the coyote. Used in a sabot in a 50 rifle it, in my opinion, is an excellent choice.

However, it is too hard for me to enjoy sizing it to fit a 45 rifle. When it was run through the smooth die, and brought down only 0.0025", it was far more strenuous than desired. Other bullets used in my 45 rifles, are easily sized from 0.453" to 0.4502" using just one set.

Seems unlikely this bullet will ever go hunting again. Why fight it?
The MonoFlex in this thread is .458 caliber that I load in my Marlin 1895, I think you are referencing the muzzleloader version which is .452 and has no cannelure.

I sized some of the .452 MonoFlex's yesterday for today's shooting and you are spot-on when you say they are far more strenuous than desired. I had to use a cheater bar on my press.
 

ronlaughlin

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Your guess is correct. My experience is with the 0.452 bullet. Didn't realize there was much difference between the bullets other than diameter.
 

Hatchet Jack

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I sized some of the .452 Mono Flex to shoot sabotless out of my smokeless. Have not shot them yet. They were the most difficult bullet I ever tried to size. Had to size them in lots of stages in order to pass them thru the sizing die. Extremely hard bullet. It took me for ever before getting them to fit my barrel. I don't foresee myself using them sabotless in the future.
 

goco4game

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The MonoFlex in this thread is .458 caliber that I load in my Marlin 1895, I think you are referencing the muzzleloader version which is .452 and has no cannelure.

I sized some of the .452 MonoFlex's yesterday for today's shooting and you are spot-on when you say they are far more strenuous than desired. I had to use a cheater bar on my press.
You are using some type of lube on those bullets when you're sizing them, right? I have not tried sizing copper bullets, but when resizing brass centerfire cases, it is mandatory that you apply some kind of lube. Imperial Case Sizing Wax is a popular choice, and I assume it will work well on bullets as well.
Without lube, a brass case can easily get stuck so badly that you rip the head right off the case body when trying to extract it. RCBS sells a Stuck Case Removal Kit for such purposes.
 
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