New .41-caliber bullet

[Lee Martin]

Here's a new .41-caliber bullet I designed through Mountain Molds.



And the spec sheet:

Weight = 290 grains
Diameter = 0.412"
Front band dia. = 0.412"
Nose length = 0.410"
Meplat = 74%
Alloy - Linotype
Crimp groove = 0.055"
Ogive - Tangential
Front band length = 0.070"
Base = 0.392"
Groove angle = 45 degrees
Shank height = 0.105"
Body bands = 3
Lube grooves = 2
Band length = 0.076"
Overall length = 0.913"
Groove c-2-c = 0.144"
Lube weight = 0.611 grs
Naked weight = 283.1 grs
Sectional density = 0.244
Final weight = 290 grains
Nose/overall length = 44.2%

The 585 LFN I did with Mountain shot so well I mirrored it in .41. Meaning they're proportionally one in the same. From the get go the 585 would be dual purpose - a heavy for caliber .500 Maximum and a longer range cast for my .50 Alaskans. I started with the nose. After shooting a lot of WFNs at 100 yards I'm always left wanting more. Yes I've had some great groups with them in .45, .475, and .50 caliber but they're very load sensitive (side note- most like being pushed hard but the window is narrow. Outside that sweet spot they become erratic at distance). In contrast, the 585 LFN grouped tight at 100 in three different guns and three distinct velocity ranges - .500 Maximum Ruger @ 1,200 fps, .50 Alaskan BFR @ 1,400 – 1,500 fps, and a .50 Alaskan Mauser @ 1,900 – 2,000 fps. My gut tells me the bullet is balanced, the CoF & CoG are properly dispersed, and the nose aids stabilization.

Keith styles, especially Elmer's, are the most accurate cast slugs I've used at 100 yards. That isn't gospel, just my experience after shooting many SWCs, LBTs, SSKs, and RNFPs. And at first I considered that profile for a heavy 0.512". But someday I'll convert a Marlin to .50 AK and its driving band could hurt feeding. Therefore I went with a tangential ogive.

The make-up of the Martin LFN is simple. A 74% meplat is retained and is in line with traditional LFNs. I then assessed the nose of a 435 WFN using an optical comparator (poured from my LBT mold). Contrary to popular belief it isn't hard to duplicate Veral's contour. Like any bullet the ogive can be measured in arc radians and replicated (single or double radius, rounded or straight edge). That curvature is mimicked on mine plus four alterations: 1) the nose is longer than the normal LFN, 2) the front band is a hair taller, 3) the crimp groove is big like the original Keith, and 4) the base is higher putting more lube ahead of the gas check.

290 Martin LFN as cast (left) & sized, lubed, and gas-checked (right):



Next to its big brother, the 585 gr LFN:



Recently I cast these 41's from pure linotype and they dropped beautifully. Since the Lyman 61 was up and hot, I also ran a few hundred 585's:

Melting the linotype and pre-heating the mold:





We'll see if this 290 LFN performs like the 585 at 100 yards. If it does, the next version will be a scaled 475 around 445 grains. However due to the nose length, it'll only work in 480 Ruger brass.

 

[rjwinz]

Woah! 290 grains in a .41? What powder, what loads, what guns, where can I get some?

 

[Hairy Clipper]

I think you have a winner Lee! Are there any plans to scale it to the .401 PowerMag?

 

[djw54]

Here's a new .41-caliber bullet I designed through Mountain Molds.

And the spec sheet:

Weight = 290 grains
Diameter = 0.412"
Front band dia. = 0.412"
Nose length = 0.410"
Meplat = 74%
Alloy - Linotype
Crimp groove = 0.055"
Ogive - Tangential
Front band length = 0.070"
Base = 0.392"
Groove angle = 45 degrees
Shank height = 0.105"
Body bands = 3
Lube grooves = 2
Band length = 0.076"
Overall length = 0.913"
Groove c-2-c = 0.144"
Lube weight = 0.611 grs
Naked weight = 283.1 grs
Sectional density = 0.244
Final weight = 290 grains
Nose/overall length = 44.2%
....
We'll see if this 290 LFN performs like the 585 at 100 yards. If it does, the next version will be a scaled 475 around 445 grains. However due to the nose length, it'll only work in 480 Ruger brass.

So, if the scaled 475 needs to be run in shorter brass, how does the 41 fare? At .410 nose length (coincidence?), this would make cartridge overall length for a .41 Rem Mag of 1.70". I thought max coal for 41Mag is 1.59", isn't it? I know you do some great wildcats, so is this bullet meant for one of those, or will it fit in my factory 41Mag? Time to break out the calipers! (Blackhawk, Redhawk and 657). 290 grains. Good grief.

 

[Lee Martin]

The nose of the .475 equivalent will be too long for .475 Linebaughs. However it'll crimp and have an OAL that'll work in .480 Ruger.

My 290 LFN is really designed for long cylinder .41 Magnums (Redhawks, Dan Wessons, etc). I'll mostly shoot them in my 5-shot .414 Martin pictured below:



That cylinder is a little short for the 290 LFN. Later this summer I'll blank a new 5-shot that uses the entire frame window. Of course, that'll necessitate trimming the barrel shank and redoing the forcing cone.

 

[Lee Martin]

I think you have a winner Lee! Are there any plans to scale it to the .401 PowerMag?

I plan to swage these 290's to 0.401" for use in my Ruger Powermag:



As you can see, that gun was set-up with a long cylinder.

 

[contender]

Excellent Lee. I have enough irons in the fire to prevent me from wanting one of these designs, but they look great in your gun!

 

[rjwinz]

I almost hate to see a .41 Magnum Bisley! Man did I miss the boat on that one! Don't make a lot of gunshows but never see them at the ones I do attend. Not that I don't like my RedHawks, but it's not exactly my favorite trigger type. Definitely need a Bisley! Hell, I'd settle for a Super Blackhawk in .41 Magnum, but I never hear about it, or heard about it when small production runs have been made. :wink:

Davidson's lists two .41 Super Blackhawk Hunters, one a Bisley. There appear to be 5 of the regular grip available at this time:

http://www.galleryofguns.com/RugerStore/SearchResults.aspx?guntype=revolver&model=All&caliber=41M&instock=0&view=D&zip=56001

Its tempting, but I already have two NM's in .41 and am looking for a DA.

 

[okie44]

Good looking bullet, should work well in the 405 Winchester as well.

 

[rjwinz]

Where do you get a Bisley grip for a NM Blackhawk?

 

[Bucks Owin]

Good looking bullet, should work well in the 405 Winchester as well.

That was my first thought, 405 WCF... 8)

I'd be a little leery of putting that much of the bullet into the .41 mag's boiler room. Heavy bullet + reduced case capacity = Pressure.. :?

What kinda velocity is anticipated?

 

[Lee Martin]

Good looking bullet, should work well in the 405 Winchester as well.

That was my first thought, 405 WCF... 8)

I'd be a little leery of putting that much of the bullet into the .41 mag's boiler room. Heavy bullet + reduced case capacity = Pressure.. :?

What kinda velocity is anticipated?

Finally tried my 290 in the 5-shot atop .41 Mag brass. The loads were held to 6-shot maximums using 18.5 grains of IMR 4227. They went a consistent 1,260 fps and printed tight at 50 yards (~2.0"). Next time I'll stretch them to 100. I should get the same or slightly better speed with H110. And loaded as a 5-shot I expect 1,350 and 1,400 – 1,450 fps from my .414 Martin. Of course, thinking comes from not knowing. We'll see what the chronograph returns.

We also have two .405 Winchesters that'll taste this bullet. One is an 1895, the other is a stainless Ruger No. 1. Turns out they drop 0.413" and I have a 0.412" sizer.

 

[Bucks Owin]

Sounds like you have a winner Lee... 8)

And yeah, I expect the H-110 will add a few fps... :wink:

(Maybe even more than a "few"... :shock: )