Vihtavuori N340 for .44-40?

[eisenhower]

Has anyone here loaded Vihtavuori N340 for .44-40?

The only load Vihta provides for .44-40 is a "cowboy" load, moving a 200 grain RNFP cast bullet at about 707 fps. Would like to use the powder for something a little more upper end (but not pushing the line) for the cartridge.

Anyone have any loads with this powder?

Thanks,
DeWayne

[Encore64]

First thing I'd ask is what gun?

[eisenhower]

Colt SAA, 5.5"barrel.

[bryanaustin]

Jul 3, 2024 16:58:07 GMT -5 eisenhower said:

Has anyone here loaded Vihtavuori N340 for .44-40?

The only load Vihta provides for .44-40 is a "cowboy" load, moving a 200 grain RNFP cast bullet at about 707 fps. Would like to use the powder for something a little more upper end (but not pushing the line) for the cartridge.

Anyone have any loads with this powder?

Thanks,
DeWayne

Define "pushing the line"

Loading for velocity with fast burning pistol powder can get ya into "pushing the line" fairly quick.

Back in the day, factory loads used a true 13,000 lbs (cup) max while handloaders used "maximum safe pressures" 15,000 lbs (cup) for REVOLVERs.....but loaded revolvers to 16,000 lbs (cup). This was during the 1920's and 30's. These loads ranged from 900fps to 1,115fps in revolvers.

Bullseye has been in use since Mosses and the great flood, 7gr within 13,000 cup pressures at 910fps.

As an example (N340 is claimed to be like Trail Boss)...
A caseload of Trail Boss, where the (427098) type bullet is seated on top of the powder with no compression, comes up to about  9.3gr and an estimated CUP pressure of nearly 16,500cup, debunking the trail boss "formula" many tend to misuse, since trail boss says not to use the formula when load data is published....of which 6.4gr is the published max.

Velocity with 9.3gr came in at 1,250fps from a 20" (.429) barrel. 6.4gr gave  1,034fps from the same barrel...while the website load data claims 12,000cup, my result was estimated to be 9,000cup. All of my results are psi and "softly" converted to cup.

Hodgden's laod data is listed as psi and is so very incorrect it aint funny....unless they are exceeding SAAMI max "psi" pressures of 11,000psi for the 44-40. Thus their 12,900psi loads exceed SAAMI max of 11,000psi by 1,900psi...UNLESS their data is truly CUP, in which 12,00cup falls under the max of 13,000cup.

[eisenhower]

I'm looking for something around 850-950 fps. Would love to use Unique but can't find it anywhere, so bought some N340 only to find load data is harder to come by.

[dougader]

I'd use the Hornady N340 data for their Cowboy loads as a starting point and work my way up using a chronograph. Find a safe, comfortable load around 850-900 fps and you should be right where you want to be.

You can compare their Unique data which is listed for the Cowboy loads and the higher velocity jacketed bullet loads as a similar sample to get an idea on how the N340 will act. The Unique data for the jacketed bullet starts a bit above the Cowboy data maximum load.

[bryanaustin]

Jul 4, 2024 8:46:00 GMT -5 eisenhower said:

I'm looking for something around 850-950 fps. Would love to use Unique but can't find it anywhere, so bought some N340 only to find load data is harder to come by.

Looking back to 2013, I found a target using 6.4gr of Trail Boss in a revolver, gave me 898fps...again in 2017 @ 800fps.

If N340 is close to Trail Boss as they say, I'd start low and work the velocity up to 800-825-850. I'd stick with .427/.428" soft lead.

Hornady shows 6.4gr N340 as a starting for a Rossi 92, and a max load of 7.5gr using .427" Hornady lead cowboy bullets (discontinued)

Here: static.hornady.media/site/hornady/files/obsolete-data/44-40-winchester-rifle.pdf

[eisenhower]

Great info, thank you! I'm new to reloading, so forgive my ignorance, but if I'm experimenting with different bullet sizes larger than .427", I need to back off the charge, correct?

Vihtavuori suggests 7.2-7.8 grains of N340 for a .427" 200-grain RNFP as a cowboy load.

So, let's say I want to start with their 7.8 grain suggestion, which they say will get me 707 fps. If I then want to try a .429" or .430" bullet in my pistol, how much should I reduce the charge to try to achieve roughly the same velocity? Is there a way to figure that?

[Encore64]

So, let's back up and do this correctly.

There's no way we can suggest a bullet diameter. I highly recommend measuring your cylinder throats and go from there. I've seen 44-40s .426"-.434". So, it's a crap shoot for us to guess at this.

Starline Brass is generally .0015" thinner at the case mouth compared to other brands. This is so you can seat larger bullets and ammo still chambers.

My Colt New Frontier has .431" throats, so I use .430" Coated Cast SWC or GT HPs for outstanding accuracy.

[eisenhower]

Right, I have slugged my bore and cylinder throats. The bore is .4275"-.428", the cylinders all are between .429-.430.

.427 bullets are shooting fine, but literally fall through the cylinder mouths, so I'm interested in seeing if a bullet that fits the cylinder mouths better will show even better accuracy.

[bryanaustin]

Jul 4, 2024 18:08:44 GMT -5 Encore64 said:

So, let's back up and do this correctly.

There's no way we can suggest a bullet diameter. I highly recommend measuring your cylinder throats and go from there. I've seen 44-40s .426"-.434". So, it's a crap shoot for us to guess at this.

Starline Brass is generally .0015" thinner at the case mouth compared to other brands. This is so you can seat larger bullets and ammo still chambers.

My Colt New Frontier has .431" throats, so I use .430" Coated Cast SWC or GT HPs for outstanding accuracy.

Actually "I" can...listen closely

Early 44-40 barrel bores ranged from as small as .4225" to .434". Most pre-1880's bullets I have measured range from .425" TO .427".  Cramming a .434" hard cast bullet into a .4225" bore could be disastrous, but using a .425" soft lead bullet in a .434" bore goes poof!

Meaning the differences in pressures using the same powder change can change drastically. So yes, I can suggest .427" to .428" bullets all day long.

As you mention, the chamber itself...
Most modern chambers are large enough, but some, like Ruger, use standard 44 WCF cuts, which were used with the smaller diameter bullets...namely the .4255" Winchester jacketed bullets from 1895 to current. The softer pure lead .427" lead bullets would swage down the .427" body diameter to sometimes .424", mimicking closely to the JSP...thus leaving only a small forward driving band of .427" Actually the lead procedure came first, thus the reason the JSP's were of a smaller diameter.

Thus, since the original poster seems to have already be loading for his revolver, one can only assume he already knows what will and won't fit his chamber.....thus I left out the further details of chamber size.

I have an entire website dedicated to the 44-40 cartridge, thus I have no desire to post all of that information here in one reply.

However, if I did speak prematurely of the bullet diameter advice, you can check details here: sites.google.com/view/44winchester/chasing-the-44-40

[Encore64]

Yep, education is good. But, a guess is still a guess.

Best to get exact measurements and go from there.

Clements built me a number of 44-40s and I went with .430" throats in all of them.

Still best to measure throats and probably slug the bore.

When a cartridge is made as many years as the 44-40, dimensions are bound to vary.

For me, reloading is an art of precision.

[Encore64]

Highly recommend Handloader Magazine #335 published December 2021.

Brian Pearce did an excellent job cutting through the myths and published tons of data using modern powders.

Back issues are available from the publisher...

[eisenhower]

As I say, I have slugged bore and chamber mouths to the best of my ability and limitations of my caliper.

Bore slugs .4275-.428 depending where I measure on the slug. Cylinder mouths measure between .4295-.430".

[Encore64]

Great information. Using Starline Brass?

Get yourself a Lee .429" Bullet Sizer Die and push commonly available .430" cast bullets thru it and never look back.

My Colt has .431" throats as I posted earlier. I shoot .430" bullets with zero issues.