Variations in Vihtavuori loads in different manuals

[tlawler]

I changed the recoil spring in my .38 Super 1911 to a 15 lb. Spring that is recommended for full power .38 Super loads. The guy I bought it from used it in competition and had a very light spring in it. I wanted to use some VV N-105 that I had on hand, as it seemed like I could get into the fps range I wanted pretty easily. I always compare loads across a few manuals to see if they’re all on the same page, so to speak. I’m looking to load some 124 grain jacketed flat point bullets. The ranges I see in the manuals have a fairly wide variance. The VV and Lee ranges are similar to each other, as are the Hornady and Lyman, but differ significantly from each other.
Here are the numbers:

Start Max/do not exceed
Hornady. 8.2 gr. 8.9 gr.

Lyman. 8.2 gr. 9.2 gr.

Lee. 9.9 gr. 10.4 gr.

Vihtavuori 9.9 gr. 10.9 gr.

There is a full 2.0 gr. difference between Hornady max and VV max. These are all .38 Super and not Super Comp.
What do the experts say?

 

[pantannojack]

I'd go with the Hornady/Lyman loads until I proved to myself I could go hotter. I read in a load manual long ago: "If more power is needed, get a more powerful caliber."

 

[burneyr]

VihtaVuori load data is what I use with their powders. Until BE-86 came along 3N37 was the only powder I could find that would make the velocity I wanted in 9mm. To be honest if availability of their product had been remotely consistent I would still be using it.

I never had a problem or any high pressure indications using 32 pounds of their powder with 9mm. I was skeptical and even measured case head/web diameter with a micrometer after firing. Nothing was ever out of spec.

My take is the European CIP standards differ from SAAMI here in the states. They take pressure measurements differently, but each organization adheres to their own testing protocol. My belief with Lapua, VV, and SK being European (NAMMO group) is their manuals align with CIP which is in general hotter than SAAMI.

I have noticed the same powder variance across manuals for their rifle powders also. In my experience - no problems in that regard either.

I would use their data with confidence.

 

[DWalt]

You did not specify what the fps range you wanted was. If it is in the 1400+ range, you should be using Starline 9mm Super Comp brass instead of regular .38 Super brass. The 9mm SC case will take higher pressures better than the .38 Super case. If you are intending to load in the more typical 1200-1300 FPS range, .38 Super brass will be OK. Also, many believe that the rimless 9mm SC brass will feed from the .38 Super magazine a little better.

The 9mm SC case has a slight taper, but that is OK. I have used it in my 1911 for years without problem, and I reload it using .38 Super dies. Also, small rifle primers should be used for higher pressures. And of course a heavy slide spring.

The problem will be in getting 9mm SC brass from Starline. BTW, my top load in the 9mm SC case with 124 grain jacketed bullets is 8.7 grains of AA #5, to get a MV around 1450 FPS. I have loaded to MVs over 1500 FPS, but am not comfortable with them being that high.

 

[Alk8944]

With any caliber and propellant if you look closely you will see the same sort of variation from manual to manual, not just VV.

I have only been reloading for a bit over 60 years, and back then about the only choice we had was the Lyman manuals, so this wasn't an issue. Over the intervening years I have developed a feeling for which manuals I trust, and which I do not. In this vein I have chosen to use the powder manufacturers data first, since I know they have the capability of pressure testing their data. This applies Especially when starting with either a new cartridge or propellant!

Right now I have the capability to load something like 110 different cartridges, some of which I can guarantee many of you have never even heard of!

 

[boatbum101]

If possible I'd find data for the exact bullet you're going to load . Horn XTP's are on the harder side & their data often shows lighter charges & arguably Hornady is conservative . Lee is just an amalgamation of others published data without Lee doing any pressure testing whatsoever ! Lyman does pressure test their data with components listed . Vihtavouri used to list CIP data which is often showing higher charges than SAAMI data . Most of the VV handgun powders show linear progression in their pressure curves & can be compressed , N 105 does not & does not like to be crowded .

 

[Ivan the Butcher]

Lee doesn't test loads themselves, they reprint the manufacturer's manuals. Looks like they knocked off half a grain to keep the lawyers happy. The data appears to be taken using a 5.5" barrel, what were the others using?

Ivan

 

[Nevada Ed]

When ever I see large difference in loads with the same powder and weight bullet

I look for the length of barrel used and the length of the OAL used.

If it will plunk in you gun, I start with the longer OAL and the lower amounts of powder
if they are a starting load and will not cause a squib, with the long OAL.

If you need to start with the shorter OAL, go with the starting loads.

 

[rockquarry]

I changed the recoil spring in my .38 Super 1911 to a 15 lb. Spring that is recommended for full power .38 Super loads. The guy I bought it from used it in competition and had a very light spring in it. I wanted to use some VV N-105 that I had on hand, as it seemed like I could get into the fps range I wanted pretty easily. I always compare loads across a few manuals to see if they’re all on the same page, so to speak. I’m looking to load some 124 grain jacketed flat point bullets. The ranges I see in the manuals have a fairly wide variance. The VV and Lee ranges are similar to each other, as are the Hornady and Lyman, but differ significantly from each other.
Here are the numbers:

Start Max/do not exceed
Hornady. 8.2 gr. 8.9 gr.

Lyman. 8.2 gr. 9.2 gr.

Lee. 9.9 gr. 10.4 gr.

Vihtavuori 9.9 gr. 10.9 gr.

There is a full 2.0 gr. difference between Hornady max and VV max. These are all .38 Super and not Super Comp.
What do the experts say?

Lots of variance because of all the changeable factors involved: different operators, different test guns, different barrel lengths, different chambers, different primers, different powder batches, worn guns or equipment, and many more.

The 124 grain jacketed flat point bullet is unidentified and they're not all the same; different bearing length and maybe even enough variance in the diameter to make a difference.

The bullet maker's recommended loading data would be a good place to start. Without that, use the lowest starting charge and work up cautiously, ever mindful of pressure signs as indicated in the front of all load manuals. A chronograph is indispensable in this sort of load development. Compare your chronograph figure with book figures.

Published overall cartridge length is often an arbitrary figure. Seat to maximum magazine length IF the cartridge will chamber and feed flawlessly. If not, seat to the maximum length where everything works as it should.

The Lee book is a good reference source, but use data from other paper load manuals where they actually shoot to obtain the data. Much of the data in the Lee book doesn't even identify the bullets used and who knows where the data comes from. Good luck-

 

[WR Moore]

The variables between manuals is due to many variables between the firearms/test barrels used. There's also the difference noted between CIP and SAMMI with respect to how to measure pressures and what they consider maximum to be.

My experience is that in most cases, the data from powder companies is determined in specially made (dead minimum tolerance) barrels in universal receivers. That you'll get the same velocities for the same amount of powder, highly doubtful. Usually less.

There's threads here that cover the differences between CIP/SAMMI/DOD/NATO STANAG pressures and how they're measured if you want the really grimy details.

 

[ArchAngelCD]

Even though I buy far to make manuals much of the time I look at the data supplied by the bullet manufacturer and the powder company. Before the NET had so much data available when loading a new cartridge I would use several book sources and check bullet depth, shape and construction material to find the one that closely matched the bullet I was going to load. Then I usually started somewhere in the middle and worked up until I found an accurate load without pushing over the max recommended charge.

 

[oysterer]

The data looks all the same when taken into account the speed. Hornady as usual is the most conservative and stops at 1200. Thats plenty fast for my taste unless you need to make competition power factor. If you feel the need to go hotter, slowly approach the VT data and see how your guns doing. Lee: I don't look at that, neither equipment nor books.

 

[Karl Haemmerlein]

So many variables between all manuals. The chamber they fired in whether test barrel or real firearm. The specific primer they used, and the lot number of that primer. The specific case they used, no two manufacturer's cases are even close to the same. The specific bullet they used, no two manufactures XX grain bullet in XXX caliber is the same as far as the pressure it takes to move it down the barrel, worse yet the same manufacturer and same bullet from a decade apart may actually be different in jacket material. OAL makes a big difference. Nobody has the same lot number of powder, burn rate and density changes from lot to lot, and sometimes more than you would believe. So many variables, to expect to see the same recipes in everyone's manual is crazy. All of this together is the biggest reason why you start on the low side always and work your way up to what you want if it is safe to do so.

edited to add, I just noticed the VV data is +P while the others you listed are not. Every word printed in the loading notes, not just powder and grains is important to that load.

 

[ArchAngelCD]

........

edited to add, I just noticed the VV data is +P while the others you listed are not. Every word printed in the loading notes, not just powder and grains is important to that load.

The VV data is not marked +P, they list the case as a Remington +P case. There is nothing there that I can see designating the data as +P.

 

[tlawler]

I want to thank everyone for their input. I always learn something new when I post a question here. I didn’t know the specifics of how manufacturers get their numbers and I sure didn’t know that Lee just republishes known data.

I ended up loading up 10 each of 9.0, 9.1, 9.3, and 9.5 VV N105. The 9.0 would cycle the slide enough to cock the hammer, but usually not enough to eject the spent casing and chamber the new round. I think it fully cycled about 3 of 10 rounds. The 9.1 and 9.3 was better, full cycling, but some FTF’s and stovepipes. The 9.3 was better than the 9.1. Finally, the 9.5 fed and cycled all 10 rounds flawlessly. Fireball was pretty impressive, especially with the compensated barrel. Accuracy was really good, with the reddot, i put up a pretty nice group with my last rounds. I wish I had loaded up more of the 9.5 gr. rounds; I was really starting to have fun with the last mag.