Hybrid 100V and the .375 Ruger

Boomer

CGN Ultra frequent flyer
Uber Super GunNutz
Rating - 100%
21   0   0
As soon as I heard about Hodgdon’s new Hybrid 100V powder last winter, I thought this might be a useful propellant for the .375 Ruger. We were having trouble getting sufficient velocity from with the Nosler 260 gr Accubond, and while I was looking for an honest 2700 fps, couldn’t get much beyond 2600. The problem was that I needed a burn rate a little slower than H-4350 which was showing pressure signs, but Re-19 was bulking out before the velocity could be attained.

Enter Hodgdon’s Hybrid 100V. Unlike the Extreme powder line from Australia, Hybrid 100V was developed and is produced in the US by the St Mark’s Powder Company, a subsidiary of General Dynamics. The burn rate is said to be between H-4350 and H-4831. What makes Hybrid 100V unique is that it is an extruded powder with very small granules which have rounded edges and flows much like a ball powder. Like the Extreme powders, it is temperature stable, and if you visit St. Marks web site, (http://64.233.167.104/search?q=cach...marks+powder&hl=en&ct=clnk&cd=4&client=safari) they provide the measurements of air burst over-pressure in temperatures from 140 F to -40F. We’ll see this winter if the claims hold up. The Extreme powders lost their zip in the cold. St Marks also claims that the powder has a low flame temperature and as a result the barrel life of high cyclic rate military weapons is improved. High loading densities, low flame temperture, and stability over a wide range of temperatures are ideal characteristics for a propellant for the .375 Ruger.

After pestering Higginsons for several months, I finally got a case of Hybrid 100V a few days ago. It runs through a powder measure without any issues due to its small granule size and shape. I loaded 260 gr AB’s, 270 gr Hornady IL’s and 300 gr TSX’s in the .375 Ruger. The 260 gr AB’s in the Ruger were first, and I started at 79 grs and increased in 1 gr increments to 83 grs. The maximum load listed on the Hodgdon website was 82.0 grs. The 83 gr load made 2666 fps, and there were no pressure signs on the brass, nor had the velocity increase plateaued. Likewise, the load data recommended a maximum of 78.5 behind a 300 gr bullet, but 79.0 grs, again approached in 1 gr increments from 75 grs, behind the 300 gr TSX produced 2470 fps. The maximum velocity with the 270 gr Hornady was very close to that of the AB, 2662 fps from 83.0 grs. Again, there were no pressure signs on the brass, nor was there a velocity plateau.

A quick trip home and I put together some more rounds. The 260 gr AB made 2734 fps when the powder charge was increased to 86.0 grs. Again, there was no velocity plateau, and no pressure signs on the case, but this load was compressed and I used a drop tube to charge the cartridge. The 300 gr TSX made 2522 with 81.0 grs, but again the load was compressed and I used a drop tube. Last winter I just made 2500 fps with the 300 gr TSX pushed by Win-760, but the velocity had plateaued so pressure was high, Hybrid 100V is a better choice.

From my observations, Hybrid 100V is a great choice for the .375 Ruger. I also tested some .375 Ultra loads, with similar results, an increase in velocity and low pressure. Anyone who loads with Re-19 or similar propellants should give this powder a try. I think you’ll like it.
 
Last edited:
Once agan Boomer, I find your post totally interesting, I always seem to learn something new when reading your stuff. At the risk of sounding a little "green", what exactly do you mean when you say that velocity plateaued? I know the definition of plateaued but don't quite get how you apply it here. Do you mean that you've reached the maximum attainable velocity without causing excessive pressure? Also, do you think that this powder will also work well in the .375 H&H? :)
 
Great to hear your Higginsons purchase worked out!;)

I suppose there must be a difference in temperature/elevation/rifles between your buddys 375 Ruger and mine, and hwo it works wiht H4350. Yesterday at the range I chronoed 270gr Hornadys at about 2760 fps and 260gr AB at 2780fps, with 83 and 83.5gr H 4350...No pressure signs whatsoever, although it was a warm day.

Just goes to prove that there is more than one way to skin a cat, and what works for one may not work for another.:)
 
Once agan Boomer, I find your post totally interesting, I always seem to learn something new when reading your stuff. At the risk of sounding a little "green", what exactly do you mean when you say that velocity plateaued? I know the definition of plateaued but don't quite get how you apply it here. Do you mean that you've reached the maximum attainable velocity without causing excessive pressure? Also, do you think that this powder will also work well in the .375 H&H? :)

It's a trick a learned from the boys at Sierra a few years back. If you are working towards a maximum load, provided you increase with equal increments, the velocity increase will suddenly drop off as you approach maximum pressure. With any luck this will happen before there is any pressure sign on the brass or the bolt get sticky. Once you've seen it a few times it becomes easier to read, but the key is to keep the increments exactly the same. Often a guy gets nervous as he approaches what he believes is maximum and drops the increment to a half grain, but unless you've been increasing by a half grain all along when you do this your chronograph doesn't tell you anything.

This morning I was working up the load for the 380 gr Rhino with the Hybrid 100V in the .375 Ultra. Starting at 83 grs my velocity was 2242, 84 grs was 2258, 85 grs was 2317, 86 grs was 2357 but when I tried 87 grs the velocity was still 2358; this is the plateau. Usually the plateau occurs prior to any other pressure signs, and more often than not happens without the suddenness that I observed this morning as the bolt was a bit sticky when I ejected that round. Usually the plateau velocity is an increase of about half of the previous velocity increase, and most often the plateau occurs one or two increments below a sticky bolt. So with this new powder my working load will be 86.0 grs with the 380 gr bullet.

I would like to try the Hybrid in a .375 H&H. It may result in compressed loads as did the .375 Ruger, but I think you will experience higher velocity with less pressure than with 4350 or 760. If you do try it let me know what you think.
 
Great to hear your Higginsons purchase worked out!;)

I suppose there must be a difference in temperature/elevation/rifles between your buddys 375 Ruger and mine, and hwo it works wiht H4350. Yesterday at the range I chronoed 270gr Hornadys at about 2760 fps and 260gr AB at 2780fps, with 83 and 83.5gr H 4350...No pressure signs whatsoever, although it was a warm day.

Just goes to prove that there is more than one way to skin a cat, and what works for one may not work for another.:)

Temperature certainly plays a role, and our high yesterday was about 4, today made 13. Rifles are individuals too, an not everyone like the same flavor of ice cream. I was real disappointed with 4350 in the cold last winter, I hope that the temperature stability St Marks promises works out at low temperature.
 
That is something that I had learned about but had never associated it with the "plateauing" terminology. Makes sense though, and for sure something that I will pay much closer attention to. If I do end up loading some up in the H&H I'll surely post the results. Thanks again Boomer, you're a wealth of good information.
 
Back
Top Bottom