Powders equivalent thurstability and light charges. Please educate me

[Motard]

Hallo, I just started learning about light charges on my 30-30 win, 308 x-bolt and soon on my 45-70 sbl. I have the Lyman Cast Boolits III edition, the Modern Reloading Lee's Book aswell as others current manuals. I do not still bought Quickload software because the 3.9 ed is not on sale here, and 3.8 wouldn't run on my Win 10 Pc. But some forumers have often heleped me with load data. Cause most of the powders listed in light and reduced charges are not available here my quest is about using the equivalents listed here http://www.adi-powders.com.au/handlo...quivalents.asp. Say the Lymans Cast Bible list a starting load 11 gr Unique with a 420gr 457193 boolits can I confidently start working up my cartrige with equivalent Viht n330 and the 457643 424gr boolits dropped from the mould I have? I appreciate any input
thankyou

[phonejack]

I use the 6.5 gr. Load. I think this info appeared on this forum some years back. Groups were measured at 50 yards. If you will notice the highest velocity load also has the biggest group size. This is because it is barely supersonic. By the time it gets to 50 yards it has gone subsonic and the bullets have started to yaw. So, if you want a load fast enough to be supersonic, load high enough to stay that way at the longest distance you will shoot. I've had people come over and ask about what kind of load I'm shooting. They see holes appear in my target, they hear a muffled pop and they don't see my rifle move while touching off a shot.

[Motard]

Le me see if I get it all. I better stay subsonic alla the way bullet fly to achieve a good group. Or entirely supersonic. Starting supersonic and endig sub is NO good. Having not ballistic tables when loading this low charges how can I know speed at targhet? I am about shure if I place my crony at the paper I will kill it rather fast

[357Mag]

Motard -

Howdy !

FWIW - Hogdons has a list of reduced loads for various cal's, using their H4895 and a suggested mathematical formula.
H4895 can be utilized in a wide variety of calibres. The question becomes: is the lowest " formula-derived " charge low enough to suit your needs ? The more data one can review, the better idea one might get.

In my Marlin M-336 XLR .35 Rem, a full case of " Trailboss " was still a little too low on oomph, for my needs.
At the same time, H4895 charges could not be reduced quite low enough, to be where I wanted to be.
I also could not get IMR8208 IMR4166 charges " low enough " ( no hints of oncoming " secondary explosive effects " ).

So far, IMR4759 has proven better/best for " reduced loads " in .35 Rem, than anything else I've tried ( my loads, my gun ).

My next range cession will be to prove-out the lowest practical charge of H4198 I can use in the XLR ( IMHO ).

Film @ 11:00......


With regards,
357Mag

[William Yanda]

Motard,
Have you asked the manufacturer of the powders which are available to you about whether or not they can be used with reduced loads?
Regards from the new world,

Bill

[fecmech]

Starting supersonic and ending sub is NO good.

Sometimes yes, sometimes no. It seems to be somewhat bullet dependent as some styles handle the sonic transition better than others. I would suggest you load to the velocity level you desire and see if it matters.

[fryboy]

Black powder amigo pretty universal on both sides of the pond ,one can load it down by using filler wads to take up any air space
Sadly I'm not familiar enough with the Vv powders to give you a good recommendation, suggest starting with the faster to medium faster ones ( aka shotgun types ) and work your way up until either you find what you want or reach too high of a pressure ,it's been done countless times with unknown powders in this fashion

[Motard]

Black powder amigo pretty universal on both sides of the pond ,one can load it down by using filler wads to take up any air space
Sadly I'm not familiar enough with the Vv powders to give you a good recommendation, suggest starting with the faster to medium faster ones ( aka shotgun types ) and work your way up until either you find what you want or reach too high of a pressure ,it's been done countless times with unknown powders in this fashion

Allo Fryboy, I am not too keen on BP cause of cleaning tasks involved mainly, and secondary because I hold powders at home.....
As for the starting load You are right: nobody can take place of personal involving. Neverdeless I have trouble on choosing the right starting point for my testing. I try to explain. Due to help of other forumers here I can see a good starying point for my light loads in N340 from 9 to 12gr. There is a restricted manouvre area in such fast pistol powders. Different is with rifle powders where range is way wider. Ie: manual's listed loads for N140 is starting near 30gr. But I donwngraded my loads to 16,7 plus filler (as per input from reputable reloader) and tested it with good resoults. This is something I would have never tried if I had to rely only on my knowing.

[Hick]

I use 6 gr 700x and 9 grains of Herco in my 30-30 and they do just fine out to 100 yards with a 165 grain CB. The 30-30 seems to really like light loads of fast powders.

[Wolfer]

Some observations I've made with cast boolits and no data.

When using fast powders and cast accuracy will usually be good when it's the right amount but will fall apart before you get to max pressure. Notice I said cast. I believe my method could get you in trouble using jacketed.

I start with a standard fast cast friendly powder. Bullseye, unique, 2400 etc or something equiv.
I start with enough to get it out the barrel. Keep working up until accuracy falls off.
If accuracy is good at 5 gr of powder "A" but not at 7 gr then I start at 7 gr of powder "B". When accuracy falls off that tells me where to start with powder "C"

As you work up through the alphabet velocity will of course get higher. After a point you'll reach a letter that you pass useable velocity with your starting load but there's not enough for good ignition.
This requires something I don't have much experience in. Fillers, harder alloy, black magic etc.

[44MAG#1]

What the devil is thurstability?

[Motard]

Some observations I've made with cast boolits and no data.

When using fast powders and cast accuracy will usually be good when it's the right amount but will fall apart before you get to max pressure. Notice I said cast. I believe my method could get you in trouble using jacketed.

I start with a standard fast cast friendly powder. Bullseye, unique, 2400 etc or something equiv.
I start with enough to get it out the barrel. Keep working up until accuracy falls off.
If accuracy is good at 5 gr of powder "A" but not at 7 gr then I start at 7 gr of powder "B". When accuracy falls off that tells me where to start with powder "C"

As you work up through the alphabet velocity will of course get higher. After a point you'll reach a letter that you pass useable velocity with your starting load but there's not enough for good ignition.
This requires something I don't have much experience in. Fillers, harder alloy, black magic etc.

Oops. I know my english is horrible. Apologize about. My intent was meaning something that one can thrust. When at home I wil find correct term on voucabolary.habe not it on phone

[Motard]

Reliable. This is the term that didn't whant to come to my mind.

[fouronesix]

Le me see if I get it all. I better stay subsonic alla the way bullet fly to achieve a good group. Or entirely supersonic. Starting supersonic and endig sub is NO good. Having not ballistic tables when loading this low charges how can I know speed at targhet? I am about shure if I place my crony at the paper I will kill it rather fast

For the most part I think your theory and approach are correct. (Is it significant enough to worry about in most instances?- I don't know.) As a bullet's velocity drops through the boundary between sonic and subsonic it's stability may be disrupted. Probably the best tools for attempting to avoid that transition are a chronograph and ballistic calculator. I like JBM Simplified… and there are other free ones out there. You'll need at least an estimate of the BC of the bullet. If none are published for an individual bullet, just find a similar bullet and guess or extrapolate a BC. Given the BC and muzzle velocity (along with other particulars), the calculator will show velocities out to wherever you set the parameters. Then you'll know what muzzle velocity is required for an individual bullet to remain super sonic out to a specific range. http://www.jbmballistics.com/cgi-bin...j_simp-5.1.cgi

As to equivalency of powders? That territory is a "can or worms". I'll let others guide you on that one. Like whether or not Unique and VV330 are really equivalent enough???

[rsrocket1]

N330 should be a good powder to start with in .308 and 30-30. In a .308 gun, 10 grains under a 170g cast bullet will get you about 430 m/s (1400 fps) with a peak pressure in the 20,000 psi range. That should give a clean burn and far below any dangerous pressure that you would have a lot of latitude to adjust the charge up or down. In a 30-30, you should drop down by about a grain. Your peak pressure will go up to about 25,000 psi and your muzzle velocity will be about 400 m/s (1300 fps) which should keep you supersonic beyond 100 yards.

I have not found Unique to be very good at subsonic levels. The pressures generated at such low charge weights will not expand the cartridge case and a lot of gas escapes through the chamber which leads to erratic velocities and loss of accuracy. I would suspect N330 would do the same thing. For subsonic loads, I found a very good load of 6.5g Red Dot under a 200g Lee cast bullet. Here's a 50 yard 5 shot group.


For reduced recoil supersonic loads, I like Alliant Reloader 7. It is a fast rifle powder. A possible equivalent would be VV N120. These loads are very mild in recoil but definitely supersonic plus they fill the case much fuller than shotgun/pistol powders


For these loads, I used Quickload and the Optimum Barrel Time spreadsheet to predict what load would work best in my 24" .308 Remington 788. It worked amazingly well.

[Motard]

Rsrocket1. Tankyou. This is exactly the kind of info I was looking for. Not for carbon copy the loads but because this are feed for mind. I can compare my data and try to undrestand better how the whole Reduced loads worls goes on.
since now I have only tried
cal 308:
Lyman CB 190 gr: N130 23-25gr 1711-1823 speed (lacking accuracy at 100 mt)
lee C309-170F CB 175 gr: n140 16,6gr 988 Fps (good acuracy at 100 mt)
lee C309-170F CB 175 gr: n340 9-11 gr 1210-1377 Fps (very good accuracy at 100 mt)

in 30-30
I have tested
N340 9,0/11,0 gr CB MP154 gr FPGC with speeds from 1407 to 1728 but some sign of pressures from 10,2 gr up (good accuracy)
N130 19,1gr LEE C309-170F CB 175 gr: 1840 Fps (good acuracy)