Velocity, Smokeless Powder, Cast Bullets & Accuracy

[insanelupus]

Has anyone noticed any type of relationship between higher velocity cartridges with cast bullets (2100-2500 fps and gas checked designs) and any certain smokeless powders which seem to shoot accurately on a consistant basis?

I know IMR 3031 has always been listed on a consistant basis, but I've just never had much luck with it. My go to powder is often either H4895 or IMR 4064 with jacketed bullets. I'm just curious if there is much difference in what would be termed a medium velocity cartridge (2100-2700 fps for sake of argument) between jacketed bullets and lead bullets as far as consistant powder performance with similar weight bullets.

[leftiye]

Cast produces lower pressures as compared to jacketed with a (any?) given load, and usually higher velocities too. Beyond that, cast boolits are usually shot quite a bit slower than jacketed, so there often becomes a problem in selecting a powder that will burn consistently at the resulting pressures. To screw things up more, with higher velocity cast loads it is good to use a relatively slower powder to minimize the spikeyness and intensity of the pressure curve and reslutingly keep boolit deformation down (for accuracy).

You don't specify cartridge/ caliber, and what is a fast or slow powder varies hugely with bore, boolit weight, case capacity, so I don't know where to begin in specifying a powder.

[mpmarty]

Crazywolf I too like 3031 and use it quite a bit. That said I find that RL-7 works nicely too. You just have to play with it and see what works for you in your particular firearm.

[onondaga]

leftiye has a good answer for you there. I would add that I've had luck looking at the lists of recommended charges for any given cast bullet weight and cartridge, then selecting the powder with only one thing in mind---which of the powders listed has the lowest pressure? This works for me with cast loads.

Gary

[Bass Ackward]

Has anyone noticed any type of relationship between higher velocity cartridges with cast bullets (2100-2500 fps and gas checked designs) and any certain smokeless powders which seem to shoot accurately on a consistant basis?


Define HV cartridges?

For higher velocity cartridges that approach overbore status such as the 30-06 case family. I look in a manual and find the powder which produces the highest velocity with a jacketed bullet of the same weight. The powders that work for me will be two IMR burn rates classes away from the peak powder.

Lets say we are talking 4064. Then the best powder selections would be 3031 and faster or 4831 and slower. Of course, I am not advocating IMR. Offerings from other companies in the same burn rate class are acceptable as well. It's just easier to associate with what you grew up with.

The smaller the case capacity is to bore diameter, the closer to the same powder speed as the top powder can be used. ie, a 44Mag or 22 Hornet will use the same powder if you define a 22 Hornet as a HV cartridge.

On the opposite end of the spectrum, a 7mm Rem Mag might need three burn rate classes away from the peak velocity producing powder with the same bullet weight. And the odds for success will be tilted to the slower powder selection spectrum.

This is basically a get the pressure up (faster burn rates) or let's elongate the pressure wave (full cases of powder) theory.

[Moonie]

Keep in mind that Hodgdon says 60% max load of H4895 is safe, it is where I usually start with cast in HV cartridges. I found 18gr H4895 cycles my AR 15 with 55gr bator boolits.

[geargnasher]

Cast produces lower pressures as compared to jacketed with a (any?) given load, and usually higher velocities too. Beyond that, cast boolits are usually shot quite a bit slower than jacketed, so there often becomes a problem in selecting a powder that will burn consistently at the resulting pressures. To screw things up more, with higher velocity cast loads it is good to use a relatively slower powder to minimize the spikeyness and intensity of the pressure curve and reslutingly keep boolit deformation down (for accuracy).

You don't specify cartridge/ caliber, and what is a fast or slow powder varies hugely with bore, boolit weight, case capacity, so I don't know where to begin in specifying a powder.

+1.

I'll add that I've recently been playing with RE7 and it seems to burn pretty well at low pressures, much better than some other similar burn-rate powders at similar pressures, but the jury is still out. I'm just delving into this realm in fine detail, especially with heavy straight-wall calibers. Looks like I'm going to have to get Quickload soon for a better understanding.

Gear

[insanelupus]

Specifically I was looking at the 35 Whelen. But I was asking about the question in general, expecially cartridges based on the .308 and .30-06 cartridges, as well as 375 H&H.

But I was looking at a general guideline, lower pressure or slowest burning, etc.

[Larry Gibson]

In that velocity range with medium to heavy for caliber bullets I favor 4895 as the fastest powder to use with AA4350 and H4831SC as good choices for slower powders. With lighter weight bullets for caliber in that velocity range I favor 2400, 4227 and 4759 with 5744 and 4198 also being good ones to try also.

Larry Gibson

[runfiverun]

now i understand the question better.
i look at the lower pressure stuff for a start.
i will generally do like bass said also, and go down a notch or two in speed.
your 35 whelen should do well with the slower twist bbl it has, a slower powder and a good boolit fit.
the 35's are blessed from the beginning.
the first thing i tried in my 358 was a winner, and all i had to do was adjust the powder level to tweak accuracy.

[NHlever]

Boolit alloy, hardness, and "pull" resistance also play heavily in the results at times. I remember working with a .35 Remington years ago. I wanted to use a soft alloy for hunting purposes, and I was working with IMR4895. I just couldn't stuff enough of that powder in that case to build the pressure, and velocity I was looking for. I reduced the expander ball diameter, but that actually swaged the boolit diameter down, defeating the purpose. Making the boolit harder worked in getting the velocity I wanted, but was not what I wanted for hunting. Eventually I ended up going up the powder burn rate scale until I found the combination I wanted. In that case it turned out to be Reloader 7. These days I am using AA2015 behind the RCBS 35-200 FN, in that old gun, and am very happy with the combination for full power hunting loads. ( it worked really well for relieving a jeering shooter at the range of $20 one day too :D)

[BOOM BOOM]

Hi,
I wish some one on the board would address this issue, but discuss the available military surplus powders.
I have read the thread and appreciate the input that has been made already.