I have a very accurate rem. 700 I built a few years ago . I put a very heavy Shilen match barrel & a jewel 2 ounce trigger & bed it into a boyds laminated stock. With a match 52 grain bullet from barts or burger it will shoot .250-.300 at 100yds. off a harris bypod. I have recently built a 308 about same except in a H-S precision stock. I have high hopes for both with cast bullets when I find right load.
Howa .308 Win. at the range.
- Thread starter Ben
- Start date
Spindrift
Well-Known Member
This is how I think, when I consider using a powder for reduced pressure loads where I lack background knowledge from other people's experience:
There are two ways the manufacturer can manipulate the burn speed/pressure curve of a powder.
1) Kernel geometry; larger kernels burn slower. Added channels in the kernel change the pressure curve (towards neutral, or progressive).
2) Flame inhibitors; surface treatment that inhibits the burn. Thus, a powder can burn relatively slow despite relatively small kernels.
My impression is, powders with less flame inhibitors tend to act more "linear" and predictable at reduced pressure loads. While heavily inhibited powders tend to work best at normal pressures.
If a powder has smaller kernels than other powders of a similar burn speed (like H322) it must be more heavily coated with flame inhibitors - and vice versa.
A powder with relatively large kernels for it's burn speed (like many IMR powders) will be more likely to work well at reduced pressures. Unfortunately, they will also be less cooperative in a powder measure.
Just my thoughts on the subject.
There are two ways the manufacturer can manipulate the burn speed/pressure curve of a powder.
1) Kernel geometry; larger kernels burn slower. Added channels in the kernel change the pressure curve (towards neutral, or progressive).
2) Flame inhibitors; surface treatment that inhibits the burn. Thus, a powder can burn relatively slow despite relatively small kernels.
My impression is, powders with less flame inhibitors tend to act more "linear" and predictable at reduced pressure loads. While heavily inhibited powders tend to work best at normal pressures.
If a powder has smaller kernels than other powders of a similar burn speed (like H322) it must be more heavily coated with flame inhibitors - and vice versa.
A powder with relatively large kernels for it's burn speed (like many IMR powders) will be more likely to work well at reduced pressures. Unfortunately, they will also be less cooperative in a powder measure.
Just my thoughts on the subject.
CZ93X62
Official forum enigma
IMR-4198 gets a lot of use over the past 8-10 years at my casa, mostly to create smokeless loads at black powder pressures & velocities using Ross Seyfried's method. Briefly, Seyfried counseled to take the nominal BP charge--e.g., 70 grains in the 45/70--multiply that number by 0.4--(70 x 0.4 + 28.0) and load that weight (in this instance) into 45/70 cartridges under 405 grain bullets.
IME this practice yields BP velocities in the several cartridge calibers I have tried this with--45/70, 44/40, 38/55, 32/20, and 25/20. Revolvers leave a few unburned zombie powder kernels in the bore, but rifles burn pretty cleanly.
IME this practice yields BP velocities in the several cartridge calibers I have tried this with--45/70, 44/40, 38/55, 32/20, and 25/20. Revolvers leave a few unburned zombie powder kernels in the bore, but rifles burn pretty cleanly.
RicinYakima
High Steppes of Eastern Washington
My problem is finding IMR or DuPont 4198.
fiver
Well-Known Member
Spin you got it down pretty good.
for example 700-X and 800-X were the exact same powder recipe.
they manipulated the burn rate between them by making 800 with larger flakes and the center was thicker.
no deterrents or other manipulations needed, the thicker flake was enough to slow the burn down almost 2 full steps.
for example 700-X and 800-X were the exact same powder recipe.
they manipulated the burn rate between them by making 800 with larger flakes and the center was thicker.
no deterrents or other manipulations needed, the thicker flake was enough to slow the burn down almost 2 full steps.
richhodg66
Well-Known Member
That Lyman manual is still my go to. I have a couple of them, but it's on Marvin Stuart's page for free download.
I really need to check out those Hawas, I sure have heard a lot of good things about them.
I really need to check out those Hawas, I sure have heard a lot of good things about them.
Ben I think I have the same as yours mold that I bought from Arsenal, I forgot # but it said 170gn Ranch Dog & my bullets look just like yours. What I would like to know is how much bullet seats below the neck. I used a standard 308 reamer when I built the rifle. jam length seats mine below the neck. mine is also a flat base. I heard it was not good for a lead bullet to be below the neck. Congregations on having a fine rifle & load but mostly on having a great kid to shoot it with.
Not certain I understand your question ?
If everything I have read is correct, seating a lead bullet below the case neck in a bottle neck case will cause base of bullet to mushroom up if you are using pistol powder or any high pressure loads. with my bullets lower lube groove nearly in the shoulder area looks like it would be a easy spot for the bullet to give. I have also read it is not good for even a jacketed bullet to be below neck unless it is a boattail. At the very high pressures a lot rifle bullets are shot even a jacketed bullet will be deformed a very very small amount. I know we will not be shooting a lead bullet at the pressures or velocities of a jacketed bullet but a lead bullet is a lot easier to deform.
fiver
Well-Known Member
we will be shooting lead bullets at the same pressures and speeds as a jacketed bullet.
try looking at the pressure that 'the load' of red-dot produces, your right there at the limit of a small ring Mauser.
anyway your just as likely to mush up a bullet jammed into the rifling, as you are running one normally seated.
getting a run at the rifling no matter where it comes from with powder coat will allow it to slide into the barrel at a much lower pressure.
the key is to get it in there straight.
try looking at the pressure that 'the load' of red-dot produces, your right there at the limit of a small ring Mauser.
anyway your just as likely to mush up a bullet jammed into the rifling, as you are running one normally seated.
getting a run at the rifling no matter where it comes from with powder coat will allow it to slide into the barrel at a much lower pressure.
the key is to get it in there straight.
I am looking for a load with 170 gn. ranch dog bullet at about 1200-1300. I have tight group, 231, some trail boss, bullseye, IMR4198 & reloader 7. I have several other powders but the ones I listed are some that mite work. fiver you are right about lead bullets mushing up anywhere they can but when they do it in the case below the neck there is nothing to it to mush up to. Looks like that would be worse. Am I correct ?
RicinYakima
High Steppes of Eastern Washington
The pressure is equal on the sides of the bullet in the powder space as the bottom. If it has any free run to overcome inertia, it is a non issue.