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Factory Ammo?
Late-Bloomer
Member Posts: 249 ✭✭✭
Several of my rifles perform quite well to extremely well using assorted factory ammo.
I am new to reloading, but I plan to reload very soon! I've been reading all my manuals & handbooks, but there are so many powder choices, powder charges for any one weight of bullet, really, just how can that be? I mean, I realize its a compilation of recipes presented so one might be able to find a given load for his specific rifle, but........
My question is this,
How do these large ammo mfg's decide on which load for each specific grain of bullet that they market. For example, .270 Win. 130 Gr. & 150 Gr.
With all the different combinations available, what is their criteria for the most optimum powder, load weight, in any given cartridge?
They must be putting their money down on an OPTIMUM POWDER & OPTIMUM CHARGE WEIGHT for a given Cartridge? Their own R&D has discovered (this)+(that)= reasonably excellent accuracy in most modern rifles.
Is there any such data around for the average reloader, especially for a novice, such as myself, other than what the common reloading manuals list?
What are the classic powders/loads for the .270, 6.5x55mm, .308, 30-06, 7mmRM?
Any replies would be greatly appreciated!!!
Thank you
I am new to reloading, but I plan to reload very soon! I've been reading all my manuals & handbooks, but there are so many powder choices, powder charges for any one weight of bullet, really, just how can that be? I mean, I realize its a compilation of recipes presented so one might be able to find a given load for his specific rifle, but........
My question is this,
How do these large ammo mfg's decide on which load for each specific grain of bullet that they market. For example, .270 Win. 130 Gr. & 150 Gr.
With all the different combinations available, what is their criteria for the most optimum powder, load weight, in any given cartridge?
They must be putting their money down on an OPTIMUM POWDER & OPTIMUM CHARGE WEIGHT for a given Cartridge? Their own R&D has discovered (this)+(that)= reasonably excellent accuracy in most modern rifles.
Is there any such data around for the average reloader, especially for a novice, such as myself, other than what the common reloading manuals list?
What are the classic powders/loads for the .270, 6.5x55mm, .308, 30-06, 7mmRM?
Any replies would be greatly appreciated!!!
Thank you
Comments
I like to use a powder that will give good velocity acceptable pressure and fill the case to the bottom of the cartridge neck.
thanks perry shooter-
BTW, how might I get a lists of powders that would fill my cases for the cartridges mentioned and then go from there. I've heard that several times before from several posters about powder/case capacity. I believe it was referred to as, load density.
What are the benefits of a powder that fills the case up to the bottom of the neck vs. a powder that only fills 1/2 of a case per se.
How does a newbie like me determine which powders will fit that criteria. Is it just from trial & error from studying various loading manuals; or are there time-proven classics that have been documented somewhere?
Thank you, sir!
filling a case to a high load density serves to promote a very uniform ignition from round to round. When the case is close to full, the ignition will start at the base of the powder column and work it's way fwd to the bullet very uniformly. A low density will leave a lot of air space inside the case, which as the bullet is taken from vertical to horizontle (in the rifle magazine) the powder will then lay down and allow the air space on top of the powder load. This random settling of propellant with different shapes and air in different places from round to round, will affect the burn rate in such a way as to become less consistent from round to round. That change in ignition affects the pressure curve from round to round, which will then directly affect the MV, which then creates larger spreads in Extreme Spread as well as Standard Deviation. When these spreads grow, the groups will grow by default.
also, if too little charge is used, and the load does not fill at least 50% of the case up PAST the flash hole, this can allow what we call the "secondary ignition effect" which means the flash from the primer will jump across the top of the entire load igniting it completely rather than initiating a burn from case head to case mouth. When that entire charge is ignited at once, it will cause such a quick spike in pressure, that the bullet, for lack of a better way of saying it, the bullet just can't get out of the way fast enough, and something has to give. This will usually be the action and magazine that blow, and the shooter collects the remainder of the escaping gasses in the face and hand located near the floor plate.
Thanks a bunch for the explanation, I think I got the picture now. I don't think I'll be wanting any of that "Secondary Ignition Effect" happening in my action, right up next to my face though!
GREATFUL!
Look at it this way, powder X gives you 3,250 FPS and takes 59 grains to do it. Powder XX gives you 3,190 FPS but takes only 51 grains to get the job done. In this case powder XX is very efficient for this case/bullet combo.
The .270 is a offspring of the 30-06 slow powders like IMR7828, H-4350 and H-4831 will tend to give the best performance in this size case/bore. Your gun will pick the powder, load and bullet combo it likes best. The only way to find the sweet spot is to try several powders and bullet combos.
Don't make a common beginner mistake of using the maximum FPS listed as a sign of efficiency and accuracy, it may be misleading. I never saw a groundhog that was concerned about the difference in impact that 150 FPS muzzle velocity makes.
Go for nice round groups that you can repeat as a sign you are on the right track. Seating depth and charge refinements will do the rest in getting peak performance out of your hand loads.
GOOD LUCK, happy safe shooting!
Do you know of any INDIVIDUALS who "marry" their own powder mixtures or experiment with the procedure?
No need to read between the lines, I'm honestly curious if any individual is so "deep" into reloading that they try their own "mixes"?
My own take on factory loads is "What will the public buy?" For instance you can hardly find any .257 Roberts in any store nowadays in anything but 117/120 gr. We used to be able to find 87 gr. bullets everywhere. It's a kind of goofy thing because all of the older .257's had either a 1-12" twist or a 1-14" twist. Those twists will stabilize 100's and 87's. But, you need a 1-10" twist to stabilize a 120 gr. It's a case where companies don't want to seem to go head to head with the .243 or 6mm maybe.
That's the first thing I consider when I'm reloading. Is the twist in my rifle going to stabilize what I'm shooting? Secondly, what are you shooting? For game pick a performance bullet. For target shooting pick an accuracy bullet. For varminting pick a light accurate bullet designed for fast terminal performance instead of one for game.
The powder loads that people use are all good points. One thing I think was left out is that lighter loads of faster powder where the case isn't uniformly filled will not only affect MV is will affect barrel harmonics. In most modern loads you are in the 50,000 psi range, and even though powder burns it does so at the rate of a slow explosion. That will send a vibration down your barrel. If the powder stack is slanted too far it will want to send a vibration going up and down down your barrel. Getting the harmonics to match is what I like to look for when reloading. What I like to do is work in moderately slow powders for the case and then use faster powders. I never usually use the slowest. Something to look for and avoid if you can concerning slowest powders is MUZZLE BLAST. You will typically find it with too short of barrel for caliber rifles. Like using magnum powders in a 30-06 or .270 Win case. The escaping gases come around the bullet as it leaves the barrel and affect accuracy. The only way to use super slow powders is to have a super long barrel, i.e. 26-30".
The best poweders I have found for the rounds you listed are 4895, 4064, 4350 VV N140, VVN150, and 4831. The military uses RE-15 for the 118 Special Ball ammo. It burns right around 4895/4064 speed but gives higher pressure.
This is a good subject and many of us could go on and on about what to change where to change etc. But I think you have a lot of good replies here. Take some time and soak them in. -good luck
okay, I've wondered for quite some time:
Do you know of any INDIVIDUALS who "marry" their own powder mixtures or experiment with the procedure?
No need to read between the lines, I'm honestly curious if any individual is so "deep" into reloading that they try their own "mixes"?
I personaly know one guy that "kinda" does, and have seen on another forum a second guy that "mixes", but they are both using a small charge of fast powder as a "booster" charge under a large charge (275+gr) of slow powder.
In years gone by (back when Phil Sharpe* was still in diapers), a small charge of smokeless powder was often placed under the main BP charge to reduce fouling by benchrest shooters.
*Phil Sharpe wrote and published his first reloading manual before WW-2.