Max powder reloading question?

[basshusker]

Is it pretty much a rule of thumb that if you have 2 really tight (i.e. one hole) and one wierd flyer that you bump the powder. I am at the book max but showing no pressure signs. As I went up the flyer got closer.

I am assuming that it isn't the powder or brass or primers because I have 69s one holing and the 55s one holing. They are using more powder and in my manuals it seems like bigger bullets max at less powder. Not sure about the physics of it. Thought I'd need more powder to push a bigger bullet. Bigger bullets equal that much more pressure is everything else is the same?

I'd really like to push the 75 a-maxs with their high BC if I can get close velocity and be safe on the pressure.

In a .223 do you just go .2 at time past the book max.

Appreciate everyones thought.

 

[5R Milspec]

Re: Max powder reloading question?

one thing to always remember.it takes less energy to push a heavy bullet.so when you see a max load for that one weight of a bullet you should work up to that load.the powder people have done the home work for use.we just need to follow it.but in some case's we can go over.just look at the case and primer area when you shoot.and don't look at just one.one case may be a little different and might not show the same as the other.a really bad flattened primmer or one that falls out will tell you to stop and rethink.

even different case brands will give you different pressure signs.just what are you loading the A-max for?if you are loading it for paper one doesn't always have to load it as fast as they can.I would rather push it with less powder than alot.the reason I say this is because if I get good accuracy with a mild load I am saveing my barrel,and money.but if you want it too give a good punch for a kill then I would push it as fast as I can with safe pressure signs.and yea you can work the load up by .2 grains.and for me I always gor for a 5 shot group.never been one for the 3 shot group.the next 2 may open up the group or shoot right in the same place.just think that 5 shots tell me a better story.just keep looking for pressure signs and you should be OK.but hey this is just my opinion.

 

[ChadTRG42]

Re: Max powder reloading question?

Is this for an AR-15 chambered in 5.56 or a bolt gun in 223 Rem? 223 is a 55K PSI round and 5.56 is a 62K PSI round. If you are looking at 223 Rem data for an AR-15 chambered in 5.56, you can go over max charge by about .6 to 1.2 grains (depending on bullet and powder choice) to reach max for a 5.56 chamber. You will typically find your best groups in a 5.56 chamber above 223 Rem data for an AR-15.
I go up .2 grains at a time and load 7-10 rounds per charge. I test them at 200 or 300 yards to see how they shoot for longer range shooting.
If you use the same powder, the heavier the bullet, the less the charge weight.

 

[bohem]

Re: Max powder reloading question?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 5R milspec</div><div class="ubbcode-body">one thing to always remember.it takes less energy to push a heavy bullet.
</div></div>

I think what you're trying to say is based upon the idea that you can't put as much of a specific powder behind a light bullet as a heavy one.

The result is true, however it's not because it takes less energy.

It takes more energy to throw a heavier bullet at the same speed, KE=mv^2

What's really going on is that the powder burn releases energy at a specific rate, when you have heavier bullet in the case, it moves out of the way at a lower rate than the lighter bullet. The inertial effect of that stationary heavy bullet keeps it sitting in the case longer as the powder continues to burn.

As the powder burns the pressure increases, which increases the burn rate, which increases the pressure even more, all the while the bullet is taking its sweet time getting down the barrel.

This continuing effect is why you can't take a 30-06 and put 55gr of BLC-2 behind a 208 Vmax, but you can do it 150gr bullet and the action won't go all to pieces on you.

 

[basshusker]

Re: Max powder reloading question?

Shooting out of a Savage 12 1:9 twist in a McMillan a2 with an Aluminum bedding block.

1 have the 69 gr SMK shooting 1 clean hole with same brass, primers, push by 26.0 of Varget. GM205 match primers. So I don't think brass, powder, or primers are giving me consistency issues.

Just trying to figure if there is a rule of thumb for powder burn rates as you progress to larger bullets.

I'd like to get that gain in BC from the SMK to 75 AMax if I can. Someone on another forum suggested bumping the powder since I am not having any pressure signs to fix the 2 in basically the same hole and an odd stray.

I have some H335, RL15, and Benchmark to try. Just wondering if there are some rough guidelines for powder burn rates in relation to moving up to a bullet with more surface area on the lands (i.e. bigger bullet), weight of the bullet, etc.

I am pretty new to reloading and have had really good advice getting the loads for the 55 Nosler BTs and 69 Sierras which are boring a clean hole. Varget works superb for those but I am starting to wonder if I hit outside its range to do the same with a different burn rate and the 75s.

The bergers are looking really nice (70s and 73s in my initial go round with varget) in my first round of OCW load development. I went 24 24.5 and 25 and could cover 17 shots with a quarter with 3 charges. 24.5 had middle POI so I am just gonna start messin with OAL. At the lands those 5 were .312.

I hope my .260AI shoots half this good when I get it done.

 

[Greg Langelius *]

Re: Max powder reloading question?

If the rule of thumb isn't borne out by direct correlation to what's in the more popular reloading manuals, treat it as pure bunk.

There are <span style="font-style: italic">no</span> effective (and especially, no safe) rules of thumb that base escalating a powder charge based solely on any one factor.

Read the books, follow the instructions, experiment only after respectable experience, and do so at your own significant peril.

Thus endeth the lesson...