ladder test

[nice one]

whats a ladder test:confused:

[DaveK]

There you go mate

http://www.lima-wiederladetechnik.de/Englisch/Laddertest.htm

Ray you're a troll and should be banned:p:p:p

[Paul.]

There are 2 methods or variations on the same theme. The basic theory is that with the same brass, primer, powder type, and bullet seated to the same lengt. You then load one round at the starting charge (gotten from a reloading manual) then increase the charge .2-.5 grains for the next round and continue loading one round at each wieght until you hit the recommended max charge. This should give you anywhere from 9-15 rounds each with a slightly higher charge.

Next you fire those rounds slowly (so your barrel doesn't heat up) at the same point of aim. 100 yrds is acceptable but I hear 2-300 is preferred by alot of people. For this to work you MUST record the shot placement for each round on the target. When you are done, in theory you will have 2 maybe even three "groups" on the target. For instance shot 5,7, and 9 group tightly with 7 in the middle of the group. This would mean that round sevens powder charge was optimum for the rifles harmonics not necessarly the fastest or most effecient.

Then load 3-5 more at that same charge and fire for an actual group...theory says it would be the best out of your gun...I will be verifying my first ladder tests today so we shall see.

[nice one]

mmmmmmmmmmm i see its worth a shot :D

[markbivvy]

There you go mate

http://www.lima-wiederladetechnik.de/Englisch/Laddertest.htm

Ray you're a troll and should be banned:p:p:p

ha ha ha troll. the banned parts right though.

[bullbarrel]

It's also called the Audette method and is best carried out at 300yds or so

Why is the distance significant? Perhaps it gives a bigger distance between shots.

I was doing a load test last week on my 7.62 and found about 2 inches difference from my lowest to highest poi.

[Hunter_zero]

Why is the distance significant? Perhaps it gives a bigger distance between shots.

I was doing a load test last week on my 7.62 and found about 2 inches difference from my lowest to highest poi.

The greater the distance the more room there is to analyse the grouping. Your trying to find the natural harmonics of the barrel and match them to a reloaded round.

One of the best ways I have found to achieve a good reloaded is to first find the correct bullet length (using greenhill's formula), then find a bullet that matches that length. Next is to look for a powder with the greatest velocity variation and thus bulk with the option of creating a compressed load. Using clean cases and BR primers I'll knock up a batch of ten lots of five and ladder test the rounds. To date I have not found a faster way of creating optimum reloads for my rifles.

John

[MikB]

Interesting thread on an interesting technique. :)

And there was me thinking it was a naval gunnery shooting pattern for rangefinding... :D:o

Regards,
MikB

[phessy007]

ha ha ha troll. the banned parts right though.

The 'Master of all' has spoken !! :D:D:D 70553R

[markbivvy]

The 'Master of all' has spoken !! :D:D:D 70553R

whats up raymond , no forum members to rob.
or are you behaving with your new name.

[baz]

I have found getting the seating depth right is more important when starting to load for a new rifle, charge weight comparisons come later

If you have the ideal COL for the chosen bullet, and are using a known powder then charge weight variations are next in line

Whats the point in getting best charge weight if you dont know best bullet and seating depth?

[Hunter_zero]

I spent a whole lot of time playing with a stony-point OAL tool. I found an average of 8% improvement seating just of the lands with a new rifle. As the throat erodes the COL needs to be adjusted to match. The erosion is proportionate to the type of loads being fired and also has specific variations with the type of cartridge being shot.
It was for this reason I settled on using COL to fine tune a load. The very first step in producing an accurate round is to find the correct bullet length which has dramatic effects on accuracy. IMHO a lot of "black arts" has crossed over from BR shooters who try to eliminate all errors no matter how small. Some would place a viable argument on the benefits of case neck turning & measuring internal volume of the cases. As much as I agree that all these things will effect a rounds accuracy each can only play a small part in my findings. Some older rifles have such a jump to the lands that seating depth makes the round unsuitable for hunting purposes and I have seen one or two nearly new rifles the same. Even the best cases vary in volume in a manner that seem very drastic yet makes little different to the final group at 300 yds. I do admit that I have a very narrow line of thought with reloading and that is to use the right bullet, the best powder for that round and simply match the velocity to the harmonics of the barrel but even this has issues if you look at ambient temperatures and the like :)

The other major issue for me is time. I haven't the time or inclination to load test 100's of rounds. I have done in the past but these days I want to work a load up in a jiffy so to speak. The last load I worked up right from scratch was for my new .243". It took me a morning to make a batch of rounds. Couple of hours to test them. In effect a Sunday.
The results are clover leaf groups at 100 yds using 100 grain bullets. I could fine tune the round but why when my shooting will not complement anything better :)

John

[Tedward]

Hi Hunterzero,
Yours sounds like a very practical approach, I'm happy with your bullet length selection, but don't understand:
"look for a powder with the greatest velocity variation and thus bulk "
what powder did you decide was best suited to your .243?
Tedward.

[Hunter_zero]

Yours sounds like a very practical approach what powder did you decide was best suited to your .243?
Tedward.

The first and biggest problem is being happy with your bullet selection. This is the greatest hurdle I had to overcome. My question is 'why are you happy with the bullet? shape? colour? weight? terminal ballistic effect?'
Once you (not you personally) have over come this you need to find the twist of the barrel and use greenhills formula (there are calculators on line) to find the exact bullet length that will be stabilised in the barrel. I'm not trying to preach or to cover a topic that you understand but this step is critical (IMHO). Sometimes it can take weeks to find the right bullet as manufactures don't like to give this information, I started to ask myself why that was :D but never the less I refrained from buying vast amounts of their bullets to experiment with!!
A trip down the gun shop with a caliper sorts most issues out :D

Now for the primers. Primers alone can launch your bullet! so to my mind you need the best and I opt for Federal gold BR primers. I did think about using plastic bullets and measuring the velocity variations to find out exactly how uniform these primers were BUT again we are going back to the dark arts of BR shooting.

Now for the cases, all I do is to re-size and tumble and wash the cases in meths. Check the OAL and trim. Clean the primer pockets and then finally wash. Cases done! (don't forget to re-lube the neck opening).

Okay 3/4 of the way there.

Powder next. Check all your reloading data. Look at the min. charge weight and the max. charge weight and NOT velocity (sorry my mistake on last posting)!

If we take hodgons 26th edition manual as an example.
P.167 to be exact.
Lets say that you have found a 100 grain bullet with the exact length you need to stabilize in you barrel.
and that the only powders available are hogdons powder.
Looking at the data. The least suitable powder is H1000 because the min. charge weight is 47 grains with the max. charge weight of 48.5 grains. The most suitable is H4350 as the min. charge weight is 39 grains with a max charge weight of 43 grains which gives a deviation of 4 grains. There are better powders out there with more deviations but in this example we have selected H4350 (also of interest is that powder manufactures seem to recommend specific powders for specific bullet weights, it's funny how these powders normally equate to the selection).
Now, we need to divide this by a factor. This factor depends upon how methodical you want to be.
A factor of 10 means 55 rounds to test (I have used a factor of 5).
If we go for a factor of 10. This means we need to increase our loads .4 grains each time (Charge variation divided by the factor or 4/10 = 0.4)
So thats five rounds charged with 39 grains, five rounds with 39.4 grains, five rounds with 39.8 grains, five rounds with 40.2 grains, five rounds with 40.6 grains, five rounds with 41 grains, five rounds with 41.4 grains, five rounds with 41.8 grains, five rounds with 42.2 grains, five rounds with 42.6 grains, five rounds with 43 grains. Why five rounds? Well you can be sure if you load up three there will be a flier and the tests will not be complete and more than five and your not really going to get anymore data. Even with a variation of four grains of powder the velocity will only fluctuate by an average of 400 fps (looking at my test records), thats about half the speed of a .177 pellet not much but this is where the harmonics thing comes in to it but all said and done a variation of 10% charge weight gives a final variation in velocity of about 25% and a drastic increase in internal pressure which will always be the case with nitro-powders.

You can even cut this stage short as I have found that things don't get interesting until mid charge weights are reached but you never know what the harmonics of your barrel might produce and you run the risk of hitting a hot load!Bang!

Okay, now you need to load up your rounds and get to the range. You need a big target. Now set your target up about 1 and 2/3 your normal shooting range for most people 175 yards will be okay. Place a mark on the target and shoot the first lot of five rounds (as always checking for black streaks and making sure the cases are expanding and sealing. As you work your way up your looking for signs of high pressure as apposed to lack of case expansion. I always combine a chronograph with the tests so I can see how the different charges effect velocity and explain unexpected fliers. Looking back on my .243" tests a 1 grain increase gave an average of an extra 100 fps but amazingly this effects the harmonics of the barrel). Back to the test. So you have shot your first five rounds, next measure the group size using which ever method you normally use and then on to the next batch of rounds and so on.
When you are finally finished (do not adjust POA during the tests as you are not zeroing, just watching the group size) and you are happy that all the rounds have been safe, you need to match the smallest group size up with the relevant charge weight. Make a batch up and zero!

Simple as that with all the crud cut away and all the black arts removed. You could go and 'fine-tune but I have never seen any real benefit. One possible scenario is that you don't really see much difference in group size during the tests. You can either increase the range or go with the best velocity (if you stalking deer for example but not necessarily the hottest load!) or your groups are blown apart like SSG from a shotgun (never happened to me) if thats the case I would look at the bullets and the powder charges again.

One thing I would like to say. This method of reloading has taken me many hours to prefect, many rounds and many frustrated hours on the range. Anyone who tries this method I would appreciate your feedback. I've never seen this method described before but have spend time talking to bullet manufactures about bullet length and my thoughts on this method. One of the most helpful and informative discussions I ever had was right at the beginning with Walt Berger whose company makes some excellent bullets. I have also had people tell me that such and such a powder is the best or such and such a bullet is the best but when quizzed over why the answers become less and less convincing and more based on cost or personal preference as apposed to theory or testing. I honestly believe the above method gives an excellent base line to produce some of the most accurate loads but of course 'pet loads' will be better but how much time and how much testing has gone in to producing these pets loads, not to mention wasted bullets and powders. Fine tune and you have your pet load in half the time with little or no waste at all. Gone are the days when I used to buy several boxes of bullets or several tubs of powder to find the best load, I simply follow the above and am always happy with the results. Good shooting to all!!

John

[Tedward]

Bloody hell John, that's what I call a reply! Seriously though, many thanks for going to all that effort.
I'll give it my "best shot" and let you know how I get on,
many thanks, Tedward.

[richness]

what an interesting thread :)
John's method is, i'd say, 9000% more methodical and scientific than mine ;)

[Hunter_zero]

All you need to remember is only use the best bullet for your barrel, the best primer, the best powder to match the harmonics of your rifle & barrel and clean cases as dirty cases are inherently inconsistent.

Simple as that.

If we look at the complete path of the bullet right from the firing pin striking the primer to the bullet hitting the target. The primer, case and powder plays a very small part, the barrel a slightly bigger part, yet both combined play a critical part in the flight of the bullet. Try not to lose sight of the part each component actually contributes to the over all flight. What you are trying to achieve is a uniform pressure curve to send a bullet in to the barrel. Everything else is more or less out of your hands and is basically mechanical. If the bullet isn't stabilized by the barrel twist, then you haven't a chance and once the bullet leaves the barrel there is nothing you can do to change or correct the flight of the bullet. Obvious I know but easy to forget. It is at this stage things get messed up by the black arts of how to get each bullet in to the barrel exactly the same each time at the exact same speed and location. By all means carry out experiments with these variables but don't get hung up on them because for most of us with normal hunting rifles these variables don't really make a massive difference.

You should be able to work a new load up first time, first box of bullets, first tube of powder. Even a first time re-loader should be able match the skills of experienced re-loaders as long as they make sure each charge is the same and the cases are all prepared correctly and the bullet is correctly stabilized.

Good luck and let me know how you get on.

John