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Ladder Testing

Posted: Sun May 02, 2010 10:12 pm
by MoA
Shooting a ladder is a fairly straight forward concept.
You load up a number of cartridges with the weight of powder increaseing incrementally, and shoot them sequentially. The weights that impact closest to each other are the one's that are likely to be most accurate.
So I decided to load ten cartridges with a 105 Scenar, and weights varying from 29.0 grains to 30.0 grains of Varget powder in 0.1 grain increments.
Ignore the four shots in the bottom right hand side of the Target.. those were random fouling shots comprising of differing bullets and powder types and charges.

Image

Sometimes things do go wrong... and it is a good idea to plot your shots with a pen and paper. The suares are 1 inch each..

Hence this target was a waste of time... next time I will plot the shots.

Re: Ladder Testing

Posted: Mon May 03, 2010 2:04 am
by Vikram
Very nice.And something new to learn. What distance and what calibre?Thanks.


Best-
Vikram

Re: Ladder Testing

Posted: Mon May 03, 2010 1:24 pm
by MoA
Viram,
The distance is 100 meters and the caliber is 6mm Norma BR.

Re: Ladder Testing

Posted: Mon May 03, 2010 4:39 pm
by eljefe
Am very tempted to get a new barrel in 6mmbr for my Tikka after I do another 200 in the 6.5x284. Been reading very nice things about the 6mmbr-Maybe a heavy 32 inch MADDCO? lets see...
If the damn rain lets up, I can try laddering the Stevens with a checked and tightened scope :oops: did have some very promising 2 holes touching, until the scope went loose and the rain let on like cherapunji was going out of style-some jinx about rain and my off days
laddered up some loads in 69 gr SMK and 75grn Amax, using ADI 2208-the closest I have to Varget-But I need to go fishing first. 8)

Re: Ladder Testing

Posted: Mon May 03, 2010 6:50 pm
by dr.jayakumar
yet to learn these 'grain' thing ,does not enter my small brain :stupid:

Re: Ladder Testing

Posted: Mon May 03, 2010 7:47 pm
by Amit357
Hi dr.jayakumar,grains is basically a subdivision of the gram,roughly 16.8 grains make a gram ,Its easier this way when measuring either the projectile or GP loads of small arms cartridges,think its was a Brit concept they didnt belive in Miligrams :lol: .Hope this helps :cheers:

Re: Ladder Testing

Posted: Mon May 03, 2010 8:39 pm
by MoA
eljefee: 6 BR is a great caliber. However for ultimate accuracy try the .30 BR to about 200 M and the 6 PPC. They run rings around 6 at that range. Beyond that the 6 BR is hard to beat.
Funnily enough there are some people starting to shoot the 6-6.5x47 Lapua at 600 yard BR and getting top five finishes.

Re: Ladder Testing

Posted: Tue May 04, 2010 4:10 pm
by eljefe
MoA-
just popped the action off the stock of the ' 7th attempt at bedding 223 Stevens'- 6 attempts on the factory polyethylene stock was a total biche.Lets see if I can get some mag pics for WtP
This time the stock was a Boyd and used Acraglas gel, gave it a full week to set in.Looks good.As usual rained enough to deep six shooting, but I did catch up on my fishing...
Caught up with my Gunny and I just might live upto the new rifle in 6mmBR,step 'up' (?) from the 6.5x284. I am told I wont need vicks formula 44 for gale mein khich khich-6mmBR is far easy on the throat with a barrel life of 2000-2500? Cant afford 2 rifles-I hardly shoot once in 3-4 mo-at least F class.Let me start with the 6mmBR- a 32inch x 1 inch barrel - MAB or MADDCO-who ever can deliver earlier, on the Tikka T3, same stock and scope...I freak on 600 and 900m shooting, but am going to get Re hammered on the Redding dies and bells and whistles

Re: Ladder Testing

Posted: Wed May 05, 2010 1:06 am
by MoA
Biche=Deer..

6 BR 1:8 is great. Figure out the throat you want. A 77 gr throat is too short for 105's and a 105 wont allow you to shoot the 70 bib's that need to be touching the rifling.

I dont know the barrel makers or whats available in Koala land. Or the general page in the Atlas. Get the best you can...

Theoretically.. 2500 is accurate. Competitive.. nope. Sub MoA is about it.

6 BR is all about Gale mein Kich Kich.. drop me an email.

An easy.. not so accurate 600-900 caliber is funnily enough the .300 WM.. I cut my teeth on it.

Re: Ladder Testing

Posted: Wed May 05, 2010 4:50 pm
by eljefe
Want to save the 300 , but in Wea, for some long range ' hunting'
My brother has been coaxing me towards a 338Lapua,both of us love big boomers I guess...I've promised him one if he gets here 8)
Yup lots of planning to do-on paper and the budgeting.

Re: Ladder Testing

Posted: Wed May 05, 2010 8:35 pm
by MoA
.338 Lapua Magnum without a muzzle break and/or Suppressor is a very difficult rifle to shoot. The recoil is very very stiff and felt recoil is significantly more than the .375 HH.
What ever you do, do not try to shoot a .338 LPM in a cheap lightweight rifle. It will hurt.

Re: Ladder Testing

Posted: Thu May 06, 2010 1:12 pm
by TwoRivers
Amit357 wrote:Hi dr.jayakumar,grains is basically a subdivision of the gram,roughly 16.8 grains make a gram ,Its easier this way when measuring either the projectile or GP loads of small arms cartridges,think its was a Brit concept they didnt belive in Miligrams :lol: .Hope this helps :cheers:
Amit: Not quite. It's 15.4 grains to the gram. 7000 grains to the pound. Simply the old British system of weights, still in use in the US. And since handloading as we now know it originated in the US, reloaders and shooters worldwide tend to use the system. The notation "42 grains" somehow is more appealing than "2.727 gram". Cheers.

Re: Ladder Testing

Posted: Thu May 06, 2010 3:22 pm
by skeetshot
Ladder Testing is a useful tool for determining the optimum combination of various factors for obtaining the best accuracy for one rifle and ammo for it.

I use it extensively and have obtained good results for my 30-06.

While most people use it to determine an optimum powder charge, I believe seating depth and bullet seating force play a greater role in obtaining optimal accuracy of one rifle/ammo system.

Fortunately, the ladder system is also a great help here, only one fires a min of three cartridges at each setting and sometimes it helps to change targets between settings as the groups print rather close to each other near optimal settings.

Re: Ladder Testing

Posted: Thu May 06, 2010 9:10 pm
by MoA
Skeetshot,

In a ladder it is pretty much one shot per charge weight. You then pick the wieghts that printed the closest together, and load up on those.

Once you figure out which ones group the closest using five shot groups, then begin to play with OAL and seating/Jam depths.

Doing a ladder with more than one shot at a given weight is more time consuming and cumbersome.

OCW(Optimal Charge Weight) and OBT (Optimal Barrel Time) are other popular methods as well.

In my limited experience with Jam depths, I have found that having a jam into the lands, half as wide as the lands are is about ideal. However most days I just shoot with a 0.010 jam when shooting naked bullets, and a little more when using coated.