Ladder Test question

[apache12]

so I'm not a novice at ladder test, but i believe I should test the initial loads at 200 to 300 yards, and increase load by .3. I have also read some people skip the lower charge weights because they what to find the most accurate charge at a highest velocity for obvious increased performance. If as some suggest the initial powder charge test is around 20 rounds as you go up in increments does anyone recommend cleaning a barrel during this 20 round group? If you start with a clean barrel will there by that big of an effect on the 20th round if you're just looking for the string load?

 

I plan to use the same bullet and seat depth and three different powders. 20 rounds in each powder, to find the powder and charge weight to start with and then go to bullet seat depth.

 

Does that sound like the right plan? I think I'll do this over three days.

Open to any suggestions from the more experienced

[lancetkenyon]

Shoot your ladder tests on a fouled bore. Don't clean between shots.

I always ladder test at 400 yards.

I go up in .5 grain increments.

Shoot and mark each shot.

Ladder test one powder per target.

I usually start at about middle of published load data, and go above max load by 2 to 3 grains. Start at your lowest charge weight and go up, watching for any signs of pressure and stop when you see any.

[azsugarbear]

In order to understand the effects that a clean barrel has on changes in velocity and point of impact, the Sniper 101 series on youtube.com is a great place to start. In a nutshell, a clean barrel has no place in any accuracy test. As you shoot a clean barrel, it will begin to build up copper and carbon. As this occurs, the velocity of the same load will steadily increase until the barrel reaches 'stabilization. The velocity hits a plateau - usually anywhere from 25 to 40 rounds into a cleaned barrel. This stabilization could continue from 250 to 400+ rounds before you will begin to see a spike in pressure. Then it is time to strip it all out and start over.

 

Each barrel is different. Some foul quickly (think custom barrels) while others take longer. Most can go several hundred round before cleaning is required. Your mileage will vary, so go slow and record your shots. You will see your velocity curve develop as you go.

 

Going up 0.3 grains for your incremental increases works well with the smaller calibers, but once you get up to the larger magnums using 70 to 100 grains of powder, I tend to use 0.7 to 1.0 grains of increase with each load when looking for nodes.

 

If you are shooting long, heavy-for-caliber bullets, they may not even begin to stabilize until 300 yards down range. I have some first hand experience where my 338 shot smaller groups at 300 than it did at 200 yards. A longer distance can also open the group up more so it is easier to see the 'nodes'.

[apache12]

great responses. thanks. I should have added that this is for my 257 wby. so I suppose .3 increments are not wise. I usually shoot at Ben Avery and only can get 200 yards, then I go to the desert and shoot to 500. it sounds like from what you guys are both saying id be better off getting to the desert and ladder testing at 400 to 500.

 

AZsugerbear, are you saying that i could go 250 or more rounds without cleaning? Maybe I'm cleaning to often. I usually clean my rifles after each trip to the range. I'm all for cleaning less.

[Hoss50]

If you are cleaning your rifle every time you are cleaning to much. Once you have a load dialed in, don't clean the rifle until the groups start to open up. Then clean and foul the bore again. Shoot til the groups start to open up again.

 

I used to do the same thing as you. Now I don't clean my 257 weatherby very often, probably 120+ rounds at a minimum before cleaning for my 257.

[Jake J]

And even though you may go many rounds with no barrel cleaning, I would still clean your chamber at least every other outing.

[300RUM]

A competitive benchrest shooter with a clean barrel will fire a seires of shots, called foulers, into the backstop before he fires at his target for score. The clean barrel shots will not be as consistent as the ones fired through a fouled bore. I have a .308 that the first clean bore shot can be 2 MOA off. Remember if you are going on a hunt to take the rifle with a fouled bore, not a clean one. Your scope will be zeroed for the fouled bore impact point.

[Swivelhead]

What do you guys consider "cleaning"? Full blown copper removal or would a powder solvent & minor brushing qualify? I realize that

a solvent & brushing does require a few fouling shots.

[Jake J]

The .338 gets one patch and no brush about every 12 rounds. Does not get a scrub until it opens up, wich I would say is every 100 rounds or so, but I would have to ask my dad to be exact. The chamber is cleaned after each session with a soft brush and a dab of liter fluid. Bolt also gets a little attention. The other guns get cleaned after every session because they get neglected due to the Edge lol.

[azsugarbear]

Every gun is different. But each of my rifles go several hundred rounds before I need to clean them. I do, however, pull a dry boresnake through them every fifty rounds or so.

[DesertBull]

300/400 rounds in between cleaning on my hand lapped custom barrels. 80-100 on my factory barrels

[Tac]

My rifles seem to like clean barrels. I clean after each trip to range. My 338 shoots great with clean barrel and 6.5 just shoots well clean or dirty. All my barrels are factory Sako barrels. I have a 270 win in rem700 that just shoots well as long as you don't string rounds has a thin barrel and doesn't like heat.