24hourcampfire.com
24hourcampfire.com
Previous Thread
Next Thread
Print Thread
Hop To
Page 1 of 58 1 2 3 57 58
Joined: Jan 2009
Posts: 11,488
Kenneth Offline OP
Campfire Outfitter
OP Offline
Campfire Outfitter
Joined: Jan 2009
Posts: 11,488
Educate me please on the ladder test, What are we finding, Pressure? accuracy? How and why please.

300 yards is sufficient?

1 ladder test is sufficient for that particular load? Does anyone repeat to verify?


BP-B2

Joined: Feb 2001
Posts: 8,694
Campfire Outfitter
Offline
Campfire Outfitter
Joined: Feb 2001
Posts: 8,694
Two things.
Find the top end of your load.
Find the node where your rifle is giving you the least amount of vertical on the target across the biggest range of powder charge.

The farther away the better.
I like to shoot dual ladders at 500.
500 because I can still see the bullet holes.
One in early morning and one about 2 pm.
Usually good conditions early morning.
Usually crap at 2 in the afternoon.
Average it out.


dave


[Linked Image]

Only accurate rifles are interesting.
Joined: Dec 2007
Posts: 1,522
G
Campfire Regular
Online Content
Campfire Regular
G
Joined: Dec 2007
Posts: 1,522
The goal IMO of the ladder test is to find velocity/pressure nodes that give the best accuracy with slight variation of the velocity. These nodes help alleviate inaccuracy due to environmental factors or reloading variation that can affect velocity. It may or many not be at the top end. Usually there are two or three nodes present, depending on how low you start the ladder. I usually pick the case, bullet, primer, powder type, and seating depth I want to use and then vary powder charge. I choose the nodes which are evident by bullets forming "groups" and then shoot additional five shot groups to quantify/verify the accuracy of each node. Select the node you feel most confident in and meets your velocity criteria. Additional ladder testing can then be done to tweak seating depth, keeping aware of the max pressure. Hera again you are looking for the least accuracy sensitive length.

I've found I burn less powder to find a good load for a given bullet/powder combo. 300yds should work well, longer the better as distance makes the velocity variation stand out. 200yds will work, but 100yds is worthless IMO and you are better off trying three shot groups at 100. The variation just doesn't stand out.

Joined: Feb 2001
Posts: 8,694
Campfire Outfitter
Offline
Campfire Outfitter
Joined: Feb 2001
Posts: 8,694
Only thing I use 100 for anymore is to zero the rifle.
Dont even know how well it shoots at 100.

dave


[Linked Image]

Only accurate rifles are interesting.
Joined: Jan 2009
Posts: 11,488
Kenneth Offline OP
Campfire Outfitter
OP Offline
Campfire Outfitter
Joined: Jan 2009
Posts: 11,488
300 yards is all that's available to me.

Lets work up a ladder test for my .300 wsm, Here's my normal load development for this Cartridge,

165 TSX or GK, 64-67 grains of H4350,with 65 grains almost always showing the best group, I use a difference of 1/2 grain of powder with 5 shells loaded per charge.

Stay with .5 grain increments or drop down to .2 increments?
Still focus around 65 grains with .2 diff?

IC B2

Joined: Mar 2006
Posts: 20,787
R
Campfire Ranger
Offline
Campfire Ranger
R
Joined: Mar 2006
Posts: 20,787
It was always stated by many that .."58 gr's of Imr4831 & the 130 gr bullet in a 270 go together like apple pie & ice cream."

The same is true with 66 gr's of H4350 & 165's in a 300 WSM.

I have had good success with 1/2 grain increments. Save the minutia for fine tuning if need be. 66 gr's H4350 stacks my 165's in there.

And, fortunately my rifle accurately digests Superformance with 150's. Love it!


Throttle fixes everything. If it doesn't fix the problem, it’ll end the suspense.
Joined: Jan 2005
Posts: 57,368
R
Campfire Kahuna
Offline
Campfire Kahuna
R
Joined: Jan 2005
Posts: 57,368
10% of case is generally what we've always done.

With that, 0.5 grains is MORE than enough.

I'd only load one of each personally.

Go shoot em at whatever distance you have.

It weeds out the bad ones to start with. Run over chrono so you can see the max coming speed wise/vs pressure.

Then I load up 3 of each of the best 3 in a row generally and shoot again to see.

That will start to confirm. I may do that 2-3 times. Then I'm down to 5 of the best. And from that load I may see if I need to tweak neck tension, seating depth or even something drastic like primer change to see what each one does with the best load at that point.

My loading with your info would be 64, 64.5 and all the way up to 67 or 67.5 depending on what max says, vs your bullet, coated or not and so on, IE all the variables.

Remember, you DON"T HAVE to shoot every one you've loaded if pressure shows...

Jeff


We can keep Larry Root and all his idiotic blabber and user names on here, but we can't get Ralph back..... Whiskey Tango Foxtrot, over....
Joined: Mar 2006
Posts: 97
W
Campfire Greenhorn
Offline
Campfire Greenhorn
W
Joined: Mar 2006
Posts: 97
I've been "fiddling" with loads for a cpl months now. Came up with a load to get .75" at 200 yds where I zero, but at 400 groups were junk. Finally did a ladder test on Friday, shot to confirm today. I should have done the ladder months ago.


[Linked Image]


Confirmation of 71.5gr @400 yards on 2" dot.

[Linked Image]

Joined: Mar 2006
Posts: 20,787
R
Campfire Ranger
Offline
Campfire Ranger
R
Joined: Mar 2006
Posts: 20,787
WapitiBob,
I comprehend your premise but not your findings based on the ladder target shown. How could you zero in on 71.5gr based on that example?


Throttle fixes everything. If it doesn't fix the problem, it’ll end the suspense.
Joined: Feb 2011
Posts: 11,273
Campfire Outfitter
Offline
Campfire Outfitter
Joined: Feb 2011
Posts: 11,273
To me, 71.5gr makes sense because it's in the midst of a "node" of shots showing very little vertical deviation. That's what we all want....

Tanner

IC B3

Joined: Mar 2006
Posts: 97
W
Campfire Greenhorn
Offline
Campfire Greenhorn
W
Joined: Mar 2006
Posts: 97
I shot 71.5 and 71.8 based on the dispersion noted by Tanner.
71.5 was best but I moved my sight at 71.8 so I'll go back later and re check those two loads.

Joined: Mar 2006
Posts: 14,435
Campfire Outfitter
Offline
Campfire Outfitter
Joined: Mar 2006
Posts: 14,435
I'd roll 71.7, tweak seating depth, and call it a day.

Joined: Jan 2005
Posts: 57,368
R
Campfire Kahuna
Offline
Campfire Kahuna
R
Joined: Jan 2005
Posts: 57,368
71.2 is out of the node, 71.5 is the next closest charge, hence the note, I agree I think I'd be much safer/happier around 71.8 or so rather than only a few tenths off a major change.


We can keep Larry Root and all his idiotic blabber and user names on here, but we can't get Ralph back..... Whiskey Tango Foxtrot, over....
Joined: Nov 2004
Posts: 7,045
Campfire Tracker
Offline
Campfire Tracker
Joined: Nov 2004
Posts: 7,045
I like the ladder test because it is the closet thing to simulating changes in conditions mainly temperature that you can get. what you want is a forgiving load that will shoot roughly the same in a variety of conditions. in order to do it you really need the ability to load at the range.

Joined: Jul 2005
Posts: 1,416
Campfire Regular
Offline
Campfire Regular
Joined: Jul 2005
Posts: 1,416
All shots are cold-bore shots or one after the other?


Support your local Friends of NRA - supporting Youth Shooting Sports for more than 20 years.

Neither guns nor Liberals have a brain.

Whatever you do, Pay it Forward. - Kids are the future of the hunting and shooting world.
Joined: Aug 2007
Posts: 713
Campfire Regular
Offline
Campfire Regular
Joined: Aug 2007
Posts: 713
A couple of examples of Audette ladders

[Linked Image]

[Linked Image]

For me a ladder is just to find the powder weight charge that will give me the approx. velocity I want to shoot that bullet at. Predicting accuracy nodes is a little like reading tea leaves IMO

Then the tweeking comes with a seating depth test. The seating depth test will identify best grouping, lowest velocity extreme spread and lowest velocity standard deviation. Varying seating depth will vary you velocity by about 10 or 15 fps per every .015" deeper you seat, so you are essentially timing the bullet exit from the muzzle

[Linked Image]


"The beauty of the 2nd amendment is that it will not be needed until they try to take it" - Thomas Jefferson

Criminals prefer unarmed victims and dictators prefer unarmed citizens
Joined: Apr 2013
Posts: 198
Campfire Member
Offline
Campfire Member
Joined: Apr 2013
Posts: 198
gives me where different powder charges shoot.find best then start to fine tune them

Joined: Dec 2010
Posts: 878
R
Campfire Regular
Offline
Campfire Regular
R
Joined: Dec 2010
Posts: 878
I like Jordan's .7! the .5 off to the right and lower is what would have probably lead me to .7

The 400/71.5 looks very good, I would have to try it again at .7 just to see? Or as Jordan mentioned - carry on.


Randy

Joined: Sep 2005
Posts: 4,274
G
Campfire Tracker
Online Content
Campfire Tracker
G
Joined: Sep 2005
Posts: 4,274
On the 3rd page of a post on 1000 yd load development, I posted 2x, the 2nd posting a detailed method I fine tuned from Rcamuglia. Saves on barrel life and components and yet results give me typical 1/2 moa or better loads.

http://www.longrangehunting.com/for...detailed-article-video-42881/index3.html

Alan

Joined: Jul 2009
Posts: 8,923
RDW Offline
Campfire Outfitter
Offline
Campfire Outfitter
Joined: Jul 2009
Posts: 8,923
I agree Alan, three shots at 71.8, 71.7, 71.6 and 71.5 would narrow the load down further, preferably at 600 or longer. After ya'll posted the method in my thread last year, I started using it and works well.

Three groups adjusting the seating depth deeper .01, .02 and .03 would further fine tune

It is interesting how a load that shoots almost no vertical at 200 completely blows at 400.

[Linked Image]


Dave

Page 1 of 58 1 2 3 57 58

Moderated by  RickBin 

Link Copied to Clipboard
YB23

Who's Online Now
661 members (17CalFan, 10gaugemag, 1beaver_shooter, 1minute, 10ring1, 12308300, 75 invisible), 2,739 guests, and 1,329 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums81
Topics1,187,640
Posts18,399,000
Members73,817
Most Online11,491
Jul 7th, 2023


 







Fish & Game Departments | Solunar Tables | Mission Statement | Privacy Policy | Contact Us | DMCA
Hunting | Fishing | Camping | Backpacking | Reloading | Campfire Forums | Gear Shop
Copyright © 2000-2024 24hourcampfire.com, Inc. All Rights Reserved.
Powered by UBB.threads™ PHP Forum Software 7.7.5
(Release build 20201027)
Responsive Width:

PHP: 7.3.33 Page Time: 0.085s Queries: 14 (0.003s) Memory: 0.9043 MB (Peak: 1.0401 MB) Data Comp: Zlib Server Time: 2024-03-28 17:27:28 UTC
Valid HTML 5 and Valid CSS