How much "jump" do you like to initially start with?

[IA_shooter]

When just starting load development/ladder testing/etc., how much "jump" do you guys like to start with and why?

I'm just starting some loads for a .308 and decided to start about .020" off the lands and would love to hear others opinions. Thanks.

 

[Sheldon N]

I like the recommendation of .015 to start. That way when you do seating depth testing you can go from kissing the lands through .030 and never be more than .015 off your initial testing load. I'm sure 0.020 works just as well though.

 

[dmoran]

Myself for seating tests, I start IN and work in one direction, to OFF.

Good Luck
Donovan

 

[21shooter]

Hi I always start at 0 .... What if the sweet spot is .005 off .. With Respect .... Thanks, John

 

[Comrade Terry]

for a .308 and decided to start about .020" off the lands

That's where I start.

 

[dkhunt14]

I start in because then there is only one to go. Most times my guns shoot best in. I put them in and then go to powder and see where I can go. Matt

 

[savagedasher]

When just starting load development/ladder testing/etc., how much "jump" do you guys like to start with and why?

I'm just starting some loads for a .308 and decided to start about .020" off the lands and would love to hear others opinions. Thanks.

Bullet design is your choice . When I pick a bullet I want one t

That's where I start.

How far off is bullet dependent. I find hybrids like to be jumped so they are my choice. .020 is where I start . As I move forward my ES isn't as good. and the neck tension get more critical . I start my tests buy shooting the vertical out with powder drop. Then move the bullet back to .030 or more. My method is different Because I use a TUNER. But you still take vertical out with powder charge. Larry

 

[AckleymanII]

Hi I always start at 0 .... What if the sweet spot is .005 off .. With Respect .... Thanks, John

I am on board with this line of thinking, with a touching or Jam length is where I start with most, but....

There are exceptions, and I do believe that this has something to do with certain calibers and certain styles of bullets, such as Berger VLD's or any VLD style of bullet for that matter where a 0.020 jump may be best to START.

A 6.5x47L shooting a 140g Berger VLD is much different than a 7mm Rem Mag with a 140g Nosler ballistic tip. The 6.5/284 may not even be able to touch the lands and still use the magazine in a brand new rifle...so all you can do is hope and pray for a magic jump at Mag box length.

So, the questions are:

Secant Ojive are best at????

Tangent Ojive are best at????

Vld best at.....

Berger Hybrid are best at???????

Berger Hunting are best at??????

Now throw a skunk in the mix with, "my mag box is x.xyz" in length and I can't touch the lands, what is the best bullet design that will give me the best accuracy?"

Sierra MK are best at??????

 

[Mozella]

Hi I always start at 0 .... What if the sweet spot is .005 off .. With Respect .... Thanks, John

I think the question had to do with initial charge weight testing where the shooter loads, for example, groups (often 5/group) of 8 or so different charge weights but seats the bullets all at the same depth.

Then, after determining which charge weight shows promise, many folks load 6 to 8 groups of five seated to different depths and conduct a seating test. I'm aware that some folks test seating first and then charge weight while some test both at the same time, but that never seemed to me to be a good idea.

I used to only test from .015" or .020" OFF to .015"IN in increments of .005" until I read Bergers VLD blurb about seating depths. Now, at least with Bergers, I test a much wider seating depth range to begin with and then conduct a second seating test over a narrower range. If the "sweet spot" is .005" OFF, it will be found, but probably not during the initial charge weight test.

 

[ShootDots]

There is enough information on bullets out there that a "starting point" can easily be found. "Generally" speaking Berger Hybrids like a jump of "about" 15K.. Vld's of most sorts "generally" like it "about" 10K INTO the lands. "Most" Tangent ogive bullets like to be "about" 10K off the lands. It has also been my experience that VERY "Sleek-for-Caliber" bullets, that are tangent ogive, like to be "about" 7-8K into the lands. So depending on the bullet I intend to use, I use those "guidelines" as a starting place. BUT, barrels are like women, THEY will let you know what it likes or does NOT like..

Example: 1.) Experience has told me that 6.5 / 123 Scenars like to be about 7-8 K into the lands.. They are a very "sleek for caliber" 6.5 bullet. Today, I just got my NEW barrel from my 'smith out to the range for the first time. It is a 6.5 X 47 Lapua. I STARTED the 123 Scenars 8K into the lands>>>My first 5 shot group was right at 1/2" @ 300 yards! The second was about the same, 3rd was a bit larger, the 4th, the wind picked up quite a bit and spread it out horizontally about 1.25" and the last I tried, and was successful to wait til the wind dies to some degree and I shot a 1" group. Groups like that from a new barrel, tell me a few things. 1.) True to form, it probably likes the Scenars in the lands close to the initial starting point. 2.) It also tells me it likes the RL-15 I was using and 3.) it is a VERY good barrel. BUT the Scenars "generally" like be at a shallow depth INTO the lands..

Example#2: My "straight" .284 uses 180 Hybrids. So initial load development started them at 15K off the lands. I started there, found a great load, tried several seating depths and wound up right back at the initial starting point, true to form for most Hybrids!

That is how I start initial development... Is it the ONLY way? No way! But it has worked for me for quite some time now! So I don't try and "fix" what ain't broke!

 

[ShootDots]

If I didn't have a bunch of experience with a certain bullet in a certain reamer, I would do seating testing first.

Tom

Hey Tom, my friend Tom Holbrook (his name on here is his own name) does it the way you described. He has had great success with it.. If I had not always done it the way I do mine, I would use that way first..

 

[/VH]

So, do you guys find it common for two different bullets to like the same seating depth in a particular barrel? The reason I ask is because I have a 6.5x47 that shoots well with either the 140 Hybrids or the 136 Scenars at the same comparative seating depth. Also, with the same powder charge for what that's worth.

 

[M14AMU]

None!

 

[Hntndad]

Shootdots and Tom, I was always told that a particular bullet will perform best at a certain seating depth regardless of powder charge. I always start at the lands. But say you shoot groups from touch to .030 out with your starting load, your best repeatable group should determine your seating depth. Then work on charge. Whenever I do opposite and find charge then work on depth, I always have to tweek charge after finding depth. Thoughts?

 

[DennisH]

I have tuned many 308's.

All VLD's seem to like to be around .010 in, I may go as far as .020 in out to .020 out.

All Hybirds, I start kissing the lands and work out to .080. I do this as I had one barrel that love the Hybirds .050 out. I wore the barrel out, replace it, and the replacement barrel like the bullet .005 off the lands.

The barrel that like the Hybirds .050 off is probably one of the best 308 barrels I have ever owned. Looking back, I should have keep the barrel and figured out why it shot so well.

Varget is the powder my barrels have liked, but others have come very close.

Now, I start with a new barrel with 5 .010 in, 5 kissing the lands, 5 .025 off the lands, and 5 .050 off the lands. I look at the groups then decide what area to work with. I usually get a load pretty quick.

JMO, Dennis

 

[dkhunt14]

It's kind of a catch 22. If you're in a spot it hates for seating depth, it won't look to good with about any powder charge. If you're at a scatter node for powder charge, it won't be pretty with any seating depth. Most all the things I work with, I have a pretty good idea where is going to be close on both. Most all my stuff that is good, shoots between 10 in and 10 off.

I use the method to find my ZERO/touch, that Alex posted a video about. In case you missed it, wheeleraccuracy.com - information page- "finding the lands". Now, if I was to suggest a starting point, I would say +5 from ZERO. Anything BUT -2-+2, as right close to touch is when I've seen bad things happen. I'm not saying you won't eventually end up at +2 or -2, but I would avoid it when trying to guess. There's a spot in there where it will paint stripe, and powder charge won't make it go away.

Tom

I think you will find most guns don't like the touch to -5. I start in about 10 and put in a charge that usually shoots good in that cartridge. Then I will go 5 off and 10 off and see if it gets better. If nothing shows better I will play with the powder charges. Usually the best bullet seating does ok with different powder charges. That's why I try and find it first. Matt

 

[savageshooter86]

I find my loads generally end up 15 to 20k off touch. But I do start in. Like others said, if you start there only one way to go for seating adjustments

 

[dragman]

I always start with a jam seat.

 

[DeadEyeDick45]

I don't know how most of you find the "target point" for exactly being off the Lands, but here is a fantastic video to show how one maker does it.
http://www.wheeleraccuracy.com/#!information/p62ad

 

[Paddyd]

I have the recommendation from the letter Berger Bullets sent me to be the best all around way to start. Note, it pertains to their VLD bullets, but the procedure would be the same for any rifle cartridge being reloaded.