How far off the lands do you start?

[bnewt3]

Im assuming once you work with a rifle/barrel a bit you learn generally what it likes, but what is your default when developing a load on a new rifle/barrel?

 

[wapitibob]

.020 on this stw and 195's, will be around there when I swap to a 7PRC. Will look at some load data from guys I trust, pick a distance and leave it there.

 

[Chris in TN]

I won't say seating depth doesn't matter. I'll just say it doesn't matter enough for me to bother with it. Start at 0.060" off the lands and find the speed I want. If suitable accuracy isn't there, the rifle probably isn't going to suit my needs very well:

https://precisionrifleblog.com/2020/03/29/bullet-jump-load-development/

 

[TaperPin]

Often the magazine dictates the maximum length. Many new rifles have shown up opening day and the magazine won’t feed because the cartridge length at the very top of the mag seemed fine, but down lower it is too long, so make sure and cycle at least one full magazine before the season.

If the magazine doesn’t limit length, .020” is commonly picked because it’s close enough without usually causing issues. The danger of being too close, like just a few thou from touching, is slight differences in length might put some bullets into the lands and other not, which is never good.

 

[blksno]

Depending on what I'm loading for...I start at either .010 off the lands or max magazine length and work away from the lands.

For example, in a 25 Creed with 135s...I start .010 off the lands and see how it looks in the mags. If I need to seat deeper to fit in the mags...then that's my new starting point....then I go deeper if needed.

For things like a 22 Creed with 64 TGK...I just start .010 off because I'm not gonna be anywhere near mag length anyway.

 

[justin davis]

I usually load .040-.060 off and have good luck with that range

 

[wind gypsy]

I usually set them about 50-60 thou off the lands to start. Reason? This article came out a while back and it made sense to me. https://precisionrifleblog.com/2020/04/05/bullet-jump-load-development-data/ Along with others indicating things are less likely to get wonky as throat wear occurs if you've got a longer jump. I tend to start with bullets not known to be particularly finicky about jump and am happy to avoid bullet jump testing most of the time during load dev these days.

Obviously mag length and how much bearing surface is in the neck plays a part too. A tikka 6.5 creed chamber for example seems to need a longer jump if you want a 140 hybrid to have a decent bit of bearing surface in the neck or fit a mag.

 

[Packmansion]

Mag length or 20 thousandths. Jump doesnt seem to matter much. I have a 300 win that prints very small groups with a huge jump due to mag limits i think its a .25 jump. I like 20 thousandths because you get that extra little bit of capacity and it just feel efficient.

 

[MallardSX2]

.020

 

[Vern400]

0.010 tangent ogive bullets and test upward
0.050 secant ogive bullets (very high BC) test upward and downward.
264 284 and 308

 

[307_timberstalker]

The old Cortina method has worked for me on every rifle. Jam a dummy round, measure it, subtract .030 and go. So far with Berger hybrids they all seem to be perfect right there.
I try to stay with bullets I know.
As many others have stated too, mag length also dictates.
In that situation I will go .010 off mag max and start.

 

[doc holiday13]

Might depend on caliber you load for. My buddy and I have seekins rifles. He has a 300 PRC and I have 7 PRC. I'm .120 off and I think he said he's .125 off. Those were the most accurate jumps and honestly i'd rather have that much jump because it gives me LOTS of space to seat longer as the throat erodes. Starting with SAAMI spec drawing might be the most helpful for getting started.

I started at .120 simply because I had some factory ammo and used that to set my seating die. Kinda of dumb luck but makes sense

 

[Dave Thomas]

I start at .020 off jam and work back unless it is too long to fit the magazine then I set them at a safe mag length.

 

[JGRaider]

I start at .020 off jam and work back unless it is too long to fit the magazine then I set them at a safe mag length.

This is the only way to fly........find pressure with varying powder charges, then jack around with seating depth if you want.