Off the lands bullet seating?

Alderman

Handloader
Apr 5, 2014
1,149
221
Do any of you have a standard off the lands seating depth that works best for you with a particular bullet? Such as is there a standard setting that works best with Ballistic Tips, Partitions, etc.? Even if it doesn’t always work best is there a particular off the lands setting that you start with?
Or is each load and caliber different for each rifle?
 

DrMike

Ballistician
Nov 8, 2006
35,715
2,683
For cup-and-core bullets, I opted to begin at 0.010 inches off the lands. The most accurate loads have almost always been at or near that distance from the lands. This includes the Partition, by the way. For monolithic bullets, I found that they gave me the best accuracy at or near 0.100 inches off the lands. Think E-Tips, TSX, TTSX, etc. The GMX was an exception to this rule in my experience. It preferred to be seated much, much closer to the lands. My findings were verified in conversations with ballisticians at Hornady. I can't speak of the newer CX bullets. The Bonded bullets have always given me the greatest accuracy between 0.070 and 0.100 inches off the lands. This included the A-Frame as well as almost every other bonded bullet.
 

hunter24605

Handloader
Apr 30, 2016
1,790
1,916
My experience pretty much mirrors Dr Mike’s. In fact I used to believe everything had to be kissing the lands because that’s what I read. Then about 5 years ago I took the above advice from the Doc and a few others here, and I’ve saved a lot of time and components development accurate loads.
 

ShadeTree

Handloader
Mar 6, 2017
3,101
2,040
If I'm going after the greatest accuracy in something like a 22-250 I'll develop my load with it jammed into the lands .010. When I find the best charge for that powder, I then try being off the lands .010. That way at least in theory it should be lower in pressure going to .010 off. 1 or the other will shoot the best and you can go with it from there. Trying to kiss the lands or be .002 off, etc, is dang near impossible to hold.........being that precise is a lot to ask of standard bullets, dies, etc. Sometimes being slightly against, and the next time just off, is in and of itself inconsistency.

All that being said I have zero interest in running hunting bullets .010 off. The type of rifles I generally am using and the type of hunting I do, in my mind is unnecessary and is just asking for a problem that I don't need to add to the mix. I can find better accuracy than is needed for farther than I have the ability to shoot usually somewhere between .040-.060 off with C&C bullets.

Function and reliability is paramount to me when things are happening fast. Same way with magazine lengths. Loaded length .045 shorter than magazine at a minimum for me. I've tried running closer to accommodate a bullet length I wanted to load at, and it can work fine, until it doesn't. Others may disagree and that's fine. Gotta do what works for ya.
 

TackDriver284

Handloader
Feb 13, 2016
1,923
699
What Mike said.
I normally start .010" off the lands if my magazine allows it, if not, I generally seat .020" shorter than mag length. I adjust seating depths deeper until I find the groupings I like and / or longer by .010" at least to find a sweet spot. Most of my rifles likes seating depths of .010" off or more. The only rifle that likes kissing the lands is my 6 BR.
 

Brinky72

Beginner
Jan 25, 2019
198
61
I’m with Mike! My old XLC’s liked .05” but those don’t exist anymore so it’s a moot point.
 

desertcj

Handloader
Sep 27, 2010
839
81
I always start at .005" off the lands. I've played with deeper, but so far I pretty much stay at .005". Never stuck a bullet and yes I know the bullet is getting further away as I shoot and the throat erodes...
 

Darkhorse

Handloader
Mar 14, 2014
757
33
I usually start my rifle loads at .030 off the lands. Though this may change during load testing.
 

Cleveland48

Handloader
Jul 28, 2015
1,951
110
Pretty much what DrMike said. If magazine length allows I’ll start at .010-.020” off the lands with target bullets especially, and cup and core bullets. The mono bullets seem to really like a long jump, around .075”-.100” or even more.
 

pharmseller

Handloader
Feb 13, 2012
531
38
I start just kissing the lands, then move back in 0.04” increments. That’s what Berger recommends but it’s worked for me with several bullet styles.

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All I changed was the seating depth.




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