Off the lands bullet seating?

Alderman

Handloader
Apr 5, 2014
1,310
762
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?
 
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.
 
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.
 
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.
 
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.
 
I’m with Mike! My old XLC’s liked .05” but those don’t exist anymore so it’s a moot point.
 
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...
 
I usually start my rifle loads at .030 off the lands. Though this may change during load testing.
 
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.
 
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.

D80F881D-F9F9-4EA1-AE82-5F3A7429F6CE.jpeg

925A732F-71EA-4216-B049-C47A59C22D65.jpeg


AAECF2B7-0D9D-49E9-AE9E-E6E2B2E607DB.jpeg

All I changed was the seating depth.




P
 
So to me the bullet overall length is getting longer and getting better accuracy or am I reading this wrong…. Sorry I have just started to really try to get better groupings so trying to learn ok.

Don’t tear me a new one just yet 🤪
 
I can't add much to what's already been said. I too pretty much use 0.010 as a standard with everything and usually find a accurate load at that distance. The only exception was with the TSX and i tried 0.010 with those and accuracy wasn't pretty at all. After looking at the little insert in the bullet box and seeing Barnes recommended starting at 0.050 off the lands that's what i did and accuracy was spot on.
 
Last edited:
All that is good if your magazine allows the length needed. Win Model 70s (long action) are limited to 3.350" or so. Loaded to 0.010 off the lands won't load in the magazine on some long bullets. (270, 7mm mag, 30-06 for example) So I start at 3.34 oal and work back if I'm having accuracy issues. All my rifles that allow the length, I'm with Mike.
 
All that is good if your magazine allows the length needed. Win Model 70s (long action) are limited to 3.350" or so. Loaded to 0.010 off the lands won't load in the magazine on some long bullets. (270, 7mm mag, 30-06 for example) So I start at 3.34 oal and work back if I'm having accuracy issues. All my rifles that allow the length, I'm with Mike.
Agree due to factory free bore.
In this case, I load to just shy of max magazine length I had that issue with my 338 RUM
When I got it rebarreled, no free bore.

JD338
 
I've usually found my best accuracy between .010-.020" off the lands. Agree on Barnes, .050" is the sweet spot.

JD338
I’ve read over and over again about copper mono’s preferring a lot of jump. I don’t know what I’m doing differently but I personally have not seen that. My best Barnes TTSX loads are .005” off the lands….in my 7mm-08.
 
0.020” off is my starting point with standard calibers. Weatherby's with the long freebore seating depth is not as critical for me , it’s more about single feeding or mag feed.
Barnes recommended COAL is my starting point with their bullets.
 
There are often at least a couple of sweet spots but I found .030" off the lans with .257 Accubonds gave me the greatest accuracy, but hey that's in my K95 rifle.
I found Sierra Game Kings & Hornady SST in my other rifles are somewhat different
 
Back
Top