When starting new load workup, how much space space between bullet and the lands (bullet jump) do you like to start with?


Thanks

For most of the longer sleeker bullet .050 works well.

In the old days kiss the lands was they starting point, but even after doing OAM (bullet seating depth testing) runs I found that 50 thousands even out to 80 thousands is good.

A very well known gunsmith saidseating depth means nothing if the rifle is put together correctly. He then loaded to different seating depths and proved his point.

I found this article informative regarding bullet jump.

Bullet Jump Load Development Data

Start at magazine length, go from there.

I have never measured bullet jump but I do like to be back just off the lands. I load the first bullet long to hit the lands and then seat a bit deeper each time till I can no longer feel the bullet touching the lands when closing the bolt and can no longer see the land marks on the bullet. In my rifles I can actually close the bolt and not feel the lands but still see very small marks where the bullet touched them. My opinion about the bullet jump is it is only worthwhile for competitive shooter's.

this............^^^^^^^^

when I build a dog barrel.........

I request -0- freebore

but they are s/shot actions

I usually do 30 thousandths.

Magazine length is a consideration with rifles for larger animals, but since this is posted in varmint rifles... magazine length doesn't matter to me. The rifles can be single loaded. Sometimes loaded cartridges fit the magazine, sometimes they dont. A couple of half-fast rifles have shown remarkable improvement in accuracy by seating long to touch or even into the rifling, so I've begun handloading trials with middle of the road powder charges that show promise with bullets just short of touching, juggling the powder charge for best accuracy then going shorter incrementally with OAL for fine tuning. Sometimes going longer works better, again reducing then working upward with powder charge until you find a safe load you're happy with. The 1st time is a bit of a hump, but it gets easier once methods are developed, procedures are learned, & a maybe few new tools are acquired. You will need a dark colored Sharpie to check for contact when finding the base measurement. A bullet comparator is very useful & fits on your dial caliper. The Stoney Point/Hornady OAL guage is useful but not necessary.

I generally go by mag length. I have a very accurate older 700 adl in 22-250 and while finding a good load I then played a bit with seating depth to see just how it effected accuracy and with this rifle my most accurate was with book length 2.350".

I read the article that NVhntr provided a link to and decided to start at .040 but after adjusting the die actual measurements ended up at .042 +/-
Initial test loads were shooting ok so i just left it there and started trying different powders and charges. I found 3 different loads that will probably shoot better than I can hold.

I shoot for .020 as a starting point and if it doesn't feed well through mag, I adjust. A 708 I recently loaded for had to be .040 back to reliable feed.

I remember the first rifle I used a ogive gauge on, a m77 22-250. Calculated the jump I wanted, loaded round, had to keep on pushing that thing back to fit in mag box. Ended up dead on 2.350...and it shot great.

Another for 0.020”, unless the mag won’t allow me to go that long.

I’m not saying that bullet jump matters or not, but I have personally had some loads go from 1.5MOA down to the 0.5-0.75MOA range by doing nothing but adjusting seating depth.

Seating depth matters. There's almost a "correct" depth for each bullet and each rifle, sometimes the difference is amazing. I've had jumpers and kissers, but for the most part my varminters like 10 to 15 thousandths the best. And, necked only fireformed.

It depends on what you are looking for, and what type of bullet.

Accuracy wise with not Barnes Bullets can often = close to lands...

Barnes = 30+ thousands jump

High Volume consistency = putting the bullet back from 50-80 thousands... there was just a study done on this due to the accuracy changing as the throat errodes and the jump to the lands moves back naturally. consistency wise the group size change is less if you are much further back with good accuracy, than it does if you are kissing the lands and it moves.

I may be bypassing some better OALs, but what I've done for many years is start about one tenth of a caliber off the lands. I generally end up seating three to five thousandths longer after fiddling with it a bit. I guess that puts me anywhere from about 18 to 25 thousandths off the lands with anything from .22 to .30 caliber.

I do sometimes wonder if I'm missing something and I have tried stuff up to about 80 thousandths off, but that has never worked for me. I shoot mostly Partitions, Ballistic Tips, V-Max, and occasionally others but no monolithics or VLD type.

I try to be consistent on seating depth. I use a chamber all gauge. Generally I’ve found closer is better.
Except with Barnes bullets. Hasbeen.