Long Jump to the Lands

[Jud96]

I’ve been doing a lot of research lately on freebore and bullet jump. Does anyone have experience with purposely jumping bullets 0.100+ to the lands? Bullets have seating depth nodes obviously, but has anyone tried jumping them really far to gain velocity or lower pressures? Also, I’m talking about having the bullets seated above the neck/shoulder junction and not buried in the case. I’m curious if you’ve tested this, what your accuracy, consistency, and velocity was like. Thanks!

 

[Terry]

I had a .270 that liked .120 jump with 130 smk.

 

[FeMan]

I have several rifles where I am jumping well over 0.100" and a few in the 0.250" range. All shoot extremely well (7 STW, 300 RUM, 6.5 SAUM). I have done this out of necessity due to mag length vs throat length. So it is not exactly what you are asking. Weatherby's are chambered that way by design. They are not "match" rifles but do have a reputation for shooting well.

In my match rifles, I do purposely test out to around 0.080" though. IME the nodes there are often wider and more forgiving to throat erosion. That decreases or eliminates the need to tune as the throat wears.

 

[Chubbs]

At the moment I am jumping my 6.5CM at .192" and its hitting well at 1000 yards.

 

[hambone1971]

I have a .223 that is jumping .200 and is a 1/2 moa gun it has thousands of rounds
down the barrel which is the reason for the large jump. Still accurate.
Also I have a Savage 12 in 6.5CM with over 5000 rounds down barrel and large jump still accurate shooting 1/2 moa also. I believe there are nodes up and down the bullet seating depth range part, you just find them with powder charges and seating depths. JMO
Velocity is down a little from new but still accurate rifles....... HB

 

[Murray Brook]

I own a 7/08 that nearly drove me crazy. I did ladder tests with many different bullets and powders out to .060 off lands but just couldn't get good repeatable results. I only went as far as .060 as with every rifle I owned in the past accuracy was obtained with in this #. As a last resort I tried a ladder test out to .130 off and found the repeatable accuracy I was looking for at .120 off.

 

[JB10]

I have a Remington 700 in 308. Has a long jump if i want loaded to fit in mag. I have a load i found for hunting with 175gr bergers that shoot about 1 inch at 100 yards and thats the best out of several bullets i tried. If i load same bullet touching lands it shoots 1/4 inch all day. Its kinda heavy to pack arround so i just shoot it from a bench and single feed the long rounds.

 

[Tokay444]

Mark Gordon of Short Action Customs has been compiling data on the subject for a quite a while, and has shared with Cal Zant at the Precision Rifle Blog.
Here are the links.

Bullet Jump: Is Less Always Better?

About 2 years ago, Mark Gordon shared some preliminary research he’d conducted with the Applied Bal...

precisionrifleblog.com

More Bullet Jump Research!

This is the 4th article in a series on some new research on bullet jumps. Here is a recap of the pr...

precisionrifleblog.com

Mark’s 18-Shot Bullet Jump Challenge!

Are you one of those guys who has been reading this series of posts on bullet jump, and thinking to...

precisionrifleblog.com

Bullet Jump Research: Executive Summary & Load Development Tips

This is the last post in a series of articles focused on bullet jump research that has been conduct...

precisionrifleblog.com

The takeaway for me was, it depends what type of cartridge you’re loading, how much shooting you’re doing, and what type of shooting that is. If you’re shooting a 308 twice a year to sight in and and get a deer, then you may decide to take the most precise but most sensitive seating depth node. If you’re shooting PRS with a hot 6 and your lands are migrating .007-.014” over the course of a match, you’re going to to want to find the least sensitive node you can find. If you’re shooting bench rest and loading right on the bench and chasing the lands, then you’re probably looking at the precise and sensitive node as well.