How far do you have to jump the lands?

[Aeolus]

I have a 7 stw that is 300 thousands bigger than mag leingth. I couldn't get a thing to shoot! So I called the smith he said it had to be a 150 nosler bt. And 7828. So I shot that 3/4 moa and sd of 9 at 3450 fps.

Does anyone else have to jump that far ?

 

[Alaska2006]

I have a 7 STW that has to jump a mile of used as a repeater. It shoots very well either way. I can't remember the exact jump but its in the .100 range as I recall with 168 Berger VLD.
I shoot a lot of Nosler AB and don't worry much about the jump, I can seat them long and still cycle through my Sako AV action and box.

 

[FearNoWind]

Alaska2006 I sure am glad you know what he's talking about. I haven't a clue. If you get a minute perhaps you can translate.

 

[Aeolus]

Umm, ok in a nut shell. It's the distance the bullet has to travel from the time it leaves the case until it actually inters the barre and rifleing. So when you see people post
Jammed it means they are in the lands and grooves it also causes a lot of pressure
Kissing means they are barely touching
3, 5, 10, 15 thousands are common in a rifle to jump.
300 thousands it crazy far. The smith that did my work had his hay day in the 70-80s and back then it is my understanding, they thought jumping the lands was more accurate. I do believe it causes more speed. Weatherby was jumping the lands on his rifles and I think everyone followed. The thing is bullets and powder has come a long way now and that isn't required. I don't want to shoot the 150 nosler because the bc on the 162 Amax or the 168 Berger has so much more bc.
Anyway today I judge how much barrel life I have shot out by my lands. It seems every 400 rounds I am having to seat the bullet out 1000th.
I hope explained it kind of ok.

 

[ODAVID]

First off I feel the main factor is how you measure the distance to the lands.

Assuming you are doing like I am then Using 168 berger hunting bullets seated .060 off lands with a comparator COAL LENGTH tightest group was 4.092 1/2" groups at 200 yds. second tightset group was 4.086. 3rd tightes group 4.094.

I was told Start at 4.088 go higher or lower in .002 intervals. Works for me as barrel wears I will increase length of COAL to try to get what life I can from barrel until being replaced.

IF THIS MAKES NO SENSE TO YOU I COULD ANSWER SPECIFICS IN PM> BUT NOT GENERAL QUESTIONS.

PASS THE HELP ALONG TO OTHERS IS ALL I ASK>
ODAVID

 

[Lefty7mmstw]

I have a 7 stw that is 300 thousands bigger than mag leingth. I couldn't get a thing to shoot! So I called the smith he said it had to be a 150 nosler bt. And 7828. So I shot that 3/4 moa and sd of 9 at 3450 fps.

Does anyone else have to jump that far ?

I also have a rather large jump to my lands if I load my rounds at mag length. I'm at better than .2". I am actually using the 140 nos ab and rl25 in my rifle (at a rather sedate 3350 fps) even though it is a 8" twist. Nosler bullets are really forgiving to jump and will put the hurt on a critter when you hit one with them. I have other bullets to use in this rifle, but haven't finalized any heavy pill loads.

 

[WildRose]

I load everything to magazine length and don't worry about it. I've found that unless you're shooting VLD's for the most part most bullets are not particularly sensitive to seating depth.

 

[emp1953]

So far, all of my bolt action centerfires shoot sub moa groups at 0.018 to 0.020 off the lands. I re-establish a new Cartridge overall length with every bullet brand change as the bullet dimensions are usually different, the ogive is either more or less aggressive thus the point where it contacts the rifling is different. I made a portable loading bench that inserts into my trucks trailer hitch. I mount a single stage press, a bullet puller die and my final seater die. While at the range I will hone in on that off the lands distance. I always have accurate dial calipers on hand. This had helped me discover how much recoil can adversely effect cartridge length in the magazine. I always keep detailed records of what I've done and discovered just incase memory gets foggy.

 

[General RE LEE]

My Rem 700 Sendero has a long jump to the lands so I've been loading for fun stuff just off the lands and using it as a single shot. I will probably hunt this way as well.

 

[FEENIX]

I hope that the OP had his issue resolved after 5 years.

 

[Northkill]

I enjoy seeing revived threads by times. Always something to learn / new ideas to file. And good dialogue here.

 

[hicountry1]

I load my STW to mag length. It shoots one hole groups with 160 partitons and 7828 at 3250.

Have no idea how far the jump is, don't really care.

 

[xsn10s]

General rule if you have to jump great distances use a tangent or hybrid ogive bullet. More forgiving than secant ogives for jump. But I've had VLD secant types shot with .250" jump or greater shoot sub moa or even half moa. It all depends on the barrel. Like people they just like what they like.

 

[josh_127]

Dragging up a old thread....I'm at round count 231 on my bartlein barreled 7mm stw...it burned exactly 20 thousandths of throat in 214 rounds...it shoots 1/2 moa with a jump from .023 to .030 with the 195 bergers...I'm expecting to burn the barrel out before I'm out of mag room (wyatts cfe9 magazine box).