.308... to jump or not to jump?

[thefitter]

I've read that some feel that a .308 prefers a jump to the lands but that others set their loads kissing the lands.

I'm going to assume it's a individual rife preference as so much of this process is, and I'm just going to have to experiment.

 

[Rarebreed93]

Re: .308... to jump or not to jump?

I think you should do that.
I found that "Jumping" to the lands gave me nice tight groups.

 

[cdennyb]

Re: .308... to jump or not to jump?

for what it's worth, I shot a nice 1 MOA group with factory ammo at 100 yds in my new Savage 300 Win Mag, and then the following weekend, took out some handloads that I left the bullet out enough to get 1- against the lands, 2- .010 back from the lands, 3- .020 back from the lands and 4- .030 back from the lands.
I loaded up 5 of each and was shocked by the lack of accuracy of the tight ones.
The further back I seated the bullet the better they turned out downrange. I know this is still pretty fresh but if it likes the jump, then I shall provide a decent gap and keep experimenting.
Next is some halfway between the .030 and factory seated.

 

[jasonahull]

Re: .308... to jump or not to jump?

I think jumping or not some times depends on the bullet too.
Some one some where it seems like, told me that some hunting bullets are not designed to be seated into the lands.
So I think you are right to experiment and try different depths until you find the "sweet spot".

 

[vman]

Re: .308... to jump or not to jump?

The angle of the ogive will often determine seating depth.

Very aggresive ogives tend to be better off seated right in front of the lands. Combine that with loads that have next to zero run out and you will get a highly accurate round.

Then you have your hybrids, with a VLD type nose and a less agressive ogive towards the shoulder... probably more forgiving on the seating depth.

I myself tend to just seat right in front of the lands. I have had good accuracy with Scenars doing this.

Seating depth is probably the most boring topic on the planet when it comes to research and load development... so i just stick with the tried and tested results from past experiments

Read this for some interesting information

http://bulletin.accurateshooter.com/2010...lassic-article/

 

[SScott]

Re: .308... to jump or not to jump?

Don't get all sucked into thinking that you have to load to the lands. Only "your" rifle and bullet will determine that.
Think of the most accurate factory load, in most factory .308 rifles, Federal Gold metal match, depending on the rifle it is a long way from the lands.
Research the bullet that you want to use then keep track of the seating depths listed in the Reloading section, use that as a starting point for your reloading.
Good luck and happy shooting.
SScott

 

[jasonahull]

Re: .308... to jump or not to jump?

That was an interesting article.

 

[Niles Coyote]

Re: .308... to jump or not to jump?

I have several 308's and Ive had good luck jumping everything but VLD design bullets with two exceptions. 4 of my rifles wear factory barrels and the 5th has a rock creek barrel. The rock barrel will shoot VLD's well touching the lands and jumped once you get back aways. Same goes for a FN SPR wearing the factory barrel.

 

[Fuzzball]

Re: .308... to jump or not to jump?

"I'm going to assume it's a individual rife preference as so much of this process is, and I'm just going to have to experiment."

Your assumption is correct.

 

[BlackRain1]

Re: .308... to jump or not to jump?

IM new to this forum and new to reloading but have a few questions about LC brass. Anyone know anything about tha stuff?

 

[BlackRain1]

Re: .308... to jump or not to jump?

Had a question about LC brass can you help?

 

[jasonahull]

Re: .308... to jump or not to jump?

Can i help? Maybe

 

[8up]

Re: .308... to jump or not to jump?

what is the LC brass question?

 

[sniperaviator]

Re: .308... to jump or not to jump?

What I do is:
Using longest round that will feed from the magazine, make 10 rounds of .5 increments from smallest charge to largest charge and see which load shoots the best.

Using the above load, take and make 10 rounds, incrementing OAL from minimum OAL listed in load book to maximum that will fit in magazine and see which shoots the best.

Now using that OAL vary the powder charge .1 grain increments above and below the best from above and see what groups best.