How much bullet jump do you use

[aulrich]

When constructing loads for my bolt guns I tend to make the rounds as long as possible either just about touching the rifling or as long as the magazine would allow.

Is there a "rule of thumb" for Handi's for how much jump to have for best performance or is it really bullet/gun dependent and I'll need to test that variable too.

[handirifle]

aulrich
That has just about beat to death with attempts to find the right spot.  Honestly, most I believe will tell you that on the Handi's just load to factory COAL and let it jump.  Many calibers you cannot load the bullet out far enough to come near the lands, not all but many.

The 223 is a good example of that.  The 45-70, is one you could load close to the lands though.

[Donaldo]

On my 223 UV you cannot load a bullet of normal weight to "almost touch the lands".  If you do there is nothing left to put in the case.  The WW econo box 45 JHP stuff has about 1/4 inch jump to the lands.  It has been the most accurate other than one handload that I recently found, after about 200 plus rounds of searching for handload.  It is seated a bit longer than the 45 JHP stuff but not by much.  These guns seem to have loooooooong throats.  Be that as it be, some shoot real good.  Contrairy critters they are.

[jim_in_fla]

aulrich
My .223 Ultra is pretty much like the rest of them,  a very long throat!
Like everyone else here, mine likes the Win 45gr Varmint 'White Box' ammo too. Of all the the different reloads and lengths I've tried, my rifle shoots the best with an OAL of 2.21" with any 50gr bullet I've used, which is the OAL of the Win 45gr Varmint 'White Box' ammo.
FWIW, the 69gr Sierra Match King bullet touching the rifling on my rifle is .035" outside the case (trimmed to 1.75").  Another thing I've discovered with my rifle is, it likes everything crimped with the Lee Factory Crimp. I've tried every load and length with and without the crimp and it definitely shoots tighter groups with the crimp.

Hope this helps a little bit  :?

[aulrich]

So  then given the long throat what would be the minimum seating depth.  1/2 caliber or 1 caliber or to the base of the neck.  

What would you use as a start point.

[AZ223]

If you have a factory ammo that shoots reasonably well, I'd start with that. Otherwise, go with the data that's published for whatever caliber you're shooting. I did the same as jim_in_fla; my two favorite factory loads are the Win 45JHP and Ultramax 50gr V-Max. The Ultramax are around 2.245"; longer OAL "cheap" ammo (2.26") doesn't shoot as well so I keep it at 2.245" or less with 50gr Nosler BT's and it's worked fine for me.

[RussB]

In my 45-70, I load to where it just barley touches the lands.

My son-in-law has the same rifle, shoots the same cast bullets I do, but he backs off to an OAL that is much shorter than mine for best accuracy. And, strange enough...we both prefer the Lyman 457658, at 475gr as our best cast bullet.....go figure!

So, I think the person giving you an absolute on this may want to re-think what he's saying.

There seems to be two measurements for seatings in my gun..one that is touching the lands is good. Any other length, jump is not so good.

Yes, it has been beat to death. And all for good reason.

Russ

[RodentRidder]

I load my UV223 with 40gr Nosler BT with a OAL of 2.320 seem to work great for my gun if I could keep it from copper fouling with these bullets so fast.

Rodent Ridder

[aulrich]

As a start point I decided to copy some factory loads COL and work from there. And as it turns out the bullet ends up seated at the base of the neck.