the jump or lack of...

[300WSM]

Obviously every rifle is different but as a general rule of thumb how much jump or lack of do you start with...

new bullet, new gun, new cartridge, whatever...

where do you find yourself going to for a starting point?

 

[Joec7651]

I start at .020” if magazine length permits. After determining max load or node I’ll change seating depth to check impact on groups. It’s just my rule of thumb though, where I start. You can start longer or shorter if you prefer.

Edit: it works great too. My last one shot group with a 7mm RM came it at .284”

 

[JD338]

I'm with Joe, starting .020" off the lands if the magazine allows. My 308 was different, starting at SAAMI 2.800". I ended up at 2.810". My 338 RUM was based off magazine length as there was no way I would get close to the lands with all the free bore in the factory barrel. No free bore in the Krieger barrel. Ended up .025" off the lands.

JD338

 

[TackDriver284]

Obviously every rifle is different but as a general rule of thumb how much jump or lack of do you start with...

new bullet, new gun, new cartridge, whatever...

where do you find yourself going to for a starting point?

I like to start at .010" off the lands, if it fits the magazine, and do my work ups, then tweak seating depths later if needed. With Bergers its a different story, it needs to be seated deeper to fit the magazine, and cup / core hunting bullets are very forgiving and can be seated longer and can fit the magazine.

 

[Aussie Wanderer]

As long as my magazine will allow so long as it is not touching the lands of the rifling.

 

[SJB358]

With a cup and core I start at the rifling, not jammed, but a square touch, bonded or monos I won’t mess with them any closer than .050” off. Saying all that, if the mag isn’t long enough for either I’ll start .010-020” under mag length for feeding and function.

 

[diverdown]

I had an extra long magazine in my Christensen Arms .300 Mag and a short throat that allowed me basically no room other than about factory length. Really no room for moving the bullet around. I solved that problem with a good gunsmith. Now the throat gives me plenty of room and I start at .015 with Cup and Core and up to .050 with monos. Worked out well.

 

[bdbrown66]

See my post last night in this other thread:

Post in thread 'How much .005" seating depth can change patterns' https://forum.nosler.com/threads/how-much-005-seating-depth-can-change-patterns.47971/post-527876

 

[DrMike]

With cup-and-core bullets, I generally start at 0.010 inch off the lands if the magazine allows. With monolithic bullets and bonded core bullets, I almost always allow 0.100 inch jump to the lands. Works well for me across a wide range of actions and bullets. Lever guns are a special case; they are always fixed on COAL by the action itself.

 

[filmjunkie4ever]

Obviously every rifle is different but as a general rule of thumb how much jump or lack of do you start with...

new bullet, new gun, new cartridge, whatever...

where do you find yourself going to for a starting point?

I generally start with the bullet manufacturer’s recommended COAL in the loading manual. Typically this is a winning combo right out of the blocks. In fact with hunting rifles (versus match/target rifles) it will shoot <1.5 MOA with the book COAL (cartridge over all length) leaving me to only play around with powder charges. The Nosler AccuBond and Ballistic Tips have been very consistently accurate in my guns at least by utilizing the book COAL recommendations.

If it doesn’t shoot well, I play around with COAL and powder charge until it is acceptably accurate for my intended application.

 

[George Foster]

What I have done when I find a good load with the book COL with the powder charge and bullet, I want to use I will start working on seating depth. I start at 0.10 off the lands and load a series or three rounds for each 0.10 back to 0.60 off. I usually find a sweet spot that I stick with for the bullet and powder combination in the rifle. When I find the best COL of the test, I load a box of 20rounds, I shoot one three shot group and then three five shot groups to ensure the load is a good one. I have had very good luck with this method over the years.

 

[RL338]

I have done it different ways. Most lead core bullets I start 0.020” off. Barnes I start with the recommended COAL. Cutting Edge seat to the Seal-band. My Creeds and some of the Wbys seat to the neck/shoulder junction.