How much jump do you use?

depends what we are jumping? a bike , a puddle, our wifes /gfs bones ??

i sit between 10-15 thou off my lands and its givin me the best results so far in my 5r
 
just to make sure were on the same page, your .015 off the lands?



and lol, your wifes / gf's bones ??? what kinda skeletons are in your closet
 
Load 24 rounds at the following COAL if you are a target competition shooter who does not worry about jamming a bullet:
1. .010 into (touching) the lands (jam) 6 rounds
2. .040 off the lands (jump) 6 rounds
3. .080 off the lands (jump) 6 rounds
4. .120 off the lands (jump) 6 rounds

Load 24 rounds at the following COAL if you are a hunter (pulling a bullet out of the case with your rifling while in the field can be a hunt ending event which must be avoided) or a competition shooter who worries about pulling a bullet during a match:
1. .010 off the lands (jump) 6 rounds
2. .050 off the lands (jump) 6 rounds
3. .090 off the lands (jump) 6 rounds
4. .130 off the lands (jump) 6 rounds

Shoot 2 (separate) 3 shot groups in fair conditions to see how they group. The remarkable reality of this test is that one of these 4 COALs will outperform the other three by a considerable margin. Once you know which one of these 4 COAL shoots best then you can tweak the COAL +/- .002 or .005. Taking the time to set this test up will pay off when you find that your rifle is capable of shooting the VLD bullets very well (even at 100 yards
 
That's a good method. I never thought of using such large gaps to get a baseline # to tweak in.

I asked the Q because of that. Im in the mist of testing right now. Bullets im using are 175smk. I have a great load but ive yet to adjust this one important area. I spent a ton of time trying to find my ogive oal. tape on a cleaning rod, cut neck case, removed firing pin .... ect. I was never 100% confident in any of the #'s. Finally I got a hornady oal guage with a modified case. What a tool! pretty excited to finally finish a full out tune with this load.
 
Probably still the best method is to take your firing pin assembly out of your bolt. This takes away any stress on the bolt when you "#### it". Next take a resized brass and seat a bullet too long on purpose. Insert the bullet in the gun. Go back and seat the bullet in small increments. When the bolt just closes with slight pressure you are at the lands. Take your bullet comparator and measure the cartridge. Write this number down, do this about 3-4 times and take the average. After this is done you will no exactly where the lands are when a cartridge is chambered. Not sure if this makes sense, but here is a video pretty good to watch.

http://www.youtube.com/watch?v=Jv-D1mEI514
 
For some reason the barrel on my main target rifle (Millennium action with a Bartlein barrel) like .020" jump with all 155 gr bullets. Tried everything from jammed to .040" off the lands but .020" seems to be the sweet spot.
I have a new Krieger going on in a few weeks so the process will start again.
 
I don't jump anything. All the bullets I use like to be at the lands or as much as 20 thou into them.

My 338 Federal gets loaded to mag length...
 
Moose284 said:
Probably still the best method is to take your firing pin assembly out of your bolt. This takes away any stress on the bolt when you "#### it". Next take a resized brass and seat a bullet too long on purpose. Insert the bullet in the gun. Go back and seat the bullet in small increments. When the bolt just closes with slight pressure you are at the lands. Take your bullet comparator and measure the cartridge. Write this number down, do this about 3-4 times and take the average. After this is done you will no exactly where the lands are when a cartridge is chambered. Not sure if this makes sense, but here is a video pretty good to watch.

http://www.youtube.com/watch?v=Jv-D1mEI514
Click to expand...

I tried this method and it is good. Still, the hornady OAL guage beats it.
Only problem with the remove firing pin method is ( with a factory action ) your bolt still has tension. Enough were it leaves you unsure of the exact #
 
155.5 bergers jump like crabs from friday's entertainment- no problems and the results are good.
as others have eluded, depends on the bullet and barrel. It'e always nice when your rig and bullet of choice agree to jump, as you don't have to keep adjusting as your throat erodes- again we're back to friday night...
 
My 223... 8 twist Tikka Varmint likes em 15 thou off....with 69 gr scenars.
For a new project, I'm going with the 80 gr A-Maxes in the very near future...wanna see how many poor helpless little paper targets are going to be executed and annihilated....hoping to make them suffer it out too...slowly through one little ragged hole! ;) ;)
 
Ron AKA said:
So far all the bullets I have tried in my 6BR do best with a 0.010" jam. I have not tried any Berger VLD's, but Berger is reporting they do well with a significant jump.
Click to expand...

I was aware of this anecdote and then saw Beger's published comments. have tried this every which way from sunday in multiple 6mm's, 6.5's and in a friend's 284 with absolutely horrible results.

More experimentation = more bullets consumed = profit for the bullet company.

I stick with what I know works and resist the temptation to screw with things.
 
Moose284 said:
Probably still the best method is to take your firing pin assembly out of your bolt. This takes away any stress on the bolt when you "#### it". Next take a resized brass and seat a bullet too long on purpose. Insert the bullet in the gun. Go back and seat the bullet in small increments. When the bolt just closes with slight pressure you are at the lands. Take your bullet comparator and measure the cartridge. Write this number down, do this about 3-4 times and take the average. After this is done you will no exactly where the lands are when a cartridge is chambered. Not sure if this makes sense, but here is a video pretty good to watch.

http://www.youtube.com/watch?v=Jv-D1mEI514
Click to expand...

At first I thought this video was going to be another semi-worthless opinion based video.. now im SO happy I've seen this! Makes total sense, you could do it other ways of course without the high-tech seating die, just make it maybe 0.020-0.030 thou bigger or until your bolt won't lock, and slowly make it smaller manually and measure with a caliper. Very smart... too bad I have already handloaded all my 30-06 brass haha maybe next time :)
 
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