how far off the lands?

lightmag

lightmag

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I was told by an avid shooter, reloader and rifle builder that you want to get the right length so your bullets are as close to the lands as possible without touching to reduce bullet jump.

He said he just dumby loads a shell, purposely seats it a bit shallow and then just loads it in his gun, if he can feel it when loading he takes it and sinks the lead alittle further and repeats, he does this until it just barley touches, then seats it a tiny bit deeper so it not touching and that's his measurement? says that's how he has done it for years and he shoots 1/2 inch or less groups.

does this make sense, will it work? is there a better way? and to just to make sure i'm on the right page, you want to reduce bullet jump and you want the bullet close to the lands correct??
 
Some loads work best with the bullet seated just off of the lands,while others prefer more of a jump to the lands.The only way to know what works best in your gun,is to experiment with your gun.
 
Usually 10 to 20 thou depending on the cartridge and the chamber. Trial and error is one way. You can make a DP round with a loose bullet seated long(not shallow), chamber it(the throat should push the bullet in) then seat a tick deeper.
Playing with the OAL is a target load tweaking technique. Something you do after you have a load. Not so necessary for a hunting load.
 
It's gonna depend on the caliber, and the chamber reamer used, too, at least to some extent.

Try to seat Weatherby caliber just off the lands, is tougher, for example, as they ran a lot of freebore to keep the pressures down.

Each rifle and barrel is an entity unto itself.

Cheers
Trev
 
lightmag said:
I was told by an avid shooter, reloader and rifle builder that you want to get the right length so your bullets are as close to the lands as possible without touching to reduce bullet jump.

He said he just dumby loads a shell, purposely seats it a bit shallow and then just loads it in his gun, if he can feel it when loading he takes it and sinks the lead alittle further and repeats, he does this until it just barley touches, then seats it a tiny bit deeper so it not touching and that's his measurement? says that's how he has done it for years and he shoots 1/2 inch or less groups.

does this make sense, will it work? is there a better way? and to just to make sure i'm on the right page, you want to reduce bullet jump and you want the bullet close to the lands correct??
Click to expand...

Do you have a reloading manual? In the topics relating to bullet seating depth, do they suggest that method? The closest thing I have seen in print is to paint the bullet with a marker, seat it loosely and longer than required into the cartridge, and then chamber the round. When the round is chambered, the bullet is pushed back into the case after contacting the lands. The bullet will likely stay in the chamber when the case is then extracted, but after you tap it out with a cleaning rod (I use a smaller caliber bullet dropped down the barrel) the scrape marks on the marker from where it was pushed back into the case will be visible. You can then reseat the bullet to where the scrape marks indicate and measure the OAL of your cartridge. From there you could adjust your die to get the desired OAL.

Usually you would repeat this a few times to get an accurate measurement.

I highly recommend an OAL gauge. Fairly inexpensive and IMHO far more accurate that the above method. Coupled with a bullet comparator of the appropriate caliber, you will only have to repeat this measurement periodically as the throat wears in your rifle. The time savings alone are worth the cost.

If that guy truly gets 1/2MOA from his rifle, I'm guessing it is more of a fluke that his scientific methods. ;)
 
Seating as dummy round to the lands is reliable with a sharp new chamber. Once your barrel has had a number of rounds through it, you will find some differences round to round. Try five, determing the shortest, and then using that to index your dies, seat a little deeper. My .22-250 might be getting to the end of its life, and this is what I found.
 
horseman2 said:
Seating as dummy round to the lands is reliable with a sharp new chamber. Once your barrel has had a number of rounds through it, you will find some differences round to round. Try five, determing the shortest, and then using that to index your dies, seat a little deeper. My .22-250 might be getting to the end of its life, and this is what I found.
Click to expand...

rifle is a new x bolt 300 wsm, approx. 55 rnds thru it to date.
 
Every rifle is different, some more fussy than others. My .308 does'nt care much about seating depth, my .223 shot better when I lengthened the "jump" by 7 thou(from 3 thou to 10 thou), and my K hornet groups like a 12 gauge if the bullets are'nt actually touching the lands. I want to try single loading bullets in my lever action .32 win just out of curiosity to see if longer rounds shoot better.
There as lots of factors to play with like different powders/charges/bullets etc.
Once handloading really gets hold of you, it will fill your waking thoughts with striving for the most accurate load!
 
Pretty much agree with the above statements that each rifle is going to have its own preference but for hunting I keep bullets at least .020" off the lands to prevent a possible stuck bullet and powder dump which can spoil your day. :(
 
I agree with the above and there are alot of diff. gauge instruments being made to help one with this, including one from hornady(formerly stoney Pt.). I don't use these gadgets and I don't know how they work,for my cast bullet ACCURACY loads, I like the bullet as far into the rifling as possible. For hunting or field loads, esp. big bores, I seat bullets well out from the rifling, because, what can go wrong...will!!
 
One thing to keep in mind if you are loading "monolithic "bullets (Barnes bullets, Nosler ETip, Hornady GMX) - anecdotal evidence suggests that these bullets like to be seated far from the lands (e.g., Barnes recomends .080"-.030"; Nosler Etips .100"-.050", etc.).
 
So what happens when it is just not possible to get near the lands. My Stevens has a throat that is way to long to come close, at least with the 55 grainers I have. I have to load them to 2.370 to touch the lands, but when loaded at 2.37o the bullet is hardly in the case. I have loaded up a batch at 2.300 to see how they do.
 
Magazine length is often the limiting factor so you do what you can, also as a barrel wears the throat erodes to the point where the bullet is way back from the lands, usually accuracy suffers and sometimes not so much. My wife's Browning BLR 308 has a short magazine but shoots quite well so yours may do the same, good luck.
 
ben hunchak said:
I agree with the above and there are alot of diff. gauge instruments being made to help one with this, including one from hornady(formerly stoney Pt.). I don't use these gadgets and I don't know how they work,for my cast bullet ACCURACY loads, I like the bullet as far into the rifling as possible. For hunting or field loads, esp. big bores, I seat bullets well out from the rifling, because, what can go wrong...will!!
Click to expand...

I have the Stony Point gauges, headspace and bullet comparator, they are used with modified cases which you have to purchase seperately. They allow precise measurements. Go to Horady site as they have taken over Stony Point . I highly recommend.

One of the other posts mentions jump to lands, with my Rem 700 mtn rifle it is impossible to seat the bullet far enough to reach the lands,the throat is so long, however it still shoots well. Also the post about using the reloading manual for the bullet being used is sound as different manufactures ie Barnes suggest .050 as a starting point then .005 - .010 to find best accuracy.
 
I think this "close to the lands" concept is horribly over-rated as far as the average sporting rifle is concerned, and likely to cause more problems than benefits. I recently put a M-38 Swede through its paces - the throat was fairly worn - even 140 grainers would unseat before hitting the lands. However, the rifle shot 100 grain Hornady's into a nickel at 100y - the gap to the lands was more than a quarter inch.
At the other end of the scale, if you set your bullets very close to the lands (say 20 thou or less), you run the risk of jamming the bullets if:
- you use them in another rifle
- you buy another box of the same bullets (ogive profiles are not the same from lot to lot.)
- you are not reloading consistently/repeatably.

I like to shoot several rifles with a common load, with the intent of using the load for hunting or recreational target shooting. I do an assay of the rifles to see which one has the tightest leade and chamber (not necessarily the same rifle) and size the cartridge accordingly. I leave a 30 thou gap to the lands. You'd be shocked at the difference in freebore between commercial sporting rifles of the same caliber.
 
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