# Reloading accuracy "jam the lands"??



## Huge29 (Sep 17, 2007)

I have just begun reloading a few months ago and picked the brain of many on here, thanks again to the many who have helped!
I have read very little of the Berger Bullets on here, my primary source of info, but I have heard from numerous people how much they love Berger Bullets including neighbors and gun counter guys. In researching these, I came upon the Berger site (http://www.bergerbullets.com/information/) and I would like to better understand what this "jam the lands" reference means:


> The VLD bullet design is a combination of two very specific features. The first is a boat tail which is common on long and heavy bullets. The second and most important design feature is the long secant ogive. It is this ogive shape that allows the bullet to experience less drag as it flies to the target. This reduced drag is how the VLD shoots flatter and is less affected by wind (less drift) than other bullets. Reduced drag also translates into higher retained velocity. These are important results if you want your bullet to help improve your accuracy by requiring less sight adjustments when conditions change.
> 
> For years we have relayed that *it is best to jam the VLD into the lands for best performance*. This works for many rifles however there are many rifles that do not shoot the VLD well when the bullet is jammed. We have learned that the VLD can shoot best as much as .150 jump off the rifling. VLD bullets can be sensitive to seating depth and it has been found that these bullets shoot best in a COAL "sweet spot". This sweet spot is a COAL range that is usually .030 to .040 wide.
> 
> The quickest way to find this sweet spot is to load ammo at four different COAL. Start with a COAL that allows the bullet to touch the rifling. The next COAL needs to be .040 off the lands. The third COAL needs to be .080 off the lands. The last COAL needs to be .120 off the lands. One of these COAL will outperform the other three by a considerable margin. It has been reported that the VLD bullets don't group as well at 100 yards but get better as the bullet "goes to sleep" at further ranges. We have learned that by doing the four COAL test you will find a COAL where the VLD bullets will group well at 100 yards. Once the COAL that shoots best is established you can tweak +/- .005 or .010 to increase precision or you can adjust powder charges and other load variables. Frankly, those who do the four COAL test usually are happy with the results they get from this test alone.


Is this as simple as measuring the COAL before chambering and if it is shorter after chambering then it was too long and his new shorter COAL is where the load is jammed? What are your experiences with this? Any other related info would be appreciated. I am just eating up all of this info, thanks guys!


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## sagebrush (Sep 8, 2007)

there are numerous ways to to find out how far you can seat your bullets. I'll let you you do the searching yourself, once you find this out take that measurment and the recommened length for your caliber, and go from there. on my experience with the berger bullets is my rifle likes them at the coal recommened for my caliber which is the 300 win mag. jamming in the lands is just that, but as they stated it is best not to do this.


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## Squigie (Aug 4, 2012)

Seating the bullet into the lands is the most reliable method for creating consistent start pressures.
Since consistent start pressures can be argued to be one of the most important factors in extreme accuracy, it's a rather important consideration.

In addition, some long range shooters have shown that jamming bullets into the lands can help eliminate some of the undesirable affects of having a sloppy chamber. By jamming the bullet into the lands, it centers the neck in the chamber, and aligns the bullet better.

HOWEVER - 
Most rifles do not have magazines long enough to accommodate an OAL that has the bullet jammed into the lands - especially with VLD type bullets. So, you have to single-load, or let neck tension and bullet jump to the lands determine your start pressure.

I load a few Berger bullets in 6mm and .30 caliber. None of the .30s are in the lands, most are 0.120" to 0.150" off. None of the 6mms are in the lands. The 80 gr 'Varmint' LDHP (low drag HP) is the closest at 0.020" off the lands, but still isn't touching. (I also load Swift Scirocco IIs, another VLD bullet, and none of them are in the lands.)
All of them have a jump, because I load _everything_ to feed and cycle reliably in the magazine(s).

Bergers are very consistent bullets. But, don't let all the hype about terminal performance get into your head, until you try one yourself (if you're considering hunting with them). Even the 'Hunting' versions of Berger bullets are extremely fragile. They grenade inside the animal, like a time-delayed V-Max. It's great, if the bullet is in the right spot; but an absolute disaster, with improper placement.


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## Cooky (Apr 25, 2011)

Jamming a bullet into the lands works well as an impromptu bullet puller if you extract the cartridge without firing it. The powder all down inside the action is wasted though.


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## longbow (Mar 31, 2009)

I jam in a couple of my guns but they are target guns. One has as little as ~.0015 neck tension. That's pretty light. I nearly always leave my bullet in the lands if I don't shoot. I have jammed into the lands on hunting rifles but they typically have .005+ neck tension. That's a pretty tight neck.
I wouldn't jam into the lands right now. I'd work up a load the way Brian at Berger recommends. 
With the Berger's secant ogive, you might not have enough bullet seated in your neck once you touch the lands. Just something to think about


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## paddler (Jul 17, 2009)

How are you guys measuring COAL?


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## Cooky (Apr 25, 2011)

viewtopic.php?f=15&t=36582


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## Huge29 (Sep 17, 2007)

I finally got a reply for the reloading data from Berger, very nice gentleman! I was not aware of Berger having their own load manual as I have not seen them anywhere. The Berger said that you are all mistaken and to jam the lands, just kidding! I did not realize that there are three different "4350" powders, I was not aware of AA4350. This is the only data I have seen in which they did not designate a most accurate powder or most accurate powder amount.


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## paddler (Jul 17, 2009)

I have a comparator system that uses a cleaning rod with spacers to measure the difference between the bullet tip and the bolt face, then the comparator to determine COAL. It's quite simple. I think it's a Forster product, but I bought it ~20 years ago. Anybody have one of these?


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## DallanC (Jan 13, 2009)

You all that "jam the bullet into the lands" better make darn sure you are marking those bullets to fit a specific rifle. I'd hate to see a buddy with the same caliber gun try to borrow some ammo in the field and shoot it, or you mistakenly use it in a different gun you own of the same caliber.


-DallanC


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## longbow (Mar 31, 2009)

Huge29 said:


> I finally got a reply for the reloading data from Berger, very nice gentleman! I was not aware of Berger having their own load manual as I have not seen them anywhere. The Berger said that you are all mistaken and to jam the lands, just kidding! I did not realize that there are three different "4350" powders, I was not aware of AA4350. This is the only data I have seen in which they did not designate a most accurate powder or most accurate powder amount.


I'd save that email. Walt Berger makes a point of answering all his reloading data emails. Lisa and I had the great pleasure of meeting and shooting against him and his wife Eunis at a shoot in Arizona. They seemed more concerned with us doing well than thenselves. Good, good people.

I've used all three 4350 powders. I keep records of all my loads and all 4350 loads show that they are extreemly simular. H4350 being the most slightly temperature stable. However, stick with published reloading data for each.


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## longbow (Mar 31, 2009)

DallanC said:


> You all that "jam the bullet into the lands" better make darn sure you are marking those bullets to fit a specific rifle. I'd hate to see a buddy with the same caliber gun try to borrow some ammo in the field and shoot it, or you mistakenly use it in a different gun you own of the same caliber.
> 
> -DallanC


Glad you brought that up Dallan. Throat lenght has a lot to do with pressures.


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## Squigie (Aug 4, 2012)

Huge29 said:


> I finally got a reply for the reloading data from Berger, very nice gentleman! I was not aware of Berger having their own load manual as I have not seen them anywhere. The Berger said that you are all mistaken and to jam the lands, just kidding! I did not realize that there are three different "4350" powders, I was not aware of AA4350. This is the only data I have seen in which they did not designate a most accurate powder or most accurate powder amount.


AA4350 is pretty decent.

I use it in .30-06, 7.62x54R, and something else (.30-40 Krag, maybe)...

IMR4350 has its place, but I've come to like the Accurate version more for the loads in which I've run the two powders head-to-head. 
(I haven't used H4350 in a very long time.)


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