Seating into the lands

[corbin9191]

Well lately I have been experimenting with the 168 grain berger target VLD in my 7mm wsm. I have been reading a lot about the seating depths and everyone is getting their best groups seating the bullet into the lands. Well I tried the test that Berger says to do with their bullets. And I found that seating the bullet at 3.006 inches gave the best group. the group was .735 inches at 100 yards. The load consist of 70 grains of H Retumbo and a 168 grain berger Match VLD bullet, winchester brass and a CCI-BR2 primer. That bullet is seated quite a ways away from the rifling's. So my question is how can I tell exactly how far that bullet is seated into the lands? Thank you

 

[Desert Fox]

By using this tool:

http://www.sinclairintl.com/product/104 ... -Tools-OAL

you need a dummy round though.

 

[RiverRider]

Another way is to use a case with a split neck. Take one of the bullets in question and start it into the split-neck case, then chamber it in your rifle. If the bullet profile and the way the chamber is cut allow it, the lands will seat the bullet. Then *carefully* extract the case and measure its OAL. Do this several times to check for consistent results. Once you are satisfied that the extracted case and bullet represent zero distance to the lands, you can use your OAL measurement FOR THAT ONE, INDIVIDUAL BULLET as a reference. What this means is that the difference between the zero-to-lands OAL and the OAL you get off your press with your seater die set up with THAT ONE INDIVIDUAL BULLET represents how far from the lands you are.

The split-neck case needs to allow the bullet to easily seat, yet hold the bullet well enough to get consistent OAL measurements. The gadget is unnecessary.

 

[1Shot]

Over on longrangehunting.com in the reloading section they have information from Berger that tells they have now found that their bullets shoot really well waaaaay off the lands. I had also found this kind of by accident. I wanted to use their 30 cal 155 VLD in my 30X47 HBR for hunting so I loaded the bullet to the length that would work through the magazine. It is 35 thousands off the lands and it would put them in the same hole at 100 yards.
I use the split case method. Take a case and FL size it. Take a cutting tool and cut a line from the case mouth down to the shoulder on one side of the neck. Before each use size the neck of the case so it will hold the bullet well but still allow the bullet to be pushed back into the case by the rifling.

 

[JD338]

The concern of putting a bullet into the lands is that you could unload your rifle and end up with a bullet pulled out of the case and stuck in the bore.

Not an ideal situation if you are hunting.

JD338

 

[Antelope_Sniper]

The concern of putting a bullet into the lands is that you could unload your rifle and end up with a bullet pulled out of the case and stuck in the bore.

Been there....Done that.....And then you mash the bullet in even further with the next live round, because you can't figure out why it won't chamber. :shock:

 

[corbin9191]

The only time that I will have a bullet in the chamber when I am out hunting is when I am sure That I am going to take the shot. So I shouldn't have to worry about having to eject the live round out of the chamber when I am out in the field. But what I am hearing is that I should just stick with the load and seating depth that I have right now and just try to tune that and not worry about seating the bullet into the land. For tuning the load what procces should I use? the powder that I am getting these groups with is H Retumbo. Should I just play with the seating depth in .005 increments first and then try the the charge of powder?

 

[rick smith]

If you are happy with your groups and the round functions through the magazine, leave it alone. I don't seat into the lands for any of my hunting rounds. Sooner or later you will stick a bullet and dump powder into the action which puts the rifle out of service until you can get all the powder and bullet removed.Rick.

 

[JD338]

If you are happy with your groups and the round functions through the magazine, leave it alone. I don't seat into the lands for any of my hunting rounds. Sooner or later you will stick a bullet and dump powder into the action which puts the rifle out of service until you can get all the powder and bullet removed.Rick.

Murphy's Law,
It will happen at the worst possible time too. :wink:


Play it safe and keep the bullets off the lands.

JD338

 

[corbin9191]

Ok, I will keep the bullets off the lands and just fine tune either the powder charge, or seating depth by .005 inches either way I have to go, (I have a long ways before I get close to the lands at the seating depth that I am at right now). I would like to see the groups shrink a lot more than what they are shooting right now so I can use this load for a farther distance and be more accurate.

 

[Big Squeeze]

Well lately I have been experimenting with the 168 grain berger target VLD in my 7mm wsm. I have been reading a lot about the seating depths and everyone is getting their best groups seating the bullet into the lands. Well I tried the test that Berger says to do with their bullets. And I found that seating the bullet at 3.006 inches gave the best group. the group was .735 inches at 100 yards. The load consist of 70 grains of H Retumbo and a 168 grain berger Match VLD bullet, winchester brass and a CCI-BR2 primer. That bullet is seated quite a ways away from the rifling's. So my question is how can I tell exactly how far that bullet is seated into the lands? Thank you

.....................Are you doing hunting loads or range loads? Isn`t 3.006" COAL too long for your magazine? At 3.006" you`re still quite aways from the lands?

Seating to or into the lands is ok for range loads, but not for hunting.

For hunting loads along with more bullet jump, you will probably need to experiment with more powders other than just the Retumbo to achieve good accuracy.

Try a somewhat faster burning powder. Retumbo imo, is a little too slow for the 7 wsm.

 

[Richracer1]

Well lately I have been experimenting with the 168 grain berger target VLD in my 7mm wsm. I have been reading a lot about the seating depths and everyone is getting their best groups seating the bullet into the lands. Well I tried the test that Berger says to do with their bullets. And I found that seating the bullet at 3.006 inches gave the best group. the group was .735 inches at 100 yards. The load consist of 70 grains of H Retumbo and a 168 grain berger Match VLD bullet, winchester brass and a CCI-BR2 primer. That bullet is seated quite a ways away from the rifling's. So my question is how can I tell exactly how far that bullet is seated into the lands? Thank you

.....................Are you doing hunting loads or range loads? Isn`t 3.006" COAL too long for your magazine? At 3.006" you`re still quite aways from the lands?

Seating to or into the lands is ok for range loads, but not for hunting.

For hunting loads along with more bullet jump, you will probably need to experiment with more powders other than just the Retumbo to achieve good accuracy.

Try a somewhat faster burning powder. Retumbo imo, is a little too slow for the 7 wsm.

Sorry, but Retumbo is listed by Hodgdon and usually gave them the highest velocity in the 270WSM & 7MMWSM. It works do to the overbore nature of that big fat case and the little 270 & 7mm bullets. 300WSM uses the slightly faster 4350, 4831 powders.

 

[corbin9191]

Well lately I have been experimenting with the 168 grain berger target VLD in my 7mm wsm. I have been reading a lot about the seating depths and everyone is getting their best groups seating the bullet into the lands. Well I tried the test that Berger says to do with their bullets. And I found that seating the bullet at 3.006 inches gave the best group. the group was .735 inches at 100 yards. The load consist of 70 grains of H Retumbo and a 168 grain berger Match VLD bullet, winchester brass and a CCI-BR2 primer. That bullet is seated quite a ways away from the rifling's. So my question is how can I tell exactly how far that bullet is seated into the lands? Thank you

.....................Are you doing hunting loads or range loads? Isn`t 3.006" COAL too long for your magazine? At 3.006" you`re still quite aways from the lands?

Seating to or into the lands is ok for range loads, but not for hunting.

For hunting loads along with more bullet jump, you will probably need to experiment with more powders other than just the Retumbo to achieve good accuracy.

Try a somewhat faster burning powder. Retumbo imo, is a little too slow for the 7 wsm.

3.006 inches will fit into my magazine very nicely. These bullets are going to be used for hunting. My magazine will allow the bullet to be a COAL of 3.045 inches.

 

[Big Squeeze]

Well lately I have been experimenting with the 168 grain berger target VLD in my 7mm wsm. I have been reading a lot about the seating depths and everyone is getting their best groups seating the bullet into the lands. Well I tried the test that Berger says to do with their bullets. And I found that seating the bullet at 3.006 inches gave the best group. the group was .735 inches at 100 yards. The load consist of 70 grains of H Retumbo and a 168 grain berger Match VLD bullet, winchester brass and a CCI-BR2 primer. That bullet is seated quite a ways away from the rifling's. So my question is how can I tell exactly how far that bullet is seated into the lands? Thank you

.....................Are you doing hunting loads or range loads? Isn`t 3.006" COAL too long for your magazine? At 3.006" you`re still quite aways from the lands?

Seating to or into the lands is ok for range loads, but not for hunting.

For hunting loads along with more bullet jump, you will probably need to experiment with more powders other than just the Retumbo to achieve good accuracy.

Try a somewhat faster burning powder. Retumbo imo, is a little too slow for the 7 wsm.

Sorry, but Retumbo is listed by Hodgdon and usually gave them the highest velocity in the 270WSM & 7MMWSM. It works do to the overbore nature of that big fat case and the little 270 & 7mm bullets. 300WSM uses the slightly faster 4350, 4831 powders.

.....................Sorry? But not so fast there!... :lol:

Hmmmm!........ Looking in my `08 Hodgdon manual now and I see something interesting.

Yes! Retumbo is at the top of the list in the velocity dept for the 7 WSM using 70.0 gr behind a 168 gr Sierra HPBT @ 2921 fps. 24" barrel.

How abouts the 65.8 gr of IMR 7828 that`s also listed? Same bullet, same speed at 2921 fps.

Maybe 62.0 of IMR 4350 too? Again, the same bullet but at 2907 fps.

63.0 gr H 4831 as well? Whooops! That`s only 2892 fps!

If Retumbo works, then great! But depending on the individual rifle, sometimes the slightly faster burns can offer better accuracy with a slight increase in bullet jump, which was the reason I suggested the slightly faster burning powders.

Sorry!..... :wink:

 

[Big Squeeze]

Well lately I have been experimenting with the 168 grain berger target VLD in my 7mm wsm. I have been reading a lot about the seating depths and everyone is getting their best groups seating the bullet into the lands. Well I tried the test that Berger says to do with their bullets. And I found that seating the bullet at 3.006 inches gave the best group. the group was .735 inches at 100 yards. The load consist of 70 grains of H Retumbo and a 168 grain berger Match VLD bullet, winchester brass and a CCI-BR2 primer. That bullet is seated quite a ways away from the rifling's. So my question is how can I tell exactly how far that bullet is seated into the lands? Thank you

.....................Are you doing hunting loads or range loads? Isn`t 3.006" COAL too long for your magazine? At 3.006" you`re still quite aways from the lands?

Seating to or into the lands is ok for range loads, but not for hunting.

For hunting loads along with more bullet jump, you will probably need to experiment with more powders other than just the Retumbo to achieve good accuracy.

Try a somewhat faster burning powder. Retumbo imo, is a little too slow for the 7 wsm.

3.006 inches will fit into my magazine very nicely. These bullets are going to be used for hunting. My magazine will allow the bullet to be a COAL of 3.045 inches.

.............That`s good then! The magazine in my 300 WSM Ruger is only 2.920" long. The max COAL I use is 2.900" for the 168 VLD. Thought that maybe your 3.006" in COAL may not work in your magazine for hunting.

 

[roysclockgun]

I don't like to risk too high pressure by seating against the lands. Seating just off the lands works for me. The way that I find the OAL that touches the lands and is therefore too long for my liking, is to seat the bullet long and coat the bullet with the ink from a fiber tipped pen. Then try to chamber the round. (Use a new case, or a re-sized case that has been correctly trimmed. I use one with no propellant or primer!) On your first attempts, when the bolt meets resistance, stop and remove the test cartridge. You will see marks in the ink, where the bullet made contact with the lands. Seat deeper and try, until the bolt closes with no effort. Again, use ink to see if the bullet is making contact with the lands. Trial and error with give you the precise OAL where the bullet is just touching the lands. When you determine that OAL where contact is made with the lands, but no resistance is felt when closing the bolt, record that OAL as the length where contact with the lands is made. You should then shorten the OAL by .005" and try the ink test once more. If no marks from the lands show up, you can assume that you are now .005" off the lands. Try that length. Also try some other lengths, getting off the lands in .005" increments. You will hit a "sweet" spot in the OAL, where you get the best groups. Being off by .005" is not a magic spot, but only a reference point. All rifles will like a different OAL to shoot best.
If your "sweet" spot creates an OAL that prevents your rifle from feeding from the mag, because cartridges are too long, you then have another decision to make. I am using a falling block action, so I do not have feed problems with too long OAL. With magazine rifles, the only time that I have found that my long cartridges will not work in my mag, is when I was loading for military bolt rifles, that historically have "generous" chambers. Commercial rifles have worked fine with the longer OAL.
Steven A.