Seating VLD and AMAX bullets

DsrtRat

DsrtRat

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Just tried some 75gr AMAX bullets out of my 8 twist tikka .223. I seated them with a .030 jump. They performed OK but I had better results at long range in the wind with the 65gr sierra (which have a much worse BC).

Anyhow, it was my first time shooting them. Are these bullets (VLD/amax) designed to be seated just off the lands for best results?
 
I know Berger VLD's work best .015-.020 into the lands.
Try seating just at the lands, .010 in and .010 out and see which starts to shrink the group, you should get a good idea with a couple of 5 round shots of each.

I would try these at 200 as it will give a better indication of group growing/shrinking.
 
A bullet isn't designed with seating depth in mind, plus it would be a futile exercise as your barrel will tell you what it likes upon load development. Some bullets are definitely more tolerant, take the .30cal 155gr SMK for example, I've shot it from a .060" jump to a .010" jam and it shot the same size groups, it just didn't care. If your happy with your results at your current powder charge, finding the best seating depth usually shows itself pretty quickly with a few groups.
 
CyaN1de said:
I know Berger VLD's work best .015-.020 into the lands.
Try seating just at the lands, .010 in and .010 out and see which starts to shrink the group, you should get a good idea with a couple of 5 round shots of each.

I would try these at 200 as it will give a better indication of group growing/shrinking.
Click to expand...

For my .308 and .223 I usually jam VLDs and at the lands or a bit into with A-max
 
Keep this in mind:

You can use factory reference loads for reg OAL, then seat the bullet further out without any issues though. Just dont seat it more IN with a max load. (probably not happening alot anyway, but still)

Be aware that, as you load your cartridge progressively shorter, putting the bullet deeper into the case, you will be reducing the effective case capacity dramatically. With smaller cases, such as the .223 Rem and 6mmBR, moving from .010″ into the lands to .080″ and .120″ off the lands can CAUSE a dramatic pressure rise. So, a load .010″ into the lands that may be safe can be WAY OVERPRESSURE with the bullet seated .120″ off the lands (i.e. .130″ deeper in the case, the difference between .010″ in and .120″ out).
 
Does seating it closer to the lands decrease the chance of the bullet starting into the rifling crooked or is that strictly a function of runout?
 
seating it closer to the lands INCREASES THE CHANCES OF IT starting into the lands straight, think about it, there is less room (albeit small) for it to be off center by the brass or runout of the dies to take effect upon exiting the brass,
that is why some people jam it into the lnads to straighten out the error of the tolerances of the loading equipment, I prefer to just chase the lands and touch them gently (such that one is able) and that way the bullet does not stick or be pushed back into the case but merely it placed into position carefully and gently and hopefully properly.
Jefferson
 
In general, the difference in actual distance on an offer the lands for a precision rifle is like a couple of sheets of paper. Not much either way.

I much prefer to be OFF the lands so there is no risk of leaving a bullet stuck if I have to extract the case due to a cease fire - they do happen.

If my load is just on the lands, I make sure a stuck bullet is not in the cards.

I sincerely doubt a few thou jam can change the location of any bullet relative to the bore. Think of how little force you put on that bolt to close. Now push a bullet on a table and see how much force it takes to move it laterally.

Best to just have the bullet seated straight in the first place and that requires good dies

And proper loading technique.

Careful weighing of your charge will have a greater affect on your load tuning then a few thou of bullet location ever will.

Jerry
 
Kryogen said:
Keep this in mind:

You can use factory reference loads for reg OAL, then seat the bullet further out without any issues though. Just dont seat it more IN with a max load. (probably not happening alot anyway, but still)

Be aware that, as you load your cartridge progressively shorter, putting the bullet deeper into the case, you will be reducing the effective case capacity dramatically. With smaller cases, such as the .223 Rem and 6mmBR, moving from .010″ into the lands to .080″ and .120″ off the lands can CAUSE a dramatic pressure rise. So, a load .010″ into the lands that may be safe can be WAY OVERPRESSURE with the bullet seated .120″ off the lands (i.e. .130″ deeper in the case, the difference between .010″ in and .120″ out).
Click to expand...

Actually, according to John Barsness and the pressure labs that he's worked with, the bullet's proximity to the lands is a larger determinant in chamber pressure than is the minor fluctuation in case capacity caused by different bullet seating depths. So, unless you're severely compressing a charge, seating the bullet deeper will decrease pressure, and jamming the bullet into the lands will increase pressure.
 
I like to seat the A-Max so it's just touching the lands, in my rifles. I tend to get some pretty good results with the COAL set up this way. The VLD tends to do better for me when it's a little bit off the lands (0.010-0.015", or so).
 
Jerry,

Reading your article, you mention the best group slook like a football with very little vertical. Is that because between nodes when the barrel whip is at it's highest, the movement is up and down?
 
DsrtRat said:
Jerry,

Reading your article, you mention the best group slook like a football with very little vertical. Is that because between nodes when the barrel whip is at it's highest, the movement is up and down?
Click to expand...

Couldn't tell you what position the barrel is in and honestly, doesnt matter.

The key is keeping the powder charges between cases very tight.

Jerry
 
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