How much do you set back your bullet to start with?

[Jayjay1]

Hey guys,
I use a Hornady gauge to measure when the bullets hit the lands.

Then I normally set the bullet 0.02" back and am testing powder charges.
When I have found the best charge, I begin to set the bullet back in steps of 0.01".

Lately I´m thinking 0.02" to start with is to less.

Is it?
Where do you start?

 

[Rhed]

First thing, does your rifle take a magazin?

 

[nn8734]

Hey guys,
I use a Hornady gauge to measure when the bullets hit the lands.

Then I normally set the bullet 0.02" back and am testing powder charges.
When I have found the best charge, I begin to set the bullet back in steps of 0.01".

Lately I´m thinking 0.02" to start with is to less.

Is it?
Where do you start?

.020” off is fine for a starting point for most modern projectiles; I also do seating depth trials in .010 increments out to .090 to .100” depending on bullet, etc…

What bullet are you using?

 

[Average guy]

I start at 20 for getting a charge weight. Then from 10 to 100. I will add that I look for a depth range with acceptable accuracy. This allows more rounds before I have to retune due to throat erosion.

 

[Ledzep]

Somewhere in the ballpark of .035 and .050 and I usually never touch seating depth again.

 

[Cr1775]

I start at book col and work up to the lands after i find my load but hell what do i know

 

[Jayjay1]

.020” off is fine for a starting point for most modern projectiles; I also do seating depth trials in .010 increments out to .090 to .100” depending on bullet, etc…

What bullet are you using?

.100"?

Wth!

Several bullets in several calibers.
223, 6.5 CM and 308 mainly.

My question was more in general.

Is there a rule, depending on the bullet or the caliber?

 

[Jayjay1]

I start at book col ....

What do you mean with that?

Reloading books?

 

[Cr1775]

What do you mean with that?

Reloading books?

Yes from mfg i have found that Sierra bullets like the jump in most cases being the closer to the lands the worse they shoot.

 

[Cr1775]

What do you mean with that?

Reloading books?

I use Hornady COL tool get starting data work up loads starting at book COL then work up to my charge weight and then work up to the lands for my COL. I have a few rifles that like it best at book COL. At the end of my shooting season i recheck my COL and if i think i should seat the bullets out further i do.

 

[OREGUN]

.020 back or maximum mag length if that’s limiting. Find charge, test lengths from touching to .035 back or so.

 

[308Gunner]

I also start at the rounds factory COAL, I have never had a problem finding a load that will shoot. I work on powder charge to find a load that groups okay and then run seating depth. I am usually done with load development in less than 40 rounds, with the caveat that I am not loading for bench rest. I find a load that is 1/2 MOA or better and shoot it.

 

[memtb]

Hey guys,
I use a Hornady gauge to measure when the bullets hit the lands.

Then I normally set the bullet 0.02" back and am testing powder charges.
When I have found the best charge, I begin to set the bullet back in steps of 0.01".

Lately I´m thinking 0.02" to start with is to less.

Is it?
Where do you start?

It depends upon the bullet. If a typical cup and core near the lands.....a very rough “rule of thumb” for myself: under .27 caliber, 0.001 to 0.003” - for 27 to upper 3’s ( .375, ect) 0.003 to 0.005” - for .40 cal and up 0.005 to 0.008”. This was given to me many years ago by an older gentleman that shot a lot of informal bench-rest competition.....it’s served me pretty well through the years.

If it’s a mono-bullet (Barnes), I generally start at around 0.030” off.....though Barnes actually suggests 0.050”! memtb

 

[nn8734]

.100"?

Wth!

Several bullets in several calibers.
223, 6.5 CM and 308 mainly.

My question was more in general.

Is there a rule, depending on the bullet or the caliber?

Generally, bullets with tangent and hybrid ogives like jump while VLD bullets like to be closer to the lands. Cartridge, caliber etc doesn’t matter.

I use all hybrid or tangent ogive bullets in my loads so I go with .020-.090/.100 range because I want to see the width of my seating depth node for any given one of those. For example, my 6.5 CM-130 Beger node is .040” wide. Groups are tightest from .040-.080 and started to open at .090”.

Don’t overthink or over complicate this part of the process, it’s really pretty simple. Do your seating depth testing and let the target tell you where your node is.

Lastly don’t act shocked when you see jump figures of .090+, it’s more common than you think. Chasing the lands is for old school VLDs, and is no longer necessary for today’s projectiles.

 

[spife7980]

I start .020 off. Usually I can find best accuracy .015 above or below that.
I have found it best when seated way far back but that’s only when I’ve let rl16 cake up ways too much in the throat. Clean it and it’s back to liking it up close.

 

[Lucky Se7en]

What level of confidence does everybody have in these Hornady gauges that rely on feel to measure the lands, especially when the measurements are this precise and the moving pieces aren't very smooth (the one for gas guns is especially bad)? I've moved backwards to 0.030" to give some more wiggle room. I'm not very confident that I can pinpoint exactly when the bullet starts touching the lands and there's really no good way to see what's going on in there.

 

[nn8734]

What level of confidence does everybody have in these Hornady gauges that rely on feel to measure the lands, especially when the measurements are this precise and the moving pieces aren't very smooth (the one for gas guns is especially bad)? I've moved backwards to 0.030" to give some more wiggle room. I'm not very confident that I can pinpoint exactly when the bullet starts touching the lands and there's really no good way to see what's going on in there.

It doesn’t have to be “ultra precise”. Won’t make any difference if you measure .030 with the Hornady gauge and you’re really .029 or .033 off.

If you really need your numbers to be refined as possible, Ogive-sort all your bullets then measure multiple times with a bullet from each sorted sub population and write it all down.

In most cases it’s not necessary to be this anal about it unless you’re a BR shooter.

 

[Holliday]

My VLD bullets both in 30 cal and 7 mm have liked .090” after using Berger’s testing method.

 

[Birddog6424]

Based on the bullet jump studies done by Cal Zant and Mark Gordon, I dont start anything at less than .050 anymore.

I'm jumping 85.5gr Hybrids at .060 after jumping the freebore out from .100 to .130". The bullet is well out into the neck, giving me more case capacity and adding 30 to 50fps to my very commonly used load without pressure.

I jump my DTACs in my 6GT at .070" after moving my freebore from .120 to .150.

Same result. Better velocity, less pressure, and the load shoots for the life of the barrel.

 

[Dthomas3523]

Based on the bullet jump studies done by Cal Zant and Mark Gordon, I dont start anything at less than .050 anymore.

I'm jumping 85.5gr Hybrids at .060 after jumping the freebore out from .100 to .130". The bullet is well out into the neck, giving me more case capacity and adding 30 to 50fps to my very commonly used load without pressure.

I jump my DTACs in my 6GT at .070" after moving my freebore from .120 to .150.

Same result. Better velocity, less pressure, and the load shoots for the life of the barrel.

If you’re seating the bullet further out (and thusly increasing the capacity), unless you change powder charge, you get less pressure and therefore less velocity.

When increasing capacity, you have to increase powder charge to increase velocity.

For reference:

Effects of Cartridge Over All Length (COAL) and Cartridge Base To Ogive (CBTO) - Part 1

Many shooters are not aware of the dramatic effects that bullet seating depth can have on the pressure and velocity generated by a rifle cartridge. COAL is also a variable that can be used to fine tune accuracy. It’s also an important consideration for rifles that need to feed rounds through a...

www.bergerbullets.com

 

[Birddog6424]

If you’re seating the bullet further out (and thusly increasing the capacity), unless you change powder charge, you get less pressure and therefore less velocity.

When increasing capacity, you have to increase powder charge to increase velocity.

For reference:

Effects of Cartridge Over All Length (COAL) and Cartridge Base To Ogive (CBTO) - Part 1

Many shooters are not aware of the dramatic effects that bullet seating depth can have on the pressure and velocity generated by a rifle cartridge. COAL is also a variable that can be used to fine tune accuracy. It’s also an important consideration for rifles that need to feed rounds through a...

www.bergerbullets.com

Faster barrel then.

I've had a 28" that liked 28.5grs, a 26" and 22" that both liked 29grs. They all started out at around 2970 to 2990fps. Those were all Hawk Hill 7" twist MTU.

This new barrel is a 26" Hawk Hill 7" twist War Heavy getting 3033fps at 29grs. Kinda interesting..

 

[Cardboard Assassin]

What level of confidence does everybody have in these Hornady gauges that rely on feel to measure the lands, especially when the measurements are this precise and the moving pieces aren't very smooth (the one for gas guns is especially bad)? I've moved backwards to 0.030" to give some more wiggle room. I'm not very confident that I can pinpoint exactly when the bullet starts touching the lands and there's really no good way to see what's going on in there.

I measure multiple times until I am happy that the measurement I get is repeatable.

 

[salks]

I have just recently switched to Hornady 130 ELD-m because it is what I could find. I had a good load using 130 VLD... anyway. I am .040 off the lands. It shoots great out 1100. Strangely enough the case OAL is 2.800 same as the Hornady manual.

 

[Jayjay1]

What level of confidence does everybody have in these Hornady gauges that rely on feel to measure the lands, especially when the measurements are this precise and the moving pieces aren't very smooth (the one for gas guns is especially bad)?

Well, yes, it is a kind of a "feel-thing".

I repeat the measurement several times, with different results, until I´m confident that I´ve got it.
Worked good for me.

 

[Jayjay1]

My VLD bullets both in 30 cal and 7 mm have liked .090” after using Berger’s testing method.

Berger´s testing method?
Can you please explain that or share a link?



@all:

Thanks so far, great thread with great infos.

 

[LR1845]

Berger´s testing method?
Can you please explain that or share a link?



@all:

Thanks so far, great thread with great infos.

Getting the Best Precision and Accuracy from VLD bullets in Your Rifle

VLD bullets are designed with a secant ogive. This ogive shape allows bullets to be more efficient in flight (retain more velocity = less drop and wind deflection). While this result is desirable for many rifle shooters the secant ogive on the VLD bullets produces another result in many rifle.

bergerbullets.com

 

[OkieMike]

I measure multiple times until I am happy that the measurement I get is repeatable.

Ditto. Once I get the same measurements (within .001-.002) 3 or 4 times in a row, I call that my number.

Mike

 

[Holliday]

Berger´s testing method?
Can you please explain that or share a link?



@all:

Thanks so far, great thread with great infos.

I see @LR1845 got you....

This is my preferred method for finding lands. I have not used my Hornady tool since trying this method.

 

[SDGator]

I've got a factory barrel, so I start at .02 back from what will fit in the magazine.

 

[Geaux tigers]

I start at .010 in or .020 out depending on the rifle (discipline) I’m shooting

 

[AzLRhunter]

Watch this video by Erik Cortina
Very helpful and a good simple explanation

 

[acudaowner]

I started with a slightly longer than factory length don't know if its a good way or not just happened to work out also somone else reloaded a few for me longer than factory they also shot nice his were base to ogive 2.218 I have since settled on a 2.215ish if I can get a 2.214 I am a happy camper and my gun seems to like it so it works out nicely I hand feed my ammo so no need for me to think about what will fit in the mag . best of luck to you .

 

[Im2bent]

Except he is chasing the lands just not calling it that.

 

[Shooting blanks]

I measured CBTO on factory Hornady 140 ELD-M for my 6.5 man bun and they were .070 off jam. They shoot great out of my gun. I loaded up the same bullet at the same distance off the lands but with StaBall 6.5 and they shoot better than the factory. They are 40fps slower than the factory ammo though.

 

[DH302]

In my 6br 95gr berger vld I'm running. 060 jump shoots in the ones . Try .20, .40,.60,.80 and see what happens. You just might be very surprised.

 

[MakeSawdust]

Except he is chasing the lands just not calling it that.

Anyone who got this from the video needs to watch it again. Chasing the lands is making the load .008" longer when the lands wear .008" to maintain a particular jump or jam. He is chasing the node. He specifically states that he will shoot a load for the life of the barrel if it continues to shoot well. I will ABSOLUTELY GUARANTEE that the lands do not stay the same for the life of the barrel.

Chasing throat erosion is a cluster fuck as most of the popular rounds for prs erode .004" to .008" per 100 rounds. Also, using a bullet to measure is going to have some issues as well because the shape/sharpness of everything in the throat will change as the round count grows. This will effect the measurement. I have tried chasing the lands. I changed from a load that shot good simply because my jump was growing. The gun shot like shit. I thought the barrel was done and in a last ditch effort I loaded the old load again. Guess what? The gun returned to shooting 1/2 moa. The point of his video is if the load shoots, don't fuck with it. Don't abandon a good load just because the jump went from .010" to .018".

I have heard absurd measurements about how much the lands move. I have heard people say they only got .004" of erosion after 1000's of rounds. It is measurement error. I have checked several barrels, as have others that have posted similar results. To get a good measurement you have to use a method that is consistent like the wheeler method or the Mark Gordon method as well as the same piece of brass and the same bullet. You also need to do so on a clean chamber/throat as verified with a borescope. It is an interesting experiment when you first do it. I stopped chasing the lands and went back to my old method (similar to Erik, but I tend to add powder to get velocity back if possible when things go to shit). Life is much simpler and there is a lot less fing around than when I chased the lands.

 

[RetiredChief]

As many have stated, I start at 0.02” from my Max seating for jacketed lead bullets and .05-> 0.06 inches for all Cu bullets. Find my best load, then adj seating to refine group.

My one exception – My Winchester Md 100 semi-auto the .02 inches was to long for the clip.Had to go with .04" to fit clip For a $150 brand new it was (and still is) a fantastic deer rifle up to 150 yards. 42.5 grs of 4064 behind a 180 gr Rnd nose bullet.

I do use the Hornady gauge, and as others pointed out, I look for 3 consistent readings.

Long Before that video – in fact before internet was a twinkle-in-the-eye, My method was to neck size a once fired case to the point that I could push the bullet in with my fingers and remove with fingers (Tight as possible but still insert/removable with fingers). Worked OK for me, and for the Win md 100 didn’t have to completely disassemble the rifle. I still do this for my bolt action rifles, without dissembling the bolt if I’m not comfortable with the Hornady tool reading. Keep in mind this is a WAG to find the starting point so ±0.005 is fine.