Finding the distance to the lands

[urban]

I've read several different techniques for finding the distance to the lands. I've not heard of anyone doing the following and I'm wondering why not.

I loaded some cases with the bullets protruding as far as I could manage. I then chambered a round. I was expecting, from what I had read, the bullet to be retained in the rifling. I intended to tap it out and then keep trying with shorter and shorter COAL until it just didn't get stuck in the rifling any more. What actually happened was that the bullet was pushed back in the case as I closed the bolt. I did it three times and the resulting COAL was very consistent. It seems to me that I've found the lands with sufficient precision at this point and doing anything more complicated is unecessary.

The rifle is a .223 Howa. I'm workiing up a load for PPU 75gr HPBT match bullets. I'm intending to use them for CSR competitions - which is not a discipline for which ultra-accurate rifles/loads are essential (although more accuracy is always good, obvs). I'm messing around with COAL because I've struggled to get anywhere near 1 MOA so far.

 

[Dazb1967]

I done very similar, Crimped the neck slightly on the case so the bullet wasn't too loose and worked fine for me. Bullet never got stuck in the rifle and stayed in the case.

 

[Cyres]

Next question is how far are you going to load off the lands?
D

 

[Tikkat1x]

why not just get a Hornady OAL gauge

 

[Tikkat1x]

also, if your struggling to get "anywhere near" 1 MOA, try a different bullet, weight, or powder, a different seating depth isn't guaranteed to solve your problem.

 

[Edinburgh Rifles]

I've read several different techniques for finding the distance to the lands. I've not heard of anyone doing the following and I'm wondering why not.

I loaded some cases with the bullets protruding as far as I could manage. I then chambered a round. I was expecting, from what I had read, the bullet to be retained in the rifling. I intended to tap it out and then keep trying with shorter and shorter COAL until it just didn't get stuck in the rifling any more. What actually happened was that the bullet was pushed back in the case as I closed the bolt. I did it three times and the resulting COAL was very consistent. It seems to me that I've found the lands with sufficient precision at this point and doing anything more complicated is unecessary.

The rifle is a .223 Howa. I'm workiing up a load for PPU 75gr HPBT match bullets. I'm intending to use them for CSR competitions - which is not a discipline for which ultra-accurate rifles/loads are essential (although more accuracy is always good, obvs). I'm messing around with COAL because I've struggled to get anywhere near 1 MOA so far.

One could argue you are running before you can walk if this is the case.... you can better than shooting factory ammo

I do not subscribe to land busting loads in factory rifles/chambers
They simply do not require it to be accurate
The variance between bullet ogives and calibres at that datum point is far larger than would allow for a consistent OAL
The tools being used to measure the thousands of an inch are not capable measuring the level of accuracy being claimed
The lands are not mystical horizon but several angular points that not only erode at different rates as you shoot, but using a bullet with variance in calibre/diameter and curve of the ogive, will intersect with one or more lands with differing pressure depending on bullet seating concentricity and how the round is chambered.

This the thing you measure when you want to explore turning a 0.3MOA group into a 0.1MOA group

Its not the thing you try to make a Howa shooting PPU into a Borden shooting Berger......IMO

 

[Dazb1967]

why not just get a Hornady OAL gauge

Why spend the money you really don't need one, I load for 2 calibers and you really don't need an OAL gauge, I used one for my 204 a few years ago when I paid to do a reloading development course because the guy had one, The method the OP mentions is simple and is about as basic as it comes, I have just developed a load for my 6.5CM using the OP method and it works and the difference in the seating depth made quite a bit difference in my rifle, But then again each to their own and whatever works

 

[Foxyboy43]

Sorry - don’t be rushing off to the patent office…
Traditional route is to saw the neck down to the shoulder and gently squeeze it so that it grips the bullet at minimum seating depth then do your chambering and measuring 5 times for consistency. Lots of this on SD if you check the Search facility.

 

[fizzbangwhallop]

I put a bit of a squeeze on the neck by pressing it against the table top, just enough to grip the bullet, insert the bullet long and then run a marker pen around the bullet where it joins the case.

If the bullet then gets left behind or slightly pulled back out by the lands on extraction, you’ll see where the ink has been rubbed off by the neck leaving you a reference line to push the bullet back in to and then measure.

Cheers

Fizz

 

[kenbro]

I put a bit of a squeeze on the neck by pressing it against the table top, just enough to grip the bullet, insert the bullet long and then run a marker pen around the bullet where it joins the case.

If the bullet then gets left behind or slightly pulled back out by the lands on extraction, you’ll see where the ink has been rubbed off by the neck leaving you a reference line to push the bullet back in to and then measure.

Cheers

Fizz

You don’t used a Vernier caliper?
Kb.

 

[fizzbangwhallop]

You don’t used a Vernier caliper?
Kb.

I do…. with a comparator for consistency throughout the reloading process as I’ve had variations in bullets between batches



Cheers,
Fizz

 

[lillico]

In my humble opinion, I think you're making thing difficult for yourself.
There are people who have commented above, who have a wealth of knowledge and are trying to steer you to an easy path.
Forget the lands; you could be chasing them forever.
Find a powder charge that will group at the same height (or nearly) below, (preferably) or above the point of aim for three, or, at least two groups. Use the standard OAL.
You can fine tune this powder charge later.
If you don't have access to one, you will need a decent set of Vernier's, as suggested above .
I found these to be superb and good value. They never loose their zero.
Mitutoyo 500-196-30 ABSOLUTE AOS Digimatic Caliper 0-150mm (0-6") - DML

Also a Comparator and holder.

Hornady LNL comparator body

Hornady LNL comparator body - B2000

www.mcavoyguns.co.uk

SINCLAIR INTERNATIONAL BULLET COMPARATOR INSERT, 22 CALIBER (0.224")

Sinclair Bullet Comparator Inserts offer precise ogive-to-base measurements, eliminating wobble and ensuring consistent results for 22 caliber bullets.

www.brownells.co.uk

Not vital, but I find the Wilson type seater die the easiest to use for OAL adjustments. Use your Vernier to measure from the top of the seater stem holder to the bottom of the stem.

Start at your max magazine length for your cartridge, as long as this doesn't produce a 'jam' in the lands. If it does, reduce OAL until clear.
Using two round groups, fire a series of groups (10-20) reducing the OAL by 0.600" ( 0.1524mm) between each two round group.
You are NOT trying to find the best group, you are excluding the bad groups.
Bad groups don't get tighter when you fire more rounds at them.
You should have some suitable candidates from your first test to explore.
Don't be surprised if some tight pairs from the first test suddenly open up to 30-50mm, discard them.
When, not if, you find a length which groups reliably, you could experiment with your powder charge again, two tenths up and two tenths down.
Unfortunately, I have to inform you at this point you are well down the 'rabbit hole' and may well end up losing friends and family. Like being captured by a cult.

 

[Twodogs]

I use the Loctite method. Take a case fired from the rifle in question, blob of Loctite in two places inside the neck case, insert the bullet long, wipe off any excess Loctite, insert by hand and close bolt. Leave for ten minutes. The Loctite will set and hey presto you have a round loaded to the lands.
I would suggest a low grade locking Loctite.

Do we actually need to establish the relationship between the lands and the ogive? Factory loaded ammunition does not know any particular ogive to land dimension.

 

[eldon]

In my humble opinion, I think you're making thing difficult for yourself.
There are people who have commented above, who have a wealth of knowledge and are trying to steer you to an easy path.
Forget the lands; you could be chasing them forever.
Find a powder charge that will group at the same height (or nearly) below, (preferably) or above the point of aim for three, or, at least two groups. Use the standard OAL.
You can fine tune this powder charge later.
If you don't have access to one, you will need a decent set of Vernier's, as suggested above .
I found these to be superb and good value. They never loose their zero.
Mitutoyo 500-196-30 ABSOLUTE AOS Digimatic Caliper 0-150mm (0-6") - DML

Also a Comparator and holder.

Hornady LNL comparator body

Hornady LNL comparator body - B2000

www.mcavoyguns.co.uk

SINCLAIR INTERNATIONAL BULLET COMPARATOR INSERT, 22 CALIBER (0.224")

Sinclair Bullet Comparator Inserts offer precise ogive-to-base measurements, eliminating wobble and ensuring consistent results for 22 caliber bullets.

www.brownells.co.uk

Not vital, but I find the Wilson type seater die the easiest to use for OAL adjustments. Use your Vernier to measure from the top of the seater stem holder to the bottom of the stem.

Start at your max magazine length for your cartridge, as long as this doesn't produce a 'jam' in the lands. If it does, reduce OAL until clear.
Using two round groups, fire a series of groups (10-20) reducing the OAL by 0.600" ( 0.1524mm) between each two round group.
You are NOT trying to find the best group, you are excluding the bad groups.
Bad groups don't get tighter when you fire more rounds at them.
You should have some suitable candidates from your first test to explore.
Don't be surprised if some tight pairs from the first test suddenly open up to 30-50mm, discard them.
When, not if, you find a length which groups reliably, you could experiment with your powder charge again, two tenths up and two tenths down.
Unfortunately, I have to inform you at this point you are well down the 'rabbit hole' and may well end up losing friends and family. Like being captured by a cult.

Note, I think he means 0.006" and not as stated.

 

[lillico]

Note, I think he means 0.006" and not as stated.

Yes, sorry about that. .006"

 

[Foxyboy43]

I use the Loctite method. Take a case fired from the rifle in question, blob of Loctite in two places inside the neck case, insert the bullet long, wipe off any excess Loctite, insert by hand and close bolt. Leave for ten minutes. The Loctite will set and hey presto you have a round loaded to the lands.
I would suggest a low grade locking Loctite.

Do we actually need to establish the relationship between the lands and the ogive? Factory loaded ammunition does not know any particular ogive to land dimension.

Hmm.
I would worry about a single insertion - I have used the sawn neck approach on many occasions and for many chamberings and have been surprised at the variations in measurements. Hence the recommended minimum of five measurements to confirm COAL. By all means then glue the two together….

 

[sauer]

 

[NullMac]

It seems to me that I've found the lands with sufficient precision at this point and doing anything more complicated is unecessary.

Yup people sell you stuff you don't need >> £1000 powder dispensers - never heard of a node?

I'm messing around with COAL because I've struggled to get anywhere near 1 MOA so far.

Happy for you to prove me wrong but with 223 if you are not getting <1 moa something fundamental is going wrong. I would be looking elsewhere.

 

[hybridfiat]

I used to chase the ultimate accuracy but 'kissing' the lands was the last thing on the list.
I used a fired case where the bullet slipped smoothly but not loosely and chambered it with the bullet out long.
The round when extracted was touching but not in the lands.
Measure and seat the batch 6 thou into the lands.
Fire one and check for pressure signs before shooting any more.
I don't think it makes a huge difference but it definately does tighten the group a fraction, plus adding uniformity to the loads.
Anyway it doesn't interest me now I just hunt.

Warning: Because placing the bullet in the lands impedes it's initial progress, pressures will jump.
If you are already at the pressure limits of your case and rifle, don't chase the lands.

 

[DVS1]

This I then generally start at 20thou from that measurement