Chasing the lands is stupid...

[Wal86]

"After using a projectile to determine contact, take a good look at it. Usually there will be a small dented ring mark."

There should never be a "small dented ring mark" left on the projectile IMO.....

[Gyro]

There will be Wal86. Lapping the nose cone on the seating die with the projectile being used will grow the contacting surface area though and help with that.

[Wal86]

Gyro,

Sorry, i may of interpreted Peter Smith post incorrectly.

Is the ring from the seating die stem after seating or are the marks left on the projectile from the lead/throat after checking seating depth? Either of the outcomes are not desirable..
(Must be running some serious neck tension)

[PeteFox]

"After using a projectile to determine contact, take a good look at it. Usually there will be a small dented ring mark."

There should never be a "small dented ring mark" left on the projectile IMO.....

I have used EC’s method for a few months now. I run a mandrel through a case, seat a bullet a bit long, apply wax and chamber it. I can see marks where the lands contact the bullet but no denting.
I preserve this blank round as a gauge to adjust my seating die to. I have one for every rifle/bullet type I shoot.
I put the “gauge” into my die, screw the seater stem down till it just contacts, remove gauge and screw the stem in an additional 0.020”. I don’t know whether this gives me 20 thou jump or some other number, doesn't matter, it’s the consistency that matters.
Since doing this my groups have shrunk to the extent that I've given up thinking my eyes were the issue, or my technique was crap. Perhaps it’s still crap, doesn’t matter the target talks.
Prior to this I was using a hornady gauge but I couldn’t get consistent measurements, now there’s no measuring, just adjusting the die.
Pete

[pjifl]

The small dented ring I mentioned is from contact with the lands. If you can do all of this with very little force it will not be there but it only takes a bit more force to cause it. Ironically, once this happens, contact will then be more consistent.

All of this adds to the uncertainty - the measurement reading is 'in the hands of the operator'.

Peter Smith.

[Wal86]

Each to there own, but there shouldn't be a "dented ring mark" left on the projectile after checking seating depth.. Any photos of this ring you can share? Just curious

Ill add to the discussion, my starting seating depth is on the lands so the projectile pushes back into the case .0005" to .001"

Cheers

[GSells]

Each to there own, but there shouldn't be a "dented ring mark" left on the projectile after checking seating depth.. Any photos of this ring you can share? Just curious

Ill add to the discussion, my starting seating depth is on the lands so the projectile pushes back into the case .0005" to .001"

Cheers

Sorry I know I said before that was my last comment. But I just want to try and help here if I can ?
Ok I do the same method as Peter . So maybe not a ring but a land mark , that you can just see with a good set of glasses if your eyes are starting to go like mine . Even having a magnifying glass helps establish a “ Zero land point “ . Again repeatability depends on learnt skill of the operator . So for me I’m looking for a slight land mark on the ogive and that for me is zero .

Hope that helps ? Regards Graham.
Ps.
Also where I live conditions are always pretty much rough all the time ( there never has been a rooster shot at Dalby in scoped rifle since I’ve been there 2012! ) . I do my testing at 100 m on group shapes and chrony figures . Followed by testing at 600 yds which isn’t ideal but does give an indication of how a round may shoot at long range . But better test at 600 yds in rough conditions than none at all . Because testing in rough conditions at 900 plus is in my opinion nearly a waste of time and premium rounds and barrels .

[bruce moulds]

using the hornady tool, i have never seen a ring on a bullet.
the same holds for a case with slits cut in the neck.
trouble with the slitted case is that you are not sure that the bullet is up against the lands.
i question the ring on the bullet, compared to land marks.
could the chamber dimensions be worth looking at.?
or are we talking about a ring where the seater stem contacts the bullet.
if you want rifling marks to show more clearly, scraping the bullet radially with 0000 steel wool will help.
even then, using a hornady tool should not show any marks if you don't push hard.
when i used 6.5/284, throats disappeared fast.
the only reason i use a straight 284 is for this reason.
12 6.5 barrels taught me that with that cartridge i had to seat bullet out 0.002 longer about every 25 rounds to maintain consistent relationship of bullet to lands.
while this rule of thumb worked well, it still paid to check measure every 100 rds or so.
part of that throat wear came from fast shooting.
another guy used ar2214 and got less throat wear even though he shot fast, but i could never get that powder to perform as well as 2209.
for me chasing the lands has always proven to be of advantage.
knowing this can prevent an unexpected waste of time in the middle of a queens.
bruce.
edit to say.
i remember being in a shootoff for the sara queens with alan frazer and richard braund during a soft seating period. ( the last ever )
i chambered a round prior to the order, and decided to unload.
just as i did this the order cme, and i had locking lug recesses full of 2209.
i had to run back to my gear while the other guys were shooting, and managed to clear the gun.
luckily i had a fast marker, and managed to machine gun all my rounds just in time.
alan won that shoot deservedly.
while safety is the first priority with ammunition, reliability is second.
chasing accuracy at the expense of these two is futile.
bruce.

[John T]

An American view.
www.longrangehunting.com/chasing-the-lands. See #10 J E Custom.
Remember that this is a hunting forum.

[John T]

Bruce.

Using the traditional method of dummy loading and chambering to check engagement; after extracting the dummy you would eagerly count the land marks. (6) clear land marks was joy. Of course, this occurred in near-new barrels only. The "joy" came from the knowledge that you had quite positive contact. As a (lazy) jumper, I would increase the depth and take the punt that I would get 5 or 6 new but fainter land marks and continue until there were none. This almost never worked all the way and I had to load a new dummy or two. Bugger!
In a wearing throat, land marks were often joined by a ring. The worse the wear the less were the land marks and the more obvious the ring. I always thought the rotation of extraction contributed to this ring. Remember that these dummies were loaded in cases with my normal neck tension.

Different things happen when you use a Stoneypoint or similar. Firstly, the bullet is floating, there is no hold on it, just as there is very little hold on the bullet at the start of seating. We know that if we have a firm neck tension, the stem cone will leave a mark because the cone is really forcing the bullet into the neck. The mark is circular, same as the cone.

With the Stoneypoint, the throat is the "cone". If the bullet is forced into the throat, there will be a "cone" ring. I suspect there is another contributor to the ring. No throat wares evenly. The bullet, under forward pressure, engages Wheeler's last point, and does what? It rotates away from that resistance, strikes the second to last, and rotates some more, whichever way. Like the extraction, a ring is being engraved.

This happens every time a bullet is forced into the throat. Once it is engraved, it is pointless to use that same bullet again. To do so will produce false results. If you don't get this, re-read Peter's many comments.

Regards,
John T.
24.7.20

[John T]

Results of some Stony Point testing.
Bullet, 183 SMK. Batched by weight and bearing surface. New bullet for each test.
Barrel STD 158. Major clean, finish, bore clean and polish with Flitz.
RCBS Trigger Pull Gauge delivered the "push".
One test case was used, necked sized for each test.
Measurement of case head to ogive was by dial vernier with bushes; asses in relativity.
2.0 lb ...42
2.5 lb ...40
3.0 lb ...40
3.5 lb ...43
4.0 lb ...43
4.5 lb ...40
5.0 lb ...38.

Regards,
John T.
3.8.20

[Rich4]

Though I use the stoney point for convenience mostly, with a consistent technique I take an average of 3-5 measurements, their usually pretty consistent however I’m only getting a starting point, the most consistent method I’ve used I got from Greg Dykstra which is to remove all the hardware from your bolt and progressively seat a bullet and test like a headspace gauge, but it’s still only a starting point for testing

[willow]

Part 2 of Eric's explanation for those who are interested:

https://www.youtube.com/watch?v=9FKq8Jj8YEI

[Gyro]

Had a look and if we don't know what he's on about by now we never will haha.