"how to find your lands exactly"

[260 Rem]

For those who may be interested, google the thread title and watch the Wheeler video. With the right tools which include a bullet seater with micrometer adjustment, it is not too onerous.
In a nutshell, it involves reaching a point where the bolt (ejector removed) falls almost freely on a seated bullet that has been incrementally backed off of jamb. If looking for extreme accuracy, there may also be an advantage gained by leaving the ejector removed from the bolt.
NOTE: A tip when removing the ejector is to lock the bolt in a vise with the bolt head inside a baggie. Makes it easier to find the spring if it gets away on you
Maybe somebody can post the link (I don't know how)

[fps plus]

This is my method
Take a round that has been fired from the firearm in question . Do not resize but make sure it still will chamber in the gun . Take a bullet you want to use , put a small dab of 5 minute epoxy on the iNSIDE the case only slide a bullet in question the neck . Barely started into the neck . Carefully insert the case with bullet and epoxy into the chamber and the close the bolt . Let the epoxy cure and remove cartridge . The cartridge has the bullet seated by the land so now you have a sample to measure

[covey ridge]

What I do is drop a bullet (intended projectile) into the chamber and let it stop against the lands.

Hold it in place with light pressure from a pencil with eraser.

Slide a rod with a square tip in from the muzzle and mark rod at muzzle.

Remove projectile and close bolt on action. Put the rod in to where it stops against bolt. Mark rod.

The two marks should represent the OAL of cartridge that touch lands.

Measure and back off desired amount.

Make sure that the female end of the rod tip is not what contacts the projectile
as this will distort measurement. For me Dewey rods work well because of the male end.

I put a strip of thin tape (actually the sticky part of a post it) on the rod where I anticipate the marks to be.

Both marks are done with a razor blade held square to the muzzle. I remove the tape and paste into my notes next to bullet used.

This method is simpler than my instructions.

[260 Rem]

Of course tuning requires trial and error to find the sweet spot so the exact COAL may be relative, but given the option (and time) I am giving the Wheeler method a shot, because:
1. The epoxy/split neck methods result in the bullet being forced into the lands either by the ejector or by the extractor as it is forced over the rim, and
2. The rod method relies on a measurement made to the bullet tip rather than on the ogive.

[amosfella]

Be so much easier with a mauser action rifle... These push feeds are sooooo Cooooommmmpppplllliiiiccccaaaatttteeeddd.......

[gitrdun]

I use the Hornady OAL gauge and their comparator attachments for calipers. These are former Stoney Point tools. With the OAL tool, I take several consecutive measurements to ensure consistency. Sine I load many calibers, I make my own casing gauges from fired brass.

[covey ridge]

Originally Posted by 260 Rem

2. The rod method relies on a measurement made to the bullet tip rather than on the ogive.

As the rod measurements starts where the ogive is on the lands, and does rely on a measurement to the tip and the bolt, the result is a length where the ogive is on the lands.

[gitrdun]

Originally Posted by covey ridge

As the rod measurements starts where the ogive is on the lands, and does rely on a measurement to the tip and the bolt, the result is a length where the ogive is on the lands.

True enough. But once you have that measurement, you need to use a comparator tool to measure that very same bullet's ogive location. All consecutive measurements should be made with an ogive comparator, including that which will be used to set the seating die.

[covey ridge]

Originally Posted by gitrdun

True enough. But once you have that measurement, you need to use a comparator tool to measure that very same bullet's ogive location. All consecutive measurements should be made with an ogive comparator, including that which will be used to set the seating die.

Comparator would be nice, but if all bullets are the same and thus have the same ogive, the measurement as described will result in the correct length to put each bullet on the lands.

This was the method that was described in most loading manuals before the comparators were marketed.

[elkhunter11]

Originally Posted by gitrdun

True enough. But once you have that measurement, you need to use a comparator tool to measure that very same bullet's ogive location. All consecutive measurements should be made with an ogive comparator, including that which will be used to set the seating die.

I use the exact bullet that I use to determine the distance to the lands to adjust my seating die. That eliminates any issues with variance in bullet tips, which is common. My bullet seating dies all have micrometer adjusters, so once I record the setting, I can repeat it anytime, and I can vary the distance to the lands very easily, and precisely.

[Xbolt7mm]

I use the same kind of system as fps plus but without the epoxy. I just "pinch the neck a smidge just so the calipers can get a good reading without pushing the bullet in farther. I do this about 6 times to ensure im correct and makes sure it takes almost no pressure for the bolt to push in the bullet. Nice to see how its supposed to be done tho. I have had guns that the bullet being on the lands wont fit in the mag as they are too long.

[260 Rem]

If all bullets are created equal, measurement to the tip works fine, but some brands/tip-types have significant differences between the tip-to-ogive measurement. I have found that the plastic tipped projectiles are more consistent than those which are lead tipped.

[fps plus]

Originally Posted by 260 Rem

Of course tuning requires trial and error to find the sweet spot so the exact COAL may be relative, but given the option (and time) I am giving the Wheeler method a shot, because:
1. The epoxy/split neck methods result in the bullet being forced into the lands either by the ejector or by the extractor as it is forced over the rim, and
2. The rod method relies on a measurement made to the bullet tip rather than on the ogive.

????????? You have a misunderstanding of how an ejector or extractor works in relation to the cartridge / chamber .

[260 Rem]

Originally Posted by fps plus

????????? You have a misunderstanding of how an ejector or extractor works in relation to the cartridge / chamber .

Perhaps... always ready to be schooled.

[fps plus]

Once the cartridge is stopped in the chamber and the bolt closed ( by whatever headspace method ie shoulder ,belt , rim ,usually the shoulder if it is a cartridge fired from that firearm) the ejector or extractor cannot move the brass anymore forward.

[gitrdun]

Originally Posted by covey ridge

Comparator would be nice, but if all bullets are the same and thus have the same ogive, the measurement as described will result in the correct length to put each bullet on the lands.

This was the method that was described in most loading manuals before the comparators were marketed.

Right, but the ogive even if no bullets are creatted equal will certainly yield a more acfurate measurement than those taken off a bullet tip. Your measurement procedures will surely do well enough for hunting rounds for the majority of hunters. But when it comes to benchrest accuracy, not likely. As for myself as I will only load a very few rounds for my hunting ammo, I also prefer to load them to uber benchrest accuracy. It just gives me that piece of mind afield and doesn't take that much more time.

[260 Rem]

Correct, the difference being the headspace...hence the "difference". Not all cases used for measurment are created equal. Most certainly, if you are using a case fired in that particular chamber, there will be less variation. Did I get that right?

[500+BC]

Interesting

[fps plus]

Originally Posted by 260 Rem

Correct, the difference being the headspace...hence the "difference". Not all cases used for measurment are created equal. Most certainly, if you are using a case fired in that particular chamber, there will be less variation. Did I get that right?

Yes that is what I said "use a case fired from the firearm "

[covey ridge]

Originally Posted by 260 Rem

If all bullets are created equal, measurement to the tip works fine, but some brands/tip-types have significant differences between the tip-to-ogive measurement. I have found that the plastic tipped projectiles are more consistent than those which are lead tipped.

If the bullets brand and type one is loading are not created close to equal in relation to shape and measurement between ogive and tip they are not worthy of any expectation of accuracy.

A different measurement needs to be done with every different bullet loaded.

I agree that lead tip bullets might not be as consistent but if your batch has more than a few off the norm in 100 they are not worth much expectation.

If the bullets one is using are not consistent, then all bets are off no matter what method one is using.

[gitrdun]

Originally Posted by covey ridge

If the bullets brand and type one is loading are not created close to equal in relation to shape and measurement between ogive and tip they are not worthy of any expectation of accuracy.

A different measurement needs to be done with every different bullet loaded.

I agree that lead tip bullets might not be as consistent but if your batch has more than a few off the norm in 100 they are not worth much expectation.

If the bullets one is using are not consistent, then all bets are off no matter what method one is using.

If that were true, than a lot of bullets would be off the market. Who cares where the tip lands when we speak of thousands of an inch. The ogive reference is where you ought to your comparison criteria at. True enougn though, if a bullet manufacturer cannot place the ogive reference at the same spot every time, they ought to be discarded.

[260 Rem]

Originally Posted by fps plus

Yes that is what I said "use a case fired from the firearm "

And therein lies the weak link with tools like the Hornady OAL gauge which uses a "standard" " modified case which often has ample headspace. There are also likely headspace differences between brands of cases? And many reloaders may be using new brass. Going back to the thread title which emphasizes "exact", the Wheeler method makes a lot of sense...at least enough for me to try. I have removed the ejector from one my Barnard bolts and am going to give it a try. I have a BR type buddy that has been doing this for a long time and swears by it. He also shoots without the ejector installed as he reckons it results in offside pressure on the base which influences how the case sits in the chamber. Makes sense to me, and there is no room to argue his results.

[markg]

Funny this topic came up today, as I picked up my newly chambered rifle from my smith today. We had this very discussion in his shop. I asked him to make me a once fired case to use in my hornady comparator tool. He told me I didnt need it and he made me a rod with a tool that clamps down so you can measure the difference between the bolt face and when you put a bullet in pushed to the lands. This is his preferred method and he thinks you get a more accurate reading. I argued a bit about it needing to be measure off the lands and he responded with " the bullet is pushed into the land."
He is alot smarter than me about these kinds of things so I decided to take him at his word.

I tried to take a measurement to determine my seating length but I managed to screw it up somehow. (no fault of my smith) I just suck at mechanical stuff. I got a coal reading that is somehow short of the ssami coal so I must be doing something wrong.

[elkhunter11]

The method or tooling that you use to find the distance to the lands really doesn't matter, and in fact the actual distance to the lands doesn't matter, as long as the result is that you are able to get your seating die adjusted to provide optimum accuracy with your load in your rifle.

[260 Rem]

I should have added in post #22, that if the bullet is tight in the neck, it can easily jamb into the lands by .005 - .010 before the headspace bottoms out on the shoulder. Even with the Hornady tool, it can be a challenge to get repeatable measurements because of differential pressure on the forcing rod.
Mark...you got a pic of the rod/clamp gizmo...sounds like the same principle described by covey?

[260 Rem]

Originally Posted by elkhunter11

The method or tooling that you use to find the distance to the lands really doesn't matter, and in fact the actual distance to the lands doesn't matter, as long as the result is that you are able to get your seating die adjusted to provide optimum accuracy with your load in your rifle.

True ... it is relative and the proof is always on the paper. However, knowing the exact measurement on a new barrel also makes it easy to gauge throat erosion with subsequent measurements.

[Salavee]

Originally Posted by gitrdun

True enough. But once you have that measurement, you need to use a comparator tool to measure that very same bullet's ogive location. All consecutive measurements should be made with an ogive comparator, including that which will be used to set the seating die.

This .. and note he threads his own fired cases. That makes some difference as opposed to the unfired Modified cases from a retailer.

[elkhunter11]

Originally Posted by 260 Rem

True ... it is relative and the proof is always on the paper. However, knowing the exact measurement on a new barrel also makes it easy to gauge throat erosion with subsequent measurements.

If my accuracy starts to fade after many rounds, and a good cleaning won't restore it, I will try backing off my seating die in .005" increments. If that still doesn't solve the issue, I don't need more measurements, I need a new barrel.

[qwert]

Originally Posted by markg

snip
He told me I didnt need it and he made me a rod with a tool that clamps down so you can measure the difference between the bolt face and when you put a bullet in pushed to the lands. This is his preferred method and he thinks you get a more accurate reading. I argued a bit about it needing to be measure off the lands and he responded with " the bullet is pushed into the land."
snip

I have built similar tools, but these are more cost effective than building, (and better unless you use a lathe).
Sinclair # 749-000-266WS
Cleaning rod stop - large
Mfr Part: 021020

http://www.sinclairintl.com/gun-clea...ku=749-000-266

or a set of 4, (Possum Hollow - EJS cleaning rod stops)
http://www.brownells.com/gun-cleanin...-prod7921.aspx

If you tighten one on the rod against the bolt, then another with the rod against a bullet tip held against the lands, the COAL = distance measured between the stops + the lower stop thickness.

These stops are also useful for cleaning / lapping with J-B compound and other tasks.

Originally Posted by markg

I tried to take a measurement to determine my seating length but I managed to screw it up somehow. (no fault of my smith) I just suck at mechanical stuff. I got a coal reading that is somehow short of the ssami coal so I must be doing something wrong.

You may have not added the thickness of the lower rod stop,
or your smith may have used a reamer with a throat shorter than SAAMI spec, which may allow you to feed best COAL cartridges from your magazine. (Many/most SAAMI spec/factory chambers will be too long to allow this)

I suggest you also measure the chamber length to determine your proper trim to length, (as the custom reamer may also cut a shorter than typical factory/SAAMI chamber)
http://www.brownells.com/reloading/m...prod32925.aspx

Some very useful tools are also inexpensive.

I also suggest you compare the OD of the fire-formed neck with the resized neck OD after seating a bullet. This will determine how tight the chamber neck is and whether/how much the case neck needs to be turned.
You will also want to measure the OD before seating the bullet to determine the proper neck bushing size to obtain your desired neck tension.

Good Luck, YMMV.

[260 Rem]

Originally Posted by fps plus

Once the cartridge is stopped in the chamber and the bolt closed ( by whatever headspace method ie shoulder ,belt , rim ,usually the shoulder if it is a cartridge fired from that firearm) the ejector or extractor cannot move the brass anymore forward.

Sorry I got distracted and responded in a couple of posts..but in a nutshell, a tough ejector spring can jamb a bullet (in a snug neck, several thou into the lands before the headspace bottoms out. Extractors that have to jump the rim on many push feeds will result in a similar jamb even if the ejector is removed.
I load many bullets .010 - .013 jambed and can hardly notice the difference in bolt resistance on closing. Copper is pretty soft and etches easily. Using a fireformed case will reduce variations in hedspace, but if the bullet jambs, an inaccurate reading will result. Does that make sense?