GrizleyHunter
New member
What is the best way to measure to the lands and then how do I measure my loaded round to make sure I am off the lands a bit.
What tools do I need??
What tools do I need??
Whats best way to measure to lands of bore
- Thread starter GrizleyHunter
- Start date
Ricky Bobby
New member
Grizley, I'm no expert but have read on here that you can take a fired case from the rifle you are loading for and just barely insert a new bullet into the fired case's mouth so it will stay on its own. Then gently place the dummy cartridge into the chamber and softly close the bolt of your gun. It will supposedly be fed up against the rifling and then as you're closing the bolt your bullet will be seated to the depth of your lands. I have not tried this method yet, but I assume it would work fine as long as the bullet doesn't move any after opening your bolt back up and removing the dummy cartridge. At that point, you would know the max length your gun would accept and if you want to come off the lands a certain amount you could just deduct that for your OAL. If anyone would like to add to this, feel free! Or I could be all wrong about this, too. But I know one thing, you have sparked my interest on this and I'm about to go try it on my .204 because I will be loading for it next and it would be something nice to know before I get started. Also, I will add that if you would change the type of bullet then you would more than likely have to repeat the process.
GrizleyHunter
New member
I do have a col gage(the rod with two spacers) and I can measure the max col then back off a bit.But the second part of the question is on a rimless case it is the shoulder of the case that stops the foward travel of the loaded case so if the shoulder is not bumped to the correct position the col is then not in the position (bullet from lands) that I want it to be.
So now I have two deminsions to set at the same time,Am I correct???
So now I have two deminsions to set at the same time,Am I correct???
As has been stated, you can use a fired case and a bullet to measure distance to lands in your rifle. Be aware that this distance increases as the barrel wears. Also be aware that pressures usually increase the closer your seat your bullets to the lands, so proceed w/caution if you are close to max load.
You can fully resize a case and then split the neck lengthwise using a cutoff wheel in a Dremmel tool or just run a case into your sizing die just far enough to "crimp" the neck sufficiently to hold the bullet snugly, but not so tight that the bullet will not slide when you push on it. You may have to experiment until you get the tension right the first time.
Once you have your case altered, put a bullet in it and chamber it in your rifle, then carefully extract the round and measure the COAL (distance from the head of the case to the point on the ogive of your bullet that measures the same diameter as your bore). OAL is really not an accurate point of reference as overall bullet lengths routinely vary by a few thousandths of an inch. It is also a good idea to check the measurement a couple of times to be sure the bullet did not slip when extracted from your chamber because the lands can grab the bullet and pull it out of your case a tad.
A good tool to measure COAL is:
http://www.hornady.com/store/Lock-N-Load-.234-.678-Comparator-Set-With-6-Bullet-Inserts/
Regards,
hm
You can fully resize a case and then split the neck lengthwise using a cutoff wheel in a Dremmel tool or just run a case into your sizing die just far enough to "crimp" the neck sufficiently to hold the bullet snugly, but not so tight that the bullet will not slide when you push on it. You may have to experiment until you get the tension right the first time.
Once you have your case altered, put a bullet in it and chamber it in your rifle, then carefully extract the round and measure the COAL (distance from the head of the case to the point on the ogive of your bullet that measures the same diameter as your bore). OAL is really not an accurate point of reference as overall bullet lengths routinely vary by a few thousandths of an inch. It is also a good idea to check the measurement a couple of times to be sure the bullet did not slip when extracted from your chamber because the lands can grab the bullet and pull it out of your case a tad.
A good tool to measure COAL is:
http://www.hornady.com/store/Lock-N-Load-.234-.678-Comparator-Set-With-6-Bullet-Inserts/
Regards,
hm
Jack Roberts
Moderator - Deceased
"Also be aware that pressures usually increase the closer your seat your bullets to the lands,"
This is not true.
The results of testing were written up in the VHA magazine some years ago. Different chambers react differently. There is no fast rule. Closer to the lands lowered pressure in as many chambers as it raised pressure.
Jack
This is not true.
The results of testing were written up in the VHA magazine some years ago. Different chambers react differently. There is no fast rule. Closer to the lands lowered pressure in as many chambers as it raised pressure.
Jack
Originally Posted By: Jack Roberts"Also be aware that pressures usually increase the closer your seat your bullets to the lands,"
This is not true.
The results of testing were written up in the VHA magazine some years ago. Different chambers react differently. There is no fast rule. Closer to the lands lowered pressure in as many chambers as it raised pressure.
Jack
Perhaps a better choice of words would have been often
Regards,
hm
This is not true.
The results of testing were written up in the VHA magazine some years ago. Different chambers react differently. There is no fast rule. Closer to the lands lowered pressure in as many chambers as it raised pressure.
Jack
Perhaps a better choice of words would have been often
Regards,
hm
Hooked
New member
This explains it fairly well IMO...some insight anyway
http://www.hornady.com/ballistics-resource/internal
http://www.hornady.com/ballistics-resource/internal
OldTurtle
Moderator - Deceased
Ricky, I think that with the average .204, you will find that you have an unusually long jump to the lands...unless you have had your barrel chamber custom cut for a shorter chamber... Some will not allow you to touch the lands and still keep the bullet in the case with 40gr or lighter weight bullets..
The .204s tend to like that longer jump to the lands, but will also shoot pretty well if you can get the bullet close, but willing to load single fire..
The .204s tend to like that longer jump to the lands, but will also shoot pretty well if you can get the bullet close, but willing to load single fire..
Ricky Bobby
New member
Thanks for the heads-up Turtle! I never did get around to trying this in my .204 yesterday, but will let you know what I come up with when I try it. Instead, I gave my S&W .357mag a much needed thorough cleaning! I want to be ready for a nice weather day, so I can shoot some test loads through it that I just recently loaded.
TrapShooter12
Member
Originally Posted By: GrizleyHunterI do have a col gage(the rod with two spacers) and I can measure the max col then back off a bit.But the second part of the question is on a rimless case it is the shoulder of the case that stops the foward travel of the loaded case so if the shoulder is not bumped to the correct position the col is then not in the position (bullet from lands) that I want it to be.
So now I have two deminsions to set at the same time,Am I correct???
This is to give you an idea where to start from. You will have to adjust from this measurement. Just because you hit the lands does not mean that it is the optimal shooting length for the cartridge. Some Rifles like to be .03 off the lands some like it more. You will have to experiment with your base measurement.
So now I have two deminsions to set at the same time,Am I correct???
This is to give you an idea where to start from. You will have to adjust from this measurement. Just because you hit the lands does not mean that it is the optimal shooting length for the cartridge. Some Rifles like to be .03 off the lands some like it more. You will have to experiment with your base measurement.
shipply
New member
Originally Posted By: GrizleyHunterI do have a col gage(the rod with two spacers) and I can measure the max col then back off a bit.But the second part of the question is on a rimless case it is the shoulder of the case that stops the foward travel of the loaded case so if the shoulder is not bumped to the correct position the col is then not in the position (bullet from lands) that I want it to be.
So now I have two deminsions to set at the same time,Am I correct???
You are confusing your max coal and headspacing measurements, you do not need to know both at the same time. COAL can be done by smoking or using a sharpy and inserting a case with the bullet in , then try to remove it with out it coming out of the case, and after three or four trys you may get a close estimate of where you are. A much easier way is to take a cleaning rod, close the bolt on your rifle, then put the cleaning rod down the barrel( carefully, not banging or rubbing the crown) Mark it at the end of the barrel( fine mark as possible.) Next take a once fired case oblong the neck by pushing it down side ways on a table, when the neck is slighty out of round just start whatever bullet you will be using just in the neck, install it in the chamber and close the bolt, once again carefully install the cleaning rod and scribe or mark it. the difference between the marks is your max oal for that bullet/ogive. If you change bullets this will change.
Clear as mud eh?
So now I have two deminsions to set at the same time,Am I correct???
You are confusing your max coal and headspacing measurements, you do not need to know both at the same time. COAL can be done by smoking or using a sharpy and inserting a case with the bullet in , then try to remove it with out it coming out of the case, and after three or four trys you may get a close estimate of where you are. A much easier way is to take a cleaning rod, close the bolt on your rifle, then put the cleaning rod down the barrel( carefully, not banging or rubbing the crown) Mark it at the end of the barrel( fine mark as possible.) Next take a once fired case oblong the neck by pushing it down side ways on a table, when the neck is slighty out of round just start whatever bullet you will be using just in the neck, install it in the chamber and close the bolt, once again carefully install the cleaning rod and scribe or mark it. the difference between the marks is your max oal for that bullet/ogive. If you change bullets this will change.
Clear as mud eh?
The trick with a once fired brass and a bullet does work, but before you place your bullet draw a line on it with a sharpie.becase some time it will stick a touch pulling out and you can simply look for a scrap mark in the sharpie line to get it back to the true reading. Also note that once you have this measurement not times then not you will have to set deeper to get the cartridge to fit the internal box mag in the gun. All if my guns want longer bullets to best accuracy but the box mag wont let them be that long.
Hooked
New member
Some time back someone on this site marketed a stainless rod that was inserted in the muzzle and had two positioning stops on it. The first stop was fixed with the rod in contact with the bolt face (the stop flush to the muzzle) and the second stop was with the rod in contact with the bullet tip when a dummy round made with bullet [/u]far out is held so the bullet is touching the lands(I do this holding the dummy round in my hand so I can feel the lands).Results are very repeatable and clearly indicate the distance to the lands with no question as to whether the bullet moved or penetrated the lands or whatever. I was not able to get one of those rods but I use a wood dowel with a razor blade to mark the stops and then mike the distance. You only have to do this once for each rifle.The first bullet you make using the same bullet you used to mark the lands is run in to the exact length you want off the lands. I mark this round for future press set up, Since the press set up moves the bullet at its ogive the measurement is good for any other bullet you use since you only use the bullet to set up the press.
OldTurtle
Moderator - Deceased
Rajn Cajn (old member here) over on the National Predator Hunter's Assoc used to make and sell the ones in the post above...Not sure whether he still does or not....Simple and slick... One of those things that once you use it, you say to self.. "Wish I'd thought of that"
GrizleyHunter
New member
Old Turtle
I think I have just what you are talking about,I ordered it more than a year ago.
here is the info
R-P products
P.O. box 7692
8010 Dixie Blanchard
Shreveport LA 71107
PH# 318-424-7867 It is called C.O.L. E-Z check
I just cant remember the members name.
But I can remember he was great to deal with.
I think I have just what you are talking about,I ordered it more than a year ago.
here is the info
R-P products
P.O. box 7692
8010 Dixie Blanchard
Shreveport LA 71107
PH# 318-424-7867 It is called C.O.L. E-Z check
I just cant remember the members name.
But I can remember he was great to deal with.
brdeano
New member
Originally Posted By: OldTurtleRajn Cajn (old member here) over on the National Predator Hunter's Assoc used to make and sell the ones in the post above...Not sure whether he still does or not....Simple and slick... One of those things that once you use it, you say to self.. "Wish I'd thought of that"
I bought one from him a long time ago and really like it. You are measuring off the tip of bullet using these tools and it will give you an accurate measurement. Since there is some variance in tip to ogive length in bullets I then use that same bullet to set up a dummy round to keep in the die box for that particular load. It's a quick and easy tool that is well worth the few bucks he charges for them.
I bought one from him a long time ago and really like it. You are measuring off the tip of bullet using these tools and it will give you an accurate measurement. Since there is some variance in tip to ogive length in bullets I then use that same bullet to set up a dummy round to keep in the die box for that particular load. It's a quick and easy tool that is well worth the few bucks he charges for them.
Ackman
New member
Finding distance to the lands isn't near as difficult as some people make it.
Necksize a case then use Dremel cutoff wheel and cut a split down the neck and into the shoulder a little. File the inside burr smooth. Takes less than a minute start to finish. I also drill the flashole so something a larger can be used to push a bullet out. That's all there is to it, simple and cheap. There's no need for a special threaded case, no rods or anything else.
Adjust neck tension to where it'll hold a bullet and still let it slide. Seat a bullet long then chamber the whole thing. When it's unchambered, the bullet will be at touching-the-lands depth. Do it a few times to where you know it's a consistent read, and also get a feel for how much neck tension is necessary. With that neck split also see exactly how far down a bullet is seated.
Measuring. You can measure overall length to tip of bullet, but that's not really the way. You want to check length from casehead to bullet ogive, the part that actually contacts the rifling. From Sinclair's get a Davidson Seating Depth Checker for every caliber you shoot, it attaches to the caliper beam. Attaching to the beam makes it a whole lot easier to use. Hornady makes a LNL Comparator set that does the same thing. I have the Davidson pieces. A split neck case and something to take an ogive measurement is all you need.
A real good thing to have is a "window gauge." When rebarrelling, have the gunsmith take a little piece of the barrel cutoff - 3/4" to 1" long is plenty - and run the reamer in, just the neck/throat and shoulder. Then cut a pie shaped section lengthwise down the whole thing. That's the "window," it lets you see what's going on in there. Usual cost is about $30 or so. With this thing you can.....
1) Get initial seating depth to lands measurement without chambering the round.
2) Always be able to get that same fresh chamber measurement and compare it with measurements later taken from the chamber. This tells you throat wear. Keep the exact same bullet in the die box.
3) Get casehead to shoulder length comparisons.
4) Visually see exactly how long the caseneck is in relation to the chamber....(maybe that brass really doesn't need trimming? Hmm.)
One of these gauges should be part of every new barrel installation.
Necksize a case then use Dremel cutoff wheel and cut a split down the neck and into the shoulder a little. File the inside burr smooth. Takes less than a minute start to finish. I also drill the flashole so something a larger can be used to push a bullet out. That's all there is to it, simple and cheap. There's no need for a special threaded case, no rods or anything else.
Adjust neck tension to where it'll hold a bullet and still let it slide. Seat a bullet long then chamber the whole thing. When it's unchambered, the bullet will be at touching-the-lands depth. Do it a few times to where you know it's a consistent read, and also get a feel for how much neck tension is necessary. With that neck split also see exactly how far down a bullet is seated.
Measuring. You can measure overall length to tip of bullet, but that's not really the way. You want to check length from casehead to bullet ogive, the part that actually contacts the rifling. From Sinclair's get a Davidson Seating Depth Checker for every caliber you shoot, it attaches to the caliper beam. Attaching to the beam makes it a whole lot easier to use. Hornady makes a LNL Comparator set that does the same thing. I have the Davidson pieces. A split neck case and something to take an ogive measurement is all you need.
A real good thing to have is a "window gauge." When rebarrelling, have the gunsmith take a little piece of the barrel cutoff - 3/4" to 1" long is plenty - and run the reamer in, just the neck/throat and shoulder. Then cut a pie shaped section lengthwise down the whole thing. That's the "window," it lets you see what's going on in there. Usual cost is about $30 or so. With this thing you can.....
1) Get initial seating depth to lands measurement without chambering the round.
2) Always be able to get that same fresh chamber measurement and compare it with measurements later taken from the chamber. This tells you throat wear. Keep the exact same bullet in the die box.
3) Get casehead to shoulder length comparisons.
4) Visually see exactly how long the caseneck is in relation to the chamber....(maybe that brass really doesn't need trimming? Hmm.)
One of these gauges should be part of every new barrel installation.
GC
Well-known member
Originally Posted By: GrizleyHunterOld Turtle
I think I have just what you are talking about,I ordered it more than a year ago.
here is the info
R-P products
P.O. box 7692
8010 Dixie Blanchard
Shreveport LA 71107
PH# 318-424-7867 It is called C.O.L. E-Z check
I just cant remember the members name.
But I can remember he was great to deal with.
If you have this tool already... why the question? I guess I don't understand why the question when you already have the equipment, ect. BTW, Randy's tool is about as simple and basic as it gets and it works with any action type and comes with very good instructions. Hard to go wrong with it.
I think I have just what you are talking about,I ordered it more than a year ago.
here is the info
R-P products
P.O. box 7692
8010 Dixie Blanchard
Shreveport LA 71107
PH# 318-424-7867 It is called C.O.L. E-Z check
I just cant remember the members name.
But I can remember he was great to deal with.
If you have this tool already... why the question? I guess I don't understand why the question when you already have the equipment, ect. BTW, Randy's tool is about as simple and basic as it gets and it works with any action type and comes with very good instructions. Hard to go wrong with it.