measuring the lands

[ah141nj]

I have a new 10 FCP-K in 223. I measured the lands with a Hornady OAL tool with a Nosler 69 gr HPBT.
I have several measurements from 1.885 to 1.971. I tried to use the same pressure each time but I guess I havent been.

I was planning on using 1.966, because that came up more times.

Any suggestions for a more accurate measurement?

[ah141nj]

bump for help ???

[twarren]

If 1.966 came up more times that is what I would use.

[lal357]

i do it the same way take lots of readings and see what comes up the most then use that .

[sharpshooter]

Those measuements baffle me. If it is the overall length, it should be in excess of 2.250". I think you might have a case on the tool that has a neck larger than the diameter in the chamber, it is a common problem.
Once the case actually fits the chamber and seats against the shoulder, the bullet will stop at the throat with very little variance.

[ah141nj]

Those measuements baffle me. If it is the overall length, it should be in excess of 2.250".

I guess I must be using pressure each time. Should I just jamb it it each time

Just measured several more times. I came up with 1.954 at the ogive. The OAL isnt 2.250; its 2.325 OAL with the ogive at 1.954.


If I start loading at .010 off thats a OAL of 2.315. Should that be a factor if I am not loading for magazine length? I will be using a single shot follower.

[memilanuk]

Yes, jam it. Jamming hard is easier than trying to figure out where its 'just kissing' by far. I push hard til it won't go no more. I have the 'straight' version with the rod, not the curved version with the cable, so I push hard enough that I usually have to tap the bullet out with a cleaning rod from the muzzle, but not hard enough to bow/bend/break anything.

I usually go until I have three consecutive readings within a couple thou of each other. If I'm being really picky, I'll do three bullets picked from the box and do the same for each of them. I generally record these readings as 'bto' or 'base to ogive', which is what it really is, not OAL, COAL, etc. When I take the last reading for each bullet, I'll also record the OAL (base to tip) mostly for posterity, but it also helps when I'm trying to fit a round in the magazine, etc.

The 2.250" OAL that Fred mentioned is the default magazine length listed for .223 Remington. If you intend to fire those from say, an AR-15 you'd need to seat to 2.250" (max mag length is 2.260 +/- a bit, 2.250 gives some clearance). If you are using these in a bolt gun you might be able to seat them longer (I'd still recommend 20-30 thou jump to the lands) while feeding from the magazine as the magazine box may be considerably roomier.

[gotcha]

ah141nj, here's another angle that works for me when chkng. to-the-lands seating depth. Put a light smear of bullet lube around the ogive of the bullet before chambering. It helps prevent the bullet from sticking in the lands & yields more consistent & narrower range of readings. I'll also scuff the bullet w/ scotch- brite Just enough to make the surface that touches the lands dull & non-reflective. This will yield a bright shiny spot where lands touch bullet thats very easy to see. And also tells you how far the bullet is jammed into the lands. Jam into lands 'til ALL lands can be seen on bullet. Then shorten seating depth in .005" increments to find "sweet spot". Dale

[lal357]

the other thing i do is sort my heads by ogive take 10 heads and measure them you wont believe the difference in them you'll get .i 600 hornady match 75 gr heads and they ran .582 to .594 i bagged them in lots so when i load .01 off the lands the group was 1.926 (thats in my barrel your would be diferent) ogive.

[okie2]

Do it the easy way and save your money on all the toys.
this is how I do it and it works every time
split the neck on a full sized case cut slot & put bullet in just enough to hold it
then chamber it take out and measure it. this will tell you the max length to lands.
[img width=269 height=450]http://i661.photobucket.com/albums/uu340/OKIE2-photos/my%20guns/landfinder.jpg[/img]

[ah141nj]

Hi Guys,

Thanks for all the advice.

Giving it another try.
I measured the lands 10 consecutive times, jamming it in everytime.
With a difference of .007 between them,
I averaged out the measurements & came up 1.956 as my "BTO" (base to ogive)

I was planning on loading 5 rounds each at -.010,-.015,-.020,-.025 & -.030. I will be using the same charge of 24.5 of Varget for all.

I am using 69 gr HPBT. On the Hodgon's site, it lists Varget at 24.0 gr min / 26 gr max. I shouldnt be worried about pressure too much...should I?

Does this seem like a logical plan? Care to share your input?

[GaCop]

Do it the easy way and save your money on all the toys.
this is how I do it and it works every time
split the neck on a full sized case cut slot & put bullet in just enough to hold it
then chamber it take out and measure it. this will tell you the max length to lands.
[img width=269 height=450]http://i661.photobucket.com/albums/uu340/OKIE2-photos/my%20guns/landfinder.jpg[/img]

+1, I have a number of cases made like that because a Hornady modified case doesn't exist (like the 223AI and at the moment, 204R).

[ESSCEE]

I just used okie2's method to measure to the lands on 2 of my rifles both chambered in 30.06 in preparation for my first attempt at loading I used a dremmel to cut the slit and pushed the bullet in by hand left a small gap at the bottom of the slit so I could tell the bullet actually moved and ran it into the chamber carefully ejected it and measured very simple

THANK YOU OKIE2!

[airaddict]

i have also seen people neck size a fireformed case just enough in a collet sizing die to just barely grip the bullet which does the same thing w/o the dremeling.

or send a fireformed case to hornady and they will tap the head for you for use in their gauge. but then u gotta buy the gauge if u dont have it.

there always more than one way to skin a cat!!

brian

[gotcha]

O.K. Here's another way. Adjust your sizing die ( nk. or F/L ) to just barely touch the mouth of the case. This will also yield a "slip fit" & the tension is adjustable depending on how far you turn the die into the press. I use this method if I'm working w/ buck a piece brass or don't have a collet die for a particular cartridge. This does require you to start w/ a fired case.

[racinready300ex]

I just tap the plastic rod a couple times. Give's you a slight jam, but it's more consistant. I used it over the weekend and got 2.186 all three times I did it. Called it good.