seating depths

foreign · Posted: Fri Apr 18, 2008 5:32 am Post subject: seating depths

hey everyone. i have two questions
1. with out a way of measuring lengths of bullets how do you know when they are close to the lands. i tried the felt tip marker trick and didnt get much luck with it.
2. since diferent bullets have different shapes then some round can be longer that others and not near the lands while another of that length would be right up there. so how do you know what length to make each round. does sammi have set guide lines and if so how would you aplie these to diferent tuypes of bullets.
i lightly crimped a case inserted a projectile and chambered it( without powder ect. ofcourse Very Happy

)the projectile when i took it out was just past the boat tail. this cant be right. it must be in the lands. i now have the case neck flush with the cannula. am i just going to have to play with seating depth when i find a powder load and hope im getting it right.?

Meeker · Member Joined: Nov 09, 2005 Posts: 28 Location: Colorado

foreign,
It would help some of us to answere your question if we new what action you were reloading for. If you are reloading for a Weatherby rifle, you will not want to seat your bullet based on the depths of the lands. For Weatherby and some others you should seat your bullets according to overall length specification stated in any reloading manual, and to the length of your magazine tolerences.

Brett

Dawgdad · Posted: Fri Apr 18, 2008 6:54 am Post subject: Re: seating depths

The best way is to use a bullet comparator such as the Hornady Lock n Load comparator/OAL gauge. As you noted this length is different for every bullet type and is unique to your guns chamber.

The way this device works is by threading a case onto a rod that has a rigid cable and a set screw on it. you place a bullet of the type you want to shoot in the case well below where you think the bullet should be set. Then you insert the case into you chamber and push up on the cable until you feel the first sign of resistance. Then lock down the set screw and withdraw the case. It is OK if the bullet gets stuck of falls out because you have the cable in place to set the bullet back in the case. you then can measure the overall length or use the comparator and measure to the ogive which is the point where the bullet reaches the diameter of the lands.

Using the comparator and measuring to the ogive is more repeatable than the OAL because most bullets variation in length occurs between the ogive and the tip given the way they a drawn out during forming.

A second way that does not require the $40 investment into the OAL/comparator tools is to loosely seat a bullet into a case at an extremely long length. you then take a solid rod like a cleaning rod an insert it through the muzzle until it reaches the closed bolt face of the chamber. Mark the muzzle on the rod with tape or a slip nut with a set screw. Withdraw the rod and insert you long bullet and case into the chamber and use the pressure of closing the bolt to seat the bullet into the the case. then reinsert the rod to that it touches the tip of the bullet lightly and mark the muzzle on the rod. The distance between these two marks will the the OAL for that bullet in that gun to reach the lands.

Midway USA sells a tool like this one for about $15.

As far as having a bullet seat as far out as you have described.. it is possible if you have a very long skinny bullet and a long throated chamber.

What type of gun is it and what is its age? ( how many bullets have been fired through the gun?)

Pumpkinslinger · Posted: Fri Apr 18, 2008 7:14 am Post subject: Re: seating depths

You need to have at least a decent set of calipers if you're serious about reloading. I use the same method you did with a barely resized case neck and the bullet I want to load to determine where to start. I use a comparator from Sinclair International (http://www.sinclairintl.com/cgi-bin/category.cgi?category=RESDTCO&item=09-600&type=store)

Lots of times the manufacturers list the overall length that they tested at. If you can't determine where your lands start try starting there.

Handloader · Posted: Fri Apr 18, 2008 8:30 am Post subject: Re: seating depths

In addition, the length of the rifle's magazine can often limit loaded case length. For hunting rifles, the most critical aspect with reloaded ammo is that it functions without flaw, chambering and extracting easily. The accuracy difference between precise chamber fit, bullets seated closely to the lands and bullet concentricity (all hallmarks of carefully crafted handloads) and generic factory ammo is often measured in fractions of minute of angle. The added accuracy of handloads is a matter of pride for big game hunters and their advantage comes more into play for varminting or competitive sports.

foreign · Posted: Fri Apr 18, 2008 2:17 pm Post subject: Re: seating depths

sorry meeker im using a remington 700 .308

foreign · Posted: Fri Apr 18, 2008 2:23 pm Post subject: Re: seating depths

hey dawgdad its a remington as i mentiond before. hasent fired more than 100 round. so should be pretty much exactly factory. bullet is a hornady 150gr btsp

Deleted_User_2665 · Super Member Joined: May 06, 2006 Posts: 380

A black Magic Marker is one of the best reloading tools ever made.

Have never not kissed the lands by painting the bullet black and chambering the dummy round in a judicious effort of trial and error...

Seat it long, try to chamber it but don't force it. If it hangs up and the bolt won't close, seat it another .030 or .040 deeper. Do this until the bolt closes but still feeling a drag.

Paint the exposed bullet black with the Marker and chamber it.

You'll see the lands make distinct marks on the bullet, the ogive of the bullet will be shoved quite nicely into the lands.

Keep repainting the bullet black with the marker and seating it ever so slightly deeper until the lands marks are just a faint whisper of contact, another .005 will clear the lands and you can consider THAT Kissing The Lands.

It helps to write down what you are doing and using a dial caliper on the OAL you can subtract your incremental changes easily.

Once Kissing the Lands is determined, make seating depths from there by using a comparator that fits the ogive of the bullet if you wanna get that fussy.

Once the Lands are Kissed, I just measure OAL on that dummy, set my die to whatever depth I want off the lands for R&D by making THAT dummy round THAT much shorter (example: .050 off the lands for my 30-06/168 TSX load).

Having THAT dummy round in the box makes it easy to return to that setting whenever I need to change the die to another bullet......

Having Micro Seater Dies, a pen, and a note book, makes it a cake walk.............

Vince · Posted: Fri Apr 18, 2008 8:43 pm Post subject: Re: seating depths

What brand is your Micro Seater Die wildswalker?

I have used a similar process to you, but don't have the MS Die...I simply measure the length of the seating rod poking out the top of the die. Not the most accurate, but it works.

Cheers, Vinxce

foreign · Posted: Fri Apr 18, 2008 8:50 pm Post subject: Re: seating depths

hey wildswalker. i tried that b4 i wrote the question. i cant seem to see any markings from the lands. very strange. anyone else have any problem finding where to seat the bullets with remington 700s?

foreign · Posted: Fri Apr 18, 2008 9:12 pm Post subject: Re: seating depths

ok i jst did it again. seated it way out there coloured it in and chambered it. sure enough when i took it out there were the markings (even spaced little square marks all around the bullet. then in the die and pushed it down a little, re coloured and chambered ect. once no marks were left i pulled the bullet and measured how far into the case it had gone (easy since was area without colour. this was 2.05mm or .0807 inchs. thats not enough to hold the bullet firmly is it?

Vince · Posted: Fri Apr 18, 2008 9:25 pm Post subject: Re: seating depths

foreign wrote:

this was 2.05mm or .0807 inchs. thats not enough to hold the bullet firmly is it?

Gidday foreign. Sounds like you are having a lot of fun learning all about reloading.

Mate, its always been my understanding that the projectile should be seated a minimum of at least one "calibre" into the case neck....although I'm sure that someone with more knowledge will correct me if I'm wrong.
Very Happy

Cheers, Vince

foreign · Posted: Fri Apr 18, 2008 10:13 pm Post subject: Re: seating depths

hey vince yea i thought that too. well im just seating them up to the egde of the cannula and once i find the ocw then i will much about with seating.

Vince · Posted: Fri Apr 18, 2008 10:20 pm Post subject: Re: seating depths

Makes sense to me mate.

Whereabouts are you in the Land of The Long White Cloud?

Cheers, Vince

sniper · Posted: Fri Apr 18, 2008 11:05 pm Post subject: Re: seating depths

Foreign:
I tried a lot of stuff, smoking the case/bullet, and magic markers, as well as the comparator method and calipers to find the max. cartridge length. Frankly, I never had much success using the rifling marks on the bullet, which is a rather imprecise effort, anyway. (IMO)

Try this: Take a fired, sized case, and cut several slits in the neck, extending down into the shoulder area. I use 3, but you may wish to use 2 or 4...whatever does the best for you. They will provide a secure grip for the bullet.

Slip a bullet just barely into the case mouth, and carefully chamber it. Gently extract the round, and measure. Do this several times, to be sure the bullet is not sticking in the rifling, and use the average of your measurements, which should not vary a lot, as your "never exceed" length, and use that distance to adjust your bullet's free travel.

Of course, you have to do that for every bullet you load, but you will find, that many bullets are very similar, so the same measurements can safely be used. That simplifies matters somewhat. But, you don't know that till you measure.
Like they told us in J school, "NEVER assume NOTHING"! You WILL get fooled, even if the bullets look alike!

I have found that after getting things quantified, the differences between a comparator measurement and the old, reliable cartridge overall length is not enough to worry about, and you can safey use the old tried and true overall length very successfully for reloads.

If you want to reduce the comparator hassle to a bare minimum, and measure the actual distance from the bullet's ogive to the lands, Sinclair International sells a little hex nut looking comparator that works very well. I have lost mine, and it was the wrong calibers, anyhow, but they are ~$18 USD, and worth it. MUCH better than the Stony Creek things that you have to hang on your caliper.

Do I even have to say, "Write it down!" Very Happy

I hope this helps, just my way of making the procedure of trying to establish proper cartridge length and free travel , keeping it simple as possible , and repeatable.