Bullet seating question ?

[DEACONLLB]

Just getting back into reloading and the question is do you always seat the bullet to the ring on the bullet, the one put there by the factory. I find in seating the bullet that the lighter ones are a lot shorter than the heavier ones and I understand that. As long as the case length is right is that all I need to worry about and not the overall length of the of loaded round as long as I am at the factory ring. These are for single shot not bolt action rifle. Thanks for your help.

Deaconllb

[Czech_too]

In a single shot (Contender), I try for the longest OAL regardless if the bullet has a cannelur(sp?) or not.  Keep in mind that I still want a minimum of the dia. of the bullet seated in the case and I don't use a crimp.  This isn't to say that I want the bullet to engage the rifling though.

[DEACONLLB]

The bullets that I have are 120 grn. nosler flat point lead tip boat tail so I have to seat bullet to the factory seating chamfer or just below in order for it to work and all the spec. for over all length is in the 2.650 up to 2.80 hope that is right I checked a factory round and that is what it measures this one falls short of that, about 3/16 of an inch if it were not a boat tail I could seat it a little longer and be ok.

Deaconllb

[Land_Owner]

You are going to find cases that are longer and shorter than the published maximum overall length.  Loading long cases, without the knowledge of their length just to get the case crimped into the cannelure (groove), is going to eventually cause you problems with rounds that will not chamber, except only by compressing the bullet deeper into the case as you force the breech closed.

Take one full length sized unprimed case that has been trimmed to max length.  Cut the case lengthwise from mouth to shoulder (if caliber is a shouldered case).  Insert a bullet into the case mouth.  It should fit snuggly but not fall freely.  Carefully insert this dummy round into the chamber and ease the rifle closed. 

Carefully extract the round and measure its overall length with a micrometer.  WRITE IT DOWN.  This is the true length of your chamber for that case and that bullet to TOUCH the lands of the rifling.  Is the bullet cannelure at the case mouth?  Probably not.  I suspect the cannelure has farther to be compressed into the case before being even with the case mouth.  That's OK.  It gives you some "wiggle room".

In a single shot rifle you have flexibility in making the rounds longer (near or touching the lands - but not jambed up there) or shorter.  It is not required to crimp the bullet into the factory cannelure, but if using cannelure bullets, the thinking is"Why not go ahead and crimp there?"

If you are already satisfied with the accuracy of your current bullet/powder/primer combination, experiment next with the length of rounds until you flush out another bit of acuracy.  Sometimes a rifle will shoot well with the bullet at or about 0.002" to 0.003" from the lands. 

Being a single shot means not having to load the rounds in a magazine, which could limit the cartridge overall length.  You do not have a magazine limitation, but the bullets can not exceed the total length measured above.

[Dances with Geoducks]

I have never paid any attention to the factory lines.
I put the bullet .005 off the lands on my bolt guns, and .015 for gas and lever.

[Autorim]

With rifle ammo, I never pay any attention to the cannelure on the bullet. I seat to about .020 off the rifling leade and go from there. I like single shot rifles because I can seat the bullet to any depth I want and do not have to consider magazine length. In some of my bolt actions, the maximum cartridge OAL is determined by the magazine and proper feeding.

[Dand]

Since you are using a single shot, magazine space and loading mechanism function won't be a worry for you - but it can be if you are loading for a magazine fed gun.

Still you need to be careful of overall length for other reasons:

Too long and the bullet may jam in the riflings; if you have too hot a load you could raise pressures to high levels.

Too long and a jammed bullet may remain jammed when an unfired case is removed; powder dumps all over in the action making a mess; it can be hard to get a jammed bullet out; or if you don't notice the bullet in the barrel, loading another cartridge could REALLY jam the first bullet, telescope the second one into the case and you have a bigger mess - especially if you try to fire this.  Likely you'd notice it before you got 'round to pulling the trigger, but if you don't - its bad business.

Finally, different bullets from different makers have different shaped ogives (points) and can result in different overall cartridge lengths even with the same bullet weights.

And the cannelure (knurled ring around the bullet) may or may not be appropriate for your cartridge.  Some bullets may have 2 crimp grooves or cannelures for different cartridges: note some Speer bullets in 30 cal had one crimp groove for 30-06/ 30-40 and one for the 300 win mag.

So I do like others have said, learn where the lands touch a particular bullet in my gun in my cases. For hunting ammo I then seat the bullet a few 1/1000's deeper to be sure of easy chambering and removal. I establish the seating depth and THEN begin working up my load.

To find where my bullets touch the lands, I take a partially sized empty case and partially seat a bullet. Then try to chamber it. I keep seating the bullet deeper until I can barely chamber the round. Then I'll smoke the bullet or color it with a magic marker. Rechamber and see how much the lands contact the bullet by the scrub marks left on the bullet. I'll then seat the bullet deeper, recoat the bullet, rechamber until the scrub marks disappear. I may then screw the seater down 1/4 to 1/2 turn and lock the seater stem - this is for hunting ammo and for safety and easy functioning.

For target accuracy some folks like their bullets right on the lands, hard on the lands or like folks above said, a few hairs off the lands. There are special tools for this if you want to get fancy.

I guess this is a long way of saying that it isn't always necessary or even wise to seat bullets so the cannelure is at the case mouth. The one exception is when the bullet must be crimped. The cannelure is there to receive the crimp and hold the bullet firmly so it doesn't get pushed deeper into the case (esp in a tube magazine gun like 30-30 Win, 45-70) or back out from recoil in heavy recoiling guns. AND if you need to crimp but your best overall cartridge length doesn't place the cannelure in the right location, get a Lee Factory Crimp die and it will crimp your bullet where you want it.

I'd suggest you carefully read through several loading manuals regarding case length and overall case length and bullet seating - they really are pretty important.

[LaOtto222]

I like single shot rifles and pistols and have several of them. I do not crimp for these guns, so I do not worry about where the cannelure falls to the case mouth. I experiment with where the bullet sets in regard to the rifling and how far the bullet sets into the case, ignoring the little ring. If you have to crimp for any reason, then you set the seating die so the case mouth falls into the cannelure. Good Luck and Good Shooting

[mjbgalt]

seat a bullet in an unprimed case very long for cartridge.

color the bullet with marker. chamber it, and seat out or in until the marks from the rifling are faint. as long as you don't push the maximum on the charges, that's good to go with most rifles and bullets.