C.O.L. Question for .243 Win/55 Ballistic Tip

[Guest]

This question is for anyone that has experience, but I would really like to hear what Nosler has to say.

I am getting ready to start load development with a .243 Winchester firing 55 grain ballistic tips propelled by RL15 and Federal 210M primers all housed in a winchester case.

The question I have has to do with seating depth of the little pills. I have read on other sites that deeper is better with these as they will not come anywhere near the lands in factory chambers (mine is a Ruger M77 with no modifications). How deep should I go? I have heard 2.600, 2.550, 2.650 and several in between. When the data for the reloading manual was tested, what COL did the technicians use for the 55 Bal. Tip?

Any other tips that will help are also appreciated.

Thanks.

 

[rick smith]

The old rule of thumb says to seat them a minimum of one caliber depth in the case.Rick.

 

[Blaine]

The trouble with the 243 is that almost any bullet less than 100 grains(and that is not a sure thing with some brands) is that you can't get them anywhere near the lands. I just loaded some 95 gr BT's and Part's yesterday and to get them to set .020" off the lands, I had to use a COL of 2.924 & 2.984 (respectively). I am loading them for an Encore handgun, so length is not a constrait for me. I didn't actually figure the depth of bullet in the neck, but believe me it isn't much. I use a Lee factory crimp die so I'm not as worried about not having enough bullet in the neck. I agree though, that 1 bullet diameter is normally a good rule of thumb. Below are listed the COL's for the 4 bullets I loaded yesterday with my favorite recipe (I wanted to see which bullet the load likes best). I also wanted to keep the distance off the lands @ .020" , which is the distance my gun likes best.

100 gr Speer Grand Slam = 2.910"
100 Nosl Part = 2.888"
95 gr Nosl Bal Tip = 2.924"
95 gr Nosl Part = 2.984"

Blaine

 

[rick smith]

One problem to watch for with minimum seating depth, besides bullet pull, is concentricity. The less in the neck, the harder is is to maintain a good straight bullet. Not a problem in a single shot but running them from magazine into barrel can move the bullet.Rick.