Cartridge Overall Length for a noob

[Badblue16]

I just picked up my first 204. A remington 700 sps varmint. I have some powder coming and the LGS actually had 40 gr Nosler BT. I reload for a few calibers but this is the first rifle I'm going to seriously tinker with with cartridge overall length. I also have an invasion of prairie dogs on my property and would like to reach out into the pasture they are invading from, with an all too welcome blessing from the farmer.

I have read through most of the COAL threads that I could find on here and have figured out that 204s love more jump than many other calibers. Noting this, I tried the marker trick with the noslers and to my surprise, when I pushed the bolt in, I felt no resistance, when I brought the cartridge back out and measured it, the lands only pushed the bullet in, on average 15 to 20 thou. I kept doing it over and over with the same result. That's far and away more jump than any of my other rifles.

So here's my question, should I start my experiments from the max coal in the book, 2.250 or 2.260 depending on the manual, or do I go straight to the minimal .20 in the case mouth and work backwards?? The magazine is a non issue as I don't use it.

This may seem like a simple question, but I really don't know where to start.

[Bill K]

Just a short answer or attempt at your question. The 204 R was designed to have a very long lead/throat, so you will probably never get to jamming bullets into the factory setting/chamber.

To do so, most rebarrel to a custom chamber. For the standard chamber, start with the listed seating depth and then start playing up and down with your rifle and seating to locate a seating depth/length that it likes, for a accurate load.

[Badblue16]

Ya, that's what I gathered, I just didn't know what most would recommend. Would you load increments at the book coal, and start playing with coal with the most accurate load from your incremental test?

[Badblue16]

Ha, nevermind, you already answered that, and I didn't read it correctly. Once you start moving it out, how far do you go, .010? .050? And then ballpark it from there.

[Rick in Oregon]

In my three factory barreled 204's, I load as long as the rifle will allow and still leave one bullet diameter in the case mouth. Seems to work well in the time I've been doing it; 2006. Play with seating depth at minus .010" and + .010" at a time and your target will tell the story.

In my custom 11-twist 204 with a chamber designed the way it should have been in the first place, I can reach the lands with any reasonable seating depth, but this is NOT possible with factory barrels due to the LOOOOOONG throat the caliber was designed with to achieve the fastest velocity possible. Personally, accuracy always trumps speed to me.

Dink about with the seating depth, and soon one target will tell you what your rifle really likes.

[Badblue16]

Loaded up some incremental stuff at 2.260. Gonna test it in the morning. Ill start moving it out after the results are in. Just scored a few pounds of Rx10