Reloading .223 with a longer COAL question

[Lucky Scott]

I have been reloading for only a couple years. Not an expert, but everything I load works well. I have been loading 7mm rem mag for long distance/precision and .223 for plinking. Plus, several pistol calibers. I now want to try to load the .223 for more precision.
I have been loading 55 gr. and 75 gr. AMAX and 69 gr. SMK. However, I have been limited to the length that will fit in a magazine for a AR15.

I just got a single shot magazine follower so that I can easily load and shoot one round at a time and would like to increase my length for more accuracy. I am shooting out of a 1/7 twist barrel. I know a longer cartridge over all length will be better but am unsure on how to determine the length?

Any suggestions ?

[highpower790]

make a dummy cartridge using a sized piece of brass and bullet of choice.seat bullet long ,place in chamber to verify it wont chamber.Turn seating stem down and repeat until cartridge chambers,being able to pull out with your finger nail at the case rim.
you will be feeling for shoulder on shoulder contact when you get it right and case will fall from chamber.

[Carsgunsandchics]

There are a few ways of getting your measurement. And you will have to find out what your rifle actually likes for setback. Some run no setback and others all the way back 20thou. I'm having real good luck with 10thou setback and an overall length of 2.300 in my AR and Rem700 using 75gr hpbt from Hornady. https://www.youtube.com/watch?v=WCPgKNp8i7o

[Lucky Scott]

I have that Hornaday gauge. I just wanted feedback from the Calguns community before sitting down and using the gauge

[highpower790]

I have that Hornaday gauge. I just wanted feedback from the Calguns community before sitting down and using the gauge

I inherited a Hornady guage after many years of using the method I described.What I found when I compared the Hornady guage to my old way of doing things was that"I" was no more than .020 off of what the red tool had to show me.

[baih777]

I have that Hornaday gauge. I just wanted feedback from the Calguns community before sitting down and using the gauge

use the guage. if its a Remington rifle, you will only gain .010.
if you want more then you will need a gunsmith to make the throat deeper, but then you will be limited to that COAL and single shot for ever.

you can also convert you rifle for a AICS mag. it will hold a longer cartridge, but then again you will have to have a gunsmith make the throat deeper and stuck to that length.

I reload 223 for my bolt actions also. but I limit myself to 69gr. 52gr is really a fast load.

[Top Cat]

The goal is to find the load that is most accurate in your rifle, not necessarily the longest round.

Some bullets are designed to be shot at mag length and some are not.

Some bullets/rifles will shoot better with a slight gap to the lands, and some bullets will shoot better slightly touching.

Generally, the only reason to shoot longer than mag length in an AR is when using a longer bullet that is too long to fit in the case neck, like some Bergers and the Hornady 75 Amax.

[Lucky Scott]

The reason i want to be able to go longer is so i can use the heavier projectiles like the AMAX 75 gr. I have been shooting these projectiles but have had to load them too far into the brass to make them wrk with the mags.
My goal is to shoot farther and the heavier projectiles should help with that.
So far I have loaded some rounds at 2.300 and that seems to work.
Have not shot them yet though.

[OpenSightsOnly]

The reason i want to be able to go longer is so i can use the heavier projectiles like the AMAX 75 gr. I have been shooting these projectiles but have had to load them too far into the brass to make them wrk with the mags.
My goal is to shoot farther and the heavier projectiles should help with that.
So far I have loaded some rounds at 2.300 and that seems to work.
Have not shot them yet though.

Hornady's 75 HPBT or Sierra's 77 grain match kings are good for mag length ammo that is usable from 100 to 600 yards. Don't know what your chamber is but if you have Wylde or 556 NATO then you may want to try 24 or 24.5 grains of Varget with one of the two mentioned bullets. That combo has been vetted.

Also, if you want the best mag length bullet for .223, look no more - Lapua 77 grain Scenar.

[NorCalFocus]

Invest in a Hornady bullet comparator. It will allow you to measure from the ogive of the bullet instead of the tip. The tips of bullets are not uniformed and very. Yes even in tipped bullets like the AMax.

This is a great video going over the process using all the tools.

https://youtu.be/whln3B3DFAY