223 COAL Beyond Book Numbers

[sawacs]

I would like to try some Sierra 77gr SMK's in one of my ARP 16" 223 Wylde barrels and will be seating the bullets .020 off the lands.

My question is how should I change the powder charges based on the numbers from Hodgdon's load data site?

For example.. Hodgdon lists the starting charge, based on H4895, @20.0gr and a max charge of 22.6gr which turns into a compressed load. The COAL is listed as 2.260"

The new COAL which places the 77gr bullet .020 off the lands is 2.343".

Should I deviate from the listed powder charges and move upwards a little for a starting charge?

Advice would be appreciated!

 

[varmintshooter]

I'm not going to answer your question but I will say the book is a guide. By seating the bullet longer pressure will be less. Learn what pressure signs look like and work up your own load for your gun. Not to be a wise azz but each gun is difference. I'm sure someone here will be able to help.

 

[DLH_]

I’m also not going to answer your question directly. But just think how different the SAMMI spec chamber of a 223 is compared to an FTR chambered 223. Like afore mentioned, manuals are simply a guide.

 

[gpoldblue]

I would like to try some Sierra 77gr SMK's in one of my ARP 16" 223 Wylde barrels and will be seating the bullets .020 off the lands.

My question is how should I change the powder charges based on the numbers from Hodgdon's load data site?

For example.. Hodgdon lists the starting charge, based on H4895, @20.0gr and a max charge of 22.6gr which turns into a compressed load. The COAL is listed as 2.260"

The new COAL which places the 77gr bullet .020 off the lands is 2.343".

Should I deviate from the listed powder charges and move upwards a little for a starting charge?

Advice would be appreciated!

I would take the book max load,back off 1.5 gn and work up in .2gn to .3gn increments. You MIGHT be able to exceed book max a little bit.
Be safe. Dan

 

[hikfromstik]

https://www.google.com/url?sa=t&sou...FjAAegQIARAB&usg=AOvVaw0ewAFy0QVDzkj9RAWDK5Lw
These are AR loads

 

[rammac]

First of all I wouldn't recommend using the Hodgdon's load data, they are hit and miss on keeping their load recommendations current.

Secondly, if you are using an SMK bullet then I'd recommend using Sierra load data.

As for your question about the powder charge, you might be able to add another couple of tenths of a grain but not much.

 

[sawacs]

Much appreciated for the information gents!

The Hodgdon data was just an example. When I am loading, I find a charge in one of the reloading manuals then cross reference with other loading manuals to make sure I am in the ball park.

If manufacturers data deviates substantially, I'll call that manufacturer and ask why.

The reason I am asking about seating depth is I have never adjusted seating depth to find an accuracy node but rather always went with the book numbers.

Maybe Quickload would be a good investment

 

[LVLAaron]

Quickload is a great help if you can measure your fired case capacity.

But 77SMK's are built to be mag length loaded... So don't spend too much time, money, or barrel life monkeying with it.

 

[jepp2]

Should I deviate from the listed powder charges and move upwards a little for a starting charge?

Advice would be appreciated!

Do you have previous experience with the lot of H4895 you will be using?

How do you determine max loads in your AR?

The answer to those 2 questions will pretty much dictate how you should proceed. I use QL for all my development work and I shoot everything over a Chrony. And while I understand that velocity isn't always directly correlated to pressure, I have enough experience with reading pressure signs (in my bolt guns) to have confidence in finding the max load. I use this for my AR load development.

 

[Bc'z]

Maybe this will help ya a lil bit,I did this on our 6x45
window the front of your magazine with a die grinder/dremel tool. Now you can seat em out to mag well length.
I can seat to 2.37"coal, but they shoot in the high.2's at this length.
I'm not saying that it's ok for you to exceed max charge, but when "I " do , I go up in
.1 increments.
Edit, if you choose to window your mag remove follower and spring first.

 

[crustyrusty]

Quickload is a great help if you can measure your fired case capacity.

But 77SMK's are built to be mag length loaded... So don't spend too much time, money, or barrel life monkeying with it.

I just got done massaging my fourth savage magazine trying to get longer COAL out of the magazine... after 2 failed attempts the third time was the charm... I used my dental tools to work the inner plastic shim and high polished the rails,, then I took my rifle apart, reworked the feed ramp. saw where it was hitting on the face of the chamber... fixed it with my tools so I now have a new COAL of 2.395 with a 75gr hpbt, it places the boattail just up from the neck/shoulder junction... according to my scales I gained almost .8gr. To help facilitate feeding from the magazine I set the bullet back to 2.388 and all of my feed issues went away I am curious how a 80gr berger will fit with the new measurements!!!

 

[dstoenner]

I shoot 77 SMK in my bolt 223 loaded at 2.340. When i load for mag length my load is 23.5 Varget. When i load for my bolt gun i use the same laid i use for 80 smk at 2.450+ coal. That is 24.0 Varget. I have not seen any issues and it hammers. Stopped load development at the first load

I single load this in my AR15 but i use AICS mags in my bolt gun which allow up to 2.500 so no issues there

David