IMR 4198 load

[BigBore45]

Delete

 

[BigBore45]

Here is a link from American rifleman that explains 5.56 to .223. Reverting to the original argument that started. that states higher pressure in the 5.56. The throats are longer but the cases are identical on the exterior and 99% of the time the internal diameter of 5.56 is smaller. So that would make any .223 data loaded in a 5.56 case higher pressure anyways. Now every gun is different but he was not above a safe load for the 5.56 chamber but was above safe for the .223 chamber. No matter how they measure there pressure via SAMMI or NATO quick load still shows chamber pressure and measures that against the actual pressure from the test source.

http://www.americanrifleman.org/blogs/223rem-vs-556nato-is-it-safe/

And here is a full length version. FYI if you use 5.56 brass and .223 data you are overloading before you get to max in the book because of the reduced case capacity.

http://www.americanrifleman.org/articles/223rem-vs-556-whats-in-a-name/

 

[steve4102]

the sierra manual shows a max powder charge of imr4198 as 21.1gn for your bullet (this is in the 223 remington (ar-15) section. we normally show a warning in our posts when a charge is over the "book" recommended charge (we are a bit cautious here).

Sierra is one of the few, if not the only, manual published that does not "Pressure" test their loads/data.

They shoot their loads in regular rifles and check for pressure the old fashioned way, they guess. Not a manual I put much faith in as far as pressure and max loads are concerned.

 

[steve4102]

Here is a good read.

http://www.luckygunner.com/labs/5-56-vs-223/

 

[kerreckt]

I was once told that "if, your rifle doesn't shoot accurate with 21grs. IMR4198 and a 52 gr. bullet, then there's something wrong with your rifle". That was about 25years ago when I told an older gentleman that I was beginning to hand load .223. That statement has stuck and I have found it to be true many more times than not.

 

[heymarine1833]

wow. some of the posts here are raking me over hot coals. this how you treat new guys and new loads? jesus! not sure if i'll ever post another tack driver again. i have an idea! let's all talk about the same old loads over and over until we scream. can we be done with this argument now and move on? in the mean time, i'll send this load to the commandant of the Marine Corps and see what he has to say lol

 

[BigBore45]

I was once told that "if, your rifle doesn't shoot accurate with 21grs. IMR4198 and a 52 gr. bullet, then there's something wrong with your rifle". That was about 25years ago when I told an older gentleman that I was beginning to hand load .223. That statement has stuck and I have found it to be true many more times than not.

What if my AR-15 has a 1:9 Twist. I bet it would shoot a 65gr. bullet better than the 52 Gr. any day.

 

[Walkalong]

No necessarily.