So I loaded up my first 20 rounds of .223/5.56. Lake Cty brass trimmed to 1.755", CCI #400 primers, 17.4 grains of IMR 4198 and 55 grain Winchester FMJ BTs with crimp ring seated to 2.200". I loaded these to the minimum or “starting” load from the Hornady 7th edition manual, which their data is from a 26" Remington 700. My only question pertains to bullet seating depth. I have read that many folks here like to crimp their AR brass. When I seated my bullets they went down into the case far enough for the crimp rings to be covered. I am not so much worried about crimping, but whether 2.200" is an appropriate OAL for the AR. I measured a round of factory XM193 and it was 2.250". Should I worry about this? This ammo is for blasting, 50 yards and in, and my main criteria is that it cycles the action and feeds properly. 3 or 4" at 100 yds would be nice, but is not really a priority. Does anyone else load for similar purposes? If so, what loading/ seating depth do you use? Sorry, I am new to reloading rifle rounds and tonight was my first time. Thanks for the help! If it helps, the rifle that will be eating my reloads is a BCM middy.
Don’t be concerned with your ammo loaded to 2.200" as opposed to 2.250". I generally load my 55gr .223/5.56 AR loads to 2.250". For a general purpose range/practice/plinking round, I don’t notice a practical difference in accuracy out to 100 yards by loading shorter or longer, so I keep it at 2.250".
I think a few other folks have noticed slightly better accuracy at the shorter overall length, but my rifle skills are not that good to be able to tell a difference.
Thank you for the info. My manual doesn’t cover playing with seating depth. So when lengthening OAL, I assume a little more powder is needed. Is there any rule of thumb as far as grains per thousandths added?
Your at the starting load, shouldn’t be a problem. General rule of thumb seating too short bad! Especially with max or close to max loads! Seating longer usually helps accuracy as your closer to the lans!
Max OAL is determined by the mag -right around 2.260" depending on the mag used!
No, not really. A few thousands of an inch doesn’t require more powder.
I’ve used a 55gr FMJ with 25.0gr of Ramshot TAC and used an overall length from 2.200" to 2.250", without adjusting the charge. It’s just not necessary in 95% of situations, in my opinion.
Your manual should give you cartridge dimensions including OAL (which defines the seating depth) as well as trimming etc.
The longer the round generally the more accurate it’ll be due to the “jump” from the chamber to rifling. However if the round you’re making is for inside 50 yard blasting don’t sweat it.
To get a good over al length I simply measure the length of the ammo I’m trying to replicate. Measure your favorite NATO 5.56 round and go to town and work on the velocity you want.
Went to the range to test my ammo today. I shot a total of 8 rounds because none of it seemed to have enough to cycle the action. I was not about to hand cycle 40 rounds and waste the components. However, POI was pretty much the same as XM193 at 50 yards. Looks like I need to up the powder a smidge.
Hornady load data (7th and 8th editions, at least) is notoriously mild. I’m not surprised that the minimum powder charge wouldn’t cycle. You may consider loading a few ea at .2 or .3gr increments and working your way up. Not only do they need to cycle, but I suspect you’ll want them to reliably lock the bolt back on an empty magazine, as well.
IMR 4198 is a bitch to meter, as I am finding out, and it also has been reported to not cycle in some ARs. I am thinking about letting my dad use the rest of mine (about 2 pounds) for his .222 Remington 700 and moving to H335 for my AR.
The greater the freebore, the lower the pressures & velocities, which is what happens when seating a bullet to 223 specs and firing it in a 5.56 chamber.
Measure the freebore the chamber has and seat the bullets accordingly
Unless he’s single loading, which I doubt, he’ll be limited to mag length which is about 2.265" depending on the mag. There’s no possible way to reach the lands unless single loading.
I don’t see how measuring freebore would help, but there are always things to learn. Please explain.
For the AR load to the cannelure and call it good. Crimp if you want (I don’t). As long as they fit in the magazine they will work. Someone else said that the accuracy will be bullet dependent, thats true. Don’t worry about the depth.
If it turns out the rifle has a 223 chamber, using the OAL of the 5.56 could lead to dangerous pressure spikes. Measuring the freebore in this case, is a precaution
If I know the maker of the round and the specs are there, I load to the length the book says. Otherwise I load to mid cannelure, which
alot of times seems to be around 2.245.
