Some Advice, Please

[Achilles11B]

First batch of reloads are done! 75gr Hornady BTHP .223 to be fired from an AR15 (with a 1:7 barrel) in once-fired Federal Brass and CCI Small Rifle primers. Five batches of six with varying levels of H4895, ranging from 22.5g (recommended start point, according to the information from the Lee die set) to 24.4g (recommended max). I'm really looking forward to shooting them Sunday to test for accuracy.

My plan is this: 100 yard accuracy test with a 3-10x Leupold on the AR. The intent for the ammo is to be a 'general purpose' round, good for precise(ish) long distance (up to 500 yards) shooting but still being affordable enough to run sped drills. I have some factory 55gr FMJ that I was going to use to get bullets on paper, then shoot groups, then compare and contrast.

I am not an experienced reloader, when I say 'first batch', I mean 'first ever'. I'd love to hear about how you experienced guys conduct testing and if I'm on the right track here. Thanks in advance.

[flashhole]

H-4895 is a good powder for the 223 but you will find the 55 grain bullet somewhat lacking for what you want to do, especially if you start shooting beyond 200 yards.

[Achilles11B]

The 55gr stuff is loaded factory ammo just to get bullets on paper. I'll shoot that before I start with my reloads.

[Unclenick]

Achilles,

Since the AR is a floating firing pin gun, to avoid slamfires you need to be extra careful to be sure your primers are seated below flush with the case heads. The military uses less sensitive primers that are extra insurance against that and you can buy their sensitivity equivalents as CCI #41 and TulAmmo KVB-556M primers, but the main thing is, regardless of the primer you use, getting the primer below flush. Don't try to shoot cartridges with high primers in self-loading weapons with floating (no retraction spring) firing pins. Ideally the primers should be four or five thousandths below flush, so seat erring on the hard side rather than the gentle side when loading for these weapons. That tends to improve velocity consistency by setting the bridge in the primer, anyway. This article explains some about it.

Since you are interested in match accuracy, I would not run the 55's for sight-in unless you know they are also loaded with H4895 (and if I understood correctly that the are commercial loads, they won't be). An old rule of thumb is that it takes 10 rounds after a change in powder for the fouling pattern in the barrel to settle, so you'd do better to make up a few extra rounds of your starting load to foul the barrel and get your sight zeros with. Just drop by Wally world and pick up a couple of sheets of white poster board and staple them to the target frame side by side, long sides vertical. If you start with your sights near the bottom and aim at the center, you are almost certain to be on the cardboard somewhere.

For the firing sequence, the best method I know is the round robin. You set a series of bulls across your cardboard and fire a low charge round at the first bull, then a next larger charge at the second bull, etc., until you get to the top target. You need to examine the ejected case for pressure signs each step of the way. If you get pressure signs, stop shooting that load level or anything greater and just shoot up to the load below it. Assuming you find no real pressure signs, go back to the beginning target and load and fire your next bottom level charge and go around again. This method tends to spread fouling and temperature and other changes during the shooting session among the different loads so that one doesn't have the advantage of more stable conditions over another when you are firing them. Dan Newberry explains the system when you read through this site.

Newberry works with 3 shots per bull, but also looks for three groups in a row with the same average point of impact, so that's like looking at 9 rounds, collectively. He shoots mainly in charge increments of about .7% of maximum to get that effect without skipping too far ahead per shot. If your load increments are larger (2% steps are small enough when looking for pressure signs) then put more rounds on each bull to get a statistically better idea of the group sizes. 2% is big enough to skip over some sweet spots. I would not increment more than 1% looking for sweet spots, and like Newberry's 0.7% better.

I would fire at the rate you will use the ammo at. If you are in a service rifle match, you will have 1 shot per minute in slow fire. A lot of guys looking for sweet spot loads wait 5 minutes between shots to let the gun cool, but if you aren't shooting under rules that allow that, then there's no point in loading ammo that only works in cold barrels, so do what you actually want the ammo to do. You can shoot your fouling/sighting shots at the same rate just to keep it cool.

[Achilles11B]

I appreciate the advice, thanks everyone.

[flashhole]

You may find your gun does not like 55 grain bullets. My 223 is a bolt gun 1:9 twist. It will shoot 40 grain bullets really well and 63 grain and higher bullets really well. Everything in between gives horrible performance. Point being, if you start down the path with 55 grain bullets and your groups look more like a buckshot pattern don't blame it on the gun. Try a different bullet.

[Will Lee]

Hey Achilles,

First batch of reloads are done! 75gr Hornady BTHP .223 to be fired from an AR15 (with a 1:7 barrel) in once-fired Federal Brass and CCI Small Rifle primers. Five batches of six with varying levels of H4895, ranging from 22.5g (recommended start point, according to the information from the Lee die set) to 24.4g (recommended max). I'm really looking forward to shooting them Sunday to test for accuracy.

My plan is this: 100 yard accuracy test with a 3-10x Leupold on the AR. The intent for the ammo is to be a 'general purpose' round, good for precise(ish) long distance (up to 500 yards) shooting but still being affordable enough to run sped drills. I have some factory 55gr FMJ that I was going to use to get bullets on paper, then shoot groups, then compare and contrast.

I am not an experienced reloader, when I say 'first batch', I mean 'first ever'. I'd love to hear about how you experienced guys conduct testing and if I'm on the right track here. Thanks in advance.
__________________
Good equipment will never be a substitute for good training.

When changing or remounting a scope I bore sight my Varminter in this method:
Down the street on the side of a house at 50 yards is a sewer clean out plug.
I set my upper, Bolt carrier, removed and adjust my gun holder so that the center of the bore is lined up on the sewer clean out plug then I adjust my scope so the cross hairs are on the center of the plug, checking back and forth between bore and scope. I do this off the floor with the garage door just open. Don't want the local LOE showing up wondering why I pointing a gun at someone's house.
This method will put your POI at 100 yards with in 4 to 5 inch of your POA.