Light .223 load most accurate?

[Woodstock45678]

So I've started to do load testing (as compared to just picking a min load and loading 50 rounds at a time; learning curve I guess). I tested a group of .223 50gr HDY VMAX over 22.5,23.5,24.5,25.0,25.3 gr H335 (all in line according to HDY 7th). Weather was clear, calm, and cold, ~30deg. The COL (2.27") was longer than the book stated so that I was just off the lands in my Rem 700 ADL. My most accurate load was 23.5gr. Primers were just starting to show signs of flattening. Just to make sure that was correct, I loaded 25 more and shot the next day. All grouped at 1.02 MOA (It's not glass bedded and I'm not a good shot, hence the high moa).

So my question is: from what I've read and heard from the forums and guys at the gun store, 'hot' loads (borderline max) tend to be the most accurate. Is it odd that my mild load was most accurate? My 25.3gr load was as far spread as my 22.5gr load, which I thought was rather odd.

I know my load weights were correct. For load testing I weigh: digital scale-powder, analog scale-powder, digital-case empty, and digital-case with powder. If there are any discrepancies I start over.

 

[gdcpony]

Primers were just starting to show signs of flattening

I had this happen to me. I got punched primers on a min load. Make sure all the lube is wiped clean. It makes a huge difference. I went to neck sizing after and never lubed again for the Howa I was using. It helped with the accuracy too.
My best loads tend to happen within 1gr of max.
My .223 Howa liked 27gr H-335 w/ 40 NosBT's (28 is max). 27gr Varget is right now behind my AR load w/a 55gr SP which is .5 from max.
My 257Roberts is best at 40gr Varget w/ 100gr SPBT and that is over max (Unless loading +P).
I won't say it always holds true, but the fact that you are seeing pressure signs so soon means something is up.

 

[Woodstock45678]

I thought primers flattening out were a sign of the pressures being fine; on other light loads usually my primers back out about .002" with no signs of flattening.
Would my COL have anything to do with it? I would think a longer COL from the listed would create lower pressures and less accuracy, and would cause the primers to back out.
Also with the 25.3gr charge there was a very noticeable difference in the recoil, even compared to the 25.0gr charge. That might have been part of the inaccuracy, considering my 'bench' isn't heavy enough to handle larger recoil.

Should I try again and move from 25.0-26.5 (I think 26.5 is max, I don't have the book in front of me right now)? And what increments? I would guess .2 gr

 

[longdayjake]

my .223 load is 23 grains of whatever .223 powder you might choose and 62 grain bullets. The POI changes depending on how fast or slow the powder, but 23 grains seems to give me the most accuracy out of my gun. It also works just right in my gun so that I don't have to trim the necks. I have loaded casings so far 6 times without having to do any brass shaving.

 

[gdcpony]

I thought primers flattening out were a sign of the pressures being fine; on other light loads usually my primers back out about .002" with no signs of flattening.
Would my COL have anything to do with it? I would think a longer COL from the listed would create lower pressures and less accuracy, and would cause the primers to back out.
Also with the 25.3gr charge there was a very noticeable difference in the recoil, even compared to the 25.0gr charge. That might have been part of the inaccuracy, considering my 'bench' isn't heavy enough to handle larger recoil.

Should I try again and move from 25.0-26.5 (I think 26.5 is max, I don't have the book in front of me right now)? And what increments? I would guess .2 gr

I would consider a flat (no division between it and the pocket wall) primer a bad sign. I thought this was what you meant.
.223 is a very low recoil round even with the heaviest loads. Any bench capable of handling a .22 should be fine. Heck even prone on the ground fine.
COL will have everything to do with the accuracy. I can't say forget the books as they are meant to provide safe loads for any gun built to spec, but not all barrels are the same. There are tons of ways to figure out how deep to seat your bullets. They even sell gauges for it. Here is what I would do. Drill out a case from the primer end. Make it big enough to fit a rod into. Then size it and seat a bullet you plan to use barely enough to stay in straight. Next chamber the round. Closing the bolt will seat the bullet and push into the rifling slightly. Extract the shell and rechamber it again to finish your custom depth. Then you can subtract .001 and start from there. The drilling in the bottom is for this method. Seat the bullet by the book and toss the round into the chamber with the bolt removed. Use the rod to tap the bullet out till it touches the rifling (it will stop moving). Tap the round out from the muzzle end and use that minus .001 for your depth. I'm sure others have other ways, but these are the 2 I use.
Powder charges. I load ten rounds each in 1 grain increments. if the min is 23.5 and max is 26.5, I will load 23.5, 24.5, 25.5, 26.5. Then I take the winner of that (I have done two groups of five and one group of ten and it doesn't seem to matter) and load +.5gr and -.5gr and the original. Let's say 24.5 won. My loads to follow would be 24, 24.5, and 25gr. Take the best of those and- if you choose- go in .1 increments up and down .3. I doubt you'll find a difference here unless you have a super-duper-pasture-poodle-plasterer that cost more than your house and you dedicate your entire life to the preparation of your rounds, but I could be wrong.

 

[3wide]

I would consider a flat (no division between it and the pocket wall) primer a bad sign. I thought this was what you meant.
.223 is a very low recoil round even with the heaviest loads. Any bench capable of handling a .22 should be fine. Heck even prone on the ground fine.
COL will have everything to do with the accuracy. I can't say forget the books as they are meant to provide safe loads for any gun built to spec, but not all barrels are the same. There are tons of ways to figure out how deep to seat your bullets. They even sell gauges for it. Here is what I would do. Drill out a case from the primer end. Make it big enough to fit a rod into. Then size it and seat a bullet you plan to use barely enough to stay in straight. Next chamber the round. Closing the bolt will seat the bullet and push into the rifling slightly. Extract the shell and rechamber it again to finish your custom depth. Then you can subtract .001 and start from there. The drilling in the bottom is for this method. Seat the bullet by the book and toss the round into the chamber with the bolt removed. Use the rod to tap the bullet out till it touches the rifling (it will stop moving). Tap the round out from the muzzle end and use that minus .001 for your depth. I'm sure others have other ways, but these are the 2 I use.
Powder charges. I load ten rounds each in 1 grain increments. if the min is 23.5 and max is 26.5, I will load 23.5, 24.5, 25.5, 26.5. Then I take the winner of that (I have done two groups of five and one group of ten and it doesn't seem to matter) and load +.5gr and -.5gr and the original. Let's say 24.5 won. My loads to follow would be 24, 24.5, and 25gr. Take the best of those and- if you choose- go in .1 increments up and down .3. I doubt you'll find a difference here unless you have a super-duper-pasture-poodle-plasterer that cost more than your house and you dedicate your entire life to the preparation of your rounds, but I could be wrong.

Sorry if this is a stupid question but would .001" off the lands be ok for an AR?

 

[hershey]

well for plinking rounds i load exactly the same as longdayjake, and have found that is a very good overall load when bouncing from gun to gun mostly w/ mag feeds, i have not experimented much for general use ammo because this was my 2nd try and it ran so well i quit experimenting.

on bolt or target guns you gotta take all kinds of things into consideration, twist, barrel length, etc., a round that works well in a 16" ar-15 application could probably be improved on considerably when fired in a 24" barreled bolt gun, that extra 8" of barrel is not gonna do much to help you if the powder has done all its work in the first 16"s. i am closer to a beginner than a veteran, but my first big lesson in reloading was when i bought a 1-16 twist .223 barreled gun, it took some fellows here on this sight to help me figure out what was going on, but once i did, damn that gun would shoot. i shot a 62gr. bullet through it and it hit the target sideways, but 30gr bergers are wicked in it.

i have not found the rule that hot loads are best, if you are loading middle of the page applications for your bullet weight i/e not the fastest or slowest powder listed, then backing off of max is usually better. when using powders on the limits (high or low) of the page, that is where you sometimes discover some interesting loads. my thing is long distances, so i am usually playing w/ heavy bullets (sometimes heavier than most manuals publish) w/ slow powders...

for ar-15's you are limited to the limits of your mag, so setting the bullet out is usually not an option, unless you do like some of us and shoot it more like a single shot bolt gun that a semi auto.

 

[Woodstock45678]

I guess it was my understanding that you want a little bit of primer 'flattening.' IE the chamfer gap between the pocket and primer should be just slightly smaller than on an unfired load. This is what I was seeing with the 23.5g. Just barely a sign of flattening, almost indistinguishable.

As far as bullet seating, I found a sized case (or a once-fired case, can't remember) that was a little loose around the neck on my 50g VMAX, just snug enough where it wouldn't fall through but would still move under a little bit of pressure. I chambered it, carefully took it out, measured, looked for rifling marks, and then made a dummy round or two at length minus the length of the rifling marks. I made sure that the dummies showed no signs of rifling marks on the bullet. And it still fit in the magazine, so it wasn't too long. But was still longer than the listed COL. So I don't know what funny things it's doing to my pressures.

 

[Clark]

I bought a used Ruger #1V .223 on the internet, shipped to the FFL.

I cleaned the Copper out and put a VXIII 6.5x20x40 scope and a level on it.

33 gr Vmax, moly, 15 gr Blue Dot, 2.17", 3500 fps

Took it to the range and it shot a 0.46" 5 shot group at 100 yards.


I bought a $20 22 rimfire barrel 1 in 16" twist.
I put it on a $50 Turk Mauser and welded up the extractor.
I reamed out a .223 chamber with .250" neck, short throat reamer.
I drilled and tapped and bent the bolt.
I did a trigger job.
I loaned this $70 rifle a Leupold 40X scope for a few minutes.

33 gr Vmax moly 15 gr Blue Dot, 2.17"
0.95" 5 shot group at 100 yards.
That ugly rifle will never get another trip to the range, but it shows what can be done.