load development questions

[mapper]

the lee book I have does not go into the detail for working a load up that I would like,
I have seen articles on ladder testing, some charges for other pet loads, and powder manufacturers load data as start and max
as well as factory velocities of given projectile brand and weight

the caliber in question is 223, the powder is varget, cases are LC, primers are federal and the projectiles are 77 gr sierra hpbt, hornady 68 gr hpbt, and hornady 60 gr v max

oal will be 2.260 to fit in mags

from what I can see velocities of factory loads will be near max powder loads (within .5 gr for the most part)

I have seen articles on ladder testing and there are variations in the powder weight charge increments..

the question I have is where to start on the low end of the powder charge, and what increments to go in..

I have seen most loads posted that are between .2 and .5 gr below max

I'd rather not load from the bottom charge through the middle charge if there is no real benefit of it..
I'd rather start in the middle of the charge weight and work up..

any insight would be helpful

Thanks

[Arclight]

Mapper - Most of the Highpower shooters I know that use Varget and 77 SMKs are up around 24.0 gr and higher. 23.0 would be a good starting point.

[mapper]

thanks, from what I have seen , hogdon lists max at 23.7, and a I have seen posts of folks having sucess with 23.5, and 23.7

I'll start there..(23)

[Rumbler]

I don't have my book in front of me (I made my own), but 23.7 of Varget rings a bell with me. I am fairly certain I have used that load before without killing my gun.

[Arclight]

Mapper - You also need to watch the Federal primers for piercing when you approach max loads.

[mapper]

arclight, thanks for the heads up on that..
on these it was what i had..
any prefrence between federal. federal match, cci, winchester, and remington

[Rumbler]

I do not intend to stick my nose in Arclight's reply. I learn from that man every time he posts.

But I do have some input to offer on a FWIW basis.

CCI makes 'military primers'. They are harder than "normal" primers. Mapper as you know the AR platform uses a floating firing pin. I have never racked a round out of my poodle shooter, put there by the bolt stripping a round from the magazine, that did not have an indent in the primer from the firing pin. Never.

With that said, neither have I ever experienced an open bolt (or unlocked bolt) spontaneous discharge.

I honestly can't assess an 'issue severity' to that. But I have seen the indents, and I am aware that CCI makes hard primers because of it. So . . . . . .

I do not shoot .223 (or 5.56) match ammo. So I can't say what is 'best' for that purpose. But I do know that in my bolt (.308) gun I get better consistency over the chronograph from benchrest primers. When I can't find them, Federal match primers are very nearly as consistent over the chrono for me.

[Arclight]

Mapper - We stay away from Federal and the new Winchester SR primers because the cups are thin. Reminton 7-1/2, CCI BR4 and Tula SRM are used the most. The older Winchester SR (silver cup) are good also.

Rumbler - My statement about Federal primers was aimed at the SR primer. I use the F210M primer in our .308s. Most of the Longrange shooters use them, CCI BR2s or Tula primers. Back when I used F205M primers and hot loads of AA2520 behind 80 gr SMKs, out of 20 rounds, 4 or 5 would be pierced the rest would be heavily cratered. I quit using them (still have a bunch) and went to Remington 7-1/2s or the old WSR primers. The CCI Military primers are great for anything where rapid fire is involved.

Having seen the aftermath of an M1A firing out of battery I don't want to participate in one (cracked the receiver and blew all of the rounds out the bottom of the magazine). One of those incidents was blamed on a high primer so when the bolt came home that little mark you see from the free floating firing pin went deeper and set the round off before the bolt completely closed. Makes me check the primers after I install them (personal quality control). I know of one out of battery incident that almost cost the shooter his right eye, so no soft primers for me.

[mapper]

Arclight,
thanks for the "why"..
I'll use them in a bolt gun then, I have a 1:9 if it will stabilize them
or could go with the 68 gr hornadys, and the 60 gr v max..

any ideas about distance from the lands as where to start?

.015 a good enough place to begin if single loaded?

[Arclight]

Mapper - I don't think the 1in9 will stabilize the 77s, but should be OK with Hornady 68s. I don't know anything about the 60 gr V-Max.
For our single loaded rounds we jump 80gr, 77gr, 69gr SMKs .015, the same for Hornady 75s and 68s. VLDs we usually put them .010 into the lands.

[mapper]

if single loaded in a ar platform, and not stripped from a mag, with .015 jump,
any issues with the federal primers (1:8 twist on that one) otherthan soft, and watching for peircing and cratering..
I 'd like to see what the 77 SMK will do in it anyways..


it would not be a bad choice for me to try, as I know what the rifle will do with commercial ammo..
and I don't mind single loading..

[Arclight]

Mapper - All the information that I have given to you is based on our AR Service rifles that have 1in7.7 Kreiger barrels with Wylde chambers. When I was piercing primers I had a CLE chamber (extra virginal tight) and that might have been part of it. A 1in8 will shoot 77s and 80s just fine. The 77 SMK was designed to be loaded at magazine length for matches like the National Trophy Infantry Team (Rattle Battle) where you start at 600 yards and fire as many rounds as you can get on a target in 50 seconds.
As for the Federals, try them, if your not using super hot loads they may be fine, just start at a reasonable load and work up safely.

[mapper]

for higher charges out of the choice of federal,cci 400,or winchester primers what would be better
I,m trying for a single load that works well in bolt or gas gun, with similar lenght chambers
But diffrent lenght barrels

[Arclight]

Mapper check your PM

[mapper]

I loaded up 6 diffrent powder charges at 0.020 off the lands and headed out to the range, these were single loaded, 10 shot group 100 yds,

i'm going to shoot 2 5 shot groups next with the 24.1 and 24.5 as well as mag length and see where that takes me, primers looked good, at 0.020 from lands.. the 24.1 group had the most consistient velocity spread (29) the graph paper is 1/4" grid, and I did pull a couple of shots , comments welcome..this is out of the longest chamber rifle.

I was trying for a single load to try in a single shot, so that explains why loaded long..

1519
1518

1516

[Rumbler]

I believe that rifle can do significantly better.

I could be wrong but when I looked at those groups what came to mind was . . . . "it looks like he is breathing".

Remember to break your shot during the natural respiratory pause after an exhalation.

Again, I may be wrong and if I am I apologize to you. But that is what my spontaneous thought was.

[mapper]

1542154315441545

its indian error for sure..arrow is ok..

it seemed to like the 24.5 load, not much diffrent .020 or .100 off lands.. first 2 were mag length, next were loaded long.. 5 shot group

[mapper]

thanks to all..
these were my first reloads..
Dropping this off here for now,
Decent discussion on neck straightness
https://thefiringline.com/forums/showthread.php?t=610795