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 (.30 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.