Am I over max?

S

Shadow9mm

New member
I just loaded 5 rounds for testing, .223 with 25.5g of varget with a 68g hornady match bullet over top of it loaded to 2.260, my max OAL to fit in the mag. I found a couple loads on Hodgins site for 69g and 70g bullets with a 26g max of varget paired with match bullets of the same weight and thought I was a 0.5g under but realized my bullet might be longer and be comporessing the powder more than the listed bullets (I used the closest style I could find).

Trying to decide if I should pull the bullets and start over or if these will be ok to shoot. I don't plan on loading that hot again, but I would rather run them over the Chrono than waste them.
 
69 grain data is close enough. So is 70 grain data. One or 2 grains won't matter. Same max load of 26.0(C) anyway. The '(C)' means compressed load. Nothing to worry about. Your 25.5 is compressed too.
However, do not just pick a max load or any load and hope. You have to work up the load from the Start load.
 
A longer bearing surface will produces more pressure.
BearingSurface_zpsbac6nfsu.jpg
 
I had already run the same load with 24g of varget and came in at an average of 2615fps, whereas factory 75g came in at 2735. I figured I am about 150-180 fps low. I figured 5rnds should be fine, at 0.5g under max just to get an idea of the upper limit since i already know im low. It was kind of a last minute thing at 2am in the morning, probably not the best idea, but I dont want to waste it.
 
That's not how this works. You can't just jump up 1.5 grains in a case like the 223.....Load up 5 others @ 24.5 and 25 grains and shoot those first. Your 25.5 loads are probably fine but there is a chance that they are not.....don't take that chance.
 
I never said it was a good idea, it was 2am and i had been working on progressive loads all night with a couple powders and i had a few casings left. I checked the numbers for the load and went under max, then realized with the bullet being longer i might get more compression than I anticipated.
 
i would say it was on the low side, not the hot side based on velocity. i was about 120fps below a 75g factory load with the load I already ran. That said i dont want to run max loads, im trying to hit about 2700fps with the 68g bullets. which the factory 75g bullets were at 2735fps
 
QuickLOAD shows the Hornady 68 grain match bullet at 2.260" raising pressure by about 3% as compared to a Sierra 69 grain seated to 2.235", as Hodgdon does when they use the same load. It suggests you would only need to reduce a 26.0 grain load to about 25.7 grains to get the same maximum peak pressure value with the bullets seated to those two different depths. You would need to reduce it to 25.6 if the seating depths were the same.

Note that all this assumes the throat is far enough away not to be a pressure issue. I don't know that it will be, with the 68 grain bullet sticking out further, so I would proceed as follows: It looks like 25.6 is a possible maximum load for your bullet, so you want to run a pressure check string of 6 rounds, with the first loaded with 23 grains of Varget, then the next at 23.6 grains, then 24.1, then 24.6, then 25.1, then 25.6. Check each fired case for pressure signs as you go up through the series. Assuming none, you are then good to go with your 25.5's.
 
I'm running a .223 wylde chamber which is safe for .223 and 5.56 so the throat should not cause pressure issues. I will load up some lower power rounds leading up to the 25.5g load to see where velocities are. I'm not trying to max my loads out, just doing testing to try to find out where I need to be to get the appropriate velocities, since I was way low last time. I figured 0.5g under max should be safe and i would know where i was between 24 and 25.5, but like i said, didn't account for the extra length compared to the SMK. I was loading up some 55g hornady fmj in 0.2 incremements last night, varget from 24-25.5 (i dont like compressing loads) and benchamrk from 23-25g (25.6 was listed max) had a few primes casings left and decided to throw a couple extra test loads together to get a little extra work done since my range is a 1hr drive.
 
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i would say it (pressure) was on the low side, not the hot side based on velocity.
Click to expand...
Trying to match factory velocity is a bad idea. No way to know what pressure will be. Look for pressure signs.
th_PressureSigns.jpg
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yes and no. factory loads should be well within the safe pressure range for a given bullet weight. Handloads should be able to match the peoformance of factory loads. That being said I would never exceed max to get there, i try and stay 0.5 under max at all times, and prefer to be a full 1.0g under max if i can. im looking for good accurate loads, with good factory velocities. im running a 16" barrel and am looking for about 2950fps with 55g bullets. I was hoping to hit about 2700-2750 with my 68g bullets. while staying within recommended loadings. i made a bad call at 2am, just trying to decide if i can shoot them and test them or if i need to pull the bullets and start over. I have no plans on loading over 25.0g of varget with that bullet again, but i already have the rounds loaded.

Dont worry, I am ALWAYS looking for pressure signs.\:D i like my gun, hands, and face just the way they are
 
final result, 25.5g of varget. No bad kaboom, no signs of pressure. based on the velocities produced, this will probably be my standard load.

average velocity 2749.2 fps
high 2784 fps
low 2721 fps
spread 63 fps
 
Shadow9mm said:
final result, 25.5g of varget. No bad kaboom, no signs of pressure. based on the velocities produced, this will probably be my standard load.

average velocity 2749.2 fps
high 2784 fps
low 2721 fps
spread 63 fps
Click to expand...
FYI for others:

I had cratered/flattened primers at 25gr of Varget under 68gr Hornady, ~2.260 OAL, ADI brass, Sellier&Bellot primer in a Savage .223.

Short-leade in my rifle and a lot of crunched powder most likely contributed. At 24gr everything was right as rain and smack dab in an accuracy node.



Sent from my SM-G920V using Tapatalk
 
final result, 25.5g of varget. No bad kaboom, no signs of pressure. based on the velocities produced, this will probably be my standard load.

average velocity 2749.2 fps
high 2784 fps
low 2721 fps
spread 63 fps
Click to expand...

The bottom line is how the load performs in your rifle. Most of my AR's have Wilson match barrels. Loads developed in those barrels blow and pierce primers in my Krieger barreled AR's. When you experience blown or pierced primers, cut the load by a 1/2 grain till you stop blowing primers. I had to cut my 68, 69, and 75 grain loads by 1.5 to 2.0 grains to keep the primers from being pierced or blown in those Krieger barrels. Guys would ask what load I was shooting and I was always well below what they were packing into the case.

And something else I found out, loads developed in nice 70 F weather will pierce in 90 F weather, and during rapid fire in reasonable weather. You have to shoot them under enough conditions to really be sure of their reliability under all weather and all conditions.

And when you change powder lots, expect to do it all again!
 
I started using Varget and 69 gr bullets in a 16 in HBAR before I could find any published data.Varget was a new powder.
Both Hogdon and Nosler sent me data via snail mail per my request.
I had already used my chrono to find "max" via incremental velocity increases.
We all agreed within .3 gr that 25.5 was max.I use WW cases,CCI primers.

I certainly agree with following recommended incremental workups.

To five and dimes comments,in a bolt rifle with a .223 chamber the leade/throat are different,and your experience is to be expected.

Given the OP's situation,Given the loads are at published max for a 69 gr bullet,given that Varget is an appropriate to slightly slow powder for 5.56..
Without giving advice,I'll tell you what I would do,for myself.
I'd shoot one,and read the primer.I'd shoot two more,and read the primers.I can say"Hmm,pretty heavy crater,and a shiny ejector spot" and quit there.

If all looked good,I'd shoot them all.The only thing I would do is segregate the brass.

You are not on the verge of blowing anything up with that load.

The 5.56 case is not real strong around the primer pocket.If those end upon the hot side,you may notice the primers seat a little too easy.
That's generally where the price of loading 5.56 on the warm side shows up.
And,I tend to regard loosened pockets as a reason to scrap brass.
So,I do not push my 5.56 ammo that hard.

For myself,25.5 gr Varget was my go-to load in my 16 in H bar.IIRC,it was good for 2750 fps with the 69 gr bullets.I leaned toward Noslers as they were a little more common and cheaper.That load shot very well,with no problems in my rifle.
Twist is something to consider.My rifle was 1 in 9.A tight twist,such as 1 in 7,would increase pressure,so excersize caution.

Slamfire,I am curious,were the loads that blew primers in your Krieger barrels something you would find published in a reloading manual? And,were they 69/68 gr?
 
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63,000 psi

modulus of elasticity- Cartridge Brass-
Material is 70 copper/30 zinc with trace amounts of lead & iron , called C26000. Material starts to yield at 15,000 PSI when soft (annealed), and 63,000 PSI when hard.
Material yields, but continues to get stronger up to 47,000 PSI when soft, and 76,000 PSI
when work hardened. Modulus of Elasticity is 16,000,000 PSI. This means to pull a 1.000 inch long strip to 1.001 inch long induces a 16,000 PSI stress.
So if you pull a 1.000 inch strip to 1.005 inch long, you get about 76,000 PSI, which is the max obtainable.
 
For what it is worth from the Hornady 9th Edition.

68 gr. BTHP
B.C.: 0.355
C.O.L.: 2.250"
Hornady Part #2278
Powder: VARGET
START: 22.7gr.
Maximum Load: 24.9gr.

This is the data from Hornady. Keep in mind Hornady is known for staying conservative with their load data. Hodgdon for example as was mentioned when pushing a 69gn Sierra Boat Tail:

69gr. BTHP
C.O.L.: 2.235"
Powder: VARGET
START: 24.0gn.
Maximum Load: 26.0 (Compressed Load)

Slight difference in the C.O.L. between the two for the different bullets. I wouldn't be concerned with your load of 25.5 gn. with a C.O.L. of 2.260. Shoot them and inspect them but I suspect they will be fine.

Ron
 
I'm reading the OP's posts and I have to assume you're loading for a specific range . 500+yards I assume ??? Not sure there's another reason to start with velocity first then look for accuracy second ??? With the 223 and AR mag length there's not a whole lot of fine tuning of the load available . You're pretty much stuck with your seating depth .

My load development ALWAYS starts with accuracy first . If the most accurate load is not producing high enough velocities . I start changing components to reach the goal I'm trying for .

Why are you looking for a specific velocity ?
 
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