.223 77 Matchking load questions

[RImike]

I have 100 rounds of loaded 77 grain matchking that I have loaded up with 22.5 grains of Varget. I have seen people go up to 23, 23.5 and even 24 grains. I am getting lower than expected velocity out of my Stag model 6. I am going to re-chrono this weekend to confirm everything. I have played around with the reload data and ballistic calculations and noticed that if I can get to 2800 FPS, the load really flattens out to 200 yards. I will post back here tomorrow my findings, but I would really like to at least get my velocity to 2650 fps. Right now it's a tack driver at 200 yards, shooting 1" groups, I have been reading about this load and when velocity goes above 2800 fps, accuracy greatly suffers.

Thoughts?

 

[xtry51]

I haven't gone that high with Varget, but I've gotten pretty brave with 4320 and 77gr Sierras. The real question is the grouping. It doesn't doesnt make sense to me to push it higher unless your groups stay good and your POI doesn't get wonky.

Personally I'd just go .5gr increments with 3rds each in an OCW test until you see pressure signs. Then evaluate the POI.

 

[EddieCoyle]

I use 24.1 grains of RL 15

 

[PatMcD]

Keep dumping powder in it until you start piercing primers, then back it off .5 grain. I bet that will end up being around 24.5 grains.


P.S. don't do that.

I used 24.5 of RE15 for years with no problems.

 

[Hoon]

I guess i'll see you at TRG tomorrow, Mike.

OCW for me with 75s and Varget is about 23.1gr.

Max load for a 75gr with Varget in a 5.56 chamber (60,000 psi instead of the .223/55,000 limit) is 24.6gr, so you should have quite a bit of room to lean on that load from where you're at now.

I've seen as high as 25.5 on a 75gr A-Max (1000yd competition load) in a Tikka T3...not saying i would attempt it without careful consideration and testing, but it's been done (with fantastic results).

I've got some testing to do with my AR. Just hoping to hold 1 MOA with my 16" Carbine and cheap 1-6x glass.

 

[mac1911]

Im not sure how much you gain with a 24" barrel..... model 6 is the varmint gun correct?
Sierra 5th manual has varget starting @ 22.6, 2400fps and max 23.9, 2550fps out of a 20" AR.

 

[highscore]

All my service rifles shoot knots using 23.8 grains of Varget and 77 grain Sierras. If you want to load 80's, boost it to 24.5.

 

[josh2600]

All my service rifles shoot knots using 23.8 grains of Varget and 77 grain Sierras. If you want to load 80's, boost it to 24.5.

up charge for heavier bullet?

 

[johnN]

I played with mine last summer and tried making a load like the mk262. I got the velocity up around 2800 2850and targets looked like buck shot. backed the load down to 2600 to 2650 and was much tighter. going to play with again soon now that I have better dies and powder measure. this is with r-15 and a 18 inch barrel.

 

[PatMcD]

To get back to your original question:

24 grains of Varget under 77's is a pretty standard load for AR's. Some go 24.5 with it, but you'll want to be using a hard primer with that.
Most everybody in our game uses loads way past published maximums.

I don't own a chrono. I choose a load by how accurate it is. That's usually the one with the most powder in it.

 

[EddieCoyle]

I choose a load by how accurate it is. That's usually the one with the most powder in it.

With rifles, I find this to be true much more often than not, with many caliber/bullet combinations.

 

[RImike]

Im not sure how much you gain with a 24" barrel..... model 6 is the varmint gun correct?
Sierra 5th manual has varget starting @ 22.6, 2400fps and max 23.9, 2550fps out of a 20" AR.

Yes, it has a 24" barrel in 5.56. It is surprisingly accurate, right now I am shooting 1" groups @ 200yards

To get back to your original question:

24 grains of Varget under 77's is a pretty standard load for AR's. Some go 24.5 with it, but you'll want to be using a hard primer with that.
Most everybody in our game uses loads way past published maximums.

I don't own a chrono. I choose a load by how accurate it is. That's usually the one with the most powder in it.

I find it's helpful to get a fps reading for ballistic data, and then verify POI at various range.

I am going to try 23.5 next batch and see how the grouping goes.

 

[mac1911]

I know its not 1" groups but here is a quick test I did a few weeks ago in 20'F 20mph winds at 100 yards slung up with my RRA NM service rifle. Varget , Nosler Custom Comps. 8 shots per group
Picture needs to be rotated left 90'. I am more than pleased with the 2 good groups now I just have to do that at the matches and get them in the middle! last 2 shots on the 23.8grain target I put a little adjustment to the front sight to get closer to the X

 

[jtnf]

Rotated, cropped, and color corrected.

 

[PatMcD]

To back up a little, what range and what target are you intending to use this at?

Everything I have referenced in this thread is basic Highpower rifle data: known distance targets out to 600yds that only require 1MOA or so in accuracy.
77's are really only needed at 300 yds and beyond. They are probably not the most accurate bullet in any rifle, but offer a combination of good accuracy and good wind-bucking abilities.
If I were to shoot exclusively out to only 200 yds and closer, I'd probably look to something in the 55 grain (match grade, flat-base) department. For some reason, people seem to get bench rest accuracy out of them.

 

[EddieCoyle]

If I were to shoot exclusively out to only 200 yds and closer, I'd probably look to something in the 55 grain (match grade, flat-base) department. For some reason, people seem to get bench rest accuracy out of them.

You need the right barrel for them though. In my experience, those types of bullets shoot best when loaded into the lands, which you can't do with most ARs.

 

[RImike]

I am shooting at 200 yards and out. At 200 yards, I currently am getting 1" groups which I consider quite good. However, the velocity is quite low and as I get out to 300 yards and more, the POI rapidly begins to drop off. I am looking to boost up the velocity to flatten out the trajectory. Currently velocity is at 2450 fps with 22.5 grains of varget. I am considering going up to 23.5, but calculated velocity looks to be about 2550-2600. My concern is that my current groupings would expand. If the groupings stay the same and I can flatten out the trajectory a bit, then I might go up to 23.5 grains. Does anyone shoot 77grain matchkings out of an AR loaded with 23.5 grains of Varget and get good grouping?

 

[Hoon]

Hope you're not heading out there to test today. The wind will ruin the results. I was getting 1.5 MOA yesterday, all horizontal spread, from a rifle that typically does sub 1/2 MOA @ 200.

 

[RImike]

Hope you're not heading out there to test today. The wind will ruin the results. I was getting 1.5 MOA yesterday, all horizontal spread, from a rifle that typically does sub 1/2 MOA @ 200.

No, I am going to get a really calm day.

 

[highscore]

up charge for heavier bullet?

I don't have the velocities handy, but these charges shoot very well from 200 to 600 yards. When we started highpower, we went to 25.3-25.5 for the 80's but would pierce primers once in a while. 24.5 to 24.8 shot VERY well at 1000 yards.

And yes, the best shooting ammo isn't always the best numbers off the chronograph. Does get you in the ballpark.

 

[Jasper]

forget a chronograph unless you NEED to hit a specific number (i use one for my palma stuff, but only because I really need to be @ 2950-3000fps on a 155 to make sure its not subsonic @ 1k)

for 77s, most of us (high-power shooters) are shooting 24-24.5 of varget/re15 under a 77SMK/Nosler/etc.

its a warm load, thats for sure...but we're also shooting CLE/Wylde chambers (which in all reality should boost pressures a bit more than normal)

my 77's group ~ 1.25-1.5" @ 300yds off bags / with a scope. they shoot better than I need them to.

stick with loading them mag length. Ive seen people try to seat 77s out farther, to "improve accuracy". complete BS. its a tangent ogive bullet. they like to jump....a LOT. accuracy suffers big time when they dont.


FWIW, i have chrono'd my 77s out of my 20" service rifle barrels. @ 24.1gr of RE15, i typically see 2725-2750FPS. I dont shoot them @ 600, so i never felt a need to push em beyond that, but they shoot lights out @ 200/300



as for shooting MORE powder with a heavier bullet....realize that you cant load an 80gr SMK to mag length. these are single-load only, typically .010-.030" off that lands. pressures are actually a fair margin lower than the identical 77SMK mag length load.

 

[RImike]

I suppose what I am trying to accomplish here is to get my loads to fly a flatter trajectory as I intend at shooting at various distances that I have to range then calculate POI, with a higher velocity load, the round flies flatter, but accuracy might decrease. I intend on doing some test loads with 23.5 grains of varget and see what my grouping is. The last thing I have is when the loads are chrono'ed, I place it 10 feet from the muzzle, that distance shouldn't create a deviation between muzzle velocity and velocity at 10 feet out, correct?

 

[Jasper]

WHERE do you want it flat? 10' to 300yds is impossible, at least with a 223

10' you'll be 2" lower than 50yds, then 2" above muzzle @ 50yds, about 4-5" @ 100, and back down to 2" around 200yds, to ~ 7" lower @ 300yds

want a flatter trajectory....shoot a lighter bullet a LOT faster

 

[RImike]

WHERE do you want it flat? 10' to 300yds is impossible, at least with a 223

10' you'll be 2" lower than 50yds, then 2" above muzzle @ 50yds, about 4-5" @ 100, and back down to 2" around 200yds, to ~ 7" lower @ 300yds

want a flatter trajectory....shoot a lighter bullet a LOT faster

I don't want it flat, just a flatter trajectory then the current loads are. I am going to try and reach out to 600 yards with it, my only problem is that the calculated POI (124 inches) might drops more than scope adjustment allows.

 

[xtry51]

I don't want it flat, just a flatter trajectory then the current loads are. I am going to try and reach out to 600 yards with it, my only problem is that the calculated POI (124 inches) might drops more than scope adjustment allows.

Which scope isn't giving you 21MOA of adjustment?

 

[Jasper]

I don't want it flat, just a flatter trajectory then the current loads are. I am going to try and reach out to 600 yards with it, my only problem is that the calculated POI (124 inches) might drops more than scope adjustment allows.

youre overthinking things

zero @ 100yds

2MOA up to 200

2.5-3MOA up to 300

11.5-12.5MOA up to 600


if you run out of adjustment, put a 10-20MOA rail on the gun. I have to use one on my LR rigs, as even my NF's (90 or 100MOA of elevation) run out without a pitched rail.

 

[xtry51]

youre overthinking things

zero @ 100yds

2MOA up to 200

2.5-3MOA up to 300

11.5-12.5MOA up to 600


if you run out of adjustment, put a 10-20MOA rail on the gun. I have to use one on my LR rigs, as even my NF's (90 or 100MOA of elevation) run out without a pitched rail.

I assume he wants to stick with a 50/200 zero, but either way he should still be ok adjusting for 600 unless his scope or rings are jacked.

 

[mac1911]

Question: Why not try a powder that at least by published data get you closer to the higher velocities. The Sierra 5th on page 222 under the 223(AR) loads has
TAC data running 2750fps out of their 20" rifle on their listed max charge and AA 2520 maxing out at 2700fps Sierra data on other powders for the 77gn MK all run to 2650 or less.

sierra data http://accurateshooter.net/Downloads/sierra223ar.pdf