223 77gr SMK Load Help

[Jon D]

I need help working on a load for a 20" AR 223. I have a 7 twist kreiger barrel with a Wylde chamber. Due to the component shortage right now I want to use what I have on the shelf. 77gr smk's, lake City brass, Remington 7-1/2 or federal gold medal match primers, and varget or h4895. Loads have to be mag length. This will be used for the 200 and 300 yard stages in high-power.

Please provide input on what powder powder you would try out first, charge weight, neck tension, etc.

 

[Longtrain]

Sierra’s AR listing shows Varget 22.6 grs. as a starting load, maxing at 23.9 grs. and COAL as 2.260”

77’s will help you in the wind, especially IMO at 300. Then again, I used to shoot 52’s in the 200 yard stages, accurate with low recoil for sitting rapids.

For any XTC load you want accuracy and for the rapids, functionality, start low, make sure your load is accurate and that it ejects and loads reliably. You don’t want alibis in a match. The Wylde chamber will help feeding, one of the best chambers for XTC. Also make sure they’ll load in you mags easily.

 

[mac86951]

Both are excellent powders with 77s. 200-300y; your practice will be the biggest variable.

There's no magic with the 223 and 77s; here's what I've learned:.

1. Each barrel / rifle is different. Meaning some like Sierra, some like Nosler, and Berger 73 or 77 OTM should be tried. Lapua, and Hornady can also do well.

You've mentioned that you don't want new supplies so shoot what you have, but if you get frustrated, I've seen a manufacturer bullet change be a 1/2 minute group change at 200.

2. Varget may be a little faster than h4895; but at 600y; I've seen h4895 perform more consistently. Maybe this is due to lot-lot variation? I think it's because 3 varget kernels are about 0.1gr. both powders have low temp sensitivity so see what your rifle likes.

Weight charges carefully! My 223 WOA AR (20") showed me that the chargemaster 1500 scale wasn't accurate enough for 600y; I reverted to use it for the dispense and trickle up on a beam scale.

3. Dies! 77 is stuffed so far in the case that concentricity is super important! Forster worked best for me, but I still sorted foulers by concentricity.

I found great groups at 100; but testing at 200+ the concentricity was critical. My Wylde chamber is jumping nearer to 0.200" when the 77 is seated to 2.260"

4. Good Magazines; Pmags would take OAL 2.250 - 2.255"; but the C-Products and ASC mags would allow 2.265". Maybe a little thing but believe me it helps.

Most rifles like varget at 23.4 - 24.0. work up from start as Case Head Swipe will show you a pressure problem before anything else. I never got used to the powder crunching sound on seating those 77s...

Best of luck and I hope everything works out for you!

-Mac

 

[lb-ft]

Don't laugh too hard. It all came together for me with CFE223 powder in 223 Wylde 1:7.

 

[10XSHOOTER]

24.1 Varget with the 77gr. If you moly bullets 24.5 varget.

 

[Pawnee Bill]

Try some AR-Comp.

 

[mac86951]

Don't laugh too hard. It all came together for me with CFE223 powder in 223 Wylde 1:7.

During the last administration 'scare' I found at least 10 different powders that could do well. From a 20" barrel they all seemed to be ~ 2600-2650fps. 2700 might be possible, but that seems quite hot for case head swipe and very temperature marginal. (40 degree swings in competition are common in the SW)

-Mac

 

[Jon D]

So it sounds like something around 24 grains of varget is one load to work up to and try. Any suggestions for where I should try to end up at with the h4895? Being a little faster burning powder, it should be a little lighter charge. Just looking for a good ball park number.

 

[mac86951]

So it sounds like something around 24 grains of varget is one load to work up to and try. Any suggestions for where I should try to end up at with the h4895? Being a little faster burning powder, it should be a little lighter charge. Just looking for a good ball park number.

Another full case of powder; 21.5+. Don't start at these numbers work up. The gas system, your rifles leade and etc. Be sure to work up. 24.0 varget in one is way overpressure in another (23.5 tops in that one).

 

[PeteB]

G'day Jon,
mac has given you some good info, I use a straight pull AR15 clone with 77 for short range and may have some advise also. I use 77 SMK or Nosler seated for mag length with 23.4 of H4895 with moly pills. Don't have speeds handy but they shoot very well out of my 20" with a wylde custom .253" neck chamber. You can cut the centre front out of the GI mags which will get a seating depth around 2.330", this uses the front of the mag well as the front of the mag.
cheers Pete

 

[distinguished]

For 77's,
23.7gr Varget
23gr H4895
Our state team used 24 gr Varget with plain 77's but, it was slightly warm in my rifle (Kreiger 1-7.7 twist CLE chamber)
My most accurate load through 6 different rifles was 23.5gr N140 behind a 77gr Sierra.

 

[Jon D]

Interesting tip about cutting out the front of the mags. With the Wylde chamber there is going to be considerable jump for the 77's. No idea if that is allowed by the rules or not, but I can look it up. I believe on of my local shops still has a pound or two of n140 on the shelf. I my play with that if I get some time. With a bit of luck I can get a few rounds loaded over the next day or so and let you guys know the results. Thanks for all the help!

 

[CADDIE5]

Have several f class guys shooting AR 223rem with Wylde chamber that clean the f class target several times a season in our 300yd league competition with 23gr Varget 205M primer and Lapua brass. They have their HM Midrange card. They say it duplicates the Federal 77tmk gr gold match load for velocity.

 

[distinguished]

77's 23.5gr N140 oal 2.255" (mag length) at 200yds 2, 5 shot groups w/ 1 click left after the first group. Shot prone w/ sling. MR52 600yd reduced target.

 

[Jon D]

Distinguished, I'm fairly certain I know how you got your name. That is great shooting. Less than half moa hold, trigger break, and ammo! My wobble area is down to the x-ring slung up, but still working on breaking the trigger cleanly and making some good ammo. Up to this point for anything important I just buy loaded federal match. Hopefully I can come up with a great load like yours.

 

[Liven The Dream]

I need help working on a load for a 20" AR 223. I have a 7 twist kreiger barrel with a Wylde chamber. Due to the component shortage right now I want to use what I have on the shelf. 77gr smk's, lake City brass, Remington 7-1/2 or federal gold medal match primers, and varget or h4895. Loads have to be mag length. This will be used for the 200 and 300 yard stages in high-power.

Please provide input on what powder powder you would try out first, charge weight, neck tension, etc.

Jon,
Old Service Rifle Governors 10, Distinguished and 13c years at Camp Perry. ( think I shot a lot ).

AR 20" Barrel ( I never found 77gr. Sierra or Nosler my go to). Hornady 75 my heart beat.
Brass LC (2018 much lighter than older years). Primers Wolf SRM , Federal AR , 205M ,Old White Box Winchester .
Never got the Remington 7 1/2 Bug.
Powder R-15 or N-140 Same? 24.0 to 24.5 grs.
I have a White Oak 24" Optic Barrel Testing right now.
LC 2018 Brass (prepped and weight sorted ). Wolf SRM , World Powder S062 24.1 gr. 75 gr. Hornady Mag length.
It will clean a 600yard F-Class Target at 485 yards. ( back yard range ).
I find S062 to be great for AR's.
The same load with 80gr. Nosler will clean that 600 target at 600yards today 150-11 and 149-8 on a ShotMarker.

If you go back in time ! The Wisconsin Jr. Team set Camp Perry on Fire using 75 gr. Hornady Bullets !
We found shooting them on the Runt Target (300 reduced ). 75's at .020 off shot better than 80's .
Best of Luck

 

[LVLAaron]

Mag length 77s and 24 grains of varget. You'll find this recipe a dozen times on every forum that discusses service rifle. Ask me how I know!

However, I've switched to AR-Comp for my gas guns... much higher velocity, excellent temp stability, etc etc etc. (24g of AR-Comp on an 80g going ~2900FPS out of a 20 inch barrel.)

 

[Della]

“80g going ~2900FPS out of a 20 inch barrel”

That’s smokin. Just today I was testing 24.2 gr of Varget & Fed 205m in a 24” bolt rifle. Shoots 80 SMKs great (1/2 MOA at 500) and 2850 fps, but after 50 or so rounds and warmer temp (about 80*) I started to get nervous with a cratered primer or two.

Was thinking I may need to drop it down a tad.

 

[natdscott]

Speed kills.

It’s a .223 AR, not a .22-250 bolt gun.

Know the difference and work on Offhand instead of f#**ing with loads.

 

[chkunz]

I got good accuracy and velocity with 23.1 grains of H4895 in a similar gun. The Varget will get good accuracy also but probably less velocity.