sierra match kings bthp 77 gr ?

[rebs]

A friend of mine gave me about 470 of the bullets, he bought 500 and they do not shoot well in his 1 in 9 twist AR. I have a 1 in 8 twist AR and on the box it says for 1-7 and 1-8 twist only.
Can anyone suggest a good starting load or your favorite load for these bullets ?

[bfoosh006]

.223 Load data from the manufacturer.

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

[Reloadron]

Pushing 80gn SMK bullets through a 20" 1:7 twist barrel I had some decent groups using both H4895 and IMR 4895. It can really vary rifle to rifle. Then there are always powders like H335, IMR 4064 and I also had decent groups with powders like the VihtaVuori N133, N135 and N140. If I recall correctly my best groups were with velocities around 2500 FPS and again those were the 80 gn SMK Match King bullets through a 1:7 twist 20" barrel. Your mileage may vary.

Ron

[Slamfire]

Take a look under

Reloading Stuph at

http://www.njhighpower.com/

Basically any powder in the IMR 4895 burn rate (which includes H4895 and AA2495) will shoot outstandingly in the 223 with the 77 SMK. Varget used to be a favorite and I think still is.

[Ifishsum]

I like RL-15 and Varget for those, within the Sierra publication linked by bfoosh. I'm usually in the 23.5gr range, YMMV of course

[Road_Clam]

The 77 smk's are the go to projectile for service rifle high power competition. They do favor faster 7 or 8 twist barrels. The sierra claimed "1-7" only" claim is not necessarily law :

http://thefiringline.com/forums/show...highlight=77gr

My testing proved that while the 77 gr bullet in my 1-9 twist Bushmaster was not the best suited condition it can be done even all the way out to 600 yds without instability:

In my WOA 20" match service rifle I am at 24 gr of RL15 , and 23.9 gr of Varget. Both loads shoot about 2630 fps. Both these loads shoot about .8 moa.

[Jimro]

1:8 twist is fine, it's what the AMU uses to shoot lots of 77gr SMKs.

Pretty much 24 grains of any powder in the IMR4895, IMR4064, Varget, Re15, or PowerPro 2000 MR range will shoot them well. As always do a good load workup and never exceed max charges, but generally you'll get a good 600 yard load around 24 grains of any suitable powder.

Jimro

[T. O'Heir]

"...good starting load..." 77 grain load data in your manual. Partial to using whatever powder is given for the accuracy load if your manual has that.
There's buckets of 77 grain data on Hodgdon's site. Just so happens they used a Sierra for their tests.
"...and never exceed max charges..." 24 grains does that with a lot of powders. snicker. 22.7 of IMR4064 is max and it's a compressed load.

[Jimro]

T O'Heir,

You are correct, that is what Hodgdon currently lists. I also know for a fact that 22.7gr of IMR4064 is not a compressed charge under 75~80gr match bullets.

Snickering aside, it's good to check multiple sources. The old IMR reloading books from 2005/2006 lists 24.0gr IMR4064 compressed for 75gr bullets, and 22.7gr Compressed for 80gr bullets. In fact the 80gr bullet data is exactly the same for max charges as the 77gr load data for all powders listed except for IMR3031 where the difference is 0.1gr. Also, for the given charges in that old book, the 80gr SMK has lower pressures with the same charge generally means something is screwy with the load book, especially since the 80gr were loaded significantly closer to the lands than the 77gr bullet.

But, you have to understand, before that year IMR didn't list load data for anything heavier than 55gr in 223 Rem, so it makes sense that they recycled the 80gr data they had for the 77gr loads and just hit "publish" and once Hodgdon bought out IMR they just kept publishing the same data.

So looking to the bullet manufacturer... Sierra lists 24.1gr of IMR4064 for a 69gr HPBT and 23.8gr of IMR4064 for an 80gr Boat tail, so right at 24ish grains (23.9 to be precise) is where the calculated max would be. http://accurateshooter.net/Downloads/sierra223ar.pdf

Then again, Hodgdon lists 24.0 gr of H4895 as max with an 80gr SMK, and Sierra lists only 22.9gr with the same bullet. Go figure.

But powders do change slightly with lots, so do the load workup.

Jimro

[kraigwy]

People who shoot 77 gr SMKs normally shoot them in competition.

That means a lot of handloading. I use to use RL-15 for 77s & 80s but switched to 69 gr SMKs for 200-300 yards.

The White Oak Web site suggest AA2460. It meters well and doesn't require weighing each charge.

I tried that and WOA is correct. Once the measure is set up, its constant. I use 23.5 in my 69 gr SMKs and 22.3 with my 80gr SMKs.

I still have a lot of 77s and I'm going to work up a AA2460 starting at my 23.5 69 gr load until I find a safe accurate load that suits me.

Try a pound of AA2460 and see what happens. If you need lots of accurate match loads I think you'll find it works pretty good.

[MarkCO]

I like TAC and AA2460 for the 77s. I shoot them in 1:8s and they do great.

[rebs]

With two AR 15 barrels being both 8 twist, one is 16" and the other 20", will one shoot 77 gr smk's better than the other ? What effect would barrel length have other than a velocity difference ?

[P-990]

Originally Posted by reb

With two AR 15 barrels being both 8 twist, one is 16" and the other 20", will one shoot 77 gr smk's better than the other ? What effect would barrel length have other than a velocity difference ?

The differences are only going to be whatever inherent quirks are between the barrels. Either one should shoot the 77gr SMKs fine.

As for powders, I've always preferred to stay with the stick powders with anything in the 69-80gr range in my match loads. H4895, RL-15, Varget and I'm positive there was another powder I used to use with good results. The right combination will be fairly forgiving of minor charge variations, which lets you run stick powders straight through the powder measure if your measure will do it. The little LEE Perfect Powder Measure actually works really well for this in my experience.

And like kraigwy, I was using the 69gr bullets at 200-300 yards my last season of shooting. I honestly can't say if they were measurably more or less accurate than the 77s, but I did shoot a lot more cleans at 300 prone with them.

[TMD]

For 69gn and heavier I've found that Ramshot TAC is amazing in the accuracy department and velocities aren't too shabby either.

[rebs]

Jimro thank you for the load data, 24 grn worked great.

I loaded some with 24 gr of reloaded 15 and some of them with 24 gr of varget. I shot them today and was surprised they both shot five rounds into a large single hole at 100 yds. 24 grains was the right amount with both powders for my 16" 8 twist barrel.

[jetinteriorguy]

I've had very good results with IMR4064, RL15, and Benchmark. These three in my 16" 1/7 twist barrel work well with any of the heavier bullets.

[Jimro]

Jimro thank you for the load data, 24 grn worked great.

I loaded some with 24 gr of reloaded 15 and some of them with 24 gr of varget. I shot them today and was surprised they both shot five rounds into a large single hole at 100 yds. 24 grains was the right amount with both powders for my 16" 8 twist barrel.

Glad that your experience mirrors mine!

I'm also glad you have a good accuracy load with Varget, it is more temp stable than Reloader 15 if you end up needing consistent accuracy in inconsistent temperature situations.

Jimro

[Road_Clam]

I'm also moving away from the 77 gr as it's only costing me more money to shoot vs the 69 gr at short range. My clubs HP matches are shot at 200,300 and 600 yds. We do have a 500 yd line but I don't think we've ever used it. I see no advantage for shooting more expensive 77's at 200 and 300 over the 69's. I'm getting 1K of the Nosler 69 CC's for $138 shipped. I've started using 69's at 200 and 300 then using 80's at 600. I'm strictly an amateur and this mix seems to be a great compromise of accuracy and value.

[rebs]

where did you get that price on the noslers ?

[Ole 5 hole group]

The most accurate load for my 16" barrel AR with 1:7 twist is either the 77 grain Matchking or Nosler with 20.5 grains of VV N-135. Only flies at 2,259fps but it groups very well on a very consistent basis.