77 grain SMKs for 600 yards?

[radford56]

There's a long thread on the Competition Forum regarding NRA AR Tactical competition. The local range where I shoot has a monthly mid-range match at 600 yards and AR Tactical is one of the options. Without getting into the controversy over whether this class should be restricted to magazine length rounds, I'm looking for a good load in order to use up the over-supply of 77 grain SMKs that I currently have.

I've never really liked the results I've managed to achieve with these bullets. I've never seen much, if any, advantage over the 69 gr SMKs - at least in my experience. I would just shoot 80 gr SMKs, but I'd like to use the 77's for something useful and this class, being provisional, is just a fun shoot versus serious competition for me so it looks like a good place to use them.

Still, I want to do as well as possible. I'm using once fired LC 05 and 06 brass with Remington 7 1/2 primers in an 18 inch Wylde chambered AR-15. I have most of the usual powder choices - H4895, RL 15, Varget, and a few others. I also have some TAC and I'm intrigued by the velocity that Sierra shows in their load data for AR-15s - maybe a higher velocity is the key to making this bullet work?

Obviously I have to do some experimentation in my rifle, but I'm interested in your experience with these bullets at 600 yards.

 

[SG4247]

Fantastic results with 77 SMK at 600 loaded at 2.250” with N540.

YMMV

 

[10XSHOOTER]

24.1 of Varget or RL-15. with a bare 77gr. 24.5 with a moly coated 77 gr. I shoot that load to 770 yards on a 12" square plate. You can also use the same load with 80 gr.

 

[Wingnut00]

22.3gr of H322 with 77 matchking loaded 2.25 set off with a CCI 450 with light to medium crimp which I use a lee factory crimp die. This shoots amazing in two different 18” AR’s. Velocity for me is 2721 with single digit standard deviation.
Edit: Forgot to add that this load is also loaded in lake city brass.

 

[akajun]

That’s what the Amu shoots all the way across the course.
24.1 of varget or rl15 or 23.1 of 8208 will shoot lights out of any wylde chambered 1/9-1/7 twist barrel.
Not as good in the wind as a 80!or 82 but just learn to read the wind better.

 

[Rsadams]

There's a long thread on the Competition Forum regarding NRA AR Tactical competition. The local range where I shoot has a monthly mid-range match at 600 yards and AR Tactical is one of the options. Without getting into the controversy over whether this class should be restricted to magazine length rounds, I'm looking for a good load in order to use up the over-supply of 77 grain SMKs that I currently have.

I've never really liked the results I've managed to achieve with these bullets. I've never seen much, if any, advantage over the 69 gr SMKs - at least in my experience. I would just shoot 80 gr SMKs, but I'd like to use the 77's for something useful and this class, being provisional, is just a fun shoot versus serious competition for me so it looks like a good place to use them.

Still, I want to do as well as possible. I'm using once fired LC 05 and 06 brass with Remington 7 1/2 primers in an 18 inch Wylde chambered AR-15. I have most of the usual powder choices - H4895, RL 15, Varget, and a few others. I also have some TAC and I'm intrigued by the velocity that Sierra shows in their load data for AR-15s - maybe a higher velocity is the key to making this bullet work?

Obviously I have to do some experimentation in my rifle, but I'm interested in your experience with these bullets at 600 yards.

Check out Western powders data for TAC some are very hot.... You can download their loading manual for free at their website..

 

[Baddog0302]

Being up front , not 600 but at 300 {my limit}, using a 20" RRA with a 36X scope, I've got several sub moa 5 shot groups using 77 SMK & 77 NCC's as well as 69 SMK's and H-75 bthp's .
Powders used with the 77's; H & I 4895, N-140,TAC, XBR, and I 4064 with the 69,

 

[Rtheurer]

That’s what the Amu shoots all the way across the course.
24.1 of varget or rl15 or 23.1 of 8208 will shoot lights out of any wylde chambered 1/9-1/7 twist barrel.
Not as good in the wind as a 80!or 82 but just learn to read the wind better.

THE AMU shoots 77gr SMK all the way back to 600yds? Tell us more.

 

[radford56]

Thanks for all of the replies so far. I loaded some test rounds with RL-15 last night that I intend to try at the range today. I'm working up to the 24.1 grain load. That should push the bullets faster than I've pushed them in the past - assuming it's safe in my rifle.

 

[akajun]

THE AMU shoots 77gr SMK all the way back to 600yds? Tell us more.

According to what I’ve seen and they told me
All the bullets come out of the same box , commercially loaded ammo.
It’s amazing what little things like talent, amazing wind reading ability, and hard holding can do for your 600 ya scores.

 

[Falfan2017]

I’ve followed western powders manual for their higher pressure 5.56 loads with tac and had good results and high speeds.

 

[akajun]

Thanks for all of the replies so far. I loaded some test rounds with RL-15 last night that I intend to try at the range today. I'm working up to the 24.1 grain load. That should push the bullets faster than I've pushed them in the past - assuming it's safe in my rifle.

As long as you have a wylde, cle, or nato Chamberl your golden

 

[JimSC]

This thread inspired me, I dug out a 10 year old box of 77 SMK's and shot 10 of them at 300 today. No idea what they chronoed but they held up in the wind just as well as the 80 SMKs did. I plan on doing a full load workup next week

 

[r bose]

Thanks for all of the replies so far. I loaded some test rounds with RL-15 last night that I intend to try at the range today. I'm working up to the 24.1 grain load. That should push the bullets faster than I've pushed them in the past - assuming it's safe in my rifle.

Just built another XTC rifle and have been using 26.6g 2000MR powder behind a 77g sierra mag length. Chrono loads last weekend and had a 77g sierra mag length going 2807 FPS average with excellent accuracy. Shot a 80g seated long with 27g 2000MR at 2825 FPS. These loads are warmish....but not hot. I personally know shooters using 27+ on mag length 77g ammo and over 28g on 80 class long bullets getting over 2900 FPS. This is all with 20" service rifle barrels. 450 primers

I also bought a couple 77g RDF noslers loading 26.6g 2000MR and chrono'ed at 2775 (shorter bearing surface) but according to nosler, 70g RDF is .416 BC and the 77's should come in between .440 and .450 BC (nothing officially published yet). All loaded again at mag length.

No doubt you can drive a 77g mag length to be shot at 600 yds. Shoot what you have then give the RDF's a close look.

 

[JimSC]

No doubt you can drive a 77g mag length to be shot at 600 yds. Shoot what you have then give the RDF's a close look.

I tried some RDFs once and had the flyer problem, I may pick another powder and see how they do. I am also ordering some 80 ELDs to try

 

[DarkStar]

When I was on the Camp Lejeune Base Team (post/station team 2008-2009), all we had was Black Hills with 77gr mag length. It was the only thing that we were authorized to purchase. The Marine Corps Big Team had the Black Hills with 80's and we would bum some of their 80 grain ammo when we were shooting with them.

I regularly shot scores with an average of 195 out of 200 at 600 yards with the 77's out of National Match M16's. Highest was a 197. Easily mid-10 ring elevation on the 600 yard target if I did my part.

 

[fotohunt]

I can honestly say out of a NM AR, they shot well. I pushed them with TAC and CCI #41’s, in excess of 2800 FPS out of a 20” barrel with a wylde chamber (they shot better with a light crimp). It shoots just as well out of my 18” wylde chambered spr barrel. If you want the data I can give it to you through pm. And as far as the AMU using 77’s xtc, that is false. They used the 80 gr Sierra mk at 600 loaded by black hills running about 2800 iirc. I can’t remember the oal, but 2.55” sticks in my head. I was able to use TAC and match and/or exceed their velocity without pressure. Again I can pm the data. All of my loads were with LC09. Of course you should reduce and work up.
-Darrell

 

[Andy Legg]

I have had Great Results with the 77 Grain SMK's @ 2.260" COAL(works fine in USGI 20 rd. Magazines). I have been using Pulled Bullets when available.

Muzzle Velocities @ approx. 75' Elevation with 23.4 Grains IMR XBR-8208 & TULA Primers in Lake City Brass.
16"=2532@ 70*F BP=29.95 Humidity=74% 1/8 Twist
18"=2738@ 70*F BP=30.30 Humidity=86% 1/8 Twist
20"=2850 @ 100*F BP=30.21 Humidity=80% 1/9 Twist(Only shot to 100 yds. Bullet was stable & still grouped good).
24"= 2996 @ 100*F BP=30.21 Humidity=80% 1/8 Twist.

These are pretty hot. Depending on Temperatures I sometimes see Ejector Marks/Swipes. 5.56 NATO & .223 WYLDE Chambers ONLY!!!

Backdown the powder charge 5-10% and work it back up from there.

I Love this load out to 600 yds. It's worked great for learning to read wind. YMMV.

 

[dcali]

They don’t have the highest BC in their weight class, but I’ve found them to be accurate bullets and have adequate wind resistance at 600 out of an AR loaded to mag length.

 

[BronzeArcher]

I agree with the above comments. Great choice for mag-length loads in ARs. Definitely worth a try. Sure, you may have a rare rifle that does not like this bullet, but it probably will.