New S&W M&P 15 Sport II 69gr Loads

[RDub]

Hello
After looking at 55gr and 62gr bullets, it’s time to take a look at the 68-69gr HPBT weight class.
The previous workups are here;

http://smith-wessonforum.com/reloading/599365-new-s-w-m-p-15-sport-ii-55gr-loads.html

http://smith-wessonforum.com/reloading/599914-new-s-w-m-p-15-sport-ii-62gr-loads.html

Again, shooting this new stock S&W M&P 15 Sport II with a 1-9 twist 16” barrel, topped with a Lucid HD-7 Red dot sight.

For this exercise the Sierra 69gr HPBT Match bullet will be shot. The Sierra bullet is about .898” long.

I know this kind of ammunition needs to be shot with some good glass at distance. I’m looking at some scopes, but haven’t decided which one yet. That’s’ coming up later..

The first thing I do is examine some factory ammo. The two that I grabbed was the Federal 223 Rem 69gr Gold Medal Match loaded with the Sierra bullet, and some Hornady Frontier 223 Rem 68gr HPBT Match, loaded with their 68gr HPBT bullet with a cannalure. This sample has a length of .917”.

https://postimg.cc/gallery/vhy10aqi/

https://postimg.cc/gallery/1ts3ch8uy/

I couldn’t find any Sierra bullets locally at the time, so I picked up some Hornady 68gr HPBT without a cannalure. When I measured their length I found them to be roughly .983” long! So it looks like Hornady makes two completely different 68gr HPBT bullets. I would have thought that the two would be the same length, one just has a cannalure and one does not, but that doesn’t appear to be the case.



I loaded up a few rounds with the longer non-cannalured bullet and it was painfully obvious that this bullet is much too long for this 1-9 barrel..

So, when the Sierra bullets arrived, I loaded up some test ammo, seating the bullets at 2.255”, no crimp.
Lake City brass was used throughout.

Velocity data was taken with an Oehler 33. Screens centered 15’ from muzzle.
All of the targets were shot at 50 yards.

This will be the first time using Varget and 2000-MR in the line-up.

I shot an initial group with the Federal ammo at my range behind the house, but made the mistake of shooting after a full day of work around the property. That didn’t work out so well. But an average of five rounds came in at 2601 fps at 82°F.



On range day it was cooler, I was well rested and ready to shoot.. The Federal ammo shot much better..



So, after looking at this, two things came to mind.
First, there is no doubt that the Sierra 69gr bullet will shoot in this 1-9 barrel. And second, boy have I got some work to do!…

The velocity was lower this time as the ambient temp was 30° cooler.

Also shot two groups of the Frontier ammo;



The slightly longer Hornady bullet didn’t do quite as well..

With both the Fed and Frontier I shot one group, recorded data, and then shot a second group while the barrel was warm.

Ok, here is how all the handloads went;

Here is all the data I was working off of;








Well there is definitely an array of personalities as to how each powder handles this bullet weight out of the 16” barrel.
Now that a quality bullet is being used here, a lot of powders are showing potential.

The next day I shot a group with 26.4 grs. AA2520 as 26.1 wasn’t showing any pressure signs. It was a bit warmer and the weather was quite different. This group was pretty good, but this one was a bit warm..



Also shot a third group with the Frontier load when it was warmer, to see if velocity or group size would change. No difference either way. I any case it seems the Frontier load is not temperature sensitive.



Here is a graph for all of this;



Looking forward to see what this rifle could do with some glass on it..

Bear in mind this is all relative to one rifle, one shooter, one place and time, one set of components. Change any one variable and this could all change. Don't accept this as loading data. You must do your own work ups with your rifle.

 

[WR Moore]

You should be able to use the Horanady 75 gr HPBT bullet without issue. NOT the AMax.

 

[Nevada Ed]

Looks like you are having fun with that new rifle.
Lots of good first time groups with those loadings.
Decisions, decisions...........

Geeeeze....
that long .983" bullet must really take up room in the rifle case !!

I have a Nosler 55gr Poly tip that I use with my 22-250 and it has an OAL of .810" and I thought it was long.
However I have a 1:14 barrel twist, in my bull barrel.

One never knows if slow or "Atomic" speeds in your rifle will get
the best accuracy at 200 yards or greater.

A quality scope and rings, properly fitted and installed, can make a world of difference in improving ones groups.
Some smooth out the factory ring ridges for a smooth flush grip
and make sure it is the correct OAL Dia. for the scope and with the correct torque for the mounting screws or type of setup being used.

Best of luck with your rifle improvements.

 

[Abflyboy]

Take a look at the Sierra 69 grain Tipped MK

 

[rockquarry]

Just a few general comments based on my experience with two Colt ARs (1 in 7" barrels)....the Sierra 69 MK (plain and tipped versions) and the Sierra 65 GK are at least slightly more accurate than the Hornady 68 Match and the Hornady 75 Match.

I had hoped I could get the Hornady bullets to equal the accuracy of the Sierras because the Hornadys were considerably cheaper. It never happened. However, either Hornady Match bullet shoots much better than most of the cheap bulk stuff.

TAC powder is a popular .223 / 5.56 powder. It makes for some accurate loads and meters well through a measure, but H4895 (with the above listed bullets) has always provided at least slightly better accuracy than TAC. H4895 meters fairly well through a measure, but not with the consistency of TAC.

It's well worth doing a lot of experimenting and group shooting.

 

[Shotguncoach]

The 24.5 grain load of H335 looks to show some real promise. What's the group size without the high flyer at 1 o'clock?

I've been loading the 69 grain SMK using 23.8 grains of H335 and LC brass for years, but I use that in a 20" barrel. You might find some good stuff happens between 23.8 and 24.5. I'd definitely recommend doing a reshoot on that 24.5 load.

I've also had good luck with H4895 as mentioned above using the 69 grain SMK. The load I'm using is a "Camp Perry standard" load that is not listed in the current Sierra AR-15 data. After talking with the Sierra tech line, I worked up to it using the IMR-4895 data as a guide.

 

[RDub]

The 24.5 grain load of H335 looks to show some real promise. What's the group size without the high flyer at 1 o'clock?

7/16"..

I've heard H4895 is really good in this caliber. I've leaned toward ball powders just because they are so consistent out of powder measures.. Especially loading large volumes of ball or plinking ammo.

I would be interested in the load you found with H4895.. What primers are you using? You can PM if you wish..

 

[Shotguncoach]

7/16" = .4375"

Two bullet diameters = .448"

You may have a winner there. If I was developing a load for that rifle, I'd probably do a set of 10 round groups at 100 yards from a bench at .1 grain increments from 24.2 to 24.6 grains and then re-evaluate.

PM sent re: the H4895 load just because Sierra doesn't list that powder in their AR data. It is in the Sierra bolt gun data and within the range published by Hodgdon, but Hodgdon doesn't separate AR and bolt action loads.

Work up in increments as always.

If you don't need the distance staying power of the 69 grain bullets, you might also want to spend some time working with the Hornady and Sierra 52 grain BTHP bullets. 25.1 grains of H335 works well with both (and with 55 grain FMJ for plinking), with a slight accuracy edge to the Hornday bullet in my rifles.