M&P 15 Sport II; Sierra 65gr Game King

[RDub]

Hello
I picked up a box of Sierra 65gr Spitzer BT to see how they shoot in this rifle. Recently got a Vortex 1x6x24 Strike Eagle scope and installed it on the rifle so I'll be shooting at 100 yards now.

The Sierra manual is the only place I've found data for this particular bullet. They show H-335 and TAC to be their accuracy and hunting loads respectively.
Assembled some test ammo, enough for five round groups and two group ladders. LC brass was used, and C.O.L. was 2.255".

The powders for the first go-round were;
IMR 8208/ Rem 7½
Varget/ Rem 7½
AA2230/CCI 450
H-335/CCI 450
TAC/CCI 450
AA2460/CCI 450
AA2520/CCI 450
BL-C(2)/CCI 450

So here's how that went.
Chronograph data taken with an Oehler Mod 33. Screens centered 15' from muzzle.




It was pretty cold that morning, so much so that the chronograph was acting up. With the first group of 24.0grs IMR 8208 I only got one reading that made sense. And that was 2652 fps.
So I put the controller in the truck and warmed it up with the heater for a time. While that was happening it warmed up to the high 30's, so the controller worked OK after that.

Well everybody, with the exception of Varget, produced roughly an 1½ MOA group. IMR 8208 produced a sub MOA group. 26.5grs BL-C(2) was interesting.. Going re-shoot that.

For the next go-round I added AR COMP and AA2015. Adjusted some charges and did a re-shoot.



Well today was a most unusually warm day..
AR COMP shot a MOA group but was kind of slow. As the charge increased the groups got larger.


Lastly, I shot a group with three powders I thought were the most promising.



This time I shot three round groups. I was noticing on the previous outings that most often, the first three shots were very close and shot 4 and/or 5 would wonder off a bit. AA2230 didn't do as well as I had hoped.

Here is a graph;


Here is a good opportunity to demonstrate how temperature sensitive some powders can be, and how insensitive some can be.

Notice BL-C(2).. At 42° the 26.5gr charge produced 2733 fps. At 66° the same charge produced 2817 fps. That is an increase of 84 fps.
Yet IMR 8208, 24.5grs at 39° produced 2715 fps. At 65° the same charge produced 2728 fps. This is an increase of 13 fps.

That's it for now. I found a couple good hunting loads.

 

[rockquarry]

I've been working the the 65 GK for several years. It will shoot as accurately as the 69 MK to 200 yards; I don't shoot AR15s beyond that. I suspect as distances increase, the target bullet would be more accurate, but that's only a guess.

I've had best accuracy results with H4895. It doesn't flow through a measure as well as TAC, but it's accuracy level exceeds that of TAC in my experience. Despite that, TAC remains a good .223 powder.

I was hoping to get the Hornady 68 and 75 Match bullets to equal the accuracy of the 65 GK because they're considerably cheaper than the Sierra, but they just won't shoot quite as well even if they're close. I guess in the end I'd rather spend more for better accuracy anyway.

Good luck with your load development.

 

[fredj338]

In my 20" heavy, I got sub moa accuracy @ 100y with good vel using various 68-69gr match bullets & cfe, tac & 2520. Varget too, but I dont like the way it meters as much.

 

[Nevada Ed]

Not bad but...........................


there might be a better bullet lurking out there ....... ??

I would hope for at least two tight groups with a bullet weight............

 

[ArchAngelCD]

Using a Sierra 55gr GK bullet and Varget I can shoot subMOA 5 shot groups @200 yards. H335 doesn't open the group's much.

Forgot to give you the gun, it's a self built AR-15 with no special parts or match barrel. Barrel has a 1:9 twist.

 

[The Norseman]

For me No LC brass

Thank you again for your Indepth Study of the Sierra 65gr Game King.

One observation I have made years ago, was
that while reload'n Lake City Brass I could not
get good groups.

I decided to use my good old Remington, and
Winchester Brass. My groups settled down to
an inch, sometimes less. PMC brass works too.

I believe the LC Brass is not as eslastic, not sealing
in the NATO Chamber very well.

Interesting note; thought I would try some not
rusted Steel Cases found on the ground. Prep'd
and Reloaded as usual. Unbelieveable they are
my must accurate Reload, go figure.

Thank you again for the Range Report and Pictures!

 

[RDub]

Thank you again for your Indepth Study of the Sierra 65gr Game King.

One observation I have made years ago, was
that while reload'n Lake City Brass I could not
get good groups.

I decided to use my good old Remington, and
Winchester Brass. My groups settled down to
an inch, sometimes less. PMC brass works too.

I believe the LC Brass is not as eslastic, not sealing
in the NATO Chamber very well.

Interesting note; thought I would try some not
rusted Steel Cases found on the ground. Prep'd
and Reloaded as usual. Unbelieveable they are
my must accurate Reload, go figure.

Thank you again for the Range Report and Pictures!

Welcome..
I've been collecting more brass of other makes, pretty soon I'll have enough of one or the other to experiment.
Want to try some other primers too.

Initial trials with H-4895/Sierra 69gr MK have been unimpressive thus far. But I've managed some ¾" groups with AR COMP and IMR 8208.

Not done....

 

[Ivan the Butcher]

The only good groups I have from LC brass are in a bolt gun with 75 gr A-Max or 77 Berger VLD using lots of Varget, Rem 7 1/2. Way over SAMMI length! Produces 3" at 1000 yards! Very hot load! Locked a AR up! (But someone dumber than I did that!)

My short range load is in Lapua or WW brass (no noticeable difference!), H335, Fed 205M, and 50 gr Blitzking. In my Cooper 21 it runs 5 shots in 1/4" at 200 yards. In my AR-15 about 3/8" at 200 yards All of these are using 6.5-20 Veri-X III scopes at 20 power!

I bought a full case plus a few 50 round boxes (1200 rounds) of Black Hills Blue Box with 50 Hornady V-Max over TAC, LC Brass, and unknown primer (but it was nickel plated so it wasn't a 7 1/2) It shot 3/8 at 200 also!

Ivan