5.56 load development results (almost complete) [Archive]

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squirreld

12-27-2011, 17:34

In an effort to find the most accurate loading of TAC and LC brass, here are half of my results.
The other half I will complete in the coming months.

Bullet weight and type in the top left, powder charge of TAC in the top right in .3 gr. increments. Tula SRM primers. 4 shots at each charge. 4x12 Leupold scope. Sand bagged, took about 2 hours to send these 92 rounds down range.

Definitely a lot of losers, a couple winners.
Ran through a 16" BCM Middy @ 125 yards.
Looking for group size, not position.

I noticed that some of the lead tipped rounds did not fully chamber on charging the rifle. Fwd assist fixed that. All shots, the bolt fully closed.

Bullets fired,
Sierra 63 gr. SMP
Winchester 64 gr. PP
Sierra 65 gr. SBT
Hornady 68 gr HPBT-M

Bullets I still need to test,
Sierra 69 gr. SMK
Barnes 69 gr. Match Burner
Nosler 69 gr. HPBT-M
Speer 70 gr. Soft Point

http://home.earthlink.net/~squirreld/63%20gr.%20Semi%20point.jpg
http://home.earthlink.net/~squirreld/64gr%20Win.%20PP.jpg
http://home.earthlink.net/~squirreld/65gr%20Spitzer%20BT.jpg
http://home.earthlink.net/~squirreld/68%20gr.%20Horn.%20HPBT-M.jpg

I'm really not crazy about any of these results.
63 gr. SMP was marginal at low and max loads.
64 gr. Win. PP is an all around loser.
65 gr. Sierra SBT looked good at 24.9 gr. of TAC.
68 gr. Hornady looked good at the 2 lower loadings, you can see this pattern open up nicely.

creophus

01-05-2012, 07:12

I think your Sierra 63gr load that grouped at 1.25" is a winner. That's 1 MOA, which is plenty accurate for almost anything. What results are you striving to get?

mizer67

01-05-2012, 13:44

fredj338

01-05-2012, 14:42

If you have RL-15 handy, try 24.0 - 25.0 grains at 2.25" OAL with the 69 gr SMK.

24.7 grains is a load that'll shoot into .84" at 100 yards for an average of 3, 10-rd groups in my SS410 barreled BCMs. Not super fast, but accurate.

And again, all guns are diff. Everyone swears by Varget in the 308 & my rifle was just hohum using Varget. Accuracy starts w/ the bullet but even gold stds like the SMK aren't going to always give the best results.:dunno:

squirreld

01-05-2012, 20:38

I'm looking for the most accurate with good velocity.
Wherever that dart falls is what my load is.

I was not that impressed with most of these.
A couple were good, albeit at slower speeds.

Once I test the other bullets, Ill update this post. Might be a month or so now that the cold is upon us.

EL_NinO619

01-05-2012, 21:24

In my remington 700 SpS Tac-to-cool my best groups are with IMR 3031... Thats fine groups for a AR, my real question here is, How in the hell did you know where to aim, you pick a college rule line or what....?

Boxerglocker

01-05-2012, 21:46

Try 69g SMKs with 23.5 Tac @ 2.250.

I was testing that load today with my 16 inch DDM4V2 at 100 yards using a Vortex Viper 1-4 and Geissele SD-C trigger. That load was sub 1 moa with 3 out of 5, 3 shot groups.

Magelk

01-06-2012, 18:35

I didn't think any of the groups are all that bad out of a 16 inch middy at 125 yards. The 1.25 inch I'd take.

shotgunred

01-06-2012, 18:42

What is your barrel twist rate?

I would think that you would be better of with a 50 to 55 grain bullet with a 16" barrel.

squirreld

01-07-2012, 21:33

Boxerglocker

01-07-2012, 23:53

Boxer,
that load is on tap =-)

Shotgunred,
1:7

I ordered a 2 stage trigger.
That should help some.
I am going to cut the 64gr Win. PP's from the running as the QC on them bullets were terrible.
The 63 gr I will cut as well, a little to light for me. I went with a 1:7 for heavier bullets, not lighter ones.

:supergrin: Yeah that load was passed down to me and surprised me too. My DD is also a 1:7 twist. The Geissele triggers are awesome.