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Thread: Reloading 69gr Sierra MatchKing; M&P 15 Sport II

  1. #1
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    Reloading 69gr Sierra MatchKing; M&P 15 Sport II

    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;

    https://www.m4carbine.net/showthread...-P-15-Sport-II

    https://www.m4carbine.net/showthread...-P-15-Sport-II

    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 after shooting a few groups..

    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.
    All the targets circles are 4".

    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.
    WHY DO THEY CALL IT COMMON SENSE WHEN IT IS SO UNCOMMON?

  2. #2
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    I enjoyed reading this post. What optics are you considering?

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    Hi
    Looking at some of the 1x6x24 scopes with an illuminated reticle and bdc. Close range quick acquisition and the ability to reach out a ways. The Vortex Strike Eagle caught my eye.
    WHY DO THEY CALL IT COMMON SENSE WHEN IT IS SO UNCOMMON?

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    Quote Originally Posted by RDub View Post
    Hi
    Looking at some of the 1x6x24 scopes with an illuminated reticle and bdc. Close range quick acquisition and the ability to reach out a ways. The Vortex Strike Eagle caught my eye.
    Pony up for the PST at the least. The Strike Eagle is a terrible scope.


    Sent from my iPhone using Tapatalk

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    Reloading 69gr Sierra MatchKing; M&P 15 Sport II

    On your reloading methods, it seems to me you aren’t getting all that much data despite doing doing a lot of work. You are working with far too many variables at once. Have you considered different methodologies?

    Typically, it is easier to choose a single powder or even two with known properties to work with.

    One bullet, one case, one primer...

    I typically will start at the bottom of a load map and increase by 1% of water weight or so; typically rounding down. For a cartridge like .223, that means .2 gr increments. I will load two rounds at each charge bottom to top.

    I will do two rounds of shooting; one round from each ladder at a single target. I record velocity.

    Then I repeat it with the second round of each charge. Again recording velocity.

    Then map these in excel or other spread sheet and graph. You’ll notice that rounds are clustered into “nodes”. This will help understand what it possible with a specific powder. What you’re looking for is clusters which variation in charge weight does not have significant impact in velocity. This is where you’ll find more consistent velocity despite variance in case capacity of individual pieces of brass. Groups at 50 yards are fine, but they do not predict consistent downrange performance.

    Once a node has been established, start at the bottom of the node and work to the top of the node in .1 gr increments. Shoot for groups and note ES and SD. It shouldn’t take but one or two groups of 5 to get data at this point.

    I then chose the charge weight with the least spread and/or deviation. Charge is not necessarily based on the accuracy of the groups alone. This allows more forgiveness in my loading process as well as with component variation.

    This method has served me and many others quite well in both F-Class and PRS competition. Maybe this will help you as well as save you some time and money. The unsolicited free advice is worth what you paid

    Good luck in your venture.


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    Last edited by lsllc; 09-29-19 at 10:22.

  6. #6
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    Quote Originally Posted by RDub View Post
    Looking at some of the 1x6x24 scopes with an illuminated reticle and bdc...
    Why the BDC?

    My 2¢: Busy reticles are distracting, and it's a lot easier to hold over with a simple duplex crosshairs. (I like the Nikon "Nikoplex" instead of their BDC.)

  7. #7
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    i have been having good results with Vithivori N140 and N150 69GR SMK : 24.5 N140.jpg 69SMK : 24.5 N150.jpg
    that N 140 Load was at 100 Yds
    Last edited by junkmansj; 10-25-19 at 20:42.

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    Are you looking to create more low volume precision type ammo, or something you can crank out high volumes of?

    To that, are you doing any extra prep to the brass at all? i.e annealing, flash hole, etc

    I bought a bunch of the 69 gr Hornady’s from RMR last year, and now that it’s cooling off I’d like to start working on rifle load development.

    I mainly bought them to try and work up in my 1-8 20” barreled rifle, but I also have a 1-9 16”, and a 1-7 11.5” SBR.

    I was thinking they may be too heavy for the 1-9, but maybe not.

    I’m guessing I’ll need to work up a load for each rifle?

    I was leaning towards full case prep precision stuff for the 20” and practice self defense type rounds for the SBR?


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    "The state is the mafia posing as a human rights organization"

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    Tapatalk bug. Accidental duplicate post
    Last edited by iflyskyhigh; 10-25-19 at 21:36.

  10. #10
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    Quote Originally Posted by iflyskyhigh View Post
    Are you looking to create more low volume precision type ammo, or something you can crank out high volumes of?

    To that, are you doing any extra prep to the brass at all? i.e annealing, flash hole, etc

    I bought a bunch of the 69 gr Hornady’s from RMR last year, and now that it’s cooling off I’d like to start working on rifle load development.

    I mainly bought them to try and work up in my 1-8 20” barreled rifle, but I also have a 1-9 16”, and a 1-7 11.5” SBR.

    I was thinking they may be too heavy for the 1-9, but maybe not.

    I’m guessing I’ll need to work up a load for each rifle?

    I was leaning towards full case prep precision stuff for the 20” and practice self defense type rounds for the SBR?


    Sent from my iPhone using Tapatalk
    With 55's and 62's I'm mostly doing high volume. Not paying too much attention to the brass, other than seeing that they are in good shape. They shoot well enough for what they are.
    With the 69 SMK's, along with FL SB sizing, trimming and cleaning up the burrs. I treat the primer pockets and flash hole and make sure each five round string has brass that weigh close to the same. That's it.

    I haven't played with the Hornady products as yet. Not enough to come to any conclusions. I did notice that Hornady makes two completely different 68gr HPBT bullets.
    One, with a cannalure, is much shorter (.917") than the one without a cannalure which is just around .983" long. If you find you have the longer bullets, the 1-8" twist should be used.

    Generally, each barrel is going to have it's own likes and dislikes, but with these 223/5.56 ARs there are curtain loads (nodes) that most of them seem to like.
    Have fun..



    WHY DO THEY CALL IT COMMON SENSE WHEN IT IS SO UNCOMMON?

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