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 Sierra MatchKing 69 grain bullets in 1:9
NestorPR  [Member]
5/21/2008 3:34:29 PM
Hi again, just looking for recommendations for starting and maximum loads for a Sierra Matcking 69 grain HPBT bullet using CCI primers, Remington, LC, PMC and WCC cases and Varget powder. I've found several, for example, in the Hodgdon reloading manual, in the reference section here, and in Acuratereloading.com. Most seem to vary between 25 and 28 grains. I'll be shooting these from a 16" 1:9 twist 5.56 NATO DSC barrel, I know it won't give me MOA accuracy but I'd like to experiment with some loads you guys have already tried and liked. Thanks!
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AR4U  [Team Member]
5/21/2008 3:51:15 PM
24.5 grains of Varget is my best load for 69 gr SMK. LC brass, CCI primers, loaded to mag length.
rsgt513  [Member]
5/21/2008 3:58:21 PM
You really should start at the min and work your way up with the components you have chosen. This is the SAFEST way to work up a load.

Now, I use Sierra Infinity Suite for Load data and if memory serves me correct the starting load for SMK 69gr was 23g varget. I started there and worked up in .2gr incriments (usually 10 rounds ea) up to max. I have found with my components and my particular rifle (your results will vary due to Rifle and its components remember no two are alike.) that the sweat spot for accuracy is a mild load of 23.4g varget (that is with win case, rem 7 1/2 primer and my particular rifle.

You also listed several cases there. Remember that different cases will have different volumes thus different pressures with the same load.

Again please work up from the min load listed to be safe.
Aggie_Gunner  [Team Member]
5/21/2008 4:35:44 PM

Originally Posted By AR4U:
24.5 grains of Varget is my best load for 69 gr SMK. LC brass, CCI primers, loaded to mag length.


I use the exact same load. Brass, primers, everything. By far my favorite .223 load for my 1:9's and 1:8's.

- AG
Jackelope  [Member]
5/21/2008 6:31:28 PM
i'v got a 20" HBAR 1:9 twist AR

would a 75 grain shoot well..what i'v read so far sais that 73 to 75 is the max for 1:9

would a 69 grainer shoot better

i'm talking between 300 and 600 yds

what say you??
matt33  [Member]
5/21/2008 10:25:11 PM
A 69 SMK will probably shoot better as 1:9" can be hit or miss stability wise with 75/77's, especially at long range. To the OP, Sierra lists 26.1 grs of Varget as a maximum load with 69 gr SMK's. I've never heard of a Kaboom with Varget, but if you somehow were able to get 28 grains under a 69 SMK, it will definately be a one and done range session. At this point, you should strongly consider buying a good manual before going any further.
NestorPR  [Member]
5/22/2008 12:48:06 AM
You bet your you-know-what that I always use a good reloading manual, I have the Lyman and the Sierra volumes which are now well used. From them and your responses it looks like my present load is right there with your preferred loads, I've been using 25 grains of Varget with 55 grain Hornady FMJBT so it looks like I should lower the load to the 24.5 grains you guys mention for the 69 grain SMK (perhaps start at the 23 grains as mentioned here and work up from there) and try it out in my rifle to see what results I get.

You mention case volume, I saw in another post the chart with the different volumes for different brand cases, although the Remington case was not mentioned. Depending on volume, what is the normal relationship between a case volume and the load? Do you increase the load for larger volume cases, decrease it or leave it the same? Of course, it goes without saying that any changes should be done in small increments and in a safe manner, but what would be the rule of thumb? I couldn't find any info on this in the manuals.
Greymantle  [Member]
5/22/2008 8:29:37 PM
In discussions with Sierra on load development for 16" barrels, with the additonal requirement of low flash, they suggested I consider using Benchmark and H4895 for load development. Both are single base powders and produce minimim flash, but are relatively "fast" for more thorough combusion in the short barrel.

For 69 SMKs they suggested I use H4895. The load data from Hodgdon .223 goes from in 22 to max 26. (Barrel is 1:9, 5.56)

For 77 SMKs they suggested I use Benchmark. THe load data from Hodgdon .223 ranges from 20.5 to 22.8. (Barrel is 1:7, 5.56)

Please note these are LOW FLASH loads. You may get slightly hotter performance out of the dual base powders. Anyone else using Benchmark and H4895 on 16" barrels with these bullets? Any "favorites"

dryflash3  [Team Member]
5/22/2008 10:14:34 PM

Originally Posted By AR4U:
24.5 grains of Varget is my best load for 69 gr SMK. LC brass, CCI primers, loaded to mag length.


24.5 grs Varget, LC brass, Rem 7 1/2, mag length with the Hornaday 68 gr HPBT.

In my rifle, more powder than that = larger group.
jamie930  [Member]
5/22/2008 10:27:16 PM
I use the load of 24grains of H4895 in LC brass over a 69 Nosler CC and WSR. Thats out of 20" 1-8 barrel. It shoots better than I can hold
USMARINE1108  [Team Member]
5/23/2008 12:23:31 AM
Anyone have a good load for 69SMK, LC brass, CCI primers and R-15? Also from a 1/9 HBAR.
Blacktail-8541  [Member]
5/23/2008 1:14:01 AM
With a 69 gr nosler cc, my best load with Benchmark is 23.5 gr and win primers.

This is a max load but it is very accurate in all ARs it has been tested in.
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