SMP-842 Powder (WC-842)- .223 Cal

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11 years 7 months ago - 11 years 7 months ago #21629 by ernierod
SMP-842 Powder (WC-842)- .223 Cal was created by ernierod
Have a small quantity of SMP-842 (WC-842)and would like to use SMK bullets-69 grs. Any loadings for 60 to 70 gr .223 bullets out there would help. Thanks










(thread moved to the reloading section... :wave: Sharkey)
Last edit: 11 years 7 months ago by Sharkey.

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11 years 7 months ago - 11 years 7 months ago #21664 by LebbenB
Replied by LebbenB on topic SMP-842 Powder (WC-842)- .223 Cal
St. Marks SMP 842 has a burn rate very close to Hodgdon's CFE 223 (CFE 223 is made by St. Marks for Hodgdon), though SMP 842 is a little bit hotter.

Starting load for CFE 223 and a 69 gr SMK is 23.5 grains with a max charge of 25.8, COL is 2.235". This data is from Hodgdon's load data website. Because SMP is a little hotter, I would reduce my starting load by 15-20%.

As always be careful, start low, and observe your rifle and spent cases for signs of over-pressure.

Good find on the powder, BTW.
Last edit: 11 years 7 months ago by LebbenB.

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11 years 7 months ago #21750 by ernierod
Replied by ernierod on topic SMP-842 Powder (WC-842)- .223 Cal
Barrel 16",1:8" twist,Sierra SMK 69gr .223 bullets (#1380),New Federal Brass and WSR primers.Started at 22 grs using SMP-842. In steps of .3grain, increased to 24.4grs carefully looking for any signs of pressure-none found. It became clear,with this particular bbl(Red-X bull) that perhaps a slightly lighter weight bullet,different brand bullet or powder might reliably produce 1" groups or better, at 100yds.Hope this helps someone.

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11 years 7 months ago #21763 by LebbenB
Replied by LebbenB on topic SMP-842 Powder (WC-842)- .223 Cal
Did you chrony the load? I'd be interested in seeing what your MV was.

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11 years 7 months ago #21909 by ernierod
Replied by ernierod on topic SMP-842 Powder (WC-842)- .223 Cal
Follow up with using SMP-842. Continued with the 69gr SMK bullets-weights of 24.6,24.8 and 25.0.Primer started to flatten with 24.6 and 24.8-no reason to try 25 grs. Grouping was mediocre-1.7" to 2.25".Will settle on 24.5grs/842 before trying a 60 gr A-max developing project.No chrony testing.Cheers
The following user(s) said Thank You: LebbenB, jtallen83

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11 years 7 months ago #21981 by LebbenB
Replied by LebbenB on topic SMP-842 Powder (WC-842)- .223 Cal
Good data. Thanks for taking the time to test it and posting your results.

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11 years 6 months ago #22426 by ernierod
Replied by ernierod on topic SMP-842 Powder (WC-842)- .223 Cal
Switched to Barnes Match Burner,also 69grs,and in my rifle accuracy was better. It seems,when using either SMP 842,or perhaps WC 842 and a 69gr bullet-the range is between 22 grs and 24.8grs of this powder with no signs of pressure-in my rifle.Cheers
The following user(s) said Thank You: jtallen83

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