222mag conversion and test - original 223

[bheadboy]

well long time coming, weather final got 74f this am and 84 when I left the range, no longer 95-100f wind was about 5-7mph from 4-5:00

my 700 varmint trued, rem 26" bbl re-chambered by Bobby Hart, (for pd etc. scoped good) HS stock bedded

the factory 223 chamber was awful and bbl scoped good so re chamber/crown etc. good reamer

R/P brass, 7 1/2 primers Sierra 50bk and tried 4198, 2015, 3031, h335,LT32 -

H4198 24.gr - 3514fps 7sd, .350" 5 shot group - may try 24.2gr re case nominal expansion at pressure ring .3764
LT32 25.5gr 3573fps 16sd .381 5 shot --pressure ring .377 may try .1-.2gr less and revisit

I tried ladder test on all powders and arrived at these two re the groups and velocity, Oehler 33 and dial micrometers for case measurement.
Fun

Bob

 

[John from MN]

I took on a similar project for a family member and was very impressed with the results.

 

[pacificman]

Thanks for the report. H4198 looks very good and seems the LT32 is promising. These days it is good to have a couple of powders that you know will work well... as sometimes one powder may be out of stock for awhile and one may be easier to get. It's always fun when shooting!

 

[bheadboy]

Well second trip and the weather was good 82f and the 8-10 wind from 4-7 so the result are more value.

H4198 24.2 7 1/2 50sierra bk 3471fps 5 shots .281 yummy

2015 26.4 showed hot at 3570fps 5 into .441 - I will come don .4 and re test

lt32 25.4 a little warm 3521fps 5 into .407 I will reduce .2 and go again

it seems this bbl/chamber like 3470fps range remember this is a factory Rem bbl that was 223 with a lousy chamber 12 twist

Hart re chambered for me

Bob