223 52gr Amax and 223 50gr vmax

[ukhornet]

Anyone used theses with Vihtavuor N133  if so what was your charge weight and CL & OAL ?

 

form i have read  24gr N133 powder CL 1.75 & OAL 2.24

[gbal]

SAAMI spec brass case length for the 223 Rem cartridge is 1.760 inches.

Cartridfge Over Alll Length (COAL) doesn't tell you much-though it has to be longer than your magazine size,if you want to use the magazine.Cartridge Base To Ogive is more informative wrt 'bullet jump'/seating depth,and is a superior measure anyway-bullets simply vary in length (but much less in ogive) from the same box.

 Read Bryan Litz (Chief Ballistician at Berger Bullets) article comparing COAL and CBTO (on Brger Bullets site).OF course,for. A given COAL/CBTO that is a measure in that rifle-other chambers and throats especially may well differ-and indeed it's common to 'chase the lands'-ie load bullet further out (COAL longer) as the throat erodes,to maintain the same bullet jump to the start of the (now eroder ) rifling.

  Any given COAL can only be a very general guide for your rifle-and you need to get a comparator (have a look at the Hornady/Sinclair one,with special threaded cartridge case) and measure your "COAL" for your rifle and bullet,and seat the bullet to the desired CBTO. Someone else's measures for their gear (powder included) isn't a measure of your gear(and for powder,may give higher/unsafe pressures-check the. Book maximum,and don't exceed that-and work up to it in small steps-maybe .2g).It'sall really individual to your set up-as are the measurements-you and your comparator 'compare' but do not neccessarily give absolute/everyone agrees measures-the precision of the measure tool,and the users' sensitivity come into -"just touching the lands"  depends in part on finger sensitivity-your fingers may not be identical to someone else's,and that can vary seating depth readings by  a few thou, for the same loaded round.

Note too,seating depth changes pressure,as it changes the 'space' in the case the powder has to expand into initially-so be aware around max charges-and of course,different ( 223) brass has differnt total capacity (measured by volume of water) due to brass thickness etc.Do not 'cram' ( copress) powder into your cases to get to someone else's alleged 'safe' load. The /max'book values are what they are for a reason-safety.Another 50 fps MV won't transform your rifles performance (more likely reduce accuracy) so don't be tempted to over max velocity. The 223 isn't a long range cartridge,but is just fine to mid range (say 500y) at sub max powder/bullet loadings,and you may score reasonably with it,on mid size targets/gongs etc.Heavier bullets will do better,but your (slow?) rifling twist may not be suitable for them contrasted with the 52/53g Hornadys  you mention.V133 should be a good powder-go for accuracy,not velocity.....a miss at any warp speed is still a miss!

gbal

[VarmLR]

6 hours ago, gbal said:

SAAMI spec brass case length for the 223 Rem cartridge is 1.760 inches.   SAAMI Min is 1.730 Inches George, and Viht load data is based upon 1.752"

Cartridfge Over Alll Length (COAL) doesn't tell you much-though it has to be longer than your magazine size

,if you want to use the magazine.Cartridge Base To Ogive is more informative wrt 'bullet jump'/seating depth,and is a superior measure anyway-bullets simply vary in length (but much less in ogive) from the same box. 

Viht data for a 52gr HPBT is 2.244".  This is mag length and negates the worry over being too close to lands.  Just use this as a starting point ;-)

 Read Bryan Litz (Chief Ballistician at Berger Bullets) article comparing COAL and CBTO (on Brger Bullets site).OF course,for. A given COAL/CBTO that is a measure in that rifle-other chambers and throats especially may well differ-and indeed it's common to 'chase the lands'-ie load bullet further out (COAL longer) as the throat erodes,to maintain the same bullet jump to the start of the (now eroder ) rifling.  

  Any given COAL can only be a very general guide for your rifle-and you need to get a comparator (have a look at the Hornady/Sinclair one,with special threaded cartridge case) and measure your "COAL" for your rifle and bullet,and seat the bullet to the desired CBTO. Someone else's measures for their gear (powder included) isn't a measure of your gear(and for powder,may give higher/unsafe pressures-check the. Book maximum,and don't exceed that-and work up to it in small steps-maybe .2g).It'sall really individual to your set up-as are the measurements-you and your comparator 'compare' but do not neccessarily give absolute/everyone agrees measures-the precision of the measure tool,and the users' sensitivity come into -"just touching the lands"  depends in part on finger sensitivity-your fingers may not be identical to someone else's,and that can vary seating depth readings by  a few thou, for the same loaded round.

Note too,seating depth changes pressure,as it changes the 'space' in the case the powder has to expand into initially-so be aware around max charges-and of course,different ( 223) brass has differnt total capacity (measured by volume of water) due to brass thickness etc.Do not 'cram' ( copress) powder into your cases to get to someone else's alleged 'safe' load. The /max'book values are what they are for a reason-safety.Another 50 fps MV won't transform your rifles performance (more likely reduce accuracy) so don't be tempted to over max velocity. The 223 isn't a long range cartridge,but is just fine to mid range (say 500y) at sub max powder/bullet loadings,and you may score reasonably with it,on mid size targets/gongs etc.Heavier bullets will do better,but your (slow?) rifling twist may not be suitable for them contrasted with the 52/53g Hornadys  you mention.V133 should be a good powder-go for accuracy,not velocity.....a miss at any warp speed is still a miss!

gbal

I would add that if you are quite new to reloading, forget chasing the lands as loading close to the lands without using a seating comparator and measuring bullet COAL to lands, you run the risk of jamming one too close if you have variation in bullet tolerance from manufacture.

Just load to mag length and you'll find a decent enough node on charge weight as a good starting point.

If you have a comparator and want to load the Amax closer (I haven't tried these in 223 so don't know how jump tolerant they are) then don't start any closer than 20 to 30 thou off the lands.

In answer to your question...your stated load of 24gr would appear to be a safe load based on nothing other than Viht reloading data but don't look for a shortcut.  Start low and work up, and don't exceed recommended max load.

Keep it simple.  I would recommend that you start 7 to 10% under max  load of 24.7 (so say 23gr) and work up in 0.3gr intervals for the first three steps, then 0.2gr steps for the next 4 loads using 5 shot groups.

If you have a chrono, or access to one, look for the load where either side you have similar velocities and low ES (there will be one).  At these adjacent points, you should have similar POI to centre of group.  Choose the centre load of that group of loads and that's your load.  If you haven't access to a chrono, just pick the centre load of a few adjacent loads that shoot to the same point which has lowest vertical dispersion. Keep it simple, keep it safe.

[ukhornet]

hi thanks for the info i will take it all on board what you both have said. 

so ill start at 23gr and work my way up. 

 

 

 

[cooter]

I use 52Grn A Max and N133 as my main varmint load.

They are a short bullet and I find them to be very jump tolerant, that said I use a COL of 2.240 (tried all the way out to 2.280) only as it allows me to leave the dies in the same position for a number of bullets I use.

24 Grn gave no increase in performance over 23 Grn, and the performance of 24Grn in warm weather was erratic. Overall I found 3000fps to be optimal in my rifle (1..9 twist in a 22" barrel), which is what I get from 23Grn.

Each to his own, and what suits my rifle probably will not suit yours.

[MikeJ]

An old thread perhaps, but what did you end up with? I use 23.8gr N133 with both 52gr A-Max and the 55gr V-Max which provides great accuracy and 3150fps from a 20" 1:12" Sako.