Pressure question on max charge?

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elmerdeer

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I was doing some load development in my 7mm mag using RL22 and 160 accubonds, I checked a few books and started at 65grs and went past max at 67grs. So my velocity at 65gr was 2843 5 shot average, 65.5 gr shot up to 2990av. could not figure out why? Any Suggestions? Next 66gr back down to 2886 av. and my group shrank to.250" shots, great!Then went a touch over max to 66.5grs and speed was 2933 and it opened up some, next went up to 67grs and my group for 3 shots went into .153" excellent again but the other 2 shots opened a bit, my error I think. I see that most everyone pushes their speed to 3050 alot of times,is it safe for me to go a little higher like to 68 grs of RL22? Have not seen any pressure signs like sticky bolt.My barrel is also 26 inches long and the gun is a Sauer202, What are your experiences with the first situation of a jump of velocity? And is velocity a safe way to gauge if your getting near max? Because book velocity does not match my numbers.
Thank you
Elmer
 
elmerdeer said:
I was doing some load development in my 7mm mag using RL22 and 160 accubonds, I checked a few books and started at 65grs and went past max at 67grs. Elmer
Click to expand...

First off...

I am un-aware of any current manual containing any loading info on the Nosler Accubond. I believe Nosler reccomends that data from the current manual for 160gr be uses as a guideline.

The current Nosler 5 manual list the starting load at 59 gr of RL-22 for a 160gr bullet with a MAX load of 63 gr.

IMHO you started about 3 grains OVER the reccomended starting charge and exceeded the MAX by 4+ grains:eek:

Speer #13 does list a starting charge of 62gr, but all bullets are different as Speer and Nosler have different manufacturing processes, so using their data as a safe starting load would be un-wise.

I would not go any higher than you are at right now because you are WELL above any published data.

You are right that your speeds are not consistant with book values?

Are you using a Magnum primer?

If not be very careful if you switch to one as you are in possibly dangerous territory with your 67 gr load.
 
While not bullet specific, this data shows 66 grains as max so you are likely at max or thereabouts depending on your particular lot of R22 etc. If you are getting good groups I wouldn't worry about getting a few extra FPS.
 
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