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From SMK 155 to Scenar 155 - pressure difference?

thefitter

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May 10, 2010
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I have a decent load worked up for SMK 155. I just got in a batch of Scenar 155. I'd like to just try these with this load first and see what they do before I go through the whole OCW process. Shouldn't be a problem, right? Thanks

 
Re: From SMK 155 to Scenar 155 - pressure difference?

Ogive length will determine pressure difference.
Got a comparator gauge?
The bullet with longer bearing surface will generate more pressure.
Not likely a big deal unless you are already blowing primers with your enthusiasm for longrange proficiency. If that's the case, back off 5% minimum and work your way back.

I found the Nosler 6.5mm 140 gr bthp design had ogive beginning closer to nose of bullet than the SMK of same weight. In my rifle, long throat, chose Nosler to get less jump into lands. Good bullets the Nosler comps... Nice to have tools to diagnose and compare...
 
Re: From SMK 155 to Scenar 155 - pressure difference?

I think your research will be fine if you give yourself a little window either side of your current charge weight just incase a few grains less/more gives you better accuracy.

I would expect pressure to be very similar.
 
Re: From SMK 155 to Scenar 155 - pressure difference?

Yes you will see a presure difference, or at least I did.

I started seeing presure with the lapuas with .8gns less powder than I was shooting the sierras. I never really found the top end with the sierras but I went high enough to make me feel a little uncomfortable using varget.