Re: 7mm SAUM + 180 Berger Hybrids
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JamesBailey</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JamesBailey</div><div class="ubbcode-body">
<span style="font-weight: bold">H4831sc (my 1st powder choice)</span>
start: 57.0, with +0.5gr increases in powder up until 62.0grs, expect to see pressure around 61.0.
<span style="font-weight: bold">H-1000 (my 2nd powder choice) </span>
start: 60.0, with +0.5gr increases in powder up until 65.0grs, expect to see pressure around 64.0.
<span style="font-weight: bold">H4350 (my 3d powder choice - this is the current rave of all the F-classers) </span>
start: 54.0, with +0.5gr increases in powder up until 58.5, expect to see pressure around 57.0.
<span style="font-weight: bold">Retumbo (my last powder choice - least amount of data on this powder)</span>
start: 61.0, with +0.5gr increase in powder up until 66.0. No idea on pressure expectations.
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Bump.
I finally got out to range to pressure test and chrono my above loads. Only ran into pressure on the H4530 load at 58grs (sticky bolt lift and extractor ring). The top MV's (chrono 14' from muzzle) for H4831sc and H4530 were all around 2900fps from my 26" Krieger 9twist, OAL 2.950", 90* temp. H-1000 was doing 2850 at the top end. Barrel is brand new (only 20rds thru it on this data) so these MVs are likely to change. My chamber is reamed for the 180gr Berger Hybrid at 2.950".
I had a very smart guy (Bohem on this forum) tell me add a few grains to your top H-1000 load and run Retumbo. Any other Retumbo/7mm RSAUM fans????
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Yeah wait to you get about 100 rounds or so down the tube...your MV should increase. Mine started to get really good velocitiies just after I cracked the 100 round mark. That or my chrono started giving me better numbers
but I always verify my speeds on steel and make sure the dopes line up with the velocity my chrono gives...and its always pretty close...never perfect but directionally correct.