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Posted: Today 12:10:42 PM EST
| A while back there was a thread in GD about 77gr load velocities. Mine isn't even close to anyone else's. Im getting 2534 on average with 24gr Varget @2.26" in an 18" Aero "SPR" barrel @ 70°. Seems like most people are getting over 2700 with similar equipment. |
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Could be several things including but not limited to: 1. Chamber Dimensions & Throat Geometry: Loose chamber and/or long or wide throat = lower pressure 2. Bore & Groove Diameter Variations: Tighter bore = more friction 3. Headspace & Lock-Up Timing: slight bullet movement before full pressure |
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Typical questions back to the OP might include - What brass? What seating depth? Which primer? What headspace? IMO, it's just that your expectation is too high (>2700 fps). I looked over my data and thought you should see about 2600 fps with an 18" barrel, maybe even a little less. If you should be getting 2600 fps and are only getting 2535 fps, yes, it's a little slow, hence the questions, above. No matter the answers, the REAL question is this - are you getting good accuracy at that velocity? If the answer is yes, leave it alone. 50-100 fps more or less is irrelevant. If the answer is no, accuracy is terrible and it's slow, then you should review your load development test data or re-do the testing. |
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