hot chili powder
Member
Any thoughts on using concave/recessed base bullets (FMJ)....thinking of trying some but never used anything but flat base bullets. These would be for my 9mm CZ Duty, any pros or cons??
I guess we need to conduct another myth busting comparison range test to see whether Hollow Base FMJ produces greater accuracy over Flat Base FMJ.I agree with the idea of a lead bullet with a hollow base, but have my doubts about the usefullnes of said designs with jacketed bullets. Is there any hard facts proving the jacketed bullets really expand in the hollow region?
total recoil wrote:
Is there any hard facts proving the jacketed bullets really expand in the hollow region?
I am not aware of any, but measuring the bullet after firing would not necessarily be definitive. The gas filling the hollow base exerts pressure that can be resolved into vectors parallel to the axis of the barrel and perpendicular to the axis of the barrel. If the magnitude of the vector perpendicular to the axis of the barrel is still within the elastic range of the gilding metal/lead alloy composite of the bullet, then the vector perpendicular to the axis of the barrel would push the base into the wall of the barrel, but as soon as the bullet cleared the barrel and the pressure subsided, the base of the bullet would return to its original dimensions.
If that were true, wouldn't the same principle apply to pulled bullets that were over crimped, as in, there would be no visible indication that the bullet had been over crimped?If the magnitude of the vector perpendicular to the axis of the barrel is still within the elastic range of the gilding metal/lead alloy composite of the bullet, then the vector perpendicular to the axis of the barrel would push the base into the wall of the barrel, but as soon as the bullet cleared the barrel and the pressure subsided, the base of the bullet would return to its original dimensions.
+1. Variance in different firearms/barrels will produce different chamber pressures and muzzle velocities.After a few years and fiddling with all kinds of different bullets I have learned one fact that is true 100% of the time: The same combination of components will always behave differently in different firearms 100% of the time.
Welcome to THR!I suspect almost identical performance from both.
1. HB has the concave, but, it can't possibly expand beyond the lands and grooves.
2. The HB is jacketed (thicker copper).
3. The Berry's cross section (post 10 above by 243winxb) is thinly plated.
Well, there are many, including me who will argue chronograph readings don't necessarily translate to shot group size on target. We have verification from many members that high SD number loads can produce small shot groups.A chronograph reading of 10 or so of each, with identical sized brass, seating, crimping, bullet weights and charges may show a difference. But it would take that much sameness to eliminate other effects from the test.
I shoot them both and can't tell the difference.
Well, there are many, including me who will argue chronograph readings don't necessarily translate to shot group size on target. We have verification from many members that high SD number loads can produce small shot groups.