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Hammer bullets

So, does that mean that that only the bands are engaging the grooves of the barrel?
Only the bands on the bullet contact the grooves in the barrel. It would have to be a tight fitting sucker for the grooves on the bullet to contact the grooves in the barrel. On the ones I've tested, the grooves on the bullet don't make full contact with the lands in the barrel.
 
Only the bands on the bullet contact the grooves in the barrel. It would have to be a tight fitting sucker for the grooves on the bullet to contact the grooves in the barrel. On the ones I've tested, the grooves on the bullet don't make full contact with the lands in the barrel.

So the shank forward of the bands is a bore rider... riding the lands only and not engaging the grooves of the barrel...
 
Are there any pics of a fired, intact hammer?

These are from my bullet test a few years ago but I believe these were 152gr Hammers, but they could have been 155 at the time. Both were fired from a 1-8" twist 300 Blackout and impact velocities of both bullets was around 1200 fps, so WELL below the suggested operating range.

Cvgz3u2.jpg

The Hammer Hunter tried to expand and the Sledge Hammer actually rolled in which was a little unexpected. Both bullets perform as designed when impacts were within designed operation range. These just do a great job of showing the rifling engagement of an intact bullet.
 
These are from my bullet test a few years ago but I believe these were 152gr Hammers, but they could have been 155 at the time. Both were fired from a 1-8" twist 300 Blackout and impact velocities of both bullets was around 1200 fps, so WELL below the suggested operating range.

Cvgz3u2.jpg

The Hammer Hunter tried to expand and the Sledge Hammer actually rolled in which was a little unexpected. Both bullets perform as designed when impacts were within designed operation range. These just do a great job of showing the rifling engagement of an intact bullet.
Was this impact in dry media? I have never seen one roll in like this Sledge Hammer. Our "farm boy" down and dirty impact test media consists of a 1 gallon milk jug in front of news paper to stop the bullet. Wet vs dry news after the water makes no diff since the bullet is generally done inside the milk jug. I would expect to see the Sledge Hammer show pretty well even at 1200fps.

Another thing we see when impact testing is the higher sectional density bullets do better at low vel than the lower ones. More "poop" to drive the bullet.
 
So, does that mean that that only the bands are engaging the grooves of the barrel?
Yes. Only the largest dia point of the PDR (radius drive bands) is contacting the grooves. This allows us to cut the bullets large enough in dia to always seal the bore without creating pressure problems in tight bores. Because of the radius drive band high point being very finite, it's the reason that Hammers don't create undo pressure.
 
Haven't read through this whole thread. So forgive if it is a bit off topic. But I have tried the 6mm 101 Hammer Hunter (which actually weights 102.5gr for every single one of the 50 I have) in two different 6mm rifles.
A 1:7.5" 6SST @ 3260-3450+ into tiny groups, from high .1s to .4s with nothing more than charge weight changes.



I just tried a very limited few in my 6CM last weekend. On the off chance I draw a deer tag, I wanted an all-copper load worked up. Well, I might have found my hunting load for my August pronghorn hunt in NM. I loaded them at .020" off, and just tried 3 powder charges to see what they would do.....


 
These are from my bullet test a few years ago but I believe these were 152gr Hammers, but they could have been 155 at the time. Both were fired from a 1-8" twist 300 Blackout and impact velocities of both bullets was around 1200 fps, so WELL below the suggested operating range.

Cvgz3u2.jpg

The Hammer Hunter tried to expand and the Sledge Hammer actually rolled in which was a little unexpected. Both bullets perform as designed when impacts were within designed operation range. These just do a great job of showing the rifling engagement of an intact bullet.

What is the recommended minimum expansion velocity for the Hunters? Based on this pic, I'm guessing they would expand at 1500'/sec, maybe 1400?
 
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