Hammer .308 192gr HBC range report and verified BC

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TLDR: Advertised .662 G1 BC checked out within 0.05mils at 600yds with 2750fps muzzle velocity

I've been working with this bullet for a few range sessions now, figured I'd post an update as I haven't seen much on it outside of the Hammer Forums. I built a custom long-throat 300 WSM based on the dimensions and expected performance of this bullet, and so far I'm really happy with it. My biggest fear was reports of inflated BCs from Hammer. When you compare the form factor of this bullet with other available options (including lead) it seems like they must have inflated the number, but that doesn't seem to be the case with this bullet after verifying drops.

The goal for this rifle was to maximize performance of copper monos for meat hunting. I initially looked at 35-36 caliber options in order to take advantage of the larger frontal area with limited expansion of copper, but settled on this bullet due to the somewhat outstanding nature of it's advertised BC vs weight (i.e. form factor). My insurance against this bullet not panning out was that multiple other known-performing bullets end up in a very reasonable 3.1-3.2" COAL with this throating (190/210 ABLR, 208 LRX, and a number of other mono and lead options that I checked).

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The Rifle:
  • Defiance Ti-X Medium Action
  • Preferred Barrels 20" 1:8 twist Taperless .750 profile, chambered specifically for .030" of jump with this bullet at 3.260" COAL
  • Rokstok
  • UM Premier Medium Rings
  • UM Bottom Metal and Mags (longest COAL available for the medium action)
  • Maven RS1.2
  • Currently wearing my Sandman S can, will be switching to an AB Raptor 8 stack soon
  • 8.0lb finished weight (w/out suppressor)

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The Load:
  • ADG 300 WSM Brass
  • Aforementioned Bullet
  • 3.255" COAL (seated to second driving band)
  • H4350 powder
  • 2756fps LabRadar verified MV at the 60.6gr powder charge I'm using
Range Results:

Consistently shoots 1.2-1.5 MOA 5 and 10 shot groups. Some sub-MOA 5 shot groups during load dev. I'm confident the rifle is more accurate than this, but I'm having a hard time consistently doing much better with it due to the light weight. To be clear, this is not a recoil complaint (recoil is exceptionally mild with the can and rokstok) but more a steadying the reticle before the shot complaint (particularly in wind, which is ever-present at the 6600' elevation high-desert range I shoot at). The lighter the rifle, the harder I find to steady. 60 rounds down the tube now and MVs are settled in right around 2750fps. I saw a slight increase of velocity (~20fps) over the last 30 shots with this load, but it seems to be plateauing at this point. I'm right at the hint of ejector mark shine on the brass, though not enough to catch a fingernail. I'll probably drop another few tenths of a grain to buy some insurance at hotter ambient temps, it'll only cost me 20-30fps MV based on load ladder results.

This was my final sighter group yesterday at 100yds, just prior to moving to the long steel range to verify drops (I dialed an additional 0.1mil left after this group):
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Using my LabRadar MV and iPhone atmospherics, AB's Ballistic App returned a 3.55 MIL elevation hold for the 600yd range I planned to verify drops at (this is just shy of 2200fps impact velocity, which is what I plan to hold max range at until I can verify bullet performance on game). The wind conditions were swinging left to right quartering at 15mph gusting to 23mph (per the nearby airport weather readings, wind is usually a little worse than that report at the higher elevation of this range). AB gave about a .5mil wind hold for that speed and angle, but given the variable nature of the wind I worked back and forth with the range flags and anywhere from a dead wind hold to 0.25mils of wind hold in the appropriate direction. I held wrong on one of the shots as the wind was shifting, which went just off the right side of the target (can spot your own splash with this stock design, and splash is impressive with this bullet), but the other 9 were solid hits. I marked 8, there's a 9th, but I couldn't tell which impact was the double splash so I didn't mark it. I think the 9th was what appears to be a double-splash at the 1 o'clock edge of my black aiming mark:
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So, the advertised BC of .662 seems to be absolutely perfect in this velocity range. I dialed 3.6Mils for a 3.55Mil correction and ended up with a 9-round group that was .05 mils high. Can't get any closer than that. Super happy with these results, especially given the wind conditions.

Will be headed on a January cow elk hunt with this setup, hopefully with some terminal performance reports to follow.
 
Good write up and components.

I have never had an issue with BC's and Hammers. It's yet another "saying" that gets repeated and parroted by folks.
 
Good write up and components.

I have never had an issue with BC's and Hammers. It's yet another "saying" that gets repeated and parroted by folks.
This has been my experience as well. I measured BCs via LabRadar for a number of their offerings in .35-.36 caliber, and all were within a few percentage points of advertised number save one. The 255gr .358 HHT was significantly lower than advertised. However, the 242gr .366 HHT was significantly higher than advertised, so I call that a wash. People don't always understand that BC varies with velocity, so what's true for one measurement may not hold with a caliber in a different velocity range.
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I also forgot to mention in the original post, but I did get LabRadar verification of the 192gr HBC BC using 25 yard interval pings out to 100 yards. Over a data set of about 30 shots, that also worked back to a .665 G1 BC.
 
Keep us posted, I've been wondering about the 7mm hbc a bit.
That one is also quite impressive from a form factor perspective. I've got a proof barreled 28 Nosler that I may end up trying that with. The 107gr .257 bullet is also on my short list of things to try. It should hit 3300fps or so from my 20" 25 Pronghorn (25-300WSM)
 
People don't always understand that BC varies with velocity, so what's true for one measurement may not hold with a caliber in a different velocity range.
Also bullet stability.

One grumble folks have at times is when a manufacturer uses higher velocity and faster twists specifically for the BC data gathering and don't caveat it.
 
I always hear it was an issue with the pre-tip bullets. It seems once they incorporated tips the BCs got pretty accurate.
I’ve found this to be pretty accurate too. I don’t know if it is really the tips or if that just happens to coincide with the timeframe where they finally got called out enough for the inflated numbers that they found honesty.
 
Even the early ones? I think that is where alot of the ire came from.

I may have broad brushed that statement too much. I personally have loaded many of their bullets, and never once had an issue. I true every load at distance. However, the amount of times I've heard the inflated bc's, well it's almost automatic when a guys says Hammer bullets someone chimes in.
 
OP, I am somewhat curious as to why you chose such a heavy bullet. I understand the BC benefits, but at 600 yards and less, wouldn’t you rather have more rapid expansion that comes along with greater velocity?
 
Also bullet stability.

One grumble folks have at times is when a manufacturer uses higher velocity and faster twists specifically for the BC data gathering and don't caveat it.
This is also true. Hammer may have been shooting something smoking fast in their test rifles to come up with those numbers. Nonetheless, they should either choose something more mainstream to do the testing with, or at least state what was used so the customer can draw their own conclusions
 
OP, I am somewhat curious as to why you chose such a heavy bullet. I understand the BC benefits, but at 600 yards and less, wouldn’t you rather have more rapid expansion that comes along with greater velocity?
It was more a caliber related decision than weight. Looking at .308 and larger diameter projectiles, this one is pretty much in a class of its own from a BC perspective. I ran scads of different trajectories and this combo seemed to be a goldilocks of recoil vs retained velocity and wind drift. Edit to add I don't plan on limiting myself to 600 forever. That corresponds to 2200fps impact velocity, but using 1800 as a minimum (which I think may be reasonable, pending results on game) extends the range to almost 1000yds.

The runner up was a 242gr HHT, which I measured at .545 G1 BC. I may still build a wildcat off of it, as I've got dies for 9.3-300 WSM and 9.3-338 WM, as well as an easy neck-up of 33 Nosler (or form 36 Nosler brass from 30 Nosler). I figured stepping up in recoil was a safer bet than going full gusto right out the gate. Based on what I'm learning in this one, a larger bore Tikka (slightly heavier) build in a Rokstok may still be around the corner.
 
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