RockyMtnMT
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Wanted to share our load workup with the 6.5 PRC and our 120gr Hammer HBC. The HBC bullets are super low engraving pressure, so they do not act like conventional bullets for powder speed and amount of powder in order to get to pressure. They will want more and or faster powder than would be expected for the bullet weight in the cartridge in order to get the load to pressure.
The rifle is a Browning Hells Canyon with a 24" factory barrel 1-7". Running Peterson brass and Fed 210M primers. To fit and feed this bullet is seated with the case mouth on the shoulder at 2.84" COAL. We tried a few powders trying to find where we could get to pressure before running out of case space.
Started first with H4350 at 51gr with a very mild velocity of 3010fps. We worked up to 59gr where the load was too compressed and trying to push the bullet back out. Vel was at 3434fps with no real pressure signs.
Next we tried StaBALL6.5 thinking we could get more of the small ball powder in the case to get to pressure. Topped out the case capacity at 60gr and a vel of 3430fps with no real signs of pressure. A good start load here would be 52gr.
Still wanting to find real pressure we tried N550. Start this one at 49gr and work up. We were able to hit a hard click on the primary extraction at 58gr and a velocity of 3525fps. I would consider this a top end load and would probably back off a grain in this rifle at 3465fps.
We were loading this rifle for my sister in law and decided to go ahead and run the H4350 at 58.5gr and a vel of 3400 fps. This is technically her rifle, but I think my brother packs it more than she does. LOL! Anyway, based on finding pressure with the N550 and the correlating velocities, this h4350 load has us comfortably under pressure and a solid half moa load. By the way, this rifle is running a suppressor too.
Now I would like to talk about the ballistics of this combo. It is quite impressive at 3400fps. At 4000' elev and standard atmosphere with a g7-bc of .266, This combo is carrying 1800 fps to 1080y. At 500y the impact vel is at 2600 fps! So, I decided to run ballistics against one of the "heavy for caliber" bullets to see how it stacks up. I picked the heaviest thing that Hodgdon data shows, the 153gr A-Tip. I know it's not a hunting bullet, but we'll compare it anyway. Hodgdon shows top vel for this bullet under 2900 fps, so I used 2900 fps to run the ballistics. With the listed g7-bc of .355 the A-Tip carries 1800 fps to 1050y and has an impact vel at 500y of 2338 fps. The impact vel of the 120gr Hammer HBC at 300y is the same as the muzzle vel of the 153gr A-Tip. Then you look at the max point blank range capability for the two bullets. Based on a 5" radius target the MPBR for the A-Tip is 368y with a zero set at 311y. The MPBR for the 120gr Hammer HBC is 419y with a 355y zero. That gives the 120gr Hammer HBC 51y more range before you have to start to adjust your elevation hold on a deer.
If you want to maximize your lethal range capabilities with your 6.5 PRC, nothing runs with the 120gr Hammer HBC.
The rifle is a Browning Hells Canyon with a 24" factory barrel 1-7". Running Peterson brass and Fed 210M primers. To fit and feed this bullet is seated with the case mouth on the shoulder at 2.84" COAL. We tried a few powders trying to find where we could get to pressure before running out of case space.
Started first with H4350 at 51gr with a very mild velocity of 3010fps. We worked up to 59gr where the load was too compressed and trying to push the bullet back out. Vel was at 3434fps with no real pressure signs.
Next we tried StaBALL6.5 thinking we could get more of the small ball powder in the case to get to pressure. Topped out the case capacity at 60gr and a vel of 3430fps with no real signs of pressure. A good start load here would be 52gr.
Still wanting to find real pressure we tried N550. Start this one at 49gr and work up. We were able to hit a hard click on the primary extraction at 58gr and a velocity of 3525fps. I would consider this a top end load and would probably back off a grain in this rifle at 3465fps.
We were loading this rifle for my sister in law and decided to go ahead and run the H4350 at 58.5gr and a vel of 3400 fps. This is technically her rifle, but I think my brother packs it more than she does. LOL! Anyway, based on finding pressure with the N550 and the correlating velocities, this h4350 load has us comfortably under pressure and a solid half moa load. By the way, this rifle is running a suppressor too.
Now I would like to talk about the ballistics of this combo. It is quite impressive at 3400fps. At 4000' elev and standard atmosphere with a g7-bc of .266, This combo is carrying 1800 fps to 1080y. At 500y the impact vel is at 2600 fps! So, I decided to run ballistics against one of the "heavy for caliber" bullets to see how it stacks up. I picked the heaviest thing that Hodgdon data shows, the 153gr A-Tip. I know it's not a hunting bullet, but we'll compare it anyway. Hodgdon shows top vel for this bullet under 2900 fps, so I used 2900 fps to run the ballistics. With the listed g7-bc of .355 the A-Tip carries 1800 fps to 1050y and has an impact vel at 500y of 2338 fps. The impact vel of the 120gr Hammer HBC at 300y is the same as the muzzle vel of the 153gr A-Tip. Then you look at the max point blank range capability for the two bullets. Based on a 5" radius target the MPBR for the A-Tip is 368y with a zero set at 311y. The MPBR for the 120gr Hammer HBC is 419y with a 355y zero. That gives the 120gr Hammer HBC 51y more range before you have to start to adjust your elevation hold on a deer.
If you want to maximize your lethal range capabilities with your 6.5 PRC, nothing runs with the 120gr Hammer HBC.
