6.5 PRC Velocity Issues

[RocketRob16]

I recently noticed that my new rifle is quite a bit under the velocity I expected. Curious to know if anyone else is seeing the same or has any input.

Rifle is a Browning X-Bolt 2 Speed SPR, 20 inch barrel, Silencerco Harvester suppressor, shooting Hornady 147gr ELD-Ms. Last week I finally backed up from shooting 10-shot 100 yard groups and shot at 200 and 300 yards and had drops of 4.7" and 16.1" respectively. Punching in the data and environmentals, the velocity matched drop at around 2500 fps. I was expecting 2750 fps or so initially from what others were seeing. Is that out of the realm of what you'd expect? Just a really slow box from Hornady? I could most likely borrow a chrono from a buddy in a week or two if needed to confirm.

 

[Nine Banger]

My rifle has an 18” barrel with 57gr h1000…147 ELD…AB raptor 8 w/ reflex.

My chrono reads faster than this but was corrected based on drops recorded and manually inputted at 500,600 and 800.

 

[Halligan]

Observing what has been going on in the firearm world the following could be a possible answer:
Ways back, the big game hunting blog did a video on the reports of slow 7 prc factory load velocities from hornady. Long story short, turns out newer batches were significantly slower due to hornadys inability to procure the powder they designed the cartridge around. Per hornady, they expected anywhere from a 75-175 fps velocity drop as memory serves.
The important takeaway however, was that the powder manufacturer (alliant) also owns federal, and federal loads were meeting velocity expectations (ie able to use said powder).

Thus, if this happens to be the same case for 6.5 prc, you may be suffering from the same velocity drop issue. Might make testing some federal loads a try if you aren’t reloading.

This said, if someone knows something to the contrary, please chime in

Interesting watch:

 

[HandgunHTR]

Your best bet is to get a chrono and get the actual speeds. There is just too much shooter induced variability to reliably get initial velocity based solely on drops at extended ranges.

It is good to verify your readings with drops once you have the chrono results, but that should be to get fine tuning for going over 600.