2" barrel velocity loss in 6.5 prc and 7 prc

[davsco]

choosing a 22" vs a 24" will reduce weight a little as well as tree banging. any idea of the velocity i'll lose.. is the rule something like 25-50 fps/inch or thereabouts. not sure how sensitive the PRC's are to barrel length. thanks!

 

[amassi]

Yep you'll lose about 40 fps give or take. 2" of barrel might weigh an ounce or 2 if it's a heavy contour but it will certainly be handier

 

[Stinky Coyote]

go 20-25 fps per inch rule, it's been 22.4 fps per inch with the 6.5 Grendel's I've played with the past few years, on your set up just using a 0.6 g1 bc bullet, if it's 40-50 fps will be like 1.4% to 1.8% difference on velocity and 30-35 yards (4.3%) difference in impact velocity equalization...ie; 710 yards for 2000 fps impact vs 680 yards lol...nobody and no animal will be able to show why 24" is better than 22"

perspective is a tricky thing for us obsessives, if you're like the majority and will be killing inside 600 then a whole bunch of it becomes moot, you've got horsepower for days with those cartridges, I went a bit more extreme and dropped from 23.5" to 16.1" (7.4") and lost 110 yards for minimum impact velocity limits but it's still beyond what I intend to do afield on game so had no issue going to the short barrel

you can equalize with custom barrels vs factory also, I had a proof carbon 24" barrel which apparently come hand lapped and only 11 shot break in required, was very fast, was 88 fps faster than factory 23.5" barrel with same load, just figure out where your realistic limits need to be for impact velocity and ranges and you'll see if you really need less than 2% more velocity?, 99.99% of us and the animals will agree that you'll have more than enough with a 22" barrel to way further than you'll likely hit anything

 

[AkRyan]

I would guess 50-80fps in otherworldly not enough to worry about.

 

[davsco]

perspective is a tricky thing for us obsessives, if you're like the majority and will be killing inside 600 then a whole bunch of it becomes moot, you've got horsepower for days with those cartridges

yeah i just dropped the 6.5 PRC fps by 100 (hopefully way overkill for 2") in hornady's ballistic calculator. at 500yds (close to if not at my preset hunting limits), energy dropped from 1644 to 1523 ft-lbs, the drop went from 43 to 47" and 5 mph windage increased from 6 to 7".

not losing a lot for gaining a little handiness, so i might go that way. certainly enough oomph for whitetail and muley and i have a 300wsm for elk.

 

[AkRyan]

yeah i just dropped the 6.5 PRC fps by 100 (hopefully way overkill for 2") in hornady's ballistic calculator. at 500yds (close to if not at my preset hunting limits), energy dropped from 1644 to 1523 ft-lbs, the drop went from 43 to 47" and 5 mph windage increased from 6 to 7".

not losing a lot for gaining a little handiness, so i might go that way. certainly enough oomph for whitetail and muley and i have a 300wsm for elk.

Cut them all short! My wsm is 19" and I efin love it, also have a howa 1500 300wm at 18" thats a hoot to shoot and it's honestly more acurate than it was at 24in.

 

[CCooper]

I have a 22" 6.5 PRC and have never wished it was longer.

 

[Newtosavage]

I have a 22" 6.5 PRC and have never wished it was longer.

This. I know few hunters who ever wished they had a longer barrel when they were actually in the field hunting.

All my .308 based rifles wear 20" barrels and my .284's wear 21" barrels. I hate tree clanking.

 

[davsco]

I have a 22" 6.5 PRC and have never wished it was longer.

do you mind saying your FPS, esp if you're using factory hornady 143 eldx?

i was getting 2830 with my proof carbon 24" barrel though hornady shows 2960.

 

[CCooper]

It does 2840 with 143 eldX precision Hunter and 2823 with Berger 156 hand loads:
Adg brass
Gm210m primer
58.7 gr N565

 

[CCooper]

That’s with a #13 carbon Bart 7.5 twist

 

[Sadler]

My 16” shoots 156s at 2650 and my 18” shoots them at 2750.

 

[Firedad]

This is interesting. I was thinking 7 prc 20” so I could suppress later. I want 7 prc for elk at a distance. I’m new to all this so help me out. Will it have the velocity and carry enough energy to 600? 700? 800 yards?

 

[carter33]

This is interesting. I was thinking 7 prc 20” so I could suppress later. I want 7 prc for elk at a distance. I’m new to all this so help me out. Will it have the velocity and carry enough energy to 600? 700? 800 yards?

I haven’t necessarily “crunched” the numbers but I would say, yes, by common logic the 7PRC will get you the energy you need out to 800 yards. That being said if I thought a 7-800 yard shot was likely I’d lean towards a .30cal magnum.

On the Hornady podcast an employee stated that they were getting a MV of 2910 with the 175 eldx which is pretty impressive.

 

[Sevens]

Go with a 22” or shorter, like 20”. Once you have tried a shorter barrel, the 24” seems awfully long and unwieldy.

I ordered both a 6.5PRC and 7PRC barrel in 20”. Will probably use the 6.5 for training and most hunting, then swap to the 7PRC barrel if elk is on the menu. I don’t reload, so factory 6.5PRC is more affordable to shoot (sounds funny to say that).

I’m honestly shocked more prefits are not coming in shorter barrels now. With the increase in suppressor usage, seems like short barrels will be the norm eventually. I think once approvals actually get to 90 days, seems like suppressors will be the norm.

 

[ResearchinStuff]

Imo, the right barrel length for a prc is 16.5". That way you can run a full size 9" can and have great terminal performance out to really long range in a manageable package.

I also think that a 25 prc would have been a better new offering than the 7 prc, which doesn't seem to uniquely fulfill any performance niche.

 

[slowelk]

I also think that a 25 prc would have been a better new offering than the 7 prc, which doesn't seem to uniquely fulfill any performance niche.

What niche would a 25 prc fill? 130gr bullets at 3k? Sounds like a 6.5 prc to me.

 

[35WhelenAI]

I’m honestly shocked more prefits are not coming in shorter barrels now. With the increase in suppressor usage, seems like short barrels will be the norm eventually. I think once approvals actually get to 90 days, seems like suppressors will be the norm.

I like your thought that shorter barrels will become more the norm, however realistically what is the cost of a suppressor when considering it in total? Rank and file hunters are not in the financial position to get one. A suppressor is an elite option in the grand scheme. IMO, that's not going to change in order for suppressors to become the norm anytime soon.

 

[Samson7x]

I’d go shortest your comfortable with if using a suppressor.

Just as a point of reference, I’m getting 3000fps with a 20” proof barrel and 140vld. With ultra7, it’s a winning combo IMO.

 

[Mike Islander]

Build for velocity, not energy. 2" will lose 50 - 60 fps. 147 ELD-X will go from 1800+ fps at 900 yards for 24" barrel to 1800+ at 850. So for hunting no difference in practical terms.