Why is 20” ok for 7 PRC but not 7 Rem mag?

[DoneNOut]

It would/will be interesting to see when someone take the time to do the good old cut the long barrel down an inch at a time velocity test with the 7 prc with several powders and bullet weights.. Would be fun to do if you plan on a short barrel build to start out long and end up with the barrel length you intended.

That's been done. Gunwerks Hil County Rifles on youtube.

 

[Buffalobwana]

A friend of mine says the only thing a chronograph is good for is to ruin the sentimental value of your favorite handload.

"Comparison is the thief of joy"

- Teddy Roosevelt

 

[Buffalobwana]

FWIW, Here's a Gunwerks/Long Range Pursuits podcast that deals with this in depth - probably solid data to back up these conclusions:

Podcast: EP 59: Choosing Barrel Lengths For Long Range Hunting

www.gunwerks.com

That was helpful. This guy shoots a 18" 7 SAUM and he knows just a bit about guns!

I'm comfortable buying a 20" 6.5 PRC now.

 

[jgbenson1]

Hill Country Rifles has a good Youtube video comparison of shooting 7prc out to 1000 with 20", 22", and 24" barrels. 20" , I think, was tops.

 

[FEENIX]

I don't know if it is much. If so, It's not significant enough to make a difference.

It's negligible from my .25 to .33 cals.

 

[In_Him]

I have an E-bike

So Jimmy lives next door?

 

[cjholler]

I've only run a suppressor on 5.56 and never chronographed it. Suppressors will increase some velocity, correct

Cans will make up for some velocity lost there have been studies done with 338 lapua it added 150 yds but again this was done at extend range ie 1600 yards to 1700-1750 when the bullet became unstable. To me accuracy comes before velocity but then again my long range is only 600 yds on game animals. Take it with a grain of salt but everything is a trade off only you can decide what you need doesn't have to make sense to anyone else.

 

[cjholler]

Also when the 7 rem mag was made these new bullets with higher BC didn't exist. Yes you can throat a 7 rem mag for heavy for cal bullets but the 7 prc is set up to use the new bullets with out much worry about the bullet eating into powder capacity. If your already set up for the rem mag then really no reason to change. Just my opinion.

 

[jbur13]

You're exactly right ……the only distinguishing data that I can think of is that 7rm in 1:10 compared to 7prc 1:8 would probably differ. Both calibers in same twist are probably pretty comparable, I would maybe give the edge to 7rm 1:8. What's your thoughts…..?

exactly. The PRC can shoot heavier bullets that will stabilize in an 8twist. Standard 7RM is 9.25 and cant stabilize 180grain bullets. So, the 7RM shoots lighter bullets, 150g (factory ammo) at a little over 3000fps out of a 24" barrel. The PRC shoots 180's at a little over 3000fps in a 22" barrel. big difference in Energy! That is where the forums go sideways, they aren't accounting for the people who load their own ammo.
I had a 20" 7RM built in an 8 twist and it shoots 175g at 2925fps. and to go back to another comment, yes, it was built to carry a suppressor.

 

[ElkSurgeon]

Except I could reload them for $1.15 to $1.30 per round. Instead of the $3.00 plus tax at gun store. And that's using top line bullets.

$1.15 per round because you are already invested into equipment & components that most guys they are marketing to have no desire or need to handload…….

 

[WoodPecker Hunter]

My New built 7 PRC will have a 24 " tube ! JMO

 

[colfaxent]

Chat forums tell me 20"-22" 7mm PRC is a great choice!! Same forums trash a 20" 7 Rem Mag.

Once an idea is established in the halls of the chat forums, it might as well have been brought down from the mountain on a stone tablet.

Is it bc the 7mag barrel length debate is well established in chat as gospel, but any new chambering is open to interpretation to justify our own selection bias? (Aka, I "need" a 20" 7mag, so this shiny new thing will work perfectly!)

20 years ago a .308 would have been considered a marginal choice for Elk, now the 6.5 CM is a perfect 600 yard Elk gun. I argue that good marketing persuaded chat forum users to establish this "fact". After all, nobody was running around yelling that the 260 Rem was the perfect 600 yard Elk rifle. (Everyone knows 260 Rem > 6.5 CM … )

So, can someone explain why a 20" 7mm PRC is perfectly acceptable, but same length in a 7 Rem mag would be downright foolishness?

The PRC has a 1:8 twist, mostl ikely the 7 mag has 1:10.

 

[bultinkle]

It's fine for both. People are weird

 

[redchinviking]

Turns out twist rate and chamber specs matter. It's ok though all the 7prc deniers are more than welcome to re-chamber and/or re-barrel to a faster 1:8 twist rate with a shorter barrel so they can have …wait for it…7prc performance in their good ol' 7 rem mag… or just chop your barrel and go hunting. On second thought…just go hunting.