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

[Buffalobwana]

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?

 

[DoneNOut]

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?

In situations like these, trust your gut. If you have to question something it's because it's cross graining your gut instinct. The only reason I see going short like that in a caliber size always known to excel in longer barrels is use of a suppressor.

 

[Buffalobwana]

In situations like these, trust your gut. If you have to question something it's because it's cross graining your gut instinct. The only reason I see going short like that in a caliber size always known to excel in longer barrels is use of a suppressor.

Exactly. Suppressors weren't common back when the consensus on 7 mag barrels was reached.

Now that we need shorter barrels for suppressors, the 7 PRC saves the day!

Or are we just telling ourselves that?

 

[Slick8]

I think you answered your own questions, forums are as opinionated as the near extinct gun writer of outdoor life.

A perfect expample is what what Cody is doing with his short barreled 300 RUM. Amazing performance from a 20 inch barrel.

 

[DoneNOut]

Exactly. Suppressors weren't common back when the consensus on 7 mag barrels was reached.

Now that we need shorter barrels for suppressors, the 7 PRC saves the day!

Or are we just telling ourselves that?

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

 

[Buffalobwana]

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

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

 

[iiiNelson]

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?

Is it possible with the availability of affordable chronographs, more education on chamber dimensions, more information on powder burn rates, etc. that people are more educated (potentially anyway) on what used to be passed around as fact when it was nothing more than "urban legends?" Is it possible that people have access to more data and that they can verify data themselves (to some extent) versus just using box values for velocity? It used to be said across the board that you lose 50fps per barrel inch lost or that anything other than a 26" barrel in a magnum was "useless." With chronograph data we can assess that in some cases it's more like 20-30fps lost and with some it's 60-80fps lost. Sometimes it's just about the individual barrel and chamber IMO.

There are many 22" or 24" 7RM rifles available because many have decided the loss in velocity wasn't a huge trade off for their individual purposes. If you want to continue with the 7RM it's been killing well for 60+ years. I think it's less about attacking the introduction of the 7 PRC than it is using whatever you want that fits your purposes. Nothing wrong with either.

 

[Rosebud]

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?

When the 7 RM came out there were no range finders, no dial up scopes ,etc. There was a need for speed! Think .264 win mag , 270, 25-06. All were for speed to shoot unknown range. Long barrel equals more speed. Put in a 139 grain bullet, sight in three to four inches high at one hundred, aim right at it out to four hundred.

 

[Mike Matteson]

Back to the days of no rangerfingers. The rangerfinder sure have changed over the years.

 

[Buffalobwana]

Back to the days of no rangerfingers. The rangerfinder sure have changed over the years.

You would think the old uneducated opinions disappear with access to new info.

Nope! Too easy to repeat what you have been reading for 20 years. What everyone else is saying. The internet gospel continues. People who Google more than challenge old school though continue to post "Short barrel in 7 mag … bad!"

 

[Buffalobwana]

So, there is no real difference in 7mag vs 7 PRC when it comes to barrel length? Nothing magical about a PRC case that allows it to be immune to the horrors that await the 7mag when shortened?

 

[DoneNOut]

So, there is no real difference in 7mag vs 7 PRC when it comes to barrel length? Nothing magical about a PRC case that allows it to be immune to the horrors that await the 7mag when shortened?

There is something to the WSM line that lets them shine with 23" barrels. Powder column stacking or some schit!

 

[Elk Hunter 338]

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?

Because INTERWEB heroes say so ..
just ask them, and they will tell you you are down right an IDIOT if you do it!!
Just watch some you tube videos of the HEROES basically demanding that the 7rem mag is a piece of ****, down right no good for nothing barrel eater that belongs in a museum! (even though they sell more 7rem mags than any other chambering)
The 7PRC WILL not do anything better than the 7 rem mag can't do with little effort. barrel length for barrel length, bullet for bullet, powder for powder!! SAMEZEEZZZZZZ..

people have basically told me I'm ridiculous for shooting a 300 rum 338 rum 338 edge 338 lapua imp 300 Norma improved in 20-22" barrels and in no way will they burn that amount of powder or be accurate!!

They just HATE the fact that I'm right when I say ....""" yeah.... um..... but my 20-22" barreled magnums are shooting the same if not more velocity with the same weight of projo than your 26" super duper efficient cartridges"""

 

[DoneNOut]

Because INTERWEB heroes say so ..
just ask them, and they will tell you you are down right an IDIOT if you do it!!
Just watch some you tube videos of the HEROES basically demanding that the 7rem mag is a piece of ****, down right no good for nothing barrel eater that belongs in a museum! (even though they sell more 7rem mags than any other chambering)
IT will not do anything better than the 7 rem mag cant do with little effort. barrel length for barrel length, bullet for bullet, powder for powder!!

people have basically told me I'm ridiculous for shooting a 300 rum 338 rum 338 edge 338 lapua imp 300 Norma improved in 20-22" barrels and in no way will they burn that amount of powder or be accurate!!

They just HATE the fact that I'm right when I say ....""" yeah.... um..... but my 20-22" barreled magnums are shooting the same if not more velocity with the same weight of projo than your 26" super duper efficient cartridges"""

I'm still trying to figure out how a belted case rips the fabric of the space time continuum...