7 PRC Velocities / FACTORY Ammo

[WYCFM1]

That's not how things work and nobody designs cartridges with the desire to stuff a bullet deep in the case to increase velocity to my knowledge.

It seems like you're confusing a chamber with long freebore for how deep a bullet is seated. Long freebore allows for more powder to be burned at the same pressure because it allows the bullet to be further forward when before reaching resistance from the lands of the rifling and thus has more volume behind it for the burning powder compared to if it had shorter freebore. It also allows you to seat longer bullets out of the powder space.

People seem to give way too much credit for seating depth on velocity/pressure. If youre not on the lands, it just isnt going to make that much difference until you're playing at the extreme ends.

Correct…that’s how I understand it.


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[WYCFM1]

Although I’ve seen pressure jump with my own hand loads from bullet seating deeper I have never seen a 200fps velocity increase…not even 75fps…I only noticed worse brass life and flattened primers with Ejector marks/smears


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[Lunchbox37]

Shot 180gr ELDM out of a new Browning X-bolt Mountain Pro SPR with a 20" barrel this weekend, only 6 shots, Average velocity was 2730fps. First round showed signs of high pressure (ejector mark), all others showed no signs of pressure on the brass. In full disclosure I had bore scoped and cleaned the barrel prior to shooting. The first round had a little CLP film on it when I extracted it so definitely user error for the higher pressure on the first round.

Out of curiosity I wanted to track the fire forming on the factory brass, so I marked the brass and used a Hornady headspace comparator to take measurements before and after:

ELD Match	Before	After	Delta
1​	1.896​	1.898​	0.002​
2​	1.897​	1.899​	0.002​
3​	1.8965​	1.8985​	0.002​
4​	1.897​	1.899​	0.002​
5​	1.896​	1.8995​	0.0035​
6​	1.8975​	1.9​	0.0025​

 

[swavescatter]

Finally shooting my Proof 20" on Tikka action (barrel blank) with a Banish 30 Gold.

This is with early lot Hornady ELD Match. A bit spicy. Just bought a box of new ammo to compare velocities once the barrel is broken in a bit more. 30 rounds down so far.

 

[Cbthomas]

20” carbon6 barrel shooting 180 eldm’s, H1000, ADG brass and federal 210M

First 5 shots thru the rifle got cleaned between each shot then the rest were a pressure test, then I picked a charge .5 below the first sign of pressure and loaded 6.

6 shots Through a labradar averaged 2853

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[NickT406]

Christenson Mesa FFT 22" 1:8 twist. About 40 rounds down the pipe when I got my averages. How much can I expect to see this speed up?
Father in-law was getting 2910 fps average with 180 eldm out of his fierce. Was a little underwhelmed.

180 eldm @ 2760 average
175 eldx @ 2816 average

 

[DisplacedHusky]

I have to imagine the recoil is "technically" higher with the 7 due to science and stuff (saw one vid that placed it between and 06 and a .300 wm which makes sense on paper) but yea - totally apples to oranges in my case, but my 7 PRC has a break and a carbon fiber stock - my 30-06 is a factory tikka and is not super fun to shoot on the recoil front The 7 feels much closer to my 6.5 tikka then my 06 honestly and I can shoot it a lot without being bugged... now just waiting for my can to get out of jail as I don't love shooting braked

What are the weights on both rifles?

 

[DisplacedHusky]

Seems like everyone is shooting around 2850-2870fps out of the 22” barrels.

Which is interesting because one the Hornady 7PRC intro podcast, one of the senior ballisticians said they were getting 2910 fps out of their 20” barrel with 175gn ELDX.

 

[Tahoe1305]

Which is interesting because one the Hornady 7PRC intro podcast, one of the senior ballisticians said they were getting 2910 fps out of their 20” barrel with 175gn ELDX.

Were they talking factory or handloads?

Factory surely seems 100fps short of that but I’d buy it with handloads.

 

[DisplacedHusky]

Were they talking factory or handloads?

Factory surely seems 100fps short of that but I’d buy it with handloads.

I wrote it in the notes on my phone because I was interested in a 7PRC with a 20” barrel but I didn’t make note of whether it was factory. I’m guessing it was because they mentioned 175 eldx.

 

[TxLite]

Which is interesting because one the Hornady 7PRC intro podcast, one of the senior ballisticians said they were getting 2910 fps out of their 20” barrel with 175gn ELDX.

I don’t remember seeing that. Not saying they didn’t say that, but I’m not buying it. That’s 140fps faster than I got in my 18” with hefty pressure signs.

 

[DisplacedHusky]

I don’t remember seeing that. Not saying they didn’t say that, but I’m not buying it. That’s 140fps faster than I got in my 18” with hefty pressure signs.

I think it was episode 42. I believe it was Seth Swerczek that said it about his rifle.

 

[MT_Wyatt]

I actually made the same note on my phone. 2910 in a 20” barrel. They definitively said it.

 

[Tahoe1305]

I actually made the same note on my phone. 2910 in a 20” barrel. They definitively said it.

Did it look like this?

Sorry. I want to jump on the PRC but holding onto relics.

 

[DisplacedHusky]

Did it look like this?

Sorry. I want to jump in the PRC but holding onto relics.

A 7WSM would be on the top of my list if there were more factory rifle and ammo offerings.

 

[Flyjunky]

I actually made the same note on my phone. 2910 in a 20” barrel. They definitively said it.

You mean an ammo company pushing a new cartridge inflated the velocity…no way, I’m shocked.

 

[Darg]

Ruger American go wild 7mm prc 24in barrel
shot 20 rounds and lightly cleaned
In the next 30 shots I Measured 18 velocities.
Used 3 different boxes of ammo from 2 different lots
2880fps average.

 

[MT_Wyatt]

Holy crap fellas, just confirming what they stated since someone jotted the same thing down I did. Not saying it is infallible. When I chrono my 20” I’ll post some numbers.

Agree on 7 WSM if that had good factory ammo, hard to not use it.

 

[TxLite]

Holy crap fellas, just confirming what they stated since someone jotted the same thing down I did. Not saying it is infallible. When I chrono my 20” I’ll post some numbers.

Agree on 7 WSM if that had good factory ammo, hard to not use it.

Don’t think anyone was calling you out. I think it was directed at Hornady for advertising one-off velocities.

Even assuming 35fps/inch, they are at 70 fps higher than I was pushing, and I had a suppressor that would’ve added some velocity. And at the velocities I was hitting, I had very stiff bolt lift and ejector marks.

I don’t think their velocities are necessarily impossible if they have a fast barrel, but I don’t think that it’s probably going to be safely attainable for most folks.

 

[swavescatter]

20" Proof Carbon on Tikka action with a Banish 30 Gold Suppressor

Hornady ELDM's from a newer lot of ammo: 2722 fps ave, 12.6 STD
Hornady ELDM's from an early run: 2786 fps ave, 9.3 STD

New ammo shoots MUCH better though, like 0.6 MOA vs 2.3 MOA.