7 Backcountry Ballistics Data

[One300wsm]

7 BC vs 7 PRC is not exactly apples to apples… it’s close though.

A 16-inch 7 BC produces more velocity than an 18-inch 7 PRC (maybe even 20-inch…). It does this while having less recoil (odds are you wouldn’t be able to tell a difference).

7 PRC will have significant more factory produced ammo as I doubt manufacturers will produce 7 BC due to the Peak Alloy case that is used.

16” probably so, 18” factory ammo only, 20” not even with factory ammo.

 

[UncleNommies]

I built a 7 BC on a very lightweight Tikka build with an 18" carbon fiber wrapped barrel. Whole gun is 7 pounds 6 ounces scoped up. So far no issues with all the factory ammo I've tried. It's favorite so far is the 155 gr TAs going 3126. I am going to reload it with 160 gr Barnes LRX at some point and see how it goes. So far, I am loving the gun and has performed very well for me at the range.

Granted semi-custom versus factory could make a huge difference. A colleague of mine picked up a Seekins PH3 in 7 BC and no issues there either, that one is just heavier.

What stock did you use? I'm currently waiting to get my tikka action back machining and nitriding from Unknown and my 16.5" barrel to ship from Proof!

 

[rbenson4]

What stock did you use? I'm currently waiting to get my tikka action back machining and nitriding from Unknown and my 16.5" barrel to ship from Proof!

I went with the Peak 44 Blacktooth stock and my barrel is a BSF instead of a Proof

 

[scaast]

I went with the Peak 44 Blacktooth stock and my barrel is a BSF instead of a Proof

How do you like that BSF barrel? I just put an 18" BSF on my suppressed 300 WM build. It shot lights out when I took it to the range a couple of weeks back. I still need to get it broken in and figure out which ammo it likes. So far it likes 165gr Federal more than the heavier 200gr Federal TA.

 

[rbenson4]

How do you like that BSF barrel? I just put an 18" BSF on my suppressed 300 WM build. It shot lights out when I took it to the range a couple of weeks back. I still need to get it broken in and figure out which ammo it likes. So far it likes 165gr Federal more than the heavier 200gr Federal TA.

Every one I've had has shot lights out with not much break in so I've loved them especially being a little better price than a Proof. I've had some surprisingly long strings of fire with them in 300 WSM and others before seeing some walking from heat. Even had an AR barrel from them and that shot great too.

 

[scaast]

That's good to hear. I stumbled upon them while reading the specs of the Weatherby 307 Alpine CT. After doing more research and discovering that they have a generous veteran discount, I was sold. I'm sure this won't be my last barrel from them.

 

[rbenson4]

That's good to hear. I stumbled upon them while reading the specs of the Weatherby 307 Alpine CT. After doing more research and discovering that they have a generous veteran discount, I was sold. I'm sure this won't be my last barrel from them.

I believe a BSF barrel has Weatherbys all time three round group record as well. Just kind of a cool factoid on top of that haha

 

[Demlockian]

Update...

I just got my CA Ridgeline FFT Titanium back from Gentry Customs after having the 3‑position safety installed. As expected, the safety functions flawlessly and is, in my opinion, a substantial upgrade for any Remington 700–pattern rifle.

Unfortunately, the rifle still cannot reliably cycle factory Federal ammunition. Out of three rounds fired, two required extremely hard extraction (175gr Fusion), and the third locked the rifle up completely (170gr Terminal Ascent). I’ve submitted an RMA request to Christensen Arms, and now it’s a matter of seeing how they choose to handle it.

During the same range session, my wife put eight rounds through her CA Evoke—same ammo boxes, same conditions, zero issues.

In case CA pushes back, we took video of both rifles showcasing how they handle bolt lift and extraction (or not).

 

[Demlockian]

Christensen Arms so far hasn’t answered the phone a single time nor responded to their own RMA request…

In other news, the Evoke had 4 of 8 rounds today lock up the action and fail to extract (required a nice wooden stump to open the action each time). That officially makes a 100% failure rate for me… velocity on the Evoke round ranged from 2874 to 2934, same box of Federal Fusion Tipped 175 grain.

Really hoping CA makes it right so I don’t have to start leveraging YouTube videos…

 

[919]

Christensen Arms so far hasn’t answered the phone a single time nor responded to their own RMA request…

In other news, the Evoke had 4 of 8 rounds today lock up the action and fail to extract (required a nice wooden stump to open the action each time). That officially makes a 100% failure rate for me… velocity on the Evoke round ranged from 2874 to 2934, same box of Federal Fusion Tipped 175 grain.

Really hoping CA makes it right so I don’t have to start leveraging YouTube videos…

That’s disappointing to hear. Would be curious to hear what other people’s experience has been with 7mm BC in different brand rifles

 

[UnckleBob]

I took the Origin rifle out with a 16" 7BC barrel for the first time. 170g Terminal Ascent load

• 2,910 fps about 1.5 MOA (I was focused on my son, but wanted to get a quick velocity reading). I will test accuracy with it later.
• The exact same rifle with a 20" 280AI barrel and the same suppressor could only get a 160g Partition up to 2,788 fps.
• My actual velocity was only 30fps slower than the box velocity of Federal's 7PRC load with the same bullet. I assume the box velocity is based upon a 24" barrel
• Bolt lift was a little stiff. Feeds easy.
• Temp 82 degrees and 77% humidity.

Bottom Line:
1) Velocity promises met.
2) 7 PRC performance from very compact rifle that weighs only 6.75lb bare.
3) I don't have any scientific way to measure recoil, but recoil appeared equal to or less than the recoil of the same rifle suppressor combination with the 280AI barrel.
4) Does it recoil more than my 243? Yes. Am I afraid of the recoil? No.

 

[Demlockian]

Glad to hear your Origin rifle is working out for you! I believe Federal has a lot of work to do on the ammo... my 16-inch rifles were shooting over 3,000 FPS with the Federal 170 grain Terminal Ascent. I'm starting to think I have two issues going on:
1) Christensen Arms might have cut the chambers on the tighter side, if that's even a thing
2) Federal ammo has nearly zero quality control, resulting in variation in case and powder dimensions (hence extreme velocity spreads of 60 fps in the same box). Not to mention I have seen 170 grain ammo over 100 fps faster than your velocity from the same barrel lengths...

Christensen Arms finally responded and I have sent them the videos of both rifles malfunctioning. Waiting to see how they want to proceed with it (I'm requesting re-barrels on both rifles to a different cartridge that they offer).

 

[UnckleBob]

Glad to hear your Origin rifle is working out for you! I believe Federal has a lot of work to do on the ammo... my 16-inch rifles were shooting over 3,000 FPS with the Federal 170 grain Terminal Ascent. I'm starting to think I have two issues going on:
1) Christensen Arms might have cut the chambers on the tighter side, if that's even a thing
2) Federal ammo has nearly zero quality control, resulting in variation in case and powder dimensions (hence extreme velocity spreads of 60 fps in the same box). Not to mention I have seen 170 grain ammo over 100 fps faster than your velocity from the same barrel lengths...

Christensen Arms finally responded and I have sent them the videos of both rifles malfunctioning. Waiting to see how they want to proceed with it (I'm requesting re-barrels on both rifles to a different cartridge that they offer).

I think my barrel will speed up a little as I get more rounds through it.

 

[UnckleBob]

Glad to hear your Origin rifle is working out for you! I believe Federal has a lot of work to do on the ammo... my 16-inch rifles were shooting over 3,000 FPS with the Federal 170 grain Terminal Ascent. I'm starting to think I have two issues going on:
1) Christensen Arms might have cut the chambers on the tighter side, if that's even a thing
2) Federal ammo has nearly zero quality control, resulting in variation in case and powder dimensions (hence extreme velocity spreads of 60 fps in the same box). Not to mention I have seen 170 grain ammo over 100 fps faster than your velocity from the same barrel lengths...

Christensen Arms finally responded and I have sent them the videos of both rifles malfunctioning. Waiting to see how they want to proceed with it (I'm requesting re-barrels on both rifles to a different cartridge that they offer).

I think their chambers are messed up.

My 6.8W had the same problems you are describing. It only happened with their nickel plated brass.

Browning's repair center (who happens to be my gunsmith) fixed it by polishing up the chamber. Now, it's shoots great.

 

[Demlockian]

If anyone is curious, here are the videos I took from range day. These are quick takes while shooting, so nothing fancy or production value.

I might make another trip out to get better recordings and full length videos, however, I'm not sure it's worth potential injury or damage to the firearms.

 

[UnckleBob]

If anyone is curious, here are the videos I took from range day. These are quick takes while shooting, so nothing fancy or production value.

I might make another trip out to get better recordings and full length videos, however, I'm not sure it's worth potential injury or damage to the firearms.

You do not need more proof. There is something wrong with those rifles.

 

[Demlockian]

I believe its a two part problem: Christensen Arms and Federal. Considering the 175 grain Fusion Tipped had nearly a 100 fps deviation in velocity, it's a pretty solid indicator that Federal is not maintaining high quality control.

I'm curious to see how many people have issues with the +PEAK 6.5 Creedmoor when it comes out.