7mm Backcountry, does BC stand for best choice or bad cartridge? Let's test it!

[reynolds243]

oh and anyone curious on recoil. I am pretty recoil sensitive and FOR ME it had recoil about like a 270 unsuppressed. Granted the evoke is a fairly heavy rifle and some of those I shot out of a sled but it didnt really POP me like I thought it might.

 

[UnckleBob]

oh and anyone curious on recoil. I am pretty recoil sensitive and FOR ME it had recoil about like a 270 unsuppressed. Granted the evoke is a fairly heavy rifle and some of those I shot out of a sled but it didnt really POP me like I thought it might.

If you think about it, the powder capacity of the 7BC case and the 280AI are nearly identical and they use the exact same bullets. The only difference is the 7 BC uses a different powder (I assume a faster powder).

The recoil won't be identical, but it won't be like stepping up to a 338 Lapua.

Your velocity data confirms that Federal's velocity promises were met.

 

[reynolds243]

did some more shooting yesterday and got more velocitys etc.

Again this is from a CA Evoke rifle with 16.5" barrel and a banish 30 suppressor

155 TA = 3032FPS Only shot 3 rounds as this was the worst group ammo I tried before and it was the same yesterday at around 1.7inch group. All 3 ejected just fine

170 Terminal Ascent - 2886 FPS average. Shot 6 rounds total. 1st group was .68 and 2nd group was .49. THis one however had 2 shells that somewhat hung up on ejection. I didnt have to beat the bolt but it tooks some force to eject those 2. The rest ejected fine

175 Fusion - 2874 FPS. shot 2 groups total, 1 group was .9 and 2nd group at .94. All 6 ejected fine with no issue

 

[reynolds243]

2nd update.

Contacted Federal about the hang up issues that seem to happen more on the 170 TA rounds. They are having me send them back the cases and remaining rounds and sending me a box of those and the 175 fusions. This leads me to assume that there was a possible issue with some of the earlier batches, that could be totally incorrect but good on them for at least offering it. Will be interested to see if the velocities are the same or if I see any difference on new boxes from them.

 

[The Guide]

I finally made some time to get a scope on my 7mm Backcountry and do some shooting. I used the 175 Tipped Fusion for the bore sight and first 5 round group. Then I shot the 195 Berger EOL and finally the 168 Barnes LRX. I only had a short time to shoot as darkness comes quickly as our seasons change so I did not try either the 155 or 170 Terminal Ascent loads as from my observations, those are the ammunition being shot when people have issues with the extraction.

Speeds claimed and speeds recorded are as follows from a 20" barrel with a SilencerCo Omega 300 DTM suppressor using a Garmin Xero Crono:

175 Federal Tipped Fusion ammo:
Claimed box velocity for a 20" barrel is 2975 fps.
Actual observed velocity on 6 rounds was 2999.3 fps.



195 Berger Elite Hunter ammo:
Claimed box velocity for a 20" barrel is 2850 fps.
Actual observed velocity on 5 rounds was 2853.3 fps.



168 Barnes LRX ammo:
Claimed box velocity for 20" barrel is 3000 fps.
Actual observed velocity on 5 rounds was 2971.0 fps.



I will shoot and get 10 round groups to post from each ammo once I get the two Terminal Ascent loads shot and make sure that they aren't going to lock my action up.

My initial thoughts...

The trigger on the rifle is heavy but breaks solidly so I may see if I can turn it down to a lighter weight before I shoot groups. The recoil impulse while definitely heavier than short action cartridge was not uncomfortable and much less than a comparitable weight 300WM shot without any muzzle devices. The muzzle velocity observed is close to or in excess of claimed box velocity of the rounds I tested. Initial groups all showed promise on the new barrel and none of the ammo shot has been completed disqualified for future shooting or testing. Hopefully this Savage won't lock up like others have on the internet. My suppressor did seem to get hotter with this rifle/ammo than it has with other guns/ammo while the barrel did not get as hot as one would expect for the suppressor temp.

This is a fun rifle so far.

Jay

 

[PsRpOiGrRiAtM]

Great to hear--I've been waiting to see some of your results.

 

[Banger130]

Picked up a Weatherby 307 in 7BC this fall. Shooting 175gr Fusion Tipped at 3018fps and 170gr TA at 3063fps. from the 20” barrel with SiCo Harvester Evo, measured with a Garmin Xero. For reference, I have a Christensen Arms Mesa in 7mm Rem Mag with 24” barrel that shoots 155gr TA right at 3000fps. Post barrel break-in, the Weatherby is consistently shooting both ammo types well. TA is just under 1MOA at 100 yds. And the Fusion is consistently just over .5MOA with my last 5 shot group before taking it deer hunting measuring just .9” at 200 yds. Perceived recoil is less than my 7mm Rem Mag. No issues with extraction or bolt lift.

 

[Regulatorug]

So perhaps a dumb question, apologies, but with such good performance in 16in barrels, why are we seeing manufacturers sticking with 20/22inch barrels for 7mm BC? Only seeing a few at 18in and customs at 16in.

 

[The Guide]

So perhaps a dumb question, apologies, but with such good performance in 16in barrels, why are we seeing manufacturers sticking with 20/22inch barrels for 7mm BC? Only seeing a few at 18in and customs at 16in.

I'd say mostly because the general public isn't ready to buy 16" hunting rifles. Getting people to go from 24" and 26" barrels to 20" barrels is the first hurdle to clear.

Jay

 

[Tanner]

already does that with the 6.5 PRC. I get 2750 with my 18" suppressed PRC 140g accubonds. slightly higher on the 127 barnes.

If you are doing a 6.5BC it would have to be higher than that to push it over a tried and true 6.5PRC.

Interesting…. I’m shooting 140 ELDMs at 2620 out of a 16” 6.5 Creed. Seems like there’s something being left on the table with the PRC…