7STW Grouping Questions on Different Ammo

[Montana73]

I have a 7STW with a 26" Shilen SS barrel with 1:9 Twist. I'm not a reloader and not an expert in bullet characteristics.
I bought two factory loads to try....Hornady Precision Ammo with 162gr ELD-X advertised as 3050FPS on the box. I also bought Copper Creek 145gr LRX advertised as 3200FPS on box.

I shot a few rounds downrange to foul the barrel after I cleaned it until it looked fine with a borescope for carbon and copper. The first picture attached shows 3 shots @100 yards with the 162gr ELD-X and registered an avg of 3260fps on my Caldwell chronograph. The second picture show 4 shots @200 yards with the 162gr ELD-X and an avg of 3255 on the 4 shots. The third pic is 5 shots of the 145gr Barnes LRX @100 yards with a 3370 fps average.

A couple of questions:
1.) I guess I'm ok with the 162gr ELD-X performance out of this rifle for hunting based on the 100 and 200 yard groups since I'm only planning on 400 yards or less shooting. Am I in the ballpark here for a 7STW?
2.) Since the ammo was advertised as 3050fps and I'm getting 3260fps is this normal? The primers look normal, there is no ejector marks and the bolt operates like normal.
3). Based on my experience with the 145gr Barnes LRX, it appears my barrel doesn't like them as much as it does for the 162gr ELD-X. Is this normal as well or did I just have a bad day with the group as it is all vertical. Should I spend more time with this load?

Any thoughts would be appreciated by 7STW experienced folks.

 

[bsnyder]

Looks like your rifle doesn't like the 145 vertical stringing like that could lead to issues at distance, speed with very with altitude I don't shoot much factory anymore but I have seen that before from both Hornady and Barnes being faster than what the box said. Hope this helps.

 

[Montana73]

Just for info....shot this at NC Coast...16 feet above sea level and 70 degrees. Will have to adjust obviously for Montana hunting this fall. Just trying to get some factory ammo working properly.

 

[Montana73]

In addition, I tried to let the barrel cool down between shots (checked with IR heat gun) and I checked the barrel to ensure that it was maintaining free float for each shot and wasn't having forend pushing on the barrel.

I've read vertical stringing can be breathing but I didn't have an issue with other ammo so not sure that is the culprit?

 

[bsnyder]

Try some 160 accubonds those always shoot really well in the stws I've been around

 

[yobuck]

160 gr class bullets are a good choice for long range hunting with cartridges like the 7stw.
Id be trying the gun at a longer distance, say 400, and see how it performs there.
But other than that id suggest being happy with what you have.
It might be more fun to put some clay birds out at 400 and shoot at them, rather than worry about group size with hunting guns.

 

[boonierat68]

Try some 160 accubonds those always shoot really well in the stws I've been around

I have been using 160gr. accubonds in my sendero SF 1-9.25 twist with extremely good accuracy, 3" at 600 yds. The only animal kill was a Newfoundland moose at 385 yds. DRT loads is 74g IMR 7828
cci 250 vel 3050. Trying to find some Rel 26 to try

 

[yobuck]

7828 would be a good choice for max performance. I use 78 gr with a 162 gr in my 7x300 wby, on a 700 action. Thats getting pretty close to max in my gun even in cooler weather, but should be about the same in the stw.

 

[ODAVID]

You really should get into reloading. You can tailor your loads to exactly match your rifle. The joy if hitting a bulls eye at long range over something you made is just an ear to ear smile. It takes time but worth it. Plenty of advice here to help you with. IN MY OPINION Sometime weighing bullets will help tighten your groups..

 

[dougduey]

None of the velocities you're getting are out of bounds for the STW. The ELDX is getting max performance from a 160 gr bullet. I'm getting 140fps less than you with the same bullet, but my groups are tiny ragged holes. Some barrels are fast and some aren't.........looks like you got a fast one!! The Barnes ammo is a no go for your rifle. Like others have said, try the Nosler ammo with the 140gr Partition and 160gr Accubond. You need to try them to see if you rifle likes them. You'll love this cartridge even more if you start hand loading for it.