New 7 STW First Group Questions

[Montana73]

I finally received my H-S Precision PLR 7 STW rifle. It has their Pro-Series 2000 LA receiver, 26" fluted stainless steel barrel, 1:9 twist and Area 419 Hellfire Self-timing Brake. I have a Nightforce NXS 5.5-22x56mm mounted in NF Ultralight rings.

H-S Precision has a pretty involved 30 round barrel break-in process that I followed this morning - a long morning for sure.

After these break-in shots, I had time for two groups using a factory load I intend to use for hunting this fall.....Choice Ammunition of Montana who loaded 160 gr Nosler Accubond in Hornady brass. 3055 fps was advertised for this load.

The #31-#34 rounds thru this rifle ran out on a 3027 fps average on my Labradar. I pulled #1 a little.

The #35-#39 rounds thru this rifle ran out on a 3005 fps average on my Labradar.

I know that some would say I should be reloading to get a better group capability, but I think I can live with this factory load for hunting out to 400 yards.

A question that I have is that during break-in, I had some of this round run out at 3025-3055 fps, but not many. Curious why the last 5 came out less than the first 4 after break-in. Can I expect this barrel to improve in fps as more rounds go thru the barrel? Or is this about what I should expect? Any thoughts would be appreciated by more experienced shooters.

 

[Rick Richard]

Most, but not all barrels need to be shot some before speeds increase. In my custom barrels, it is in the neighborhood of 100 rounds or so.

 

[Unertl Eyebrow]

Looks pretty good. I'm doing the same thing right now too. I have 26 rounds through mine. Seems like with the last few shots accuracy improved nicely.
I am purchasing ammunition also. From Hendershot Extreme. We have a 150 grain accubond going 3,445 fps in 3 identical rifles. (30" barrel). I think my groups at 100 would be the same size as yours. I've been working with it at 200 yards. The last 3 were about 1" +-.
I'm keeping my empty brass. I do have dies from years ago. Maybe I'll find the time next winter to reload again.

 

[Coldfinger]

I finally received my H-S Precision PLR 7 STW rifle. It has their Pro-Series 2000 LA receiver, 26" fluted stainless steel barrel, 1:9 twist and Area 419 Hellfire Self-timing Brake. I have a Nightforce NXS 5.5-22x56mm mounted in NF Ultralight rings.
I'd have to say that's fantastic shooting factory ammunition! Only factory stuff I had shoot well enough was 257 billybob 120 grain round nose core lokt! That was 20 years ago but I gave them up and settled on 120 grain Sierra psp that cut bugholes! Guess they should have come a heck of a long ways with factory ammunition it's been long enough. The guns the men on this site build will reach to the moon and back Ammo should too
H-S Precision has a pretty involved 30 round barrel break-in process that I followed this morning - a long morning for sure.

After these break-in shots, I had time for two groups using a factory load I intend to use for hunting this fall.....Choice Ammunition of Montana who loaded 160 gr Nosler Accubond in Hornady brass. 3055 fps was advertised for this load.

The #31-#34 rounds thru this rifle ran out on a 3027 fps average on my Labradar. I pulled #1 a little.

The #35-#39 rounds thru this rifle ran out on a 3005 fps average on my Labradar.

I know that some would say I should be reloading to get a better group capability, but I think I can live with this factory load for hunting out to 400 yards.

A question that I have is that during break-in, I had some of this round run out at 3025-3055 fps, but not many. Curious why the last 5 came out less than the first 4 after break-in. Can I expect this barrel to improve in fps as more rounds go thru the barrel? Or is this about what I should expect? Any thoughts would be appreciated by more experienced shooters.

 

[dougduey]

Expect velocity to increase anywhere from 50 to 100 rounds down the pipe.
To get the most out of this cartridge, you really need to hand load. You can achieve 3200 fps with 160 gr bullets. I never got there with the 162 ELDX and H1000, but 3110 fps and a ragged hole group suits me just fine. If you really want horsepower, look at shooting 140 gr bullets. I shoot the 143 gr Hammer Hunter at a little over 3500 fps.
Don't try the 175 gr ELDX. Your twist won't stabilize it. Part of the reason I went with a 1:8 twist when I rebarreled, plus I wanted to shoot the 177 gr Hammer. The 175 gr Partition works at your twist rate.
Like all of us on this forum, I love the 7 STW. Lots of very knowledgeable members on here that will help you get the most out of your new toy, so don't hesitate to ask.

 

[vancewalker007]

Your barrel will speed up a little. If you are shooting ladders and monitoring vel you'll easily notice it. At what round count it happens is up to your barrel. I've seen them at around 100 and higher. My 6.5 26in Proof Sendero sped up recently at about 254 rounds.

A note on the STW. I shot one for years and went through 3 barrels. What I noticed is every barrel was very sensitive to case neck tension. We also noticed this on my father's old STW.

Those groups you are getting look pretty good for factory ammo. Your ES will likely drop with some careful reloading.

 

[ButterBean]

Expect velocity to increase anywhere from 50 to 100 rounds down the pipe.
To get the most out of this cartridge, you really need to hand load. You can achieve 3200 fps with 160 gr bullets. I never got there with the 162 ELDX and H1000, but 3110 fps and a ragged hole group suits me just fine. If you really want horsepower, look at shooting 140 gr bullets. I shoot the 143 gr Hammer Hunter at a little over 3500 fps.
Don't try the 175 gr ELDX. Your twist won't stabilize it. Part of the reason I went with a 1:8 twist when I rebarreled, plus I wanted to shoot the 177 gr Hammer. The 175 gr Partition works at your twist rate.
Like all of us on this forum, I love the 7 STW. Lots of very knowledgeable members on here that will help you get the most out of your new toy, so don't hesitate to ask.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
dougduey is spot on, Lots of knowledge here and the 175 Partition would be awesome

 

[H82MISS]

Great rifle combined with a super cartridge. Have fun with your new 7 STW. They are awesome.

 

[DJ Fergus]

That's nice grouping you have for factory ammo. No hate whatsoever for the accubonds but I bet it would shoot even better with the eld-m or Berger's. Don't let me keep you from shooting what you want to though. Like I said it appears to be shooting great. You should get plenty bang flop kills

 

[delta]

I have a 7mm stw I purchased from a friend over 25 years ago. Remington model 700 I have taken lots of game with this rifle recently I have had trouble with grouping I can't tell if it's me or the barrel shot out. The bullets I have been shooting are Remington 140 grain. I have purchased new bullets Nosler 160 grain. I would like to consistently shoot deer at 300 yds.

 

[Alberta Wexit]

I shoot Nosler Partitions 160gr in a 7STW. Accuracy good to 600 yards on game so far.

 

[delta]

I shoot Nosler Partitions 160gr in a 7STW. Accuracy good to 600 yards on game so far.

Thank you, I wish I knew more about the gun. (Twist or velocity) the gun stock is floated and has factory barrel that was bored out for 8 mm cartridge (I am assuming) the barrel was xxxx out rem mag and stamped stw.

 

[hicountry1]

I shoot 160 partitions and have shot 160ab out of my 7stw. Both shoot literally 1 hole groups. Velocity is in the high 3100s on both. The 160 partition is what I shoot out of it, and it flat out hammers elk.

I use 7828, and honestly haven't found any powder that shoots better with those bullets.

Loads are right out of the nosler loading manual.

 

[jake545]

I have a 7mm stw I purchased from a friend over 25 years ago. Remington model 700 I have taken lots of game with this rifle recently I have had trouble with grouping I can't tell if it's me or the barrel shot out. The bullets I have been shooting are Remington 140 grain. I have purchased new bullets Nosler 160 grain. I would like to consistently shoot deer at 300 yds.

I had a similar experience with my 7stw (Rem 700 LSS rechambered from a 7 RM back in the mid 90's) where it went from .75moa or better to shooting 1.5moa or so. I "cleaned it" until the patch cam e out clean and thought it should be good but it didnt fix it, I then bedded it and while it was a little better (1.25moa) it wasn't what it used to be. Finally i cleaned the crap out of it, Copper fouling as well as. It then went back to .75MOA. I would say clean it and look with a bore scope. This will tell you if it is truly clean and also you will be able to see any erosion. Don't trust a clean patch as that doesn't mean it is actually clean, it just means you got out all of the LOOSE material. You can get a USB borescope for $40, so its well worth that to find out that a $20 cleaning solution fixes it, instead of a $600 barrel job.