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Discussion Starter · #1 · (Edited)
I bought a new Browning X-Bolt in 7mm Mag. I shoot 160 grain Federal Premium Nosler Partitions. As I've been going to the range, I've been noticing that I start off grouping all of my shots into 1"-2" groupings, and then out of no where, everything starts shooting high. I've heard this could be due to my barrel over heating. But I never let it get too hot. When I notice it getting hot, I let it cool down. This only happens after about 6 rounds. My first 6 are usually within an 1" or 2" of the bulls eye, and then they all start shooting high. The groupings remain very close, they just shift up. Like, 4"-6" up. I've tried different stances, really focusing in on my breathing, and adjusting my scope. Could it be that my barrel is getting that dirty after only a few rounds? I clean it after every time I go to the range. I'm at a loss. This is only the second rifle I've ever owned and shoot on a regular basis. My other rifle is a Marlin 30-30 which I've used for deer hunting for the last 15 years. I've never had anything like this happen with my 30-30. If anyone can help shed some light on this, it would be much appreciated! Trying to ensure all my groupings with my new X-Bolt stay consistent before I leave for an Elk hunt in 10 days! I can't seem to fix this problem.
 

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Welcome to the shooters forum.
First off since this is a hunting rifle, I wouldn't give a toot what it does after the second shot. Knowing where the first one goes is whats important.
Next sight it in using a cold barrel. Its not a good idea chasing your warm barrel shot placement by adjusting the scope.
Do you have a fouling issue from bullet jacket material?
Is the forearm of the stock putting pressure on the barrel?
 

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The Troll Whisperer (Moderator)
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Browning rifle barrels are not as heavy as most rifles. They tend to heat quicker.

Monty's advice is spot on. Don't chase the shot groups as the barrel heats. Try 3 shot groups and let the bbl cool down completely. If it is hotter than you can comfortably clamp your hand around, it is too hot.

Try this and if still not grouping where desired, get back to us.
 

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Discussion Starter · #4 ·
Thanks for the quick reply!

I just shot yesterday and it was 38 degrees out. Barrel was cool to start with. I did not adjust my scope at all. I first shot at 100 yds, with my first three within 1/2" of the bulls eye. After that my next 2 or 3 were about an 1 1/2" high. I want to zero my rifle at 200 yds. So I shot next at 200, hoping it would be about dead on sinc emy last three were 1 1/2" high at 100. My first three at 200 were almost the same as they were at 100, 1 1/2" high. Everything after that was 3"-6" inches high at 200. The difference in the 3" high, to 6" high was my grip, that much I was able to rule out. My gut wants to tell me its a combination of the barrel getting warm and dirty?

Each time I clean it, there is not an excessive amount of fouling. It begs the question, should I clean it after each shot, every 3 shots? And see if it makes a difference?

I've run approximately 50-60 rounds through the gun since I've owned it, if that makes any difference.

I do not have my rifle with me right now, but it is a free floating barrel. I have not noticed the stock pressing against the barrel anywhere.
 

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Discussion Starter · #5 ·
Thanks Monty and kdub! I never let the barrel get to the point that it's too hot to the touch. Warm yes, but never that warm.
 

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Elk Whisperer (Super Moderator)
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Welcome to the shooters forum.
First off since this is a hunting rifle, I wouldn't give a toot what it does after the second shot. Knowing where the first one goes is whats important.
Next sight it in using a cold barrel. Its not a good idea chasing your warm barrel shot placement by adjusting the scope.
Do you have a fouling issue from bullet jacket material?
Is the forearm of the stock putting pressure on the barrel?
Browning rifle barrels are not as heavy as most rifles. They tend to heat quicker.

Monty's advice is spot on. Don't chase the shot groups as the barrel heats. Try 3 shot groups and let the bbl cool down completely. If it is hotter than you can comfortably clamp your hand around, it is too hot.

Try this and if still not grouping where desired, get back to us.
Most excellent advice from both guys. Having chased this very thing YESTERDAY and beating my head against the wall until DING!!! the bell and light went off and I realized that the stock was rubbing on the barrel of my 30 some year old Sevumag which was free floated 30 some years ago . . . . . .

I hate waiting for my barrel to cool down, that's why I free float and to "argue" Monty's point :D I WANT to know EXACTLY where shots 2 thru infinity are going regardless of how hot the barrel is.

So, if you are a much better shot than me (could be I don't know) yes, shoot your groups with a cold barrel. take a Louis LaMour book to read between shots :D or Zane Grey or Tom Clancy

I would add, check the action screw torque and or the scope bases and rings if you haven't already.

RJ
 
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The Hog Whisperer (Administrator)
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For a hunting rifle, this seems to me the perfect opportunity to ignore the 'problem'.... but up to you. Once you start chasing bedding gremlins, it can take a while!
 

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I have no knowledge of just how light your barrel is. I had a 7x57 (calibre is not an issue) it was VERY light barrelled and total weighed in at just over 6lbs ...yes very light but that is how I ordered it. That rifle would put two rounds in the same hole and then climb steadily up and to the left with any further shots. I always zero my big game rifles 1 1/2 inch high at 100yrds and that will normally put me in the killing circle out to 200. Only once did I change this and that was hunting in Wyoming for pronghorn and I let the guide advise on my 300H&H and shot two, one at 100yrds and one at two steps from 500. Your barrel does not like multiple shots, it happens. Zero with your first two rounds printing 1 1/2 to 2 inches high at 100 and you will be good to go.
Welcome aboard and I wish you hunters luck on your travels.
 

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Discussion Starter · #10 ·
Thank you everyone! I'll be getting out to shoot one last time before heading out west. Will test some of these theories and let you know how it goes!
 

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Discussion Starter · #11 ·
So my X-Bolt overall weight before a scope is 6lbs 6oz.....so I'm guessing the barrel is pretty darn light! With that, anyone know the exact weight of the barrel on the Browning X-Bolt Medallion in 7mm Mag?
 

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You said you do not have your rifle with you right now, but it is a free-floating barrel. Are you absolutely sure about that. What you describe are the classic signs of too much forend pressure under the barrel.

Barrels vibrate like tuning forks when fired, and gunmakers sometimes design the stocks to contact the barrel with upward pressure at the end of the stock to absorb and dampen vibration.

All my old model 70s came with forend pressure under the barrel, and sometimes I had to moderate that.

When a barrel has too much upward forend pressure (10 to 15 pounds), It will cause the shots to go higher and higher the hotter the barrel gets. As the barrel gets hot, the metal expands slightly and the pressurized forend bedding is a solid foundation, so the hot expanding barrel warps upward.

As an experiment, shoot 10 or 12 rounds in quick succession, and see if the rifle shoots higher and higher the hotter the barrel gets.
 

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I can understand your frustration, but the bright side of your description is; your rifle is consistent. So you should be good for deer at the ranges you described.

The free float. You checked that? Before and during your range time?

RJ's book advice is a good! I must say, I thought he'd first recommend shooting another gun while waiting...:)
 

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I've watched guys for years carefully shoot 5 shots off the bench from there hunting rifles obsessing over group sizes, waste of time and ammunition. A correct zero that matches your hunting situations is way more important that 10ths of inch on paper.
Shoot your rifle at the farthest distance your likely to shoot in field, clay targets make work nicely, shoot as many shots as the gun holds as fast as you can cycle the gun and break a good shot, if you can't hit the target everytime after the correct sight adjustments your to far away!!!
I use the Leupold LRD reticle in most of my hunting rifles, it doesn't take a benchrest rifle to kill big game, they are big targets.
For your 7mag with 160's a 250-275yard zero is about right depending on scope height and the game your pursuing with it.

FYI, Colorado division of wildlife surveys indicate that most elk are killed under 100yards, mostly because they don't stand out in the open on public land, there in the nasty dark timber after the first morning. Of course there are exceptions to that, over where RJ lives in northwestern Colorado there are some looong shots, I'm guessing that's why he has a 300 ultra.
 

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Under 2 weeks from the hunt means DO NOT MESS WITH THIS RIGHT NOW! Get it out of your head until after the hunt. If it’ll put the first three from cold into a tight cluster, then you don’t have time to waste on anything but verifying lack of a loose screw. Attack it this winter.
 

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I can think of two things that might cause that. Bind in the action. Tighten both action screws down, then loosen very slowly the front screw. Watch either at the chamber or better the forend tip for the barrel to move. If that is it, bedding can fix it. The other, though unlikely, is you have a barrel that for some reason didn't get stress relieved. Can't tell you how to check that, just learn to live with it. I got a new Parker-Hale years ago that was like that. Three or four shot's and accuracy went to h*ll. Lucky for me it was stolen out of my hold bagage coming home from Germany while I was in the service!
 

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Working up loads for my 45/70 I found that after a few loads I have to quit and wait until the barrel cools completely down. It really starts stringing them hi...some a foot, but that was when the barrel was hot.
 

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caltschwager

I have to disagree with just about everybody and offer a solution for you to consider. The changing condition of your bore from powder and or copper or lead fouling is the classic cause of vertical stringing because the fouling changes your effective pressure. This is relative to bore finish and maintenance. I recommend you try my easy and well proven bore polishing method from another forum along with a maintenance change using a clean dry Hoppe's BoreSnake pulled through once every 5 shots to maintain constant match bore condition.

Here is my bore polishing method to shoot better:

https://castbulletassoc.org/forum/thread/8364-my-bore-polish-method-to-shoot-better/

Gary
 
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