The Firing Line Forums

Go Back   The Firing Line Forums > The Hide > The Art of the Rifle: Bolt, Lever, and Pump Action

Reply
 
Thread Tools
Old May 11, 2013, 10:17 AM   #1
LED
Junior member
 
Join Date: March 10, 2013
Location: The Heartland
Posts: 174
Barrel heating: the Tikka surprise

I would like to see if someone else had a similar observation.

I bought a Tikka Varmint in .223. Bought it for the smoothest bolt action, ever. (Including Kimber 84, Browning A Bolt, Howa, TC, and forget Savage Moss & Rem). It worked great for the first 15 rounds or so. After that I couldn't hit the cardboard, let alone the target. Another cold start, and it's fine, until the barrel heats up. I carried an ice cooler to the range but eventually traded it, too much hassle.

I was a little dismayed knowing the Tikka reputation. Could it be that the steel was hunting grade (carry much, shoot at intervals), not for sports. Or maybe I should no longer wonder why a Sako is double the price for what seems the same action.

I got a CZ 527. Regular barrel, not heavy like the Tikka. Gave it 50 rounds in one session. The barrel got sizzling hot. No change in the accuracy, in fact I was able to zero a scope.
LED is offline  
Old May 11, 2013, 01:04 PM   #2
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 5,378
Most common cause of this problem is the barrel's bearing hard at one place around its shoulder against the receiver face. As the barrel heats up and expands, more pressure's applied at that point and a stress line goes down the barrel bending it.

Sometimes, even with the receiver face squared up but the barrel's not homogenous all over in its steel properties. As it heats up, the metal expands more on one side than the other and the barrel bows away in that direction.

In either instance the muzzle axis starts pointing some place other than where it did when the barrel was cold.

I'd sent that rifle back to the maker and if its in warranty, they should replace it.

All this assumes there's no external pressure being applied in increasing amounts by the shooter through the stock's fore end that touches the barrel and bends it a tiny amount. Such things often happen when someone claims a dollar bill slides easily between the barrel and fore end. A dollar bill's .0045" thick. It doesn't take much pressure on the fore end to bend it at least that much and make it touch the barrel. Most often this is the cause when resting the fore end atop something on a bench top and the shooter bears down on the stock's cheek piece with varying amounts of pressure.
__________________
US Navy Distinguished Marksman Badge 153
Former US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master
Bart B. is offline  
Old May 11, 2013, 01:28 PM   #3
LED
Junior member
 
Join Date: March 10, 2013
Location: The Heartland
Posts: 174
Excellent points Bart. It did not cross my mind to check the barrel bearing points. Best I remember it was free floating. The rifle was not on a warranty. I shot from the rest basically one handed while troubleshooting the accuracy.
LED is offline  
Old May 13, 2013, 12:15 PM   #4
Husqvarna
Senior Member
 
Join Date: May 7, 2012
Location: Sweden
Posts: 625
they do make tikkas with thicker barrels and/or fluted

how fast were you shooting?

I mean I have fired 50 rounds in one rangetrip but it is not more then one mag then check paper, move to next station that sort of thing
Husqvarna is offline  
Old May 13, 2013, 05:56 PM   #5
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 5,378
Husqvarna, thicker and/or fluted barrels poorly made or improperly fit to actions will still bend when they get hot.

I and others have shot standard weight .308 Win. barrels 24 times in 50 seconds and point of impact did not change at all. But those barrels were well made and fit to actions.
__________________
US Navy Distinguished Marksman Badge 153
Former US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master
Bart B. is offline  
Old May 13, 2013, 07:26 PM   #6
PVL
Senior Member
 
Join Date: February 20, 2013
Posts: 169
If you shoot until the barrel is "sizzling hot", then you are destroying the barrel's throat area and before long, accuracy will be a fond memory.

Never shoot a rifle that you'd like to keep for a while until the barrel gets sizzling hot. If it's too hot for you to grab and hold onto, you've just screwed up.

The best bet is to let some time go by in-between shots, with the action open.

Personally, I run a bore-snake, wet with Hoppes#9 through the barrel every three shots. - It cleans out some of the crud, and cools the barrel from inside.
PVL is offline  
Old May 14, 2013, 07:39 AM   #7
LED
Junior member
 
Join Date: March 10, 2013
Location: The Heartland
Posts: 174
PVL
You are right.
I was zeroing the scope and testing the rifle. And got carried away. That one time. Cleaned it, took back to the range for 3 control shots. She was good.
One question though: how does an AR barrel not get screwed from rapid fire?

Forgot to mention I've owned an A Bolt, a Steyr, a Savage, a Moss, two Rems, all in 223 or 243. None was heat sensitive like the Tikka. Well it could have been just my Tikka, which may or may not have been the reason why it was sold to me like new.
LED is offline  
Old May 25, 2013, 03:31 PM   #8
ndking1126
Senior Member
 
Join Date: January 26, 2008
Location: One house left of my neig
Posts: 1,652
Quote:
how does an AR barrel not get screwed from rapid fire?
Well, heat is heat and an AR barrel will wear out faster if you fire it rapidly. However, ARs typically have more metal to heat up, so the heat is dissipated a little more. Also, ARs typically aren't expected to shoot as accurately as a bolt rifle (unless you have a HBAR, then it probably is) so it's not quite as big of a deal.
__________________
The Jeep has been a lot of fun, but time to come back to my first hobby.. shooting.
ndking1126 is offline  
Old May 25, 2013, 07:58 PM   #9
Hummer70
Senior Member
 
Join Date: June 22, 2009
Location: South Carolina
Posts: 143
OK take me through the firing sequence. Are the shots stringing out in straight line or somewhat straight or is the group becoming a pattern and shooting everywhere?

I have you checked the bore for fouling. If it is a new barrel you could have some bullet jacket build up somewhere that is cutting a groove in bullet jackets coming down the barrel later. If you have access to a bore scope give it a looksee.

You can get Sweets bore cleaner or you can make Humpy's White and do the same thing.

Go to Ace Tru-Value hardware and get a quart or a gallon of the Janitor's Strength 10% Ammonia. Says it right on the bottle. If you get a quart add 4 ounces of Ivory Dish Detergent. Apply it to bore with wet patch on a plastic jag and place the muzzle on the floor on a paper towel folded square and let the excess flow out. If you have copper build up paper towel will turn purple.

Repeat the above and let it sit ten minutes and check it again. If it is purple repeat again and again till the purple stops. Dry bore sell and shoot it again.

I have a 22-250 barrel a guy left here that was shot out. I looked at it and saw it was fouled badly. I laid the Humpy's White to it and soaked it for like two hours and get clean,put it on a 03A3 action and first group on paper was under an inch at 100.
__________________
Distinguished Rifleman High Power & Smallbore Prone
President's Hundred (Rifle) US Palma Teams(2)
US Dewar Team (2),4 Man Natl.Champ Team SB Prone
Cert Test Dir. Sm Arms and Ammo,Aberdeen Pr Ground, Firefighter I, AC4HT
Hummer70 is offline  
Old May 25, 2013, 11:38 PM   #10
LED
Junior member
 
Join Date: March 10, 2013
Location: The Heartland
Posts: 174
The rifle is gone now, I traded it. As I remember, groups became patterns wider than a 12" target at 50 yards. I had scrubbed the bore with Hoppe/M Pro 7 products, but no copper solvents. Regardless, I like your simple recipe, and will try it on other barrels. Are you sure 10% ammonia is safe for the bore?
LED is offline  
Old May 27, 2013, 05:35 PM   #11
Picher
Senior Member
 
Join Date: December 14, 2004
Location: Maine
Posts: 2,878
Heating a barrel can cause it to warp a bit, but even if it doesn't touch the barrel channel, the barrel whips when fired, so some heavier hunting calibers need at least 1/16" of clearance at all times. Most rifles don't have that much clearance from the factory, some are bearing at some point along the channel.

In this particular case; however, barrel fouling may be the culprit. Barrels are more likely to foul when new, especially if heated too much.
Picher is offline  
Old May 27, 2013, 05:49 PM   #12
LED
Junior member
 
Join Date: March 10, 2013
Location: The Heartland
Posts: 174
It may well be the case. I did not suspect bore fouling at the time, but what happened is consistent with it. The only way to disprove it would be to let the barrel cool off, and then try again. I did not, in part because we had a hot muggy summer, and I was ready to leave the range within an hour.

If it was fouling undetected, I think looking back at it, that's great. Clears the way for another Tikka. I like the action, but I still don't regret letting that one go, because at almost 9 lbs and 24"bbl it was longer and heavier than I needed.
Thank you Picher and everyone who opined. This has been a great forum, I am leaving it with a probable answer that I didn't think of myself.
LED is offline  
Old May 28, 2013, 01:50 AM   #13
AZAK
Senior Member
 
Join Date: May 15, 2008
Location: the object towards which the action of the sea is directed
Posts: 2,103
Quote:
at almost 9 lbs
Tikka T3 Lite at 2.7 kilograms = 5.95248 lbs. That is just a hair under 6 lbs and even available in .223 Rem.
http://www.tikka.fi/t3models.php?lite_showdata#pagedown

Very hard to beat the accuracy and trigger out of the box for anywhere near the price. And you are correct about the action. Add the limbsaver and a light weight scope and quite the nice hiking rifle.

Quote:
The barrel got sizzling hot.
Yet another bonus of living in Alaska; not really a problem, still wait if I can't comfortably hold the barrel...
__________________
The lowest paid college major/degree in this country after graduation...
Elementary Education.

Now, go figure...
AZAK is offline  
Old May 28, 2013, 06:23 AM   #14
LED
Junior member
 
Join Date: March 10, 2013
Location: The Heartland
Posts: 174
Mine was the varmint heavy barrel model, not t3 lite.
LED is offline  
Old June 2, 2013, 12:18 PM   #15
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 5,378
Picher says heating a barrel can cause it to warp a bit.

Only if it's not stress relieved correctly, made from sloppy metals or poorly fit to the receiver. And if it's all three, they'll warp a lot more. Most factory barrels are well made and stress relieved; just poorly fit to receivers.
__________________
US Navy Distinguished Marksman Badge 153
Former US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master
Bart B. is offline  
Old June 2, 2013, 04:47 PM   #16
Picher
Senior Member
 
Join Date: December 14, 2004
Location: Maine
Posts: 2,878
I maintain my opinion that factory barrels are prone to barrel warping, or at least expansion lengthwise that may cause POI change, when heated. Your results may vary.
Picher is offline  
Old June 3, 2013, 07:56 AM   #17
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 5,378
Picher, every barrel gets longer and thicker when it heats up. So does any other round bar made of steel.

The reason why most factory barrels "warp" when they're hot is they're not fit to receivers whose face is squared up with the barrel tenon threads. When the barrel and receiver expands from heat, more pressure's applied at the hard contact point and that makes the barrel bend in that axis.

I've had three factory barrels that changed point of impact when they heated up but quit after some 'smithing. The receiver face was squared off and set back about .005" then a .005" thick shim washer was put between the barrel and receiver so it would clock in correctly for the extractor to fit the cutout in it. No more walking shot impact as the barrel heated up. Any competant 'smith can do this to most factory bolt action rifles.

Arsenals testing 30 caliber and 7.62 match ammo shoot a couple hundred shots per group; each about 20 to 30 seconds apart. Those test barrels get very hot yet still shoot good lots of ammo into 1 MOA at 600 yards; would be under 1/3 MOA at 100 yards.
__________________
US Navy Distinguished Marksman Badge 153
Former US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master
Bart B. is offline  
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 10:01 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2014 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.10175 seconds with 9 queries