How does cold affect your barrel?

[Derek M.]

I've noticed that heading west by itself regardless of temp changes still changes flight patterns.

I shot about 60 rounds each over the course of a month from my 7RM and 300RUM before I headed to WY and CO for antelope, mulie, and elk. The bullets were very consistent here. I made drop charts and taped them to the rifles.

We got to WY the day before our antelope season opened and shot our rifles for about 3-4 hours (includes MLs). My charts were trashed. The 150 Btip from the 7mag used to be 5" low at 300 with a 1" high at 100 sight in. However, in WY, it shot flatter. In fact, I popped of the first several rounds starting at 300 yards expecting them to hit between 3 and 7" low, but they were now only 1" low. I backed the target up to 100 and it was 2.5" high. This occurred on a Saturday. I shot the rifle on Thursday before we left.

Just about the same scenario with the 300RUM and 200AB.

The temperatures were roughly within 10 degrees (Casper, WY, vs. Crittendon, KY.)

The 300 rounds actually tightened up even more out west, where the 7mag 150's spread another 1" at 300.

It is rather frustrating but it is why I typically like to get to my destination 1-2 days prior to my season, so I can shoot and potentially redo a drop chart.

 

[Guest]

Becuase of the new powders that are available, that old rule of thumb really doesn't apply. Also, steel expands 1,000,000th of an inch for each one degree increase in temperature, assiting in making no two trajectories identical. One more thing, <font color="blue"> Stainless Steel Barrels </font> <font color="red"> are Not </font> recommended for shooting in freezing temperature conditions.

 

[Buffalobob]

I finally got free and went hunting today up in the Paw Paw Bends.

When I dialed in my gun in August it was about 80 degrees. Today was about 40 degrees. I kept about five cartridges in the pocket of my Tee shirt which was underneath many other layers. About Noon I got bored sitting there watching a hillside with no deer on it so I decided to check my dial in. I found a big rock at 796 yards and got the gun all set and ready to go and then I reached inside my clothes and got a toasty warm cartridge and quickly slide it into the chamber and fired. Bullet struck maybe two inches below the aiming point with a wind drift of 18 inches. Thought about that a little while and decided to see if I could do it again. Got everything ready to go and reached inside my shirts and coats and got out another warm cartridge. Quickly fired that with exact same result - maybe two inches low. At 800 yds, me and this gun would normally shoot about a 5-6 inch group so when both bullets were within two inches of the aiming point elevation wise(the wind was really nasty -swirling and gusting), I was happy. My August dial in was still good with warm bullets. I had some cold bullets but it didn't occur to me to shoot them to compare with the warm bullets.

After the deer saw how deadly I was with smacking that rock, none would venture out into the open so I came home empty handed.

 

[Timberman]

Glad you got to go for a while buffalobob. I'm still getting used to this zeiss scope. The cross hairs in this thing are like 1.5" drain pipe. I shot 2 small does yesterday afternoon at 290 yards, and 10 minutes later missed an easy 295 yard shot at a monster. I got in a hurry and pulled the shot I think, may have struck some limbs. He was checking a scrape on the field edge, and licking the branch over his head. All I could see were big long tines waving all around, so I put it on his shoulder and shot, but missed. Shot too fast I guess. You may have heard some of my profanity from your side of the bay. Gonna pour some tinks in his scrape and see if he comes out tonight.

 

[Buffalobob]

It still amazes me how after all these years of hunting I will get excited when a big one shows up and do something wrong.

Same thing with fishing. My line only tangles when there is a big fish to cast to.

 

[Hired Gun]

[ QUOTE ]
<font color="blue"> Stainless Steel Barrels </font> <font color="red"> are Not </font> recommended for shooting in freezing temperature conditions.

[/ QUOTE ]

Not recommended by who? Why not? All my serious hunting rifles are sporting stainless barrels for their weather resistance.

 

[Michael Eichele]

[ QUOTE ]
Quote:
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Stainless Steel Barrels are Not recommended for shooting in freezing temperature conditions.


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Not recommended by who? Why not? All my serious hunting rifles are sporting stainless barrels for their weather resistance.

[/ QUOTE ]

Me too. I have shot stainless steel barrels in 10 to 20 degrees below zero, meaning my rifle has been outside all night in sub zero temps before firing on more than one occasion.

I am not saying anybody is wrong. I would just like a little further information and preferably some proof. I am all ears.

 

[Guest]

[ QUOTE ]
A rule of thumb I was taught when I shot for the All-Army Rifle Team back in the early 1970's was one MOA change for every 15 degrees of temperature change. Thus, if you zeroed your rifle at 60 degrees and then later shot it in 15 degree weather, you'd be 3 MOA low. Of course, this was shooting Lake City Match ammo in Match Grade M-14's. I still shoot Lake City Match .308 ammo in my Ruger 77V, and find this rule of thumb is still pretty accurate.

[/ QUOTE ]

When I was with the team....we found that when shooting the .30x338 Any Any Rifles and the 220 gr. SHPMK from 1000 yds. that a change in temp of about 20F would change our zeros about 1 MOA for each 20F change either way! /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif

 

[Guest]

Steel chemistry… Now I am Not a metallurgist, so I would contact one and ask them; "is there a difference between the two steels and is it not recommended to use the stainless in Cold environments?" For information purposes.. Kreiger Barrels states "that a chrome moly barrel may take longer to break in than stainless steel because it is more abrasion resistant even though it is the same hardness. Chrome moly and stainless steel are different materials with some things in common and others different."

Kreiger's Barrel Break-in procedure…

-----Stainless ---------------Chrome moly
5 one-shot cycles--------5 - 25 - one-shot cycles
1 three-shot cycle -------2 - three-shot cycles
1 five-shot cycle----------1 - five-shot cycle


I mention this only to note a difference between the two steels. It is my understanding that Stainless steel is heavier, and softer than Chrome moly. This is one reason why the Bench-rest shooters utilize it, and one of the reasons that some Gun smiths would rather work with it.

In any regard, it has been conveyed to me that Stainless can become brittle in the cold; and it is my own personal experience that throat erosion has occurred much faster and aggressively in the Stainless barrels when shooting calibers such as the 6mm Remington or the 6.5 X 284, than in the chrome molly. Personally, I prefer not to use Stainless Steel Barrels any longer.

As far as correcting for temps…. Yeah, I kind of agree with you. And since you shot witht the Teams... Shooting the .300 win mag "White Box" with the Lapua load; there is a drop difference at 1,000 yards of 1 moa (almost exactly) when going from 70 degrees F to 30 degrees F. However at 700 yards, the difference is .25 moa. So out to 750 meters, the difference is not as bold.

 

[Hired Gun]

As a welder fabricator and journeyman millwright I used to work with both all the time. Stainless is far harder to machine than chrome moly. I challenge you to bust out some high speed steel drill bits and try to drill a hole through any piece of stainless. On just one hole you will dull many bits trying and when it breaks through you will break the bit. Now take same set of bits and drill some chrome moly. It drills nicely hole after hole. Stainless is used in industrial applications for its heat and erosion resistance. Now take both and try to cut them with a torch. You will whiz right through CM but when you get to the stainless you are done A torch with the oxygen stream going is way hotter than the temp of some burnt powder. This is why stainless is used in bench rest because the throats lasts longer in the heat of firing. Now days the only reason to use chrome moly for a barrel is if you are dead set on having it blued. As far as reaming stainless it takes special feed rates, special cutting fluids and an understanding that stainless work hardens as you machine it so once you stop or back the reamer out it is hard to restart it. It helps to drill it as close as possible before you bring out the reamer to finish it up. Was the reamers in question carbide or HSS?

The properties of stainless are not changing enough between 200+ degrees and 60 below to cause it to be brittle enough to crack from shooting or affect hardness measurably.

 

[wapiti13]

Hiredgun, Nice post! I know that Kreiger recommends stainless over cm for barrels. It does resist throat wear better. It is funny how ideas get turned around.

 

[Timberman]

Does anyone know which type of metal is used in the accumark barrel? It is the factory 26" fluted stainless colored barrel, with black coloring in the flutes/grooves.

 

[Hired Gun]

Usually
silver = stainless
blued = chromemoly
teflon = mystery metal

 

[Guest]

It is posts like these that leave me shaking my head. Who is right, who is wrong. Someone has to be, and according to you guys it is me. However, Mr. Krieger has conveyed his sentiments without reserve, that he prefers Chrome Molly Steel over Stainless Steel for barrels. He also states that SS is softer, that the throats polish out easier; and as I previously mentioned, is heavier, takes less time to break in, and is not recommended for freezing climates. I don't think that this has anything to do with his "Ideas" being turned around, and in fact he works extensively with metallurgists to obtain the best steel for the manufacturing of his barrels, period. But you can argue with him all you want; all's you have to do is phone him. Their contact information is s follows:

KRIEGERBARRELS.COM.
Mailing Address:
2024 Mayfield Road
Richfield, WI 53076
Phone: 262-628-8558
Fax: 262-628-8748

Also, feel free to discuss this topic with Sako of Finland or DSR, Germany. Their feelings are quite opinionated when it comes to utilizing Stainless Steel; as are mine.