Chrome lined bores and accuracy

[kgs]

For what reasons does a chrome-lined bore degrade accuracy?
And if these reasons are indeed valid, to what degree is the accuracy reduced? Also, is it rifle specific or is the degradation of accuracy (if true) the same across the board?
I ask this question with the assumption that rifles with chrome bores are less accurate than their un-lined counterparts.


kgs.

 

[Gewehr98]

I'm curious, myself.

My pre-ban Colt Competition HBAR has a chrome-lined bore, 1-9" twist, and sub 1"/100yd groups aren't that hard to obtain with the gun. Some of my Sierra 52gr MatchKing handloads, over WW748, even group into 1/2". Perhaps it's the thickness of the plating, or the way it's deposited, that causes accuracy to be either good or bad?

 

[dZ]

yep, the plating is an imperfectly deposited layer
but for a battle rifle, the corrosion resistance is a worth while investment

How accurate is a rusty bore?

For a bench shooting rifleman, that has the time to clean the bore, the non plated barrel
should out shoot the chomelined bore

IMHO a battle rifle only has to hold a 2-4 inch circle at 100 yards to complete the mission.
If i do my part my Bushie holds sub 2 inches with a chromelined bore.

dZ

 

[Poodleshooter]

My chrome bored 1x7 HBAR shoots better than I do. When I can outshoot it, then I'll worry about rebarreling.

 

[don vito]

yep the uneven crome lining is not recomended for sniper rifles, but ror a batle rifle it prolongs life of the barel and protects it from elenents.,

 

[slickpuppy]

Pretty well covered already. The chrome lined bore is perfect for a battle rifle and can give acceptable accuracy for that application.

I have several ARs that I have built and bought. They are a mix from chrome lined to Krieger and Douglas match barrels.

To be sure, the Krieger and Douglas barrels outperform the chrome lined. There is a difference in accuracy - AND price.

Decide what you want to do with the rifle and choose accordingly.

 

[MFH]

On the positive side for chrome-lined barrels, their useful life should greatly exceed that of stainless before a significant loss of accuracy occurs. I was told by bushmaster that you could essentially shoot the barrel to red-hot, dunk it in water and start again with no damage but a stainless barrel would suffer much more wear under similiar conditions. As to uneven plating, while this does account for some loss of accuracy, most barrels are air-guaged to make sure they are pretty close.

 

[Keith J]

See Link below

http://www.thefiringline.com/forums/showthread.php?threadid=54162

Chrome lining (actually hard plating) is deposited preferentially at the ends, i.e. muzzle and chamber, leading to a constriction at either end. A tight muzzle is fine but a loose middle isn't.

My AR doesn't seem to care.

 

[radom]

If you expect to shoot under 2 inches at 600yds the chrome bore is not going to do it. If you can live with just under a inch at 100yds and have the gun function well the chrome bore is the ticket in a decent barrel. I think the make has a lot more effect than the plating or not.

 

[don vito]

which cost more plated or not

 

[kgs]

Don Vito.........

Plated, regular steel barrels generally cost less in comparison to stainless barrels. However, I know at least one manufacturer that offers a 4140 steel barrel which is un-lined. I really can't say about the cost comparison in that situation. It might be more dependant on the manufacturing process of the barrel ie, the method of cutting the rifling. button, broach, etc......

kgs.