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Bore Guide?

7K views 5 replies 3 participants last post by  72 usmc 
#1 ·
I'm sure it's been discussed before, but a search didn't turn up anything for me. That having been said ...

Is there a resource, preferably online, that discusses the condition of a rifle bore, with illustrations to show a newbie what he/she is looking at? For example, "pitted bore" might be self-explanatory, but just how pitted is pitted - does one tiny pinprick pit cause a verdict of "pitted," or does the bore have to look like the surface of the moon? Are there different types of pitting? What about "frosted bore"? I have a mental image of the surface of a cake - you know, the frosting you scoop up with a finger to stick into your mouth. I know the frosting in a bore isn't exactly edible, but what does it look like? Then there's the issue of "dark" bores - how do you know a bore is permanently dark because of corrosive ammo, or temporarily dark because it's not been cleaned out? The list goes on and on ...

So is there a guide with pictures that covers this topic?
 
#2 ·
*bump* any such guides would be most helpful to those of us who are new to the hobby - ok, addiction - of mil-surp collecting. Experience is the best teacher and all that, but having a fair idea of what to look for and how to recognize the various conditions that can affect a bore can keep someone from getting burned with a potential purchase. Thanks ...
 
#3 ·
Good question

Start with a perfect bore on a new barrel. Thats is as good as it gets.

Wear causes the edges of the lands (the part of the rifling that protrudes) to slowly round off, particularly the edge that faces towards the breach of a rifle. This is the point where the greatest friction occurs between the bullet and the bore as the bullet travels from the breach to exit at the muzzle. After many rounds of ammunition have been shot out of the bore the sharp edge of the lands will become rounded off somewhat. This can also be caused by inproper cleaning, but that usually is not the case with non corrosive ammunition.

Corrosive ammunition is the principle cause of "frosting" or "pitting' of the bore. Its the same effect as mixing salt and water together and pouring it on a piece of bare metal. Sustained use of corrosive ammo without immediate attention to the corrosive effects of that ammunition will result in rust forming in the bore. The term "frosted" is a way of verbally trying to minimize the fact that the bore has suffered a certain amount of damage from corrosive ammo. Frosting is pitting, it's just microscopic pitting. Under magnification it looks like the same pitting as larger pitting from greater abuse. It takes very little neglect to cause frosting or pitting and peoples descriptions can vary greatly. A seller wants to minimize the terminology when he is trying to get a better price, while the buyer is trying to maximize the negative aspects of condition to get a lower price.

There is not a real standard as far as bore descriptions, so I may not have really answered your question. When I describe a bore condition I like to separate the description into wear condition and corrosive damage condition. Typically a frosted bore that is mechanically close to perfect only needs to have a single instance of leaving corrosive residue in the bore for a considerable period of time. The problem with pitted bores is they collect residue which exacerbates the existing corrosion. Beyond a certain point the best solution is to not use corrosive ammunition in a bore that has a certain amount of frosting, because the effort necessary to get the corrosive agents out becomes huge to impossible.

regards
badger
 
#4 ·
thanks for the descriptive responses, they do help :) But I was wondering if there was an illustrated guide to bore conditions? It's one thing to describe something like frosted bores, but it's another thing entirely to show what one looks like compared to a clean bore.

I'd imagine someone has already taken it upon himself or herself to produce such a guide, whether online or in print. Not everyone can have the singular experience of having an expert personally show him or her examples of bores with various conditions of wear and such. Though that would be priceless, going to a gun show with an expert who then picks up a 03A4T from a vendor's table, peers through the bore, and says in a loud voice, "Look at this one - it's heavily frosted. And the lands are completely worn down. Not worth half as much as the asking price, in my opinion ..."

But thanks again for taking the time to share your knowledge, folks. It is appreciated!
 
#5 ·
Folks, this issue is still much on my mind. I guess from the lack of responses that there hasn't been any concerted effort to present an illustrated bore guide, either online or offline. Perhaps someone with a large collection of mil-surps with bore conditions ranging from pristine to sewer-pipe, and who is good with a camera, should post such a guide. That would be most helpful for those of us new to mil-surp collecting :)

In the meantime, how would you describe the condition of this bore, given the poor quality of the pictures? I can't decide whether it's "frosted" or "bright," since I've never seen a bore of either condition that was identified as such to me. Shining a bore light from the opposite end makes it tough too, as I'm looking into a light with less-than-perfect eyesight. That's why the last pic was taken without light shining from the other end, if that makes any difference for the pic. Thanks ...
 
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