Bore scopes and polishing the lands ahead of the chamber

Zxthinger · 13-02-2023 08:08PM #1

I have head of falling accuracy being brought back by re-crowning the barrel and polishing the rough firecracking down near the chamber etc.

Does anyone have experience polishing out a bore. I know that cutting paste can be had but what do you use to apply it into the bore.

I explored this with a rem700 in 17rem but it never pulled the actual groups in.. BTW I used a nylon brush and about 20 stroke per cleaning with 3no cleaning

The previous owner claimed that he never cleaned the bore on my last 17rem so I could have had a real bad bore but without a borescope yer in the dark..

I also give by swift one 20 stroke treatment and it may have helped to some extent..

But if ye can visually inspect then your only left with other proxies to determine ware..such as slinging the bore.. I wouldn’t be too well versed in techniques to with air gauges or other gauging methods

The next question is what’s a good borescope to get. Digital units are defo the way to go. Any ideas on a good unit with reasonable value for money.. You’d need to be either 90 deg or 60deg looking and suit 224 at the minimum.

It seems that once you go sub 224 with a borescope selection then you’re into big money but I getting something that was 172 viable would still be a sound investment for future forays into the 17 calibre world.

Any thoughts appreciated..

clivej · 17-02-2023 09:46AM

I remember many years ago going to the Midlands range to try shooting. Used one of the clubs CZ 452 rifles at 50y. It was accurate enough. I did ask how many rounds had it shot and how often were the rifles cleaned. Thousands and never was the answer.

So I wouldn't be to worried about carbon build up for now, but I do clean the rifle when the accuracy starts to fall off, about every 500 rounds or so.

keith s · 17-02-2023 10:26AM

I would start with rails, rings and scope making sure all are good.

After that I would look at stock (action screws, barrel floating and bedding).

Then think about recrowning and anything more serious. I've seen some pics on FB, of before and after recrowning and it seems to make a big difference (if done by the right person) .

I have a bore camera I bought online (I'll try find a link if I am allowed to post here).

I've no idea how it compares to other more expensive cameras, but I will say, if you're like me, once you inspect your firearm(s), you probably won't use it much (bar others needing to check theirs). So, if you are getting something expensive keep in mine how often you are going to use and would it be better to get a shop (who can recrown) to inspect it for you.

I'm based in Dublin, so if you do want to throw a camera down, let me know. I'm no expert, but if you want to have a look no worries.

Zxthinger · 18-02-2023 01:05AM

I suppose I’m looking at examining centre fire barrels and not rim fire..

I have 220 swift that used to shoot 1/4” MOA all day but I’m has now only getting 1” moa..

Keith, if ye have a like you could PM me then m if that suits..

Regards Zx

keith s · 20-02-2023 11:04PM

I PM'd the link as I am not sure I can post it here.

Uinseann_16 · 01-03-2023 11:37PM

https://www.boards.ie/discussion/comment/120251793#Comment_120251793

Apples and oranges there, rimfire vs a caliber known to be a barrel burner ... and imho bad advice in this situation

Carbon build-up does affect the accuracy and also with centrefire you've got copper build up(fouling) too ( to a lesser extent in 22 rimfire)

As a copper jacketed round goes down a barrel it leaves copper behind this "fills" imperfections but it can build up and become excessive so you essentially tighten your bore as it builds up that's not a good thing increased friction means more heat and a barrel that burns out faster, Use a good solvent like hoppes no.9 and thoroughly clean your barrel (follow the instructions let it sit in the barrel for a while before you clean!!!)

The faster the velocity of your cartridge the faster fouling builds up so .17Rem is essentially the worst case scenario for this

And i always run a patch with 3 in 1 oil through my barrel after cleaning too

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Bore scopes and polishing the lands ahead of the chamber

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