cart SHOPPING CART You have 0 items
SELECT CURRENCY

Discussion Forums

Search forums
Forum Index > Rifles general discussion > Throat corrosion?

Throat corrosion?

13 Aug 2013
@ 08:44 am (GMT)

Michael Neeson

Hi, here are some poor, grainy photos of the throat in my SPS Tactical... are we looking at corrosion maybe? I was thinking of rolling 5 or 6 bullets in my wheeler #600 lapping paste and lightly fire lapping it out? Anyone's thoughts would be appreciated. BTW rifle shoots .4" at 100M





Replies

13 Aug 2013
@ 04:04 pm (GMT)

Nathan Foster

Re: Throat corrosion?
Hi Mike, if the photo is correct and what we are seeing is indeed corrosion, it appears to be at a point where the throat is now craze cracking and by the look of it- delaminating.

Do not use 600 grit on this bore. At this grit size, you will achieve nothing at the throat and then over polish the muzzle, decreasing bullet stability exponentially. Do not use any fine grits in this bore. You can work from 180 to 240 grit, but that is all.

In a little while from now, accuracy may fall off completely. You will just have to experiment and see how you get on.
13 Aug 2013
@ 07:58 pm (GMT)

Michael Neeson

Re: Throat corrosion?
I guess that's what you get for leaving it in storage for 5 years in someone elses safe, in another country. Anyway, In the wheeler lapping kit I have 220, 320 grits. Is there a reliable resource I can refer to on lapping technique or do I just go ahead and try the fire lapping routine on light loads? (which I am reasonably well schooled on) I can see what you what you mean about fine grit... it won't be enough to get to the grunge. Looks like I may being shopping for a new barrel MUCH sooner than I had hoped. Not what I need right now at all. The barrel has only had about 200 rnds down it. What a waste.
13 Aug 2013
@ 09:27 pm (GMT)

Michael Neeson

Re: Throat corrosion?
I'll give it scrub with scotchbrite and see how it looks after that.
13 Aug 2013
@ 11:37 pm (GMT)

Nathan Foster

Re: Throat corrosion?
PM sent
14 Aug 2013
@ 03:24 am (GMT)

Michael Neeson

Re: Throat corrosion?
STAND DOWN. It is official: I am a dick. Cleaned the barrel with scotchbrite and this was the result.





So let this be a lesson to all. Nathan knows how to get barrels clean - PROPER LIKE.
14 Aug 2013
@ 03:28 am (GMT)

Michael Neeson

Re: Throat corrosion?
Looks like it was just carbon...
14 Aug 2013
@ 06:06 am (GMT)

jason brown

Re: Throat corrosion?
how did you get such a good picture, as in the angle, the camera in the right place?
14 Aug 2013
@ 11:37 am (GMT)

Michael Neeson

Re: Throat corrosion?
Hi Jason, it's a reasonably cheap flexible "endoscope" which plugs into your computer and acts like a webcam. This particular one has a 7mm camera head with LED lights... but I still needed to put my torch at the muzzle to get a picture.

http://www.ebay.com.au/itm/200945942752?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

It's focal length is too long to compare with an actual borescope and get good closeups, but it does have it's uses. Don't bother using the supplied software, it's crap. Download a version of Yawcam, it's free and easy to use.

There are plenty out there for sale, they all seem to either have 10mm cameras or 7mm, nothing smaller. To get this one down my barrel I had to unscrew a small collar threaded near the lense, but it doesn't appear to have any use.
14 Aug 2013
@ 05:38 pm (GMT)

Nathan Foster

Re: Throat corrosion?
What a relief.
14 Aug 2013
@ 06:44 pm (GMT)

jason brown

Re: Throat corrosion?
thanks micheal, iv looked and found a 7mm one, too bad it wasn't 6mm to fit my 7mm bore.
but even at that it will have its place, iv never really been able to see in the chamber properly or the throat.

thanks for the help.
14 Aug 2013
@ 08:25 pm (GMT)

Michael Neeson

Re: Throat corrosion?
to be honest Jason, I'm not sure you need to get it into the actual bore... I have found there is very little gained in getting the camera into the bore itself - it just doesn't focus very well. However, you'll notice that the photo's I took are from inside the chamber - not the bore. The best view of the throat was gained by an offset camera angle (in the chamber) and an offset additional lighting source at the muzzle. I still think that one of these may work for you - if all you want to do is view the throat/chamber. If the chamber is reasonably fat, I THINK you may be able to use it quite effectively. Worst case scenario is that it doesn't work and you sell the $30 camera on ebay/trademe for a small loss.
It is also good for having a look around the lug recesses.
The best pictures are done from approx 25mm away (hence inside the chamber) anything closer just goes out of focus.
15 Aug 2013
@ 12:14 am (GMT)

jason brown

Re: Throat corrosion?
thanks, I see what you mean about its limits. but it does have a place. iv never been able to see in the chamber as good as your pictures.
theres some for about 30-50 on trade me. im pretty keen to give it ago, im sure I could find other uses once I have one.
 

ABOUT US

We are a small, family run business, based out of Taranaki, New Zealand, who specialize in cartridge research and testing, and rifle accurizing.

store