Saubier.com  



Go Back   Saubier.com > Saubier.com Forums > Small Caliber Discussion Board

Reply
 
Thread Tools Display Modes
  #1  
Old 03-23-2013, 07:51 PM
13Fox 13Fox is offline
Member
 
Join Date: Oct 2006
Location: Alpine, WY
Posts: 42
Default Markings on bullets

Howdy,

About 5 years ago, I picked up a Remington 700 SPS in 17Fireball from a friend. Since then, I haven’t been able to get it to shoot better than about 1” at 100 yards. But truthfully, I never had the time to get it worked out. But now I am playing with it again and getting the same results.

Today, while re-evaluating the bullet seating depth (to see if I came up with the same information again as a double check) I took it a step further and completely disassembled the bolt, save the extractor, in order to take all pressure off the head from the ejector. I also used a 17 cal. rod without an end in it to insert the bullet into to ensure the dummy cartridge would enter the chamber as straight as I could get it to do.

I am getting marks on the bullet that do not follow the typical engraving marks from rifling. The marks are also only on a portion of the diameter, not all the way around. The marks show up from approximately the 10:00 position to the 6:00 position. There are no other marks on the bullet other than these. In the past I got these marks but I hadn’t disassembled the bolt so I assumed that “perhaps” the marks could be attributed to the case scraping against the chamber as it was fed in. Todays experiment tells me that is not thecase…

Is this chamber/leade just nasty? Any other ideas or suggestions?

These are all the same dummy cartridge, just slightly different orientations to catch the marks...



Thanks,
John

PS, Its been while since I have been here and since I have had a chance to play with the small caliber stuff.
Reply With Quote
  #2  
Old 03-23-2013, 08:04 PM
Bill K Bill K is offline
Senior Member
 
Join Date: Aug 2012
Location: N.E. Kommie Kalifornia
Posts: 6,304
Default Markings on bullet

It would appear to me that the problem lies in the throat. out of kilter or lopsided.. How about a cast of the chamber and into the throat up to the rifling and see what it measures and looks like ? Bill K Or a look see with a good borescope.
Reply With Quote
  #3  
Old 03-23-2013, 09:52 PM
Jim D Jim D is offline
Supporting Member
 
Join Date: Oct 2009
Location: Iowa
Posts: 550
Default

What happens when you single feed. Just lay the cartridge on the ramp and close the bolt.

Then try seating a little deeper. They look a little long to me.

Next try some Ramshot Xterminator powder to improve groups. It worked for me in my 700 SPS.
Good luck
Jim
Reply With Quote
  #4  
Old 03-24-2013, 12:23 AM
MrMajestic MrMajestic is offline
Supporting Member
 
Join Date: Jun 2011
Location: Brickerville, PA
Posts: 795
Default

What's your bullet runout? Throat could just be tight which ain't necessarily a bad thing. Does the bolt close hard? How does it shoot? Lots of questions I know....
__________________
"That which does not destroy me, has made a huge tactical error"
Reply With Quote
  #5  
Old 03-24-2013, 01:09 AM
ae35gunner ae35gunner is offline
Supporting Member
 
Join Date: Jun 2007
Location: Southwest Virginia, USA
Posts: 334
Send a message via Yahoo to ae35gunner
Default

13Fox,
With all the preparations you did prior to, and during, your CAREFUL chambering of the dummy round, I'd say that it looks like your rifle has a poorly cut leade that has a rough place left in it. If you can get access to a Hawkeye Borescope, or something similar, it should tell you the story in a minute. I have a borescope but do not know where you live in relation to my home (8 miles outside Abingdon, VA...about 1.5 miles from the TN/VA state line). PM me and let me know if I am located so I can help you.
Regards, Charlie
Reply With Quote
  #6  
Old 03-24-2013, 12:19 PM
Al Nyhus Al Nyhus is offline
Senior Member
 
Join Date: Sep 2006
Location: S.E. S. Dak.
Posts: 348
Default

When using a marker, you can get this type of mark from extracting the round.

The best way to check seating depth is:

-Stripped bolt (incl. ejector)
-Seat the bullet very long in a f.l. sized case (plenty of neck tension)...very long as in just .020-.030 of the bullet in the neck, to start.
-Polish the bullet with 0000 steel wool.
-Now carefully chamber the round and try to close the bolt. You'll feel the bullet being jammed into the rifling (assuming the throat is short enough for the bullet to get to the rifling). If the round won't chamber, don't force it. Adjust the seating depth by .005 and repeat until you can close the bolt while feeing resistance from the bullet jamming into the rifling.
-Remove the round and look at the rifling marks on the bullet. If the bullet stays in the rifling, just tap it out from the muzzle with a cleaning rod.
-Resize the case and repeat, polishing the bullet each time and changing the seating depth .005 at a time. Pretty soon, you'll start to see the marks get fainter, then disappear. When they just disappear, record this seating depth as your 'zero'.

Try this and post some pics, okay? -Al
Reply With Quote
  #7  
Old 03-24-2013, 01:53 PM
MarinePMI MarinePMI is offline
Supporting Member
 
Join Date: Sep 2006
Location: San Diego
Posts: 1,483
Default

Looks like the marks from extraction. As the cartridge is pulled form the chamber, the ejector forces the case against the side of the chamber as it is drug back out. Even with the ejector removed the case is still being pulled from one side by the extractor, so pressure is still being applied that can cause this drag mark.

JMTCW...
__________________
MarinePMI
________________

We sleep peaceably in our beds at night only because rough men stand ready to do great violence on our behalf. -- George Orwell
Reply With Quote
  #8  
Old 03-24-2013, 04:00 PM
Daryl Daryl is offline
Senior Member
 
Join Date: Sep 2006
Location: Prince George, B.C. Canada
Posts: 4,273
Default

Al and marine- sounds legitimate. I thought perhaps the marks were due to a sized case, laying low in the chamber and when chambered all the way, one side of the bullet hit the nasty little shoulder at the start of the leade on the way into the throat.
Happening on extraction sounds much more plausible- thanks.
__________________
Daryl
Reply With Quote
  #9  
Old 03-24-2013, 04:38 PM
william t. oviatt william t. oviatt is offline
Senior Member
 
Join Date: Mar 2008
Location: Lander, Wyoming
Posts: 2,524
Default

I certainly agree with the logic in all the above posts!
What stumps me is, the marks appear to be in a direction around the bullet, not perpendicular as would show as being dragged back over a rough spot! Maybe just my inability to see correctly in the photos.
I would carefully chamber a dummy cartridge with a slight tap on the base (no bolt) and then tap back out with a cleaning rod on the bullet end. This would show if it is due to rotational movement or if there is an imperfection in the chamber.
Just a thought...
Course the bore scope would be the best if you can do that...always wanted one of those...just too stingy (me) to make the purchase!
I sure would like to hear the solution and the cause, when you find out.
Bill
__________________
"Burn Powder, Not Comrades"!
Reply With Quote
  #10  
Old 03-24-2013, 07:21 PM
hemiallen hemiallen is offline
Supporting Member
 
Join Date: Oct 2009
Posts: 1,239
Default

I also see the chamber was cut very poorly. I see a ring just below the shoulder on the straight side of the case. It looks like the chamber reamer had a defect, or a chip got hung up while finishing the chamber job.


I have a 280 remington that has the same mark, it goes about halfway around the case. It doesn't cause any issues, but it isn't pretty.


I agree with the thought that the throat was cut out of alignment with the camber, but I have seen the same marks on a gun that shoots well. It could be made while entering the chamber, or while extracting the case, as others have said. To reduce this , I would remove the ejector button from the bolt, re-mark that same round, and see if it goes away.

Allen
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 07:26 AM.


Powered by vBulletin® Version 3.8.1
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.