Feed Ramp marking bullets

[AndoOKC]

It seems my AICS mag causes my bullets to slam into the feeding ramp and scrape up the ramp and leave copper jacket bits behind on the ramp. With help from a separate thread I was able to adjust my AICS 5rd mag to not scrape the feed ramp as much. However, after extracting the bullet (carefully) i noticed that it is still slightly marking the bullet with a linear scratch traveling from the base of the bullet to the tip. I know my Savage 10FP does very little to mark up the bullet.

The purpose of this rant is to figure out if any of this bullet marking from the feed ramp effects ballistics and ultimately accuracy. Thanks!

 

[Coyote3]

Re: Feed Ramp marking bullets

I would have to say it depends on how hard its scratching it and how hard your jacking it to get it in. Take one that you have fed in and eject it. Then take a set of digital calipers to it. If you can see any change in the diameter when measuring around it, its going to affect accuracy. Sounds like the feed control lips are to narrow and forcing the round in the ramp.

 

[Accraholic]

Re: Feed Ramp marking bullets

Best way to find out if the accuracy is working is to have somebody who knows how to shoot take it for a spin, we are talking about live ammo and a fully functioning rifle here...right ?

 

[Wil]

Re: Feed Ramp marking bullets

You never mentioned if these marks are on both sides of the case....

It may be from dragging along the side when extracting...before the ejection takes place...

If this is a Remington 700 action...

I have seen this more than a few times... The ejector is trying to push the round out as you are running the bolt to the rear...pushing the round against the side of the chamber/action on the way out.

...provided that scrape is along one side and not both?

If it is on both sides of the brass, then it may just be sharp edges on the mag lips....etc... and a feed ramp as stated above.

If these marks are along the right side (or left side for left handed action) then the following should be the cause...

These marks are from ejection... when you are pulling them out of the chamber the ejector is pushing it to the right (or left if left handed action) causing it to drag along the action.

make a new dummy round... inspect it for scratches & chamber it
now... raise the bolt handle & slowly move the bolt rearward...watching the brass & bullet. I'll bet you will see the scratch along the side facing you.


As to the feed ramp issue.. I agree that it could be caused by tight feed lips...not allowing the round to sit high enough & causing it to hit too low.

-Wil

 

[AndoOKC]

Re: Feed Ramp marking bullets

thanks for all the great input...Wil i definetely thought of everything you did. I knew it was the feed ramp in the beginning because i felt it scraping and watched it scrape going up the ramp. Then as per advice from another thread I adjusted the lips of the magazine and it improved. However, I couldnt get it so that it wouldnt hit the feed ramp at all. At best I could get it so that the marks left by the feed ramp (which only occur on the side that touches the feed ramp) are slight and by slight you have to get light on it at a certain angle. The scratches are heaviest at the base then get smaller towards the tip.

When I eject the round i carefully extract and as soon as i can get my finger in there I press on the bullet so that it doesnt scrape along the side of the chamber. After extraction the only scratch is the one from the feed ramp.

So basically one single scratch, really light but leaves some chatter marks that I can feel barely with my fingernail and cant see that easily.

I know i could go out shooting but wont get a chance for the next 3 weeks so thought i would satisfy my curiosity on here.

By the way this is a remington 700 short action .308

Also, to confirm its the feed ramp what i did was let the tip of the bullet go up the feed ramp from the magazine, then i pulled the bolt back and by hand removed the round. The scratch was still there so I know its not occurring during extraction.

 

[Wil]

Re: Feed Ramp marking bullets

rgr all.. you can polish that feed ramp fairly easily if you were so inclined...

 

[AndoOKC]

Re: Feed Ramp marking bullets

I have alot of fine grit emory around the house. Anyone have a good tutorial on how to polish the feed ramp?