Reloading issues - what's causing this?

[ILoveBigRacks]

Figured I had a load worked up for my .270 Wby and loaded up a box of ammo for my upcoming trip (leave on Thursday). As I'm pushing the length of the mag box to it's limits I thought I'd cycle through them all once and make sure there weren't any feeding issues.

Well, they all cycled through just fine BUT I'm finding that every one of them, a couple worse than others, are grooving into something on there way into the chamber. Don't know if it's the mag box itself, the feed ramp somewhere, or the opening to the chamber itself. The grooves are on the bottom of the case necks (almost like a skidded groove pattern) and right up the bullet length. I can actually see a little bit of brass shavings (very small amount) beginning to accumulate at the throat area so it's in there somewhere. I stuck my finger into the throat and can't feel any burrs or anything like that but it's definately cutting in somewhere as it feeds. Two of the cases actually have a bit of an indentation into the top of the neck. What gives????

 

[gunasauras]

Have you checked the front lip of your mag box? How about the periphery of your chamber mouth, is it chamfered?

 

[knockknock]

Maybe the " experts" at Wholesale Sports can solve this for you. LOL
You are using a standard die set, and the bullets you are using have a long ogive taper, the seating plug in your dies is what is leaving the marks on your bullets. Try a 1 size smaller caliber seater plug, this will solve the ring around the bullet near the tip issue.
KK

 

[speerchucker30x378]

feed scratches

What you are seeing are feed marks. You never mentioned what type of action it was. If it is a MK V Weatherby then its in the feed bumpers in the mag box. If it a Remington or Winchester it is in the feed rails of the action or in the feed ramp just before the chamber.
Many folks have problems with the weird names given to gun parts. The throat in a 270 Wby. is .277 in diameter so I doubt you got your finger into it. Don’t sweat it. I been a practicing gunsmith for 25 years and I can’t change the oil in my car. We each have our place in life. At any rate go hunting and have a great time with the ammo you have loaded. True, in a bench rest situation a scratched bullet could cost you a couple thousandths of an inch at 100 yards with a bench rest cartridge and gun. But in a hunting rifle using a high intensity cartridge like the 270 Wby. I wouldn’t even try to compute how small the difference in group size would be. I would get the rails and bumpers polished when you get back home. Outside of looking bad with scratches on the brass it could effect feed once in a while. If you still feel uncomfortable give me your gun, your shells and your hunt! You look after my job. And I’ll bring you back something to eat lol! Have a good trip. Rod Henrickson

 

[agilent_one]

The marks are most likely from your seater die, as kk said.

 

[mylesrom]

Well, they all cycled through just fine BUT I'm finding that every one of them, a couple worse than others, are grooving into something on there way into the chamber.

From what I am reading from the write up, the marks are happening after he cycles them, not before, so its not the dies.

 

[magicchip]

From what I am reading from the write up, the marks are happening after he cycles them, not before, so its not the dies.

That is my understanding a well. If I had to guess, I'll say mag box.

 

[ILoveBigRacks]

What you are seeing are feed marks. You never mentioned what type of action it was. If it is a MK V Weatherby then its in the feed bumpers in the mag box. If it a Remington or Winchester it is in the feed rails of the action or in the feed ramp just before the chamber.
Many folks have problems with the weird names given to gun parts. The throat in a 270 Wby. is .277 in diameter so I doubt you got your finger into it. Don’t sweat it. I been a practicing gunsmith for 25 years and I can’t change the oil in my car. We each have our place in life. At any rate go hunting and have a great time with the ammo you have loaded. True, in a bench rest situation a scratched bullet could cost you a couple thousandths of an inch at 100 yards with a bench rest cartridge and gun. But in a hunting rifle using a high intensity cartridge like the 270 Wby. I wouldn’t even try to compute how small the difference in group size would be. I would get the rails and bumpers polished when you get back home. Outside of looking bad with scratches on the brass it could effect feed once in a while. If you still feel uncomfortable give me your gun, your shells and your hunt! You look after my job. And I’ll bring you back something to eat lol! Have a good trip. Rod Henrickson

It's a Rem 700 action, freshly re-chambered from .300 Win Mag. You're right, I guess I can't actually get my finger up into the throat, but rather the area of the chamber just above the feed ramp where it begins to narrow a bit more. Ran my finger around the ramp and that area and didn't feel any type of burr, etc...

Will have it looked at after the hunt or maybe just shorten the rounds a hair and see if that helps. As it is now, I'm right at the point the rounds just barely fit into the mag box so it's possible that's contributing to it snagging up somewhere enroute.

Accuracy hasn't been affected really, my biggest concern was a problem chambering a round I had at the range. Didn't like the idea of having to shove a cleaning rod down the muzzle to poke out a live round stuck in the chamber - when I had a close look at it the round had a bent lip to the case neck, just like the one seen in the first 2 pictures. I'm guessing that these ones had the lip catch up where the bullets & necks were scraping.

BTW, thanks for the input on the other marks on the bullets too. I'm not too worried about a bit of cosmetic rings on the bullets but nice to get the input regardless.

 

[mikeelliot]

Is your brass length ok?

It might need to be trimmed?

 

[ILoveBigRacks]

Is your brass length ok?

It might need to be trimmed?

Brass is good, measured each piece individually as I bought it all once fired so was nervous if it really was only "once-fired" . No, these two indents into the neck mouth both align with the scrapes that run down the bullet and the case neck. It was hard to show exactly what it's doing but the last picture I think shows the case neck with a skid/skip scrape where it was digging in.

The more I think about it the more I think it is either the length of the rounds vs. the mag box or else the feed rails need to be polished up a bit. Either way, should be an easy fix for when I return from a week of bloodshed .

 

[Levi Garrett]

May be die setup, you don't want to crimp before the bullet is seated , maybe

 

[prosper]

I have the same thing happening on a Savage of mine. the occasional round (one or two in a box of 50) will fail to chamber completely, and when I eject it, there are bright scrapes along the top of the bullet. I've never noticed any on the brass itself. All the other rounds chamber fine with no scraping. Accuracy was fine, at a consistent 1"

I never really thought much about it, if I pulled those failed rounds apart, resized and re-seated them they worked fine. I supposed there was a small burr somewhere that I hadn't seen

 

[knockknock]

I thought you were concerned on the ring near the bullet tip, sorry I misunderstood.
Those scrapes are feed issues, many smiths fail to put a chamfer in the lead edge of the barrel inside of the area that the bolt face goes into, this can cause these scrapes as well.
KK

 

[gunrunner100]

The case mouth looks like it is grabbing the forward edge of the mag box. Can you put a slight crimp on the bullet after you seat it? That may give the case mouth less of a 90 degree angle to the mag box, allowing it to skip over it and chamber.
As for the rings on the tip of the bullet, they are from the seater plug.