bullet chaffing when chambered

[flyboyjake]

hi guys. Great forum!

I am not new to precision reloading or the variables involved, however I must note that I haven't the money to spend on high dollar gun parts to really make my reloads shine. I have spent countless hours reloading precision bullets for my savage 7mm rem mag. It has a stock barrel and cheap optics, so while I understand some of the steps in my process are a wasted effort such as reducing runout and weighing my cases, I enjoy the process and do it anyway. Now to the question...

I am using an RCBS case length gauge, and use the hornady OAL tool as well. By using the data obtained, I loaded a bunch of bullets and seated them .02" deeper than what I saw from the gauge. After shooting a few I noted MUCH higher velocities than they should have been (200fps in some cases). I assumed my POS chrono was the error initially, but no such luck. I pulled a few when I got home and the powder charge was well under max. So I inspected a few and chambered them...and when extracting, I found some slight chafing on the bullet at the 6 oclock position. The bullet is not pushed any farther into the case when chambering. The barrel is clean, and a few hundred rounds have been fired from it. Is this a good time to get a new barrel? Has it been eroded so bad as to not give consistent leade now?

Ill give whatever info I left out on request, but I would love to know if this is an issue, or if I am seriously neglecting some other reloading practice which is causing my velocities to be so much higher than they should be.

 

[Ideal Tool]

Hello, You said you seated bullets deeper..this reduced case capacity, so it could increase pressure & velocity..though only .02" does not seem like it would increase that much. What was the temp. difference, was it hotter? Concerning the scuffing..were the bullets the ones seated deeper that did this, or did you pull those & reseat to original specs? could the scuffing be from case mouth? If brl. throat were truly burned..it would seem you wouldn,t be getting any contact. Were you seating out into lands? With those gages you have, your notes should tell you if that throat is getting longer.

 

[PA-Joe]

Are you setting the COL based upon the book length or did you actually meaure the distance to your lands and then set back from there?

 

[Mobuck]

Did you load the round from the mag or drop it into the chamber? How many rounds showed the scuff and how many did you try? If the bullet is touching the lands on only one side, it might indicate a cocked bullet. Generally, a burned throat will be consistent all around not on one side. I'd seat some bullets long and see what the max length might be and back off a little. I kept a burnt out 223 barrel shooting pretty good but using a bullet with a longer shank and more rounded ogive loaded as long as the mag would allow.

 

[flyboyjake]

I used the gauges to determine seating depth to the lands, then backed off according to those measurments. The scuffing problem was on every bullet I put in, and I fed them in by hand (not by magazine). Every bullet gets scuffed at the 6 oclock position on the ogive that would contact the lands. I have very concentric bullets as tested, and I dont think it would be from a crooked bullet. I am cleaning the tar out of this bore, but to no avail.

 

[Ideal Tool]

Hello, flyboyjake. Might be time for a chamber cast. Or, if you have any soft lead..sinkers or .32 round ball or soft bullets? you could tap one in from chamber end..this would give you clear imprint of throat/lands. Use wood dowel or brass rod & plastic hammer.

 

[chris in va]

.and when extracting, I found some slight chafing on the bullet at the 6 oclock position.

Is the scuff from chambering? The bullet has to be guided in and will make contact at some point.

Apples and oranges I know, but all my AK and Garand bullets get scraped when chambering. So do the ones for my CZ 527.

 

[flyboyjake]

I like the chamber cast idea. I have never done that before.

Chris, with the AK and its type, really anything with a plunger extractor, its common to get scratches on the bullet if you extract them, but mine is in the wrong place on the bullet I think for that to be the problem...man this savage has given me nothing but problems...though i did beat it up pretty bad over the years.

 

[700cdl]

If I understand you your seeing this scuffing only on the bullet, no marks on the brass that are consistent with the spot on the bullet? I'm asking because when extracting the round will get scraped against the inside of the reciever on most any rifle and it leaves some pretty deep marks. When I'm extracting my fired or unfired rounds, I always try to keep pressure on them to kind of guide them out of the reciever so they don't rub against anyting other than the chamber. I'm kind of weird in that way and am always getting on my Son's about it, because I don't like the brass getting all chewed up. Is that anything close to what you are describing?