Problem with fire formed cases

[Gina1]

OK guys, this one has me scratching my head.

Here's the problem I've got and any advice, recommendations or explanations would be greatly appreciated.
I've got a Savage 12FCV .223 and have been reloading for about a year now. I'm not sure this problem was always present or I've just become more attuned to the idiosyncrasies of hand loading.
When reloading new brass, the round will fit into the chamber with no effort, and if unfired can be ejected, with no problems or effort.

On the other hand, using fire formed brass, there is a small effort to close the bolt, and it is difficult to pull the bolt back and remove an unfired round. This happen whether using an FL die or a necking die.

Both new brass and fire formed cases, are set to the same specs. Case trimmed to length, cases are FL re-sized, so head space is the same. OCL is the same, using the same type of bullet. Bullet depth is the same.

In looking at an unfired, fire formed reload after it is removed from the chamber, a scuff mark can be seen on the bullet. The orientation of the scuff mark is always on the bottom left of the bullet.

The picture I've attached is not the best, but it does show the scuff mark.

So what's going on ?? Is something wrong with the rifle or am I doing something wrong. ?
Is the chamber out of alignment so that when the brass is fire formed, it now out of alignment?

So what advice do you have...?? Any and all help will be appreciated

Much thanks

 

[fdshuster]

If you have access to a borescope there is a good chance you would be able to see some discrepancies in the throat, particularly the leade. I've seen some factory throats that had the leade angle (usually 1 degree 30 minutes), beginning at different lengths as I rotate the tube of the borescope. In other words, the 'scope would be held so it cannot move backward/forward, establish where one leade on the land begins, slowly rotate the tube & as you do, all the leade angles should begin at the exact same location, as you go around a complete 360 turn. On a properly cut chamber/throat it will all appear as straight, evenly spaced, perfectly square, parrallel, lines, like an engineers drawing. Don't know if I made myself clear, but if possible have the throat inspected by someone who is familiar with using a borescope, like most gunsmiths. If it is not properly cut, it would be grounds for a barrel replacement by the manufacturer. This may not be the problem, just one of several area's to look at. p.s.: Another thought? You might try seating the bullet(s) deeper in increments of .010" to see if the problem goes away with deeper seating. If this happens, then you most likely have one of the leade angles that is longer ( closer to the mouth of the chamber), than the others. Interesting problem/ I'm curious to learn what you find.

 

[jonbearman]

Lets get the basics. Tell us what kind of dies and press and manufacturer of the following such as who's brass,bullets,weight of bullet,kind of powder and charge weight etc. If you have resistance to close the bolt on a full length sized case,then your die may not be touching the shell plate enough. Once you tell us what reloading stuff you are using we can further explain what is going on. As far as the scuff,I have had a few rifles that do this and it seems that in my case it was caused by the feed ramp.

 

[Skunce]

Have you checked the runout of your reloaded rounds? I had the same scuffing problem with my 7mm SAUM and it was due to the sizing die expander pulling the neck off center. It may not be your problem, but it's easy to check.
For what it's worth I checked and rechecked my chamber several times thinking it was the problem before I rolled a loaded round across the bench and spotted the runout. If I remember correctly I had +.010" when I checked with and indicator.

 

[Gina1]

Shucks jonbearman.....

In my post I said this has been happening on BOTH FL and neck sized cases. bullets are Seria MK 69 grain. Powder and primer do not play into it as I was talking about unfired ammo. Jam on my rifle is about 2.390, I've been setting bullet depth at 2.360.

In another note, I think I have a handle on the problem. (finally) New brass has a smaller diameter, than fired formed brass. Just behind the shoulder, measured with a caliber, the diameter of the new brass is 0.350. On my fire formed cases the dianeter is about 0.357. I say about becaue if I rotate the case, it varies from 0.357 to 0.355. Non-symmetrical chamber ?? It is possable there is a misalignment, between the center axis of the chamber and the throat. New brass with it's 5-7 mil slop allows the round to fit in without scuffing the bullet and easy removel of an unfired round.
More investigation to follow

Gina

 

[Gina1]

Have you checked the runout of your reloaded rounds? I had the same scuffing problem with my 7mm SAUM and it was due to the sizing die expander pulling the neck off center. It may not be your problem, but it's easy to check.
For what it's worth I checked and rechecked my chamber several times thinking it was the problem before I rolled a loaded round across the bench and spotted the runout. If I remember correctly I had +.010" when I checked with and indicator.

Thanks for you input.

All reloaded rounds are checked with a Hornady Locl-N-Load conentricity tool, and adjusted or .001 bullet runout or less.

gina

 

[BillPa]

Just toss'n an idea around.

When was the last time you cleaned the carbon out of the gap space and the freebore portions of the chamber?

Why I ask...

have been reloading for about a year now.

I'm not sure this problem was always present

a scuff mark can be seen on the bullet. The orientation of the scuff mark is always on the bottom left of the bullet.

From your picture the "scuff mark" looks and the problems you describe appear to be very similar to a 6BR I helped a guy with about 6 months ago. His issues were solved with a few applications of GM T.E.C. in the freebore and "gap space" areas of the chamber.

The gap space, as I call it, is the area from the end of the cartridge mouth to the start of the freebore. Both the gap and freebore are a great places for carbon to form and buildup over time. Rarely does it "suddenly " cause problems, they kinda sneak up on you.

Just a thought.

Bill

 

[shooter63]

seat your bullet deeper in incrediments first clean that chamber out &leade as described above your problem may go away . also how much expansion in chamber versus loaded rd. do you have good luck alan.

 

[lynn]

Gina1
If the gun has been shooting fine for a year ignore the gun issues/chamber issues and turn to the brass.

Here is a very simple approach that will get you to the problem area quickly.

If you think it is a bullet seating depth problem and I don't simply pull the bullet out of a case by gripping it with a pair of pliers while lowering the ram.Dump out the powder and try the case in the chamber.If the problem still exists it isn't your seating depth.

With the same problem case you can now cut the case in half removing the neck and shoulder area completely.You will need to de-burr the hacksaw burrs left on the outside edge first then simply drop what is left in the gun and see how it closes/extracts.If it closes and extracts like butter your die isn't pushing the shoulder back far enough so you will need to sand your shellholder down so your brass goes deeper into the full length die.

If the case or piece of the case is still hard to chamber/extract your not sizing the base enough right in front of the web area and this is a very common problem.To fix this make sure your full length die is making firm contact with your shellholder when you run the ram all the way up without a case in the press.Most new reloaders leave too much clearance.If you put a piece of paper on top of the shellholder and run the ram up the paper should not be able to be removed at all.It should get pinched very hard.

Now run the little piece of brass back into the die and after doing such put it back in the gun.It should now feed and extract properly but if not you need a small base die.

It is common for brass to fit your gun for several firings even if your not sizing it correctly as it takes time to fully fireform it.After a years worth of shooting depending on how often you shoot the problem now exists.
Let us know what you find out.
Lynn

 

[Gina1]

Well..... I can't explain it, but the problem with the scuff mark, was coming from bullet runout. After rotating the the round several times, and rechambering after ejecting it, the scuff mark was always in the same place with new scuff marks over the old ones. The reason I can't explain it is becaue I was using the Hornady Lock-N-Load concentricity tool to check runout. Runout could be adjusted out using the same tool. After adjusting runout was less than .001.
Of all places I found the answer for this was on YouTube. Seems the seating die I was using RCBS competition die is prone to causing bullet runout. (see the video yourself, search "reload dies" can't remember the exact author of the video. Have replaced the RCBS die with the Redding competition die and no longer have the problems.
Ran the Redding die rounds through the concentricity gage and have less than .5 mils out of round/ with no adjustment. With the RCBS die I always had to adjust 5-7 mils.
Went to the range yesteday and group was less than 1" at 200 yards with the new Redding seated rounds. I'm happy now. ;D

Gina... Thanks for all your input guys