Bolt closes hard ?!

[ford8nr]

In all my years of reloading never ran into this. Im thinking headspace issue but ...
Just reloaded 80 rds of mixed head stamped ammo. All cases were prepped at the same time, sized and trimmed. At the range some rounds closed very firmly to the point I ejected them and set them aside. When I got home I ran all the remaining through two guns (.308 win). About a third of the cases closed hard in both guns. Upon exam it was only FC headstamps ? Not sure if this was my brass or range pickups. Any rate I'm pulling the bullets and scrapping the brass.
Any ideas ?

 

[Orcon]

Could be lots of things. Different springback due to alloy composition, maybe it was fired in a wonky chamber, if it's FC NATO brass it may have been run through a M240B. Is this second hand brass from parts unkown or are the only person to shoot it? Are you full length sizing?

 

[ford8nr]

Full length sizing, everything else i loaded that day runs fine.
Looks like Federal commercial brass. Not sure if it was mine or range pickup.

 

[ford8nr]

Before I scrap 30 rds of brass when I get time after deer season I think I'll pull apart 1 rd,re-size it and try again.

 

[Orcon]

Maybe measure the diameter of the pressure ring on a few FC cases and compare it to the ones that chambered fine. Could be blown out of spec or something. I met a guy a while back that was having brass and chambering issues with a 6.5 CM. His brass almost looked like it had been glocked, his chamber was all dorked up and wasn't supporting the brass on one side.

Not saying yours is but if it's mystery brass, you never know.

 

[Slamfire]

I am a huge fan of small base dies because I am a dumpster diver. I will happly dive into a garbage can that has once fired brass at the bottom. As I have found over the years, some rifles have huge chambers and I need a small base die to bring the stuff down, and, I need cartridge case headspace gages.

The Wilson only measures base to shoulder, but it is very useful. Works great in figuring out chamber size in a bolt gun. You fire a case, drop it in this gage, and if the gun is correct, the case head is in between Go and No Go. Used one just this weekend to verify that a rifle was properly chambered.



This gage is cut with a SAAMI minimum reamer, so properly sized brass should drop in. If it does not, then the die is not sizing case enough.



I have some sizing dies that I have had to grind material from the bottom to push the case shoulder enough to be between "Go" and "No Go". I have one of these cartridge headspace gages. on the counter when ever I am sizing because all brass acts and reacts differently.


Small base dies may not have enough sizing capability to reduce brass fired in ultra wide chambers. For serious case head swaging, Case Pro 100 http://www.casepro100.com/products.ydev makes industrial roll sizers. Yours for $850 or so:



I recommend that you do not toss those cases. Check your range pick ups with a cartridge headspace gage, see if your dies can be adjusted so the cases are not over long or fat, and adjust accordingly. !

 

[ford8nr]

Good info

 

[ford8nr]

I do have small base dies for my 30-06 Garand

 

[Grumulkin]

I would run the loaded cartridges through a body die and see if that fixes the problem.

 

[Walkalong]

I bought 250 LR Lake City brass which should have been fired from a bolt gun. I sized it all and some stuck up out of the gauge. I had to run the sizer down some more, resize all of those, and some still stuck up out of the gauge, run the sizer down some more and finally got 99% where they needed to be. I used all of the ones that sized easily to make a batch of 200 good cases. I scrapped the ones that were the hardest to size, and I used the ones in between to do load work up, then scrapped them. I suppose I could have annealed the entire batch first, but didn't think I needed to. After all, it was "once fired" from a bolt gun, right? Hmmff.

 

[Blue68f100]

I anneal after every firing. Keeps things consistent through out the brass life. LC being heavier wall would benefit from the annealing. The thing I noticed most is that I never have to readjust my sizing die. I have some brass now with over 10 firings so it's definitely keep the brass from splitting out. My neighbor bought some once fired LC, 7.62 but he did not get the bolt only batch. I annealed 500 rounds and he said he had quite a few that where hard to fit the case gauge, and had to do it a 2nd time. He just used more lube at the base, did not adj the sizing die and it made it easier to size. Fit the gauge after second sizing. He is using a RCBS Jr press which does not generate near the force of the RC or my Redding Boss.

 

[fguffey]

Im thinking headspace issue but

I will assume you have loaded for this rifle before, I will assume you have purchased new over the counter/factory ammo for this rifle and fired the new ammo in your rifle, after firing the new ammo you measured the length of the fired case from the shoulder to the case head, I suggest you save one fired cases for comparison purposes. If your loaded ammo is longer from the shoulder to the case head than your full length sized ammo you know the bolt is going to be difficult to close. A and then there is that problem with crimping, crimping can be a bad habit. the case body/shoulder juncture can get crushed because the seating die does not offer case body support.

And then there is checking to see of the die made it to the shell holder, there are times the case has more resistance to sizing than the die, and press can overcome

F. Guffey

 

[fguffey]

I'm thinking headspace issue but

Were you thinking of case head space or the length of the chamber from the datum to the bolt face? I use the length of the case from the datum/shoulder to the case head to off set the length of the chamber from the datum/shoulder to the bolt face.

F. Guffey

 

[rsrocket1]

Take one of the cartridges that causes had bolt closing and color it completely with a magic marker. Then chamber it again and look where the ink rubs off. I knew the headspace was too long on this case but this is what you'll see if the shoulder needs to be pushed back a bit.



If this is what's happening to your cartridges, you probably aren't pushing down all the way when you full length resize your brass. You need to press the handle all the way down, take a sheet of paper and try to slide it between the die and the shell holder. When I'm processing a bunch of brass on a single stage press, I sometimes get lazy and fail to get that die to fully contact the shell holder. It usually doesn't matter because the shoulder is still bumped enough to make headspace but in a tight chamber, it might make the difference.

 

[papajoe222]

I just had this same issue last month. After pulling the bullets and checking the cases, I found I had to bump the shoulder back .02 on every case with that head stamp. I annealed and then bumped the shoulder back. Two days later, I rechecked them and they had sprung back .01. Bumped them back again and two weeks later, they are exactly where I set them. It drove me crazy as I ran them through a head space gauge after full length sizing and they were fine. Go figure. That brass had some serious memory issues.

 

[redbullitt]

I have had some brass (fired by someone other than me, possibly in a machine gun) that I simply could not get to size down enough. I figure it was fired in a loose chamber and just doesn't want to go back. I needed another .001 or .0015 to get it to play nice, whereas all the other brass on hand would easily work. Spring back or memory or something like that maybe causing the trouble.

I wound up having to push the shoulder back a bit extra using a "thinner" shell holder just for that purpose to get a little more press travel. Once I figured that out I was able to use a lot of brass that would otherwise have been junk.

It probably would be a good idea to anneal or relax the necks a bit too! I would keep an eye on the case head inside with the paper clip trick just to be safe.

 

[fguffey]

That brass had some serious memory issues.

I have fired many cases that had memory problems, the cases were hammered do hard they could not remember what they were before I pulled the trigger. I have fired cases so many times they developed an ability to resist sizing, some cases ere so difficult to size they had more resistance to sizing than the press could overcome. I have never found it necessary to grind the top of the shell holder and or bottom of the die to increases the presses ability to overcome case sizing resistance. I have decreases the deck height of the shell holder with other methods and or techniques. reloaders should use new or once fired cases, After that they need to keep up with how heavy the loads are and how many times the cease has been fired.

F. Guffey

 

[Innovative]

It looks like some of you guys should look into annealing . . . . .
That and consider "measuring" the clearance your handloads have in your particular chamber - at the shoulder.

 

[Blue68f100]

I got tired of having to readjust my sizing dies after several firings. I learned how to anneal the brass when it gets to that point 40 yrs ago. Now I have a machine for doing this so I do it every time as part of my brass prep. Doing it this way I never have to adj my sizing die. My neck tension stays constant through out it's life. Some of my 223 LC and Lapua brass has over 10 cycles and still going.

 

[joneb]

Brass is made from copper, zinc and fire. Be good to your brass and send it home to the fire again when it gets hard to deal with.