What causes difficult bolt closing on reloads?

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thomis

thomis

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In recent cases, .243 Win, .308 Win and .270 Win. I am making sure the entire case is making it in and out of the sizer die. Sometimes it seems that it is really hard to close down the bolt handle on these reloads. Other times, not so much. I am wondering if it is changes in temp, etc. like shooting on a hot day, the brass swells. I'm sure it also has to affect accuracy when you really have to cinch down to close the bolt.
Can anyone explain this?
 
It can be caused by several things. The shoulder may not be set back far enough for the headspacing of the chamber. The base not be sized sufficiently. If crimping, it could be excessive and slightly bulging the shoulder of the case, or causing a bulge at the crimp itself. You could also be seating the bullet too far out.

There are others, but those are the most common ones.

I've never seen brass swell in the heat, and I've shot in some pretty hot places.

Hope this helps.

Fred
 
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In addition to what Fred said, check the length of your cases before you load them, they could be over the correct length and need trimming. I had that happen once with some 7-30 Waters cases in a Contender, they had grown to the point closing the action was difficult.

Danny
 
" I am making sure the entire case is making it in and out of the sizer die."

Probably not. Turn your sizers down another 1/16 turn (about 4.5 thou.).
 
If your sizing die is set properly, then I'd look at case length.

Cases grow by several thou each time they are fired -not at the exact same rate though-due to brass migration. Eventually, the necks will touch the throat, a dangerous condition as a too-long neck impedes the bullet's exit from the case. So you get pressure spikes.

edit: like GP100man suggests, remember to clean the inside of the neck with a barely lubed brush before sizing the case. This will reduce the neck sizer ball's friction, which will reduce the amount by which resizing stretches the case. You see, resizing compresses a case's diameter to SAAMI specs, but it also streches the case, esp. the neck.
 
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Get out your calipers and make sure all your cases are to SAAMI length specs. If you don't have a trimmer you can use a chamfer/deburring tool until you get one.
 
Nine out of ten times, it's due to the shoulder not being back enough. Unless you have a way to measure this (there are tools that do this), you are whistling in the dark. Rarely is it due to the case OAL being too long.

Don
 
I have had problems that I traced to distorting the neck or shoulder when seating the bullet.

(That's what I get for seeing how many reloads I can get from a case before scrapping it.)
 
I sound like a Repeater...Repeat...Repeat....

The simple tool called a Magic Marker or even a candle to smut the case(messy)... is one of the easiest ways to set your die so that they fit your guns.

Mark the case, chamber it and see what is shiney brass colored. Did the round chamber easy, if not turn the die down another 1/16 turn. Keep doing the process until the round chambers easy and there is very little marking of the shoulder. Takes me longer to type it out than to does the process.

Jimmy K
 
Thomis,

" I am making sure the entire case is making it in and out of the sizer die "

How do you do that? It is possible the press whips the case, then there are presses that allow the case to win, How do you determine if the case is winning, or if the press is winning.

F. Guffey
 
If you're sure you have your dies set correctly then you need to measure and trim your brass.
 
Allright, this is all good info. I have the sizer die turned down far enough that if I look at the bottom of the case when it is all the way in the die, I can see the bottom of the die touch the shellholder. This seems to me that the case is inside the sizer die as far as it goes. I do have an old Redding case trimmer but I think the blade or cutting edge is messed up. I couldn't get it to trim the case correctly. It trimmed it at an angle and made the mouth of the case sharp as a razor blade.
 
I can see the bottom of the die touch the shellholder.
Click to expand...
Seeing it doesn't get it done.
1. Run the ram up.
2. Screw the die down until it contacts the shell holder.
3. Lower the ram.
4. Screw the die down another 1/8 turn, maybe more, depending on your press.
5. Try cycling the ram again.
6. You need to feel a definate bump or toggle-over when the ram reaches full extension.

This takes all the slack out of the press linkage, and all the flex out of the press frame.

Only when you feel the press bump-over at the top of the stroke are you really full-length sizing bottle-neck rifle cases.

rc
 
Assuming that your sizing die is of correct dimension (Which they sometimes are not.) the process outlined by RCModel above should work. After sizing but before loading the cases load them in your rifle and check closing bolt. If closure is still tight repeat the sizing operation with expander stem/plug removed. If bolt then closes easily it means you have been lengthening case when pulling expander plug thru neck, which is not uncommon. Better lubing inside of necks is a common cure, but better way is eliminating expander plug altogether by using dies with neck sizing bushings.
 
I had the same problem with my Ruger 243. What I found was my primers were not seated enough. I marked the entire shell with a black marker then chambered it and found score marks on the primer face. I use a RCBS hand priming tool but now I make sure they are completely seated. It doesn't take much sticking out to cause the bolt not to close easily.
 
The common thread

:)Good Morning: I could not help but notice all the cartridges you mension USE THE SAME SHELL HOLDER. Humm, perhaps it is not allowing the cases to be sized up far enough in their respective dies. Take some magic marker and cover the head/primer and lower part of the cace empty but sized incluiding the nick and neck edge. this will tell you where your interference is at. The answer it always there if you look close. Be safe
 
Make sure they're trimmed correctly. I almost had this ruin a hunt last season. I'm new to reloading and opening day last season I go out, load my gun and the bolt won't close. I try it with every cartridge I've got and can't get it to close.
I look behind the seat of the truck and find a box of factory ammo. I took a six point with a 16.5" spread that morning. I was lucky.
I got home and every case was too long. That won't happen again.
 
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