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Harder bolt close after sizing

Chiquita

Chiquita

Proud Armenian
Gold $$ Contributor
HOWA 1500 .308
Starline brass fired 6 times
I leave the case in the die for 3 sec. then do a 180 turn and do another 3 sec.

Fired case the bolt closes fine, When I full length size with a 1.5 - 2.5 bump back the bolt is harder to close.

Pre sizing:
Base to datum = 1.5725 to 1.5735
Case length = 1.9945

Post sizing:
Base to datum = 1.5710
Case length = 1.9970

Chamber depth checked with sinclair tool. 2.0420" So it does not seem to be a case length issue.

It is my 6th firing and EVERY TIME something is different and I can not get a consistent case prep. Something changes every single time and it is frustrating.
 
This may help - see post #4

fireform .200 line ?

1st what exactly is the .200 line? I know it's the distance from the head but? 2nd how many firings on new brass does it take to max this measurement? I have never seen this explained in detail. ty Don
forum.accurateshooter.com
 
What are the other "changes" you have noted ? Difficulty with bolt close(after sizing) is often base of case(.200 line) not sized enough, inadequate headspace, case length is to long. Sometimes reloaders will seat bullets with crimping( too much or shouldn't be crimped at all) because seating die not set correctly and it will bulge the shoulder/body junction. Case must be flush with bolt face for headspace and case length measurements. Why are you moving the shoulder, if the fired case chambers properly. Neck size, load and shoot.
 
Just looking at your measurements, something is not right- according to it, your necks are growing after full length sizing. Are those cases annealed before you resize? Cases will typically grow in length when full length sizing as the die presses the body back in, but also typically only until it touches the shoulder area in the die. I would start out measuring again from post firing - measure the case diameters at the web and somewhere below the shoulder as well- and the restart your FL die adjustment in small increments- you are either not sizing enough yet, or too much?
 
Id try trimming one case that has been sized and has hard bolt close. That should tell you if it the length or the shoulder. Even if your brass isn't hitting the end of the chambers, you could have a carbon ring starting.
 
Coyotefurharvester said:
What are the other "changes" you have noted ? Difficulty with bolt close(after sizing) is often base of case(.200 line) not sized enough, inadequate headspace, case length is to long. Sometimes reloaders will seat bullets with crimping( too much or shouldn't be crimped at all) because seating die not set correctly and it will bulge the shoulder/body junction. Case must be flush with bolt face for headspace and case length measurements. Why are you moving the shoulder, if the fired case chambers properly. Neck size, load and shoot.
Click to expand...
I have not noted other changes, The pills are not seated yet in these cases. I just don't understand when I size the case smaller, why is the bolt closing harder?
 
piie said:
Just looking at your measurements, something is not right- according to it, your necks are growing after full length sizing. Are those cases annealed before you resize? Cases will typically grow in length when full length sizing as the die presses the body back in, but also typically only until it touches the shoulder area in the die. I would start out measuring again from post firing - measure the case diameters at the web and somewhere below the shoulder as well- and the restart your FL die adjustment in small increments- you are either not sizing enough yet, or too much?
Click to expand...

I anneal after every firing and have noticed the case length grows after sizing, but I don't think I had this issue before with the harder bolt close.

I will check measurements on the suggested areas and see where it leads me.

Maybe I don't understand your term "sizing too much"? The cases were sized by a regular REDDING die, with .004 shell holder and with about .002 bump back.
 
FeMan said:
Id try trimming one case that has been sized and has hard bolt close. That should tell you if it the length or the shoulder. Even if your brass isn't hitting the end of the chambers, you could have a carbon ring starting.
Click to expand...
I trimmed the cases to 1.9965" and still hard bolt close.

I will search for carbon ring and see what it is.

ETA: if the issue is carbon ring, why would I have hard bolt close after sizing?
 
Last edited:
If you're shooting warm/hot loads I'm guessing the issue is in the base of the brass. FL dies do not size the entire brass even if you're touching the shell plate. Check for a bulge about 1/4" above the base of your brass. If you find one, buy a body sizer die
 
I would do a few things. Measure the diameter of the .200 line on another piece of brass that closes just fine and compare it to a piece that has just been fired, and then to a piece that has just been resized. Do you see a difference in that dimension?

Do you have access to a Teslong borescope? You can insert it from the chamber side to see if you have a carbon ring that has gradually built up, or anything else impeding the chamber. You can insert it from the crown end with a closed bolt (to include an empty case, not a live round) to see if your necks are too long.
 
gunsandgunsmithing said:
Use a black marker to paint a tight case. Chamber it 3 or 4 times and inspect. The ink should rub off and show where it's tight.
Click to expand...
MrBarrel said:
I will try this and see.

Thank you all for your replies and help.
Click to expand...
Pay particular attention to the neck and shoulder junction and the shoulder to body.

About the only way to increase diameter of the case while sizing would be to crush the shoulder, possibly from too soft after annealing. This would show up at the body to shoulder area.

If the sizing ball is pulling the neck forward on the way out, it would mark at the base of the neck. Sizing a problem case without the expander would prove this as the problem, if it fits after sizing.

The key is a fired case fits before you anneal and size.

What happens to a fired case that you do not anneal before you resize?.
 
jelenko said:
What were the changes/issues in the previous resizings? You mentioned that something is changing with each resizing. Maybe there's some clues there.
Click to expand...
I really can't put my finger on it. But for example, if I used .006 competition shell holder last time, this time the same shell holder does not bump it back enough. I don't.. it just seems I can not get consistent.
 
r bose said:
If you're shooting warm/hot loads I'm guessing the issue is in the base of the brass. FL dies do not size the entire brass even if you're touching the shell plate. Check for a bulge about 1/4" above the base of your brass. If you find one, buy a body sizer die
Click to expand...
I am sure the SBD may help, but, why does a full sized case have harder time. It is smaller than a unsized case so that is what I don't understand.
 
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