shakey jake
Well-Known Member
I Dont think the round on the left has had the shoulder pushed back far enough, using a line on my phone the necks start at different heights
Bolt not closing
- Thread starter Gorgon
- Start date
I think your just loading on the edge of all tolerances. Push the shoulder back, use a case length gauge, or chamber a round and see if it fits, put sellotape on the head of the case and try it. It shouldn't chamber.
Next take a sized case and cut a slit in the neck. Insert a bullet and chamber it. That'll be you max cartridge length take 20 thou off that overall length and you should be good to go.
Next take a sized case and cut a slit in the neck. Insert a bullet and chamber it. That'll be you max cartridge length take 20 thou off that overall length and you should be good to go.
I also suspect headspace - shoulder to base of cartridge. You’ll need a comparator to measure. It only needs to be a few thousandths too long and the bolt definitely won’t close. It could be the die setup to not push the shoulder back far enough or a slightly short throw on the lever. It has also been known for an expander ball to pull the neck and shoulder forward if not lubricated quite right.
How did you size the cases? Start with that first. If you full length resized them, how did you set up the die?
If you neck sized them, then you might well have fired cases that are have blown out to full chamber size and not sprung back much, potentially causing the issue.
I mean if you get properly manly with the bolt, they will likey go in ha ha ha.
Assume your primers are seated below the head and are not sat proud? They should be 3-5 thou below the head of the case.
If you are neck sizing, it is worth chambering your fired cases (not primed or charged etc) to see if they all go in fine. The .243 does suffer from fully blown out cases more than some other cartridges in my experience. When you find a case that will not chamber with ease, keep it back and use a comparator to record the measurement from a reference point on the shoulder. Then set your FL die up to push the shoulder back 2 thou of an inch from that measurement. Lock your die ring and never move it again.
If you neck sized them, then you might well have fired cases that are have blown out to full chamber size and not sprung back much, potentially causing the issue.
I mean if you get properly manly with the bolt, they will likey go in ha ha ha.
Assume your primers are seated below the head and are not sat proud? They should be 3-5 thou below the head of the case.
If you are neck sizing, it is worth chambering your fired cases (not primed or charged etc) to see if they all go in fine. The .243 does suffer from fully blown out cases more than some other cartridges in my experience. When you find a case that will not chamber with ease, keep it back and use a comparator to record the measurement from a reference point on the shoulder. Then set your FL die up to push the shoulder back 2 thou of an inch from that measurement. Lock your die ring and never move it again.
That's what I thought, but I refrained from commenting because apparently that's one of the rounds that fit!Looks a bit like the right one has a bit of a neck donut
I've read all the replies and I'm try to do the things that I can do at home. It turns out I do have a way to measure to the shoulder in the form of comparator set I bought and one insert happens to fit. The ones that fit measure 1.771". The other five measure 1.778"-1.779". Book says 1.804". I've recrimped the ones that don't fit so I'll try and cycle them again. Reload they said! It'll be fun they said!
It's not criming.
It is either: Poorly sized brass. Primers sticking out proud. OAL too long meaning bullets are engaging the lands and preventing bolt closure. You would see rifling engraving on the bullet probably if that were the case.
My money is on some kind of a sizing issue. Ignore what the book says. A comparator does not measure, it compares. It has no idea how big your chamber is. What is important is that some measurements you have taken show a significant difference in bump sizing. 8 thou is a lot, so it is likely a headspace issue from poorly sized brass. Or if you are neck sizing, some brass that has been fire formed and not sprung back fully which is now struggling to chamber. If you slam it shut, the bolt will probably close. DO NOT do this at home with loaded ammunition
It is either: Poorly sized brass. Primers sticking out proud. OAL too long meaning bullets are engaging the lands and preventing bolt closure. You would see rifling engraving on the bullet probably if that were the case.
My money is on some kind of a sizing issue. Ignore what the book says. A comparator does not measure, it compares. It has no idea how big your chamber is. What is important is that some measurements you have taken show a significant difference in bump sizing. 8 thou is a lot, so it is likely a headspace issue from poorly sized brass. Or if you are neck sizing, some brass that has been fire formed and not sprung back fully which is now struggling to chamber. If you slam it shut, the bolt will probably close. DO NOT do this at home with loaded ammunition
Don't crimp. It's not necessary.
Get yourself something similar, measuring bullets from the tip will give you variation on seating depth, they should be measured from the Ogive, try measuring the bullets from a box and see.
Sorry if this has already been mentioned.
Malxwal
Well-Known Member
Measure your fired cases with your comparator( identify the correct one for your case, .243 I think)
Check your sizing die is setup as per manufacturer instructions.
If you're not getting your fired cases to resize at .002 less than fired dimension, then proceed as follows.
Adjust your sizing die by screwing it further in/down in the press by a 1/16 of a turn, until a fired case is sized to .002" less than it's fired dimension. Keep checking your die is locked in position as you size all your brass.
Check your sizing die is setup as per manufacturer instructions.
If you're not getting your fired cases to resize at .002 less than fired dimension, then proceed as follows.
Adjust your sizing die by screwing it further in/down in the press by a 1/16 of a turn, until a fired case is sized to .002" less than it's fired dimension. Keep checking your die is locked in position as you size all your brass.
Stalker-of-the-deer
Well-Known Member
Bin the crimper off its not needed with decent brass and dies.
Make sure your resizing die cams over at the bottom of the press stroke - comes to a stop just as it hits the shell holder and then the leaver needs a little further push to bottom out completely.
Stop using cartridge overall length if your seating based off the ogive. You should measure exclusively base to ogive to get rid of any inconsistency.
Would recommend your ogive is about 20 thou short of the lands to prevent jamming as a start.
Theres probably an answer in there..
Make sure your resizing die cams over at the bottom of the press stroke - comes to a stop just as it hits the shell holder and then the leaver needs a little further push to bottom out completely.
Stop using cartridge overall length if your seating based off the ogive. You should measure exclusively base to ogive to get rid of any inconsistency.
Would recommend your ogive is about 20 thou short of the lands to prevent jamming as a start.
Theres probably an answer in there..
That's what I was thinking. The transition onto the neck looks to be longer on the cartridge on the left
So, I measured every case I sized today to the shoulder using the comparator. All but four were 1.770". The odd four were 1.775". I chambered them and found I couldn't close the bolt on any, and that's an empty case! I think this is likely the cause of the problem, so whoever said headspace or shoulder issues you were right, for now!
My question now is how did I manage to get forty six cases 1.770" to the shoulder but four 1.775"? The same press and die was used for all of them. I'm going to assume it's human error and I wasn't bringing the lever down far enough on these particular cases?
My question now is how did I manage to get forty six cases 1.770" to the shoulder but four 1.775"? The same press and die was used for all of them. I'm going to assume it's human error and I wasn't bringing the lever down far enough on these particular cases?
Stalker-of-the-deer
Well-Known Member
Measure the web of the case...
If your die isnt set properly it could be getting hung up at the rear
Don't over crimp
The die got loose?
I'll do this tomorrow and report back.
You didn't answer my question before but I will assume you were using a full length die with an expander ball attachment in. If that is not the case, ignore what I am about to write.
When you pull the arm on the press down, the ram goes up and forces the case up in to the die. The already fired case, at this point, has a neck diameter that is larger than the expander ball, so the expander ball slides in without issue. At the top of the stroke (ram at peak height) the case is effectively sized down (depending on how the die is set) body wise and the shoulder set back. The neck is also forced in to the die and effectively sized down. It is sized down less than the desired diameter needed for bullet seating. It is then sized back up again to the desired neck diameter to accept a bullet for seating, by having the expander ball drawn back through it which happens on the up stroke of the handle which forces the ram back down and the expander ball is pulled back out of the case neck, thus sizing it correctly. If you have not lubed the internal bearing surface of the brass neck sufficiently, the expander ball might have experienced significant friction and effectively pulled the shoulder back out a little on the brass.
You could try screwing out the expander ball and just sizing the brass without it in situ to see if you end up with the desired size brass. It would be prudent to compare sized brass without the expander ball, to the brass which you did successfully get to chamber. There might even be a difference there. I don't know but it is worth checking so you can understand the processes and how you interact with your equipment.
For the record, I personally don't use expander balls. I use FL dies without them and then use an expander mandrel to size the necks back up. The difference being that the mandrel is forced down in to the neck in the first instance rather than being forced out from inside the neck, this resulting in less of what i think you might be experiencing. It also works the brass less and seems to realise more consistent neck tension.
That said, you can load perfectly good ammo with a FL die with an expander ball in situ. Just make sure to correctly lube the internal surface of the necks prior to sizing.
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