The Importance of Closing Resistance

[Wm.Traynor]

After reading where it is necessary to reduce the resistance to closing a bolt, I removed the firing pin and plunger ejector from my bolt and started FLS a case. After screwing the die down 31/2 turns from where it just made contact with the shellholder, there is still some resistance. A lot less but a bit. I would have thought that after so many turns that resistance would be nil and that the bolt handle would drop into the down position under its own weight. Instead, it has to have a little help.
The rifle is an RPA with a four lug bolt in a Quadlite action.
Another thing that Worries me is the headspace of the case after all this resizing. I think that it might be so short in the chamber or the firing pin won't hit it hard enough for the rifle to fire.

As usual.................................HELP

[Oldbloke]

This is how I did it a few weeks ago. A good way.
If you don't have the bump attachment you will get away with a pistol case to measure the bump. Each time you adjust the die you can measure the change to the case length. You should aim for about 0.002"to 0.005" thou clearance.

https://youtu.be/htvk1UYOXm8?si=2ygKkf6DznRfkAz0

31/2 turns sounds like waaaay too much.

Try annealing the cases first. This often fixes this type of issue.

It's possible the case holder needs a bit sanded of the top but (last resort) again, 31/2 turns does not sound right.

[No1_49er]

After screwing the die down 31/2 turns from where it just made contact with the shellholder, there is still some resistance. A lot less but a bit. I would have thought that after so many turns that resistance would be nil and that the bolt handle would drop into the down position under its own weight. Instead, it has to have a little help.
As usual.................................HELP

Maybe I'm missing something here, but per the description of your method, why are you screwing the die down another 3 1/2 turns after it has contacted the shell holder? All you need to do is turn it down, perhaps, another quarter to half a turn after contact with the shell holder to ensure that there is consistency with the FLS process.
Screwing it down one turn, 3 turns, even 10 turns, makes absolutely no difference to the established void (for want of a better term) within the dimensions of the FLS die and the upper surface of the holder. It can not change - period.
Maybe the chamber of your rifle is right on the minimum SAAMI dimension for that cartridge. Get yourself (or borrow) another FLS die, maybe of a different make, and try again. You might be suprised. There are SAAMI dimensions, and manufacturing tolerances can make a difference.

[Wm.Traynor]

https://youtu.be/htvk1UYOXm8?si=2ygKkf6DznRfkAz0.

I watched that video OB and at 6m 45s the bolt handle does what I was talking about. That is, it closes almost under its own weight. Why doesn't mine?
And thank you for going to the trouble of posting the video.

[Wm.Traynor]

After screwing the die down 31/2 turns from where it just made contact with the shellholder, there is still some resistance. A lot less but a bit. I would have thought that after so many turns that resistance would be nil and that the bolt handle would drop into the down position under its own weight. Instead, it has to have a little help.
As usual.................................HELP

.
Screwing it down one turn, 3 turns, even 10 turns, makes absolutely no difference to the established void (for want of a better term) within the dimensions of the FLS die and the upper surface of the holder. It can not change - period.

I agree completely. All those turns amount to about A Quarter Inch! All that and I was getting nowhere That was when I quit and got on to you blokes.

[Oldbloke]

Go back to scratch.
Have you trimmed them?
Adj fls die as per instructions.
Anneal case.
Measure case at shoulder. Note length.
Size case.


If it doesn't fit chamber, measure the case at shoulder. Note length.
Screw in die 1/16th of a turn or less.
Size case & measure again. Note length.
Check it fits chamber. Note length.



IIRC 1/16" turn is about 0.005"

https://bulletin.accurateshooter.com/20 ... lder-bump/


https://bulletin.accurateshooter.com/20 ... zing-dies/

[Larry]

It doesnt matter how much you turn it down there is a fixed length between the top of the shell holder and the inside of the die. to really allow the case to be pushed further into the die the shell holder needs to be thinner to allow the case to enter the die further. That is why Redding make a set of competition shell holders they differ in height by 2 thou from each other giving a 10 thou spread.

Does your bolt drop by it self when there is no case in the chamber. It should. When the case is no longer in a interference fit in the chamber the bolt will drop in the same way.

[straightshooter]

After reading where it is necessary to reduce the resistance to closing a bolt, I removed the firing pin and plunger ejector from my bolt and started FLS a case. After screwing the die down 31/2 turns from where it just made contact with the shellholder, there is still some resistance. A lot less but a bit. I would have thought that after so many turns that resistance would be nil and that the bolt handle would drop into the down position under its own weight. Instead, it has to have a little help.
The rifle is an RPA with a four lug bolt in a Quadlite action.
Another thing that Worries me is the headspace of the case after all this resizing. I think that it might be so short in the chamber or the firing pin won't hit it hard enough for the rifle to fire.

As usual.................................HELP

Danger Danger Will Robinson
Even in an action with a very strong lock up like the RPA Quadlte, repeated firings with excess headspace are going to cause cumulative damage ranging from case head separation after only a few firings to locking lug set back.
What is so wrong with the near zero headspace of a correctly fireformed case that is then neck sized in a proper neck sizing die and not in a FLS die?
What is it that you think you are trying to achieve?

[Wm.Traynor]

Oldbloke,
I found this further down the page in your first link
https://forum.accurateshooter.com/threa ... 226/page-2

[Wm.Traynor]

Everybody Else
I am still studying and have not forgotten you

[Wm.Traynor]

Another tip from Oldbloke's first link
https://bulletin.accurateshooter.com/20 ... lder-bump/
Please note the second par where Chuckhunter's advice is at odds with Cortina. For me, in my present situation, Chuckhunter would be the easiest to follow but I have not even made the "Poor man's headspace gauge".
It's early days for me.

[Wm.Traynor]

It doesnt matter how much you turn it down there is a fixed length between the top of the shell holder and the inside of the die. to really allow the case to be pushed further into the die the shell holder needs to be thinner to allow the case to enter the die further. That is why Redding make a set of competition shell holders they differ in height by 2 thou from each other giving a 10 thou spread.

Does your bolt drop by it self when there is no case in the chamber. It should. When the case is no longer in a interference fit in the chamber the bolt will drop in the same way.

Yes to par. 2
par. 1 Thank you Larry but as said elsewhere, I have not started measuring headspace yet so there is a while to go yet

[Wm.Traynor]

After reading where it is necessary to reduce the resistance to closing a bolt, I removed the firing pin and plunger ejector from my bolt and started FLS a case. After screwing the die down 31/2 turns from where it just made contact with the shellholder, there is still some resistance. A lot less but a bit. I would have thought that after so many turns that resistance would be nil and that the bolt handle would drop into the down position under its own weight. Instead, it has to have a little help.
The rifle is an RPA with a four lug bolt in a Quadlite action.
Another thing that Worries me is the headspace of the case after all this resizing. I think that it might be so short in the chamber or the firing pin won't hit it hard enough for the rifle to fire.

As usual.................................HELP

Danger Danger Will Robinson
Even in an action with a very strong lock up like the RPA Quadlte, repeated firings with excess headspace are going to cause cumulative damage ranging from case head separation after only a few firings to locking lug set back.
What is so wrong with the near zero headspace of a correctly fireformed case that is then neck sized in a proper neck sizing die and not in a FLS die?
What is it that you think you are trying to achieve?

I am trying to achieve that very easy resistance to closing the bolt handle as demonstrated by Cortina in the link posted by Oldbloke 10/3/24 at 6:31pm. The reason for that is AFAIK, there is less wear on the locking lugs. Mine have always been lubed BTW.
Would there not be more wear on the lugs, from neck sized cases. I believe there would be, because the shoulder is set back in a FLS die.
However, if I am in error, I am more than willing to hear about it

[Oldbloke]

After reading where it is necessary to reduce the resistance to closing a bolt, I removed the firing pin and plunger ejector from my bolt and started FLS a case. After screwing the die down 31/2 turns from where it just made contact with the shellholder, there is still some resistance. A lot less but a bit. I would have thought that after so many turns that resistance would be nil and that the bolt handle would drop into the down position under its own weight. Instead, it has to have a little help.
The rifle is an RPA with a four lug bolt in a Quadlite action.
Another thing that Worries me is the headspace of the case after all this resizing. I think that it might be so short in the chamber or the firing pin won't hit it hard enough for the rifle to fire.

As usual.................................HELP

Danger Danger Will Robinson
Even in an action with a very strong lock up like the RPA Quadlte, repeated firings with excess headspace are going to cause cumulative damage ranging from case head separation after only a few firings to locking lug set back.
What is so wrong with the near zero headspace of a correctly fireformed case that is then neck sized in a proper neck sizing die and not in a FLS die?
What is it that you think you are trying to achieve?

0.002" - 0.005" certainly isn't excessive head space.

[in2anity]

WM achieving that nice feeling lockup is a really common problem in fullbore, that a lot old timers tend to ignore. Some neck size only, so their handloads are always tight to lockup. Me personally, I was once mixing my service brass with my fullbore brass, and because my service rifle had a more liberal chamber, it was largely causing this phenomina. Even when I was FLSing.

That awful feeling of potentially gauling your lugs therefore needs adressing, in my books. Which raises the question of; how?

Enter stage a couple of critical tools. 1) Small base body die 2) redding custom shell holder set (variable height)

Both of these can acheive a deeper bump.

This conversation also reminds me of a press that has top dead center at the end of a stroke vs one with cam-over. My current press has cam-over. And indeed it took a slightly deeper FLS die to achieve the appropriate shoulder bump (even when using the tallest shell holder). My cam-over is quite profound.

Moving forward one might consider the small base die which is made to reduce over-sized spent cases.

[Oldbloke]

How did it go Wm?

[Oldbloke]

Providing:
The case is not too long. (Trim if required)
The case isn't hard/springy. (Anneal)

Do this:
https://support.leeprecision.net/en/kno ... adjustment


You don't need special dies or equipment.

On rare occasions you may need to sand/grind 2 or 3 thousands of an inch off the case holder.

[Wm.Traynor]

How did it go Wm?

G'day Oldbloke. Sorry to take so long in replying to you and in2anity. Would you believe that the computer would not write?

To answer to question, I have done nothing about making a gizmo for measuring case headspace. As always, something came up. The bolt stop/bolt release was very difficult to operate and I was compelled to start fixing it because withdrawing the bolt with case held by the extractor, was becoming a pain. But of course there was another interruption, namely a scheduled visit to the dentist.
So work on the bolt release resumed this pm before and after my mandated walk. I am not at all satisfied with it but I won't bore you all with it now.
When I resume measuring cases I will get back to everyone.

Thank you for your patience
BTW, tomorrow it's the melanoma doc

[Tiger650]

Somewhere here is a thread titled I think "Outside Neck Turning"
Mostly posts between myself and a very knowledgeable and generous bloke who talked me through eliminating "donuts".
Donut symptoms are as you describe.

[Tiger650]

viewtopic.php?f=3&t=15587

[Larry]

The main point of this method is to actually find the point of adjustment on your die where there is little to no shoulder set back. From that point you can make very minor adjustments so you know exactly how far back you are moving the shoulder of the case.

[in2anity]

Must say, case head seperation is pretty rare though, even with generous bump. Mostly they neck split or ideally the pockets go first. If you are getting to the point where the pockets stretch then you know you're squeezing the most life out. Not much you can do about that, besides load cooler.

[Wm.Traynor]

At 5:30 this morning, I awoke with the usual burning need for the toilet.
BUT WAIT........................I was very light-headed and could scarcely get out of bed Not only that, I was hanging on to walls and furniture to get there in time This sort of thing does not happen to me. Later a couple of blood pressure tests a couple of hours apart, told me 177/86.
So I took it easy although after 9am the dizziness had improved but I did nothing untill after 2pm and that was not shooting related. By that time I was feeling human and I thought of dropping the bolt-stop-fix and getting on with the case measuring. Oh, I forgot! I had been checking the price of the L E Wilson Case Gauge Depth Micrometer promoted on a youtube channel, while recovering this a m. The price of that thing is what got me thinking later this arvo.
Around 4:30 pm, I took a damaged 223 case and tried out my pipe cutter on it. I had guessed the right place to shorten it and it contacts a case about half way down the shoulder. Tomorrow the cut will be tidied with my case trimmer.......................after the chores of course

[Wm.Traynor]

Success!
After more chores I took the case measuring gauge made from a shortened 223 case, out to the workbench. Slipping the open mouth over the case to be measured is quite easy; it measured 0.310". Holding the gauge and case together in one hand and measuring the total length, is no easy matter, however.
I found that holding the two in the jaws of the vernier caliper with a clamping force, was the only way that I could manage things. A reading of the combined length was able to be taken while forcing the jaws together.
After the first reading, the case was run through the body die, wiped clean and another combined measurement taken. This was 0.003" shorter than the original measurement. The Acid Test IMO, was to chamber the resized case, noting the bolt handle "Closing resistance". Success at last There was no resistance, which is what I was aiming for. Thank you Oldbloke in particular for his "Poor Man's Case Gauge", advice and to every one else who contributed, especially Larry who was very interesting.

Now to deal with that pesky bolt stop/bolt release. It's a bitch but I think if I could just get a lighter spring.....................................

[Oldbloke]

Happy to help.

Sooo,,, what did you do differently?

Yes, the Poor Man's Case Gauge is " fiddly" but it works.

PS. Sounds like you need to pay the Dr a visit.

[Wm.Traynor]

Happy to help.

Sooo,,, what did you do differently?

Yes, the Poor Man's Case Gauge is " fiddly" but it works.

PS. Sounds like you need to pay the Dr a visit.

I feel quite OK, Oldbloke and was feeling much better that afternoon.
As for "What did I do differently", weell, it was a whole lot of mistakes put together
1) The cases that I chose to body size were from my rifle's first barrel. In my defence, it is Years since this rifle was fired and that fact had been totally forgotten. People have died, gotten married and been born in those intervening years.
2) The old cases were a different brand compared to what were used in the new barrel. The fact is, they could not be body sized to fit the new barrel. I don't know why; it's just a fact.

Body sizing cases fired in the new barrel was a whiz. They could be shortened a bit too much ( 0.003" difference) so I might wind the die out 1/4 turn.

Hmmm. Come to think of it, the body die does not size the necks. Maybe it was the necks of the old cases that were hanging up. But that is something for another day. In the meantime, the bolt release has my attention.