Tight to chamber reloads

WSSX

Well-Known Member
I did post some of this in my other thread but it has been a bit buried but other discussions, so I thought I'd start a new one.

As the other thread shows, I used a Lee Loader to produce a range of .243 loads for testing from Ramshot Hunter and 100gr Sierra Pro Hunters. On the whole, everything went quite well for a first attempt.

One thing I forgot to mention in the original post, however, was that I found a few of the reloads slightly stiff when chambering / closing the bolt. I'm almost certain these were in Federal brass. I decided not to fire them because of that but like all the rest they were once-fired and fire-formed in that gun, and then only neck sized in the Lee Loader.

Any thoughts on what might be wrong here, if indeed anything is? Everything was loaded to the same OAL (checked with calipers) and I couldn't see any marks on the bullets suggesting I was jamming them into the lands. I did notice the Federal brass was tighter (neck tension?) when loading the bullets compared to PPU.

It'll be a few weeks before I get to play again so any thoughts welcome in the meantime!
 

Ttocs

Well-Known Member
A. Head space, use a comparator to check the base to shoulder length (measure the headspace for your rifle) ; you may simply need to bump the shoulder back for easier chambering of the round.
B. Case length, check the case length; you don’t want your cases longer than max as the case, if it’s beyond the chamber, can be compressed onto the bullet causing a dangrous pressure increase when fired.
Ttocs
 

jcampbellsmith

Well-Known Member

WSSX

Well-Known Member
Interesting, thanks both. I did run them through a cutter with a case length guage. Will check when I have a moment.

Showing my naivety, but from what I was reading I got the impression that fire-forming and neck sizing would mean a perfect fit to the chamber. Presumably you could check the fit once sized (and before actually reloading...) by chambering them?

Is there any reason this wouldn't be consistent across the cases? Two different brands of brass and different original (factory) loadings the only variables I can think of, although it was only a handful of random cases - I think all from a box of what was 100gr Federal soft points.
 

jcampbellsmith

Well-Known Member
......is there any reason this wouldn't be consistent across the cases? Two different brands of brass and different original (factory) loadings the only variables I can think of, although it was only a handful of random cases - I think all from a box of what was 100gr Federal soft points.
WSSX
No two cases are the same. They vary in size and weight, and the more you do to them, the more they vary. Pick a dimension of your cases and measure them all. You will find a variation in your measurements. Full length resizing addresses the variability by reducing the case dimensions so that all your cases will chamber. You wouldn't want to have a failure of a round to chamber when you are trying to take a follow up shot on a departing wounded deer would you?
Secondly, neck sizing fails rule one of reloading - always perform the same process on your brass every time.
Regards
JCS
 

Border

Well-Known Member
Also check that your primers are fully seated. Use a mirror or other flat surface. Even a hint proud can give difficulty chambering a round.
 

Dalua

Well-Known Member
Regards
JCS
This chap seems to equate neck-sizing with problems chambering the round.
However, if done in the way I'd consider 'proper' - i.e. to test-chamber the empties before reloading, and FL-resize to bump the shoulder back is any are getting tight, then I don't see a problem?
 

MAH

Well-Known Member
I found a few of the reloads slightly stiff when chambering / closing the bolt.
Hi WSSX, I agree, FLS is the most reliable. Especially if your hunting. But some people swear by NS to preserve case life..

However, to help diagnose your problem you could;
  • Cover the tight case with felt tip pen, then chamber* it.
  • Check where the ink is removed, to identify the tight spot.
At least you'll know where the problem is and adjusting your set up might solve it.

If ink is removed from the shoulder, then one cause might be, if you are seating the bullets too quickly, and the dies don't support the case wall, then you can compress the case a wee bit, which will cause it to bulge at the shoulder. It's only a fraction, but it's enough.
Loading flat base bullets would increase the chance of this.
Given the variability in that some rounds are tight and some not, it make me think this could be the cause. (i.e. you load some quicker than others).
As you say, if you test chamber a batch of NS empty cases, assuming they all fit, then load them in your normal way and chamber* the batch.
If you then have tight ones, you'll know its the seating process, not sizing process.

*Be sure your in a safe spot when chambering live rounds!!

Out of interest, pls let me know where the ink is removed from.


M.
 

WSSX

Well-Known Member
Thanks everyone, this is very helpful indeed. Lots of learning...

@MAH - I'll do as instructed when I have a moment, that sounds like a very interesting idea. The theory sounds good as I noticed it was harder to seat the bullets in the Federal brass so probably used more force. They slipped into the PPU stuff much more easily and I think these didn't suffer the same chambering issues. I'll let you know what I find...
 

deeangeo

Well-Known Member
Your slightly stiff bolt closure says to me you die hasn’t quite pushed the shoulder back far enough if you F/L sized the cases. Just resize and test an empty resized case in your rifle having turned the die sligtly deeper in the press an eighth/quarter turn should be easily enough. A bit at a time until they chamber and lock down smoothly.
Best not to mix brass manufacturers for your loads....stick with one make.
Different neck tension of bullet/neck grip will give erratic results.

Trimming cass to length is not headspacing the cases.
Fired case headspace dimensions are good to know, but adjusting the die ‘til cases are ‘right’ works too.
 

gonzo

Well-Known Member
I have also suffered from a neck bulge when crimping the bullets.
It can be just down to badly set dies. Or if there is variability in the case length (not trimmed, or a mix of trimmed and non trimmed), so resulting in different crimp pressures.
In my case (pun!) it usually the cases are mixed length and make. But for fun plinking rounds, I don't take tas much care as I would for target/deer rounds.

Using a factory crimp (collete crimp) doesn't suffer in quite the same way.
 

MAH

Well-Known Member
Thanks everyone, this is very helpful indeed. Lots of learning...

@MAH - I'll do as instructed when I have a moment, that sounds like a very interesting idea. The theory sounds good as I noticed it was harder to seat the bullets in the Federal brass so probably used more force. They slipped into the PPU stuff much more easily and I think these didn't suffer the same chambering issues. I'll let you know what I find...
Ok I look forward to your feedback.
FYI different manufactures of case will have diferent tolerance on the thickness of the brass case wall. So the PPU, seams to be thinner!

So You are right this will vary the "neck tension" and thicker cases also mean less internal volume.
In the extreme NT it leads to problems like you describe.

On another related reloading theme, variations in case volume and neck tension will not help you get good groups.
Most people only reload one manufacture of case, some target shooters go further and use cases from the same batch.

Some will say that such detail is just for the bench rest guys, and it is academic for stalking, as there are other issues that have a bigger impact on accurate shot placement.
My thoughts are every little helps and if your going toreload, why not get the best out of it.

If you don't already have one, buy one of the reloading manuals. Speer, Hornady, Berger. They all have some good technical stuff on reloading.


M.
 

WSSX

Well-Known Member
Thanks again for all of this.

Appreciate that consistency is key - the mix of cases was poor planning on my part. Each batch of a specific grain weight used the same cases but can see how that still doesn't help comparison. It was the PPU and the larger load that delivered the best group so perhaps I'll focus on those components (I actually have more of that brass anyhow!).

Just a note in response to some of the other comments: this was all done on a Lee Loader rather than a press. I was hoping I could make this work for me as I really don't have the space for anything else right now. To be fair, if I can replicate the accuracy of the last load I tested (approx 10mm group) that would be plenty enough for me - haven't come remotely close to that with factory stuff.
 

CarlW

Well-Known Member
It was the PPU and the larger load that delivered the best group so perhaps I'll focus on those components
You know that isn't good science, right? And to do what you suggest is to ignore the very advice (from @MAH, @deeangeo, et al) you have just proposed to follow?

You have no way of knowing that the PPU cases played any role in delivering those good groups. As far as you know, the cases may have had no effect on group-size, or even had the effect of undermining an 'amazing group' to make it 'the best group'.

Without single-variable testing, your data is unreliable and potentially misleading. To be blunt, I would start again with an open mind.

Kind regards,

Carl
 

Laurie

Well-Known Member
In a quite steeply tapered case with a shallow shoulder angle as with 243 Win, the shoulder tends to move forward away from the case-head under internal pressures on firing. Unlike much other brass expansion involved in obturation in the chamber, case contraction after the internal pressure drops either doesn't take place, or if it does only partially.

Whether this is an issue of not depends almost entirely on loads / pressures in such a case shape. Light loads see virtually no shoulder movement and brass can be neck-sized and refired virtually indefinitely. If the load is very light, it won't even fireform the case properly so far as shoulder position goes. (In the days when people used home-cast bullets and very light pistol powder loads, handloading pundits like Ackley and George C Nonte Jnr warned about excessive headspace in fact from such ammunition and advised segregating their cases from those used in full-pressure loads. The excessive headspace was generated from powerful military spec firing mechanisms as in Mausers whose firing pin strike pushed the case forwards hard enough to move the shoulder back. This is a cumulative process and the excess headspace induced isn't an issue with powder-puff loads except it'll see fired primers stand increasingly proud of the case-head.)

So, with light or even mildish working loads, neck-sized brass can be used and so resized almost indefinitely. I couldn't put a figure on this, but if a typical cartridge has a 60,000 psi SAAMI MAP and factory loads produce typical 57-58,000 psi levels, they probably need to be dropped by at least 5,000 psi or maybe even more to somewhere around 50,000 psi. I neck-sized old military cartridges for maybe 20 years with Lee Loaders and later on the Lee Collet Die without ever needing to FL size at their 40-45,000 psi pressures. Having returned to some use of LCDs but now allied to a body die, I quickly found tight chambering caused by shoulder position in the 243's sister design 260 Rem as an example if the Collet alone was used.

Put anything close to a maximum working pressure load in though and it's a different matter. Body sizing, or at the least shoulder bumping using a die such as the Forster Bushing-Bump NS + shoulder reset type soon becomes essential.

So, there are two options here: either reduce loads or start FL sizing on at least an intermittent basis such as say every second or third loading.

Different makes of brass can be affected differently, because 1) their capacities may vary and therefore the same load combination produces various pressures. Federal has long had a reputation for heavy / thick-wall cases with lower internal capacities which increases pressures and this may have pushed shoulders forward more than Winchester or R-P examples say. Also, the brass alloys and behaviours vary between makes depending on how ductile the alloy is and also as a result of different annealing practices / amounts on the case-shoulder area.
 

WSSX

Well-Known Member
You know that isn't good science, right? And to do what you suggest is to ignore the very advice (from @MAH, @deeangeo, et al) you have just proposed to follow?

You have no way of knowing that the PPU cases played any role in delivering those good groups. As far as you know, the cases may have had no effect on group-size, or even had the effect of undermining an 'amazing group' to make it 'the best group'.

Without single-variable testing, your data is unreliable and potentially misleading. To be blunt, I would start again with an open mind.

Kind regards,

Carl
I take your point, Carl, I did not express myself clearly - what I meant was I would remove one variable by using a single brand of case and re-run the experiment, as you're suggesting. The reason I'm singling out PPU isn't accuracy but because I have more of them and they didn't suffer the same chambering issue.

Hopefully that makes more sense.
 

CarlW

Well-Known Member
I take your point, Carl, I did not express myself clearly - what I meant was I would remove one variable by using a single brand of case and re-run the experiment, as you're suggesting. The reason I'm singling out PPU isn't accuracy but because I have more of them and they didn't suffer the same chambering issue.

Hopefully that makes more sense.
Perfect!!!!
 

bluesako

Well-Known Member
watch erik cortina as jc cambell said this guy knows is stuff imho i think its down to your neck sizing ive had mates ask me about the same thing and i first ask them are the cases neck sized? bs
 

hendrix's rifle

Well-Known Member
In a quite steeply tapered case with a shallow shoulder angle as with 243 Win, the shoulder tends to move forward away from the case-head under internal pressures on firing. Unlike much other brass expansion involved in obturation in the chamber, case contraction after the internal pressure drops either doesn't take place, or if it does only partially.

Whether this is an issue of not depends almost entirely on loads / pressures in such a case shape. Light loads see virtually no shoulder movement and brass can be neck-sized and refired virtually indefinitely. If the load is very light, it won't even fireform the case properly so far as shoulder position goes. (In the days when people used home-cast bullets and very light pistol powder loads, handloading pundits like Ackley and George C Nonte Jnr warned about excessive headspace in fact from such ammunition and advised segregating their cases from those used in full-pressure loads. The excessive headspace was generated from powerful military spec firing mechanisms as in Mausers whose firing pin strike pushed the case forwards hard enough to move the shoulder back. This is a cumulative process and the excess headspace induced isn't an issue with powder-puff loads except it'll see fired primers stand increasingly proud of the case-head.)

So, with light or even mildish working loads, neck-sized brass can be used and so resized almost indefinitely. I couldn't put a figure on this, but if a typical cartridge has a 60,000 psi SAAMI MAP and factory loads produce typical 57-58,000 psi levels, they probably need to be dropped by at least 5,000 psi or maybe even more to somewhere around 50,000 psi. I neck-sized old military cartridges for maybe 20 years with Lee Loaders and later on the Lee Collet Die without ever needing to FL size at their 40-45,000 psi pressures. Having returned to some use of LCDs but now allied to a body die, I quickly found tight chambering caused by shoulder position in the 243's sister design 260 Rem as an example if the Collet alone was used.

Put anything close to a maximum working pressure load in though and it's a different matter. Body sizing, or at the least shoulder bumping using a die such as the Forster Bushing-Bump NS + shoulder reset type soon becomes essential.

So, there are two options here: either reduce loads or start FL sizing on at least an intermittent basis such as say every second or third loading.

Different makes of brass can be affected differently, because 1) their capacities may vary and therefore the same load combination produces various pressures. Federal has long had a reputation for heavy / thick-wall cases with lower internal capacities which increases pressures and this may have pushed shoulders forward more than Winchester or R-P examples say. Also, the brass alloys and behaviours vary between makes depending on how ductile the alloy is and also as a result of different annealing practices / amounts on the case-shoulder area.
How do you know all of this? Seriously? Your like a reloaders dictionary lol
 

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