Help Requested: Random Rounds won't chamber

[DocRDS]

I'm a newer reloader, far from expert and have been 'learning'
Current setup is a Lee single stage + Competition shell holders as I have a bitch of a time get proper shoulder setback (Starline brass because I dont wanna f good brass--I'm still learning). This time I was consistently at 0.0035 Shoulder bump. I tried to be super consistent on the down stroke, (Lee doesn't "cam over")
Everyone once in a while, I still get a round that wont chamber. its roughly 1 outta 15 or so? (50 rounds today--had 3). I was checking brass throughout the process that it chambered in the rifle, and as I'm ocd, the "nearby" rounds were loaded immediately before and after chamber fine and fire off no problem.

I asked around at the match didn't get much insight, so I'll throw it out here as yet my continued struggle reloading.

 

[Kadams1563]

So what are the ones measuring that would not chamber?

I have never had this issue for sure with a .003 bump. I usually only bump .001 - .002 anyway and they chamber fine.

How many times fired? It might not be the shoulder but the case length running into the end of the chamber if they haven’t been trimmed possibly?

 

[37L1]

Are you full length sizing? What caliber?
Measure your case just above the extractor groove. That part is expanding and may not be getting resized through your die. That could cause inability to chamber in cases that have been fired multiple times.

 

[spife7980]

So what are the ones measuring that would not chamber?

Exactly. Measure them.
The answer is in the numbers.
Your sized should be smaller than your fired. If they aren’t that is the source of your interference.

 

[Kadams1563]

You could take a sharpie color where you think it’s catching and see as well.

For instance. The .223AI impacts my buddies shoot the brass will chamber fine in my CDG. On the other hand my CDG fired .223AI will NOT chamber in any of the impact guns I can try. The .200 line on my brass expands too much. They realize down fine to be chambered though.

 

[RegionRat]

In addition to all of the above advice on leaning how to adjust your dies and how to inspect your brass.....

I will throw out another suggestion. Learn to use smaller batches till you work things out. This prevents mass defects, and increases the cycles per case, and in the end speeds up your learning curve. You will know when you are ready for bigger batches.

Learn to use the rifle's chamber as a gage, but be careful to guide the cases in and out to avoid denting the necks. There is no point to priming, charging and seating a case that won't fit the chamber.

Also consider a Min Chamber Case Gage, to keep at the loading bench as you make progress. These are different than shoulder datum gages because they include the whole body. Some examples:
https://sheridanengineering.com/product-category/ammunition-gauges/rifle-caliber-ammunition-gauges/
https://lewilson.com/brass-min-dimension-gage

You should pull the ammo spec and the chamber spec as in the advice above. Using a micrometer for the critical diameters, you will want to study the virgin brass, the fired brass, and the sized brass, and especially the difference between the ones that close and don't close.

If possible, own the Go-Gage for your chamber and learn to reference the shoulder datum length in absolute terms rather than just comparative by referencing your bump gages to the Go-Gage.
Good Luck.

 

[zeroz]

If its cheap brass and you didn't trim Id definitely check OAL of the case as it could be bottoming out on the neck. What are you checking headspace with?

 

[DocRDS]

I started on some measurements (first suspect was trim length). They were normal at 1.90, 1.91

I did the "sharpie" and the case is getting "stuck" about halfway up the cartridge (1/2 way between base and shoulder) in one of my case guages (this is frustrating, I have 3 all measure differently--2 Hornady and 1 Lyman--the Lyman passes everything, I chose the tighest Hornady--"good" rounds go 90% of the way into that one but fit rifle(s) perfectly. The AI I was loading for has a tighter chamber than my Howa, but even the Howa wouldn't feed these. (and this was all AI fire formed brass)

This was once and twice fired 6.5 Creedomoor (same load 41.5 H4350, 140gr ELDM), Full Sized.

@RegionRat I actually did this and did spot checks throughout the run--checked that brass chambered ok in the rifle. Its these oddball "outliers" I'm having trouble with. Why will case B not chamber when A and C, right before and after chamber to smooth butter. Like I sad, 14/15 work great. I hear you which is why i was checking both with the rifle and the case guages. If you would do me a favor? Which dimensions generally are the ciritical ones--I've been doing Headspace (Hornady Comparator), OAL (Soon to be CBTO), Neck Diameter. I know headspace is "relative" and was getting good readings virgin vs fired vs sized brass.

And I do appreciate the assistance all of you have provided.

 

[memilanuk]

This was once and twice fired 6.5 Creedomoor (same load 41.5 H4350, 140gr ELDM), Full Sized.

Bolt gun?

 

[RegionRat]

Which dimensions generally are the ciritical ones--I've been doing Headspace (Hornady Comparator), OAL (Soon to be CBTO), Neck Diameter. I know headspace is "relative" and was getting good readings virgin vs fired vs sized brass.

Similar to the ones @spife7980 is showing.

With the 6.5CM, the ammo specs and chamber specs are online.

Left to right for diameters
Rim 0.473"
The 200 line 0.4703"
Body to shoulder facet 0.4620"
Neck 0.2950"

The lengths
Body to shoulder 1.4901"
Shoulder to neck 1.6347"
Case OAL 1.920"

You can get away with using the edges of your 6" calipers on those body facet lengths, assuming your shoulder datum gage says you are good.
You will need a decent micrometer for the diameters.

When a case doesn't fit, but you have one sized the same way that does, study the difference closely. Pull it down and run it through the size die again and see if it reduces to where it fits without drama. If it still doesn't, you may need to escalate to trying a different die.

 

[straightshooter1]

I'm a newer reloader, far from expert and have been 'learning'
Current setup is a Lee single stage + Competition shell holders as I have a bitch of a time get proper shoulder setback (Starline brass because I dont wanna f good brass--I'm still learning). This time I was consistently at 0.0035 Shoulder bump. I tried to be super consistent on the down stroke, (Lee doesn't "cam over")
Everyone once in a while, I still get a round that wont chamber. its roughly 1 outta 15 or so? (50 rounds today--had 3). I was checking brass throughout the process that it chambered in the rifle, and as I'm ocd, the "nearby" rounds were loaded immediately before and after chamber fine and fire off no problem.

I asked around at the match didn't get much insight, so I'll throw it out here as yet my continued struggle reloading.

I've got nothing much to add with what's already been suggested. However, keep in mind that brass fired in another gun can have this kind of issue as sizing brass that's fired in another gun with larger chamber can be difficult to get sized properly for your own gun. I only bring this up as I didn't see that it was mentioned whether this was virgin brass or brass fired in another gun.

 

[smoothy8500]

+ Competition shell holders

Redding Competition shellholder? That's reducing your shoulder bump.....as possibly Zero shoulder bump.

 

[MK20]

I had this exact problem years ago. It seemed completely random.

The problem was the lee press. They use sintered or mim parts for the press linkage. These developed a hairline crack on one linkage arm and when a slightly harder piece of brass would be sized it would not quite fully size it. It gave me fits until I figured it out and switched to a RCBS. All problems magically ceased.

 

[zeroz]

Was the brass fired first in a semi and now it wants to go into a bolt gun? If it is and its getting stuck halfway down you may need a small base die to get it to chamber the first time. I got some once fired brass from a buddy (friends shouldn't let friends shoot CM, but I digress) that I got to load for my nephew whose shithead dad got him a CM. They wouldn't chamber after sizing in his axis junker, which Im sure didn't have a tight chamber. I got a small base die and all was good.

 

[BuildingConceptsllc]

Hey OP, how are you doing the lube and what kind of lube are you using? The amount of lube can effect the sizing a little bit. Just throwing it out there.

 

[kthomas]

Hey OP, how are you doing the lube and what kind of lube are you using? The amount of lube can effect the sizing a little bit. Just throwing it out there.

This is a good point.

Try to be as consistent as possible with lube application for each case, and wipe off any lube when taking measurements post sizing.

 

[DocRDS]

Redding Competition shellholder? That's reducing your shoulder bump.....as possibly Zero shoulder bump.

I realize that. I've had problems adjusting the die in the past to get that 0.002 bump. This allows me to screw the die in and get a consistent measurement (or at least I thought it did)

I had this exact problem years ago. It seemed completely random.

The problem was the lee press. They use sintered or mim parts for the press linkage. These developed a hairline crack on one linkage arm and when a slightly harder piece of brass would be sized it would not quite fully size it. It gave me fits until I figured it out and switched to a RCBS. All problems magically ceased.

SOB, this could be an issue--was thinking about going to a Dillon anyway given my shooting volume.

Hey OP, how are you doing the lube and what kind of lube are you using? The amount of lube can effect the sizing a little bit. Just throwing it out there.

And now this combined with the previous--I used RCBS case slick for part of the batch and it gave me fits to the point of a stuck case. The rest I used One-Shot in a bag, extra spray--and those turned outmuch nicer (feel of press was much smooter). Some of the RCBS lube had drag marks on them including the "problem" children.

Monday is a reloading night (I'm spent today after the match, Church, Grocery Shopping) so I'll do more detailed measurements as suggested.

ALso all of these were fired in a single bolt gun, 6.5 Creed AI AT-X

 

[MK20]

Given that it's a lee press and I have had the exact problem you describe with 2 Lee presses for the same reason, I would advocate switching out the press first of all.

 

[Kadams1563]

Go team blue!

I am currently in the process of moving all my precision loads from a CO-AX to my 650. I can’t seem to reload or shoot one hole groups anyway lol.

 

[Captain8pt]

If you are crimping your bullets case length could vary and slightly crush the case

 

[BuildingConceptsllc]

I realize that. I've had problems adjusting the die in the past to get that 0.002 bump. This allows me to screw the die in and get a consistent measurement (or at least I thought it did)


SOB, this could be an issue--was thinking about going to a Dillon anyway given my shooting volume.

And now this combined with the previous--I used RCBS case slick for part of the batch and it gave me fits to the point of a stuck case. The rest I used One-Shot in a bag, extra spray--and those turned outmuch nicer (feel of press was much smooter). Some of the RCBS lube had drag marks on them including the "problem" children.

Monday is a reloading night (I'm spent today after the match, Church, Grocery Shopping) so I'll do more detailed measurements as suggested.

ALso all of these were fired in a single bolt gun, 6.5 Creed AI AT-X

I've got a MEC for sale right now. It's a really solid press and has the stand and light. Hard to beat. Just fyi.

Get rid of the Lee and make sure you lube in a consistent way with just the right amount and I bet your issue goes away

 

[DocRDS]

Did a ton of measurements and can't find one out of spec. Markered a round and forced it into a case gauge to get rubbing

Rubbing i s happening at the case/shoulder junction--bright shiny ring wear all the marker is warn off:

Diameter measures the same as a good round (0.4630), I dunno if there is a lip or that point is too far forward (that measurement is tough to get accuracte) This was measured just before the junction.

EDIT: There is indeed a "rim" at the shoulder junction that measures larger (in diameter). Right where the arrow is it increases to 0.4340+, Some how that area is getting bulged (again at random--most rounds are fine 1/15 have issues) during reloading.

 

[Kadams1563]

very odd. Have a borescope to check the chamber to see if anything looks odd?

I cannot think of anything else that would cause that location of the brass to expand but again it’s only on some of them.

Maybe the brass was out of wack when new?

Unless it’s happening in the sizing process? Hell must guessing here lol. Try and find someone else’s press to use

 

[TheOfficeT-Rex]

EDIT: There is indeed a "rim" at the shoulder junction that measures larger (in diameter). Right where the arrow is it increases to 0.4340+, Some how that area is getting bulged (again at random--most rounds are fine 1/15 have issues) during reloading.

IME, case lube issue. As in not enough applied, or it just isn't slick enough.

 

[RegionRat]

Agree, we need to scrutinize the brass there before and after sizing and see when the bulge forms.
See if the idea like @TheOfficeT-Rex is saying about lube, or if those samples are otherwise longer from firing and being sized more/different?
(Are these being annealed? How?)
With a 1/15 statistic for this to show up, I would work with small batches of say no more than 20 and 100% babysit that brass while you cycle.

 

[straightshooter1]

Did a ton of measurements and can't find one out of spec. Markered a round and forced it into a case gauge to get rubbing

Rubbing i s happening at the case/shoulder junction--bright shiny ring wear all the marker is warn off:

Diameter measures the same as a good round (0.4630), I dunno if there is a lip or that point is too far forward (that measurement is tough to get accuracte) This was measured just before the junction.

EDIT: There is indeed a "rim" at the shoulder junction that measures larger (in diameter). Right where the arrow is it increases to 0.4340+, Some how that area is getting bulged (again at random--most rounds are fine 1/15 have issues) during reloading.

View attachment 8382433

I've seen this before and it had to do with how the sizing die was set up causing pressure to push down on the neck and shoulder to cause that kind of budge at that junction. It could be something in the die, like the expander ball not being adjusted properly or something catching a little on the case mount pushing down in a way to produce a bulge at that junction. Mostly, I've seen the use of an expanding mandrel and something in the die pushed down to cause that bulge.

 

[Rocketvapor]

Polish mandrel and get it further down in the case.

 

[918v]

Case sizing, a lot of variables involved. Lube- I use imperial sizing wax. No problems sizing. No problems bumping the shoulder consistently. No problem with stuck cases. I tried Hornady wax lube. I got a lot of variance in shoulder bump. This leads me to believe that lubes are not all the same.

Sizing die- Lee dies are rough. That will contribute to sizing variance. Redding dies are smoother but not as smooth as RCBS. The smoother the die the easier it sizes.

Press- I don’t set the press to cam over. I adjust the die to act as a hard stop for the lever. So the lever doesn’t go all the way down, only 70-80%. That way I can feel I have zero clearance between the die and the shell holder. This eliminates all linkage slack.

Try the above and let us know.

ETA that AI factory chambers are bigger in diameter than most and that makes case sizing harder. The harder the sizing the more variance you’ll see.