Sizing Dilemma

Mustbenice1214

Private
Minuteman
Nov 23, 2020
60
10
38
Phoenix
So I FL resized my 6.5prc lapua brass .001-.002" . They chambered in the rifle first 4-5 rounds, so I finished the reloading process. Now they chamber, but are very tight. I have to force the bolt. Shoulder must have been borderline too tight.

So my options are:
1. pull the bullets and deprime, start over
2. shoot em and deal with having to give it some force to chamber
3. pull bullets and FL size, wipe lube off, charge, seat bullet again

Thanks in advance
 
You did 4 and they chambered so you loaded the rest and now they won’t chamber? Did something slowly (or suddenly) change or is the sizing inconsistent throughout the batch? How much smaller is the “bump” on the ones that don’t chamber easily? How many are we talking about? For what use?


I’d do 2. Unless there was some reason not to. Like it was critically important they feed fast and closing the bolt not displace the rifle.

A bigger concern is why it happened in the first place. .002” should be enough if your setup is consistent but for field use, I almost always use something more like .004”. Inconsistency could be in your process, lube related, aging brass, contamination in the die, or myriad other things.
 
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You did 4 and they chambered so you loaded the rest and now they won’t chamber? Did something slowly (or suddenly) change or is the sizing inconsistent throughout the batch? How much smaller is the “bump” on the ones that don’t chamber easily? How many are we talking about? For what use?


I’d do 2. Unless there was some reason not to. Like it was critically important they feed fast and closing the bolt not displace the rifle.

A bigger concern is why it happened in the first place. .002” should be enough if your setup is consistent but for field use, I almost always use something more like .004”. Inconsistency could be in your process, lube related, aging brass, contamination in the die, or myriad other things.
I always test first few rounds to make sure it chambers. Had no issue so proceeded. From what I can tell is even those after loaded were too tight. I can’t find any that will chamber easily after seating bullets. I sized it weeks ago before loading. Not sure if the brass grew. Brass is 4x shot. I anneal every firing. Trim to book. Frustrating. Loaded them up for my hunt so not easily chambering will be cumbersome. Unfortunately may just resize them again.
 
I always test first few rounds to make sure it chambers. Had no issue so proceeded. From what I can tell is even those after loaded were too tight. I can’t find any that will chamber easily after seating bullets. I sized it weeks ago before loading. Not sure if the brass grew. Brass is 4x shot. I anneal every firing. Trim to book. Frustrating. Loaded them up for my hunt so not easily chambering will be cumbersome. Unfortunately may just resize them again.
Are you sure it’s a sizing problem and not a bullet in the lands problem or a tight neck issue? Something doesn’t sound right.
 
I would suggest coating one or more of the offending rounds - both the case and the bullet - with a sharpie, let it dry, then chamber the round. The tight spots should be fairly obvious at that point, and will make troubleshooting a lot easier.

FWIW, I've had some rounds 'grow' in OAL over time when running a compressed load. Unless you have super high neck tension (or crimp) the powder column absolutely can push the bullet back out.
 
Doesn't sound like a sizing/shoulder problem if the brass chambered fine before seating.

As mentioned above, sounds more like either bullet in lands or your neck diameter is too wide somewhere. Check the loaded neck diameter. Pay specific attention to the mouth of the case.
 
Doesn't sound like a sizing/shoulder problem if the brass chambered fine before seating.

As mentioned above, sounds more like either bullet in lands or your neck diameter is too wide somewhere. Check the loaded neck diameter. Pay specific attention to the mouth of the case.
I’ll check that neck mouth now. It’s not the lands, I have rounds that are loaded to the same CBTO and they chamber.
In the event it’s the mouth of the case what is the solution?
 
Some good suggestions above, but prompts more questions. I’ve had brass harden quickly after a few firings and ‘spring back‘ or resist sizing before I got an AMP annealer. Had to size for about 5 or 6 thou, to end up with 2 due to spring back effect on older brass.

May I suggest pulling one of the bullets, remove powder and see if the case chambers. Will at least confirm it’s not the seating depth, seating die. If still tight, you can then (if you can do so safely) decap the live primer and try setting the sizing die for a couple of thou more bump. Retest. Was the primer fully seated ?

Blackening or colouring the loaded round and testing may be simpler depending on your equipment. As mentioned above, do you know your neck clearance, and have you trimmed cases for optimum length?
 
I’ll check that neck mouth now. It’s not the lands, I have rounds that are loaded to the same CBTO and they chamber.
In the event it’s the mouth of the case what is the solution?

Depends if the issue is thick necks or flared case mouth. May need more trimming or necks may need turning. As mentioned above, if the loaded neck diameter is fine, you can just pull one bullet and see how the brass chambers.


Measure the loaded neck diameter down near the shoulder and at the mouth of the case. Post those measurements and go from there.
 
Also, if you know what the measurement was to your bumped shoulders, you can obviously just check and make sure your shoulders are still in the same place.

As mentioned above, you may be experiencing more spring back than you anticipated.
 
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Some good suggestions above, but prompts more questions. I’ve had brass harden quickly after a few firings and ‘spring back‘ or resist sizing before I got an AMP annealer. Had to size for about 5 or 6 thou, to end up with 2 due to spring back effect on older brass.

May I suggest pulling one of the bullets, remove powder and see if the case chambers. Will at least confirm it’s not the seating depth, seating die. If still tight, you can then (if you can do so safely) decap the live primer and try setting the sizing die for a couple of thou more bump. Retest. Was the primer fully seated ?

Blackening or colouring the loaded round and testing may be simpler depending on your equipment. As mentioned above, do you know your neck clearance, and have you trimmed cases for optimum length?
Yes I amp anneal and trim to book length with a henderson trimmer every time I shoot. Deprime, wet tumble, anneal, Run through fl die, mandrel, wet tumble, dry, trim, load.
I’m going to sharpie one and report back
I haven’t touched my sizing die between this batch and the last batch. Last batch chambered fine. I do use wax though. Maybe die is caked or dirty? I can clean it and use one shot if that’s the problem.
 
Also, if you know what the measurement was to your bumped shoulders, you can obviously just check and make sure your shoulders are still in the same place.

As mentioned above, you may be experiencing more spring back than you anticipated.
I was making the assumption that he had measured the shoulder bump again but maybe he still needs to confirm that.
 
I typically measure first 4/5 rounds. See if they chamber. I measure compared to non sized brass, if it bumped back .002. I didn’t measure to the dummy round but I will.
Once first few are bumping .002 I’m off to the races.
 
It’s the shoulder. 1.6070 dummy, 1.6080 new loads. Pulled one and it chambers but also with some pressure. My first few rounds I sized must be close to the dummy if they chambered.
What would cause the variation between batches? Using wax, wax buildup? Should I go with one shot instead?

Guess I’m pulling them and bumping again.
 
You're talking .001. That can be simply just slightly more pressure with your thumb on calipers. Could be lube, could be 5 other things.

This is why we prefer to remove the extractor and size cases to fall free with gravity. Then there's never an issue of tight chambering with the ejector installed.

Just size down .001 or .002 shorter next time. Then when you have .001 variance, it won't matter. And you won't even be close to excessive headspace.

Unless it's a very hard close, or you're getting a sticky bolt after firing, I'd personally just shoot a few, if they shoot/extract fine....shoot the ammo as is.

0.001 likely isn't going to hurt you on the current ammo.
 
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It could be something building up inside the die. Do you lube the shoulders? I try to lube the neck and body only as I have had issues with crud building up in the die.

Getting a consistent bump to .001" is not easy to do. Something as small as raising the ram inconsistently can cause variation.
 
It’s the shoulder. 1.6070 dummy, 1.6080 new loads. Pulled one and it chambers but also with some pressure. My first few rounds I sized must be close to the dummy if they chambered.
What would cause the variation between batches? Using wax, wax buildup? Should I go with one shot instead?

Guess I’m pulling them and bumping again.
Just shoot them if you can. Pulling them down and resizing is a major pain, will result in not great ammo, can be dangerous if you are an idiot, and Just shooting them won’t effect anything.

If There’s only a thou between the two, which is causing the problem, it could be inconsistency in sizing lube application, case hardness due to age or annealling irregularities, cleanliness of the die, how you stroke the press, how your dies interface with the press (Hornady lock and load?), how you are measuring (can you reliably and repeatably resolve case shoulder to .001”).

Address all these potential issues if you want to be like a benchrest hero and then try to bump to more like .003”.
 
Just shoot them if you can. Pulling them down and resizing is a major pain, will result in not great ammo, can be dangerous if you are an idiot, and Just shooting them won’t effect anything.

If There’s only a thou between the two, which is causing the problem, it could be inconsistency in sizing lube application, case hardness due to age or annealling irregularities, cleanliness of the die, how you stroke the press, how your dies interface with the press (Hornady lock and load?), how you are measuring (can you reliably and repeatably resolve case shoulder to .001”).

Address all these potential issues if you want to be like a benchrest hero and then try to bump to more like .003”.
"Frustrating. Loaded them up for my hunt so not easily chambering will be cumbersome."
 
If they are cumbersome to chamber.....then they were fitting tight before the .001 extra. Which would mean OP was already on the edge of barely bumping shoulders enough to fit chamber.

If they were easy to chamber prior, then .001 isn't going to make something cumbersome.

So, guess it depends on how the OP sizes cases to begin with and how they fit the chamber and also what he considers cumbersome.
 
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“Cumbersome” doesn’t me “deal breaker”. Maybe he’s got some training to do and can cycle a dozen rounds through his process before hunting. I said “if you can”.
Like when he wounds the buck of a lifetime and wants a quick follow up ...and"Maybe" the next tight round screws up his cycling the next round enough to ruin the hunt ? We have no idea of his experience , why not stick to facts ?
 
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It’s the shoulder. 1.6070 dummy, 1.6080 new loads. Pulled one and it chambers but also with some pressure. My first few rounds I sized must be close to the dummy if they chambered.
What would cause the variation between batches? Using wax, wax buildup? Should I go with one shot instead?

Guess I’m pulling them and bumping again.

Whose wax are you using? Hornady? If so, get Imperial. It produces better consistency in shoulder bump.
 
After encountering a couple of rounds that chambered with excessive force “on the clock,” I run EVERY sized case through the rifle before loading them.
 
Are you serious? So, every case for a 2 day match? Say 300 rounds? Dude. That’s patience.
Yeah, I had one that was “stiff” going in and on the verge of needing a range rod to come out.

I figure that putting the time in before loading is an investment. Putting the time in to pull down troublesome loads, however, is wasted.

And, “virtual meetings” mean that I can multitask on occasion.
 
Yeah, I had one that was “stiff” going in and on the verge of needing a range rod to come out.

I figure that putting the time in before loading is an investment. Putting the time in to pull down troublesome loads, however, is wasted.

And, “virtual meetings” mean that I can multitask on occasion.
Cool. And here I thought I was doing something really unique by sizing .004”.