HELP!! 6mm ARC cases stuck after sizing?

[Precision Underground]

“From my experience loading for gas guns… and just from using reasoning, if a case drops into the chamber and obviously sticks before the shoulder bottoms out, the base of the case is expanded. Turning the die further in is not necessarily bumping the shoulder more and more if the base of the case is being sized before the shoulder ever contacts the die. Either way, the OP got his cases to fit in his chamber.”


Using your own reasoning, when a case expands during extraction it is going to expand in every direction, including shoulder length. Therefore the die will contact the shoulder and will size the shoulder more and more as you screw in the die.

Of course cases expand all over. You’ve missed my entire point. I’m not saying that the shoulder will not expand when fired or be bumped in sizing. What I’m saying is that the base of the case starts getting resized long before the shoulder gets bumped down. Headspace usually gets LARGER before it’s bumped back down when you resize it, especially with a gas gun. This is why brass gets longer and has to be trimmed. So as you’re screwing the die in and getting it set up you’re probably not bumping the shoulder much if at all at first depending on where you start; especially if it’s a new press/die/caliber as in this case. It’s not until the last bit that the shoulder is bumped. Sure it’s good to measure it, but it’s not nearly the cardinal sin that is being portrayed not to measure it.

So yes, when the op cammed over his shoulder probably bumped a few .001. But I’d be willing to bet the die worked as it was designed and it squeezed the expanded base up the body of the case bringing the diameter back into spec, increased the shoulder length, then once the base was small enough to allow the case deep enough into the die the shoulder was bumped back down. The die doesn’t just squish the shoulder down the whole time you’re running the ram. Some claim that these threads “are always solved by more shoulder bump” as if the shoulder is somehow bumped independent of the base being sized and physics occurring.

Either way, telling someone who turned a die in until the case would fit that they’re being unsafe or doing something wrong is just not accurate. Calling them ignorant while ranting like a 12 year old and then attacking me for telling him to screw his die in more is comical and sounds exactly like a guy who just learned how to measure shoulder bump but doesn’t understand it. That is not directed at you but the childish rant is what started this absurd, circular debate. People who feel the need to come on here and put ppl down for asking questions clearly have identity/self worth issues.

 

[Rocketvapor]

One other comment about headspace. Measure the headspace critical dimensions of your bolt.
If you ever need to replace it you can compare those measurements to the new bolt.
I have several in both 5.56 bolt head and .224V bolt head size (for 22 Nosler brass and for 6mm Hagar/22Nosgar brass).
I'm lucky that the depth and lug are the same length for both rifles.

 

[Precision Underground]

That sentence in bold says that you haven't spent much time measuring bump with cammed over setups. Different amounts of cam over does still change shoulder bump by more than that. And you're completely guessing about where his die was set before and where it is now. Literally, you have no idea, but are continuing to "give advice" that is of zero value. Just stop.

Also, you still seem to be missing the fact that most bolt actions have leverage to cam a sticking round out of the chamber, but the AR15 platform does not, at all. A round that doesn't even stick enough to be noticeable in a bolt action can completely lock up an AR. This is why you can get away with neck sizing only, or partial full length sizing, etc without any shoulder bump in a bolt action, but not in an AR.
You're making bad assumptions about what a sticking round means in an AR, and giving bad advice as a result.

Lol. You’re making assumptions about my assumptions. And your condescension is hilarious. Unless there’s something strange going on like an out of spec die or chamber the OP Will have zero issues. Of course screwing the die further and further and camming over multiple times will increase bump too much. But he said he stopped short of coming over and the case still wouldn’t fit in the chamber. Then he cammed over and now it does fit in the chamber. $100 says he bumped the shoulder no more than .005. You game?

Edit- are you actually trying to explain to me how a “bolt action” works? You’re 100% clueless as to what I’m talking about bc that’s totally irrelevant. I’m talking about DROPPING a case into the chamber with no bolt. I’m talking about using the chamber as a case gauge. Does a round with too much headspace STICK in a case gauge? How about one with an expanded base/body? Ponder that and reread what I typed again. It may dawn on you that you’re not fully grasping what I’m saying.

 

[918v]

Of course cases expand all over. You’ve missed my entire point. I’m not saying that the shoulder will not expand when fired or be bumped in sizing. What I’m saying is that the base of the case starts getting resized long before the shoulder gets bumped down. Headspace usually gets LARGER before it’s bumped back down when you resize it, especially with a gas gun. This is why brass gets longer and has to be trimmed. So as you’re screwing the die in and getting it set up you’re probably not bumping the shoulder much if at all at first depending on where you start; especially if it’s a new press/die/caliber as in this case. It’s not until the last bit that the shoulder is bumped. Sure it’s good to measure it, but it’s not nearly the cardinal sin that is being portrayed not to measure it.

So yes, when the op cammed over his shoulder probably bumped a few .001. But I’d be willing to bet the die worked as it was designed and it squeezed the expanded base up the body of the case bringing the diameter back into spec, increased the shoulder length, then once the base was small enough to allow the case deep enough into the die the shoulder was bumped back down. The die doesn’t just squish the shoulder down the whole time you’re running the ram. Some claim that these threads “are always solved by more shoulder bump” as if the shoulder is somehow bumped independent of the base being sized and physics occurring.

Either way, telling someone who turned a die in until the case would fit that they’re being unsafe or doing something wrong is just not accurate. Calling them ignorant while ranting like a 12 year old and then attacking me for telling him to screw his die in more is comical and sounds exactly like a guy who just learned how to measure shoulder bump but doesn’t understand it. That is not directed at you but the childish rant is what started this absurd, circular debate. People who feel the need to come on here and put ppl down for asking questions clearly have identity/self worth issues.

I assumed we were talking about the die screwed down to touch the shell holder vs an additional amount to produce cam over. In that narrow range the die is bumping the shoulder as the case material has already flowed upward. The only question is how much more will the shoulder be bumped.


“Turning the die further in is not necessarily bumping the shoulder more and more if the base of the case is being sized before the shoulder ever contacts the die.”

^^^ The way your sentence reads it implies the shoulder is not going to be bumped necessarily just because we induced cam over.

I agree with you, when initially setting up the die the shoulder gets bumped last. But when we’re at the point where the die touches the shell holder, because that’s how the OP set up the die, the shoulder is getting bumped and cam over will bump it more by eliminating slack in the press. See OP’s statement below:

“As I alluded to above, in my excitement to load with my new Coax Press, I set all my sizing dies to contact, but not cam over”

 

[Precision Underground]

One other comment about headspace. Measure the headspace critical dimensions of your bolt.
If you ever need to replace it you can compare those measurements to the new bolt.
I have several in both 5.56 bolt head and .224V bolt head size (for 22 Nosler brass and for 6mm Hagar/22Nosgar brass).
I'm lucky that the depth and lug are the same length for both rifles.
View attachment 7972960

Do you find much variation on these measurements?

 

[Yondering]

Lol. You’re making assumptions about my assumptions. And your condescension is hilarious. Unless there’s something strange going on like an out of spec die or chamber the OP Will have zero issues. Of course screwing the die further and further and camming over multiple times will increase bump too much. But he said he stopped short of coming over and the case still wouldn’t fit in the chamber. Then he cammed over and now it does fit in the chamber. $100 says he bumped the shoulder no more than .005. You game?

Edit- are you actually trying to explain to me how a “bolt action” works? You’re 100% clueless as to what I’m talking about bc that’s totally irrelevant. I’m talking about DROPPING a case into the chamber with no bolt. I’m talking about using the chamber as a case gauge. Does a round with too much headspace STICK in a case gauge? How about one with an expanded base/body? Ponder that and reread what I typed again. It may dawn on you that you’re not fully grasping what I’m saying.

Wow. You're really all over the place aren't ya fella? The thread's about the OP's brass sticking in his gun. I couldn't care less if you talked about something sticking in a case gauge or other nonsense; that has nothing to do with it. I'm not going to debate your illogical foolishness.

I don't know you, and can only go off what I'm reading here. But what I'm reading indicates you're way out of your lane on this topic, and at this point are just trying to defend your pride and only looking foolish in the process.

 

[Rocketvapor]

Do you find much variation on these measurements?

While you guys argue I'll go off topic here.
The AR15 drawing for 5.56, and copied to the most part for the 6.8SPC/224V (6mmHAGAR/NOSGAR) gives a somewhat narrow range for bolt headspace contribution.
I don't have a bolt that is more than 0.0005" from 0.154", bolt face to rear of lugs.
Drawing range is 0.156" -0.003, or 0.156 to 0.153
This is NOT the same as the 0.136" bolt face dimension often quoted for the 6.5G/6ARC.
I carry an extra .154 bolt in both case head types and pins for matches, just in case.
My "guess" is most quality bolts will be somewhere near the middle of this range. Is that what you get when you get an accuracy guaranty from a barrel maker but ONLY if you buy their JP bolt? What is the measurement range for a JP bolt?
Do bargain bin bolts fall outside this range?

 

[Mike Casselton]

Anecdotally - when I started reloading 6 or so years ago (I'm 41 and started when my father gave me his old scale and press - decided I had to earn the privilege and started reading and studying up) I only loaded for bolt rifle chamberings. I measured all kinds of things for my rifles then and set dies to bump the shoulder back just enough and load projectiles at the ideal jump for each rifle after seating depth tests - and for the most part it was pretty straightforward.

Fast forward 50+ firearms later, add a stable of suppressors, and a multitude of different length semi loaders/gas systems and oh how things have complicated! The import of headspace, timing, gas, etc is magnified and I frequently hit my knowledge limits.

I've since paired down my reloading chamberings to the 4 I shoot most and worked to find loads that all my rifles shoot well enough (like 140 ELDM over 41.5 h4350 or 147 ELDMs over 42.2 RL16) to load in bulk and hold out the specialty loads for my competition rifles. I borrowed a friend's comparator then, but need to add some tools to my arsenal to troubleshoot and diagnose.

As mentioned above, this simple catch was the result of a few things I HAVE learned, one of which is to check chambering/ejection of a random sampling of sized brass before loading them up. I had to pull 300 rounds of creedmoor once and never want to repeat that if I can help it.

For comedic relief, I made this neat ornament when I switched from seating 108 ELD to 58 VMax in the 6mm...View attachment 7972829

That's a 6mm George Jetson.

 

[Rocketvapor]

What your favorite load for the 6ARC?
I assume you are using the Creedmoor for 1200yd steel, not the ARC.

 

[Precision Underground]

Wow. You're really all over the place aren't ya fella? The thread's about the OP's brass sticking in his gun. I couldn't care less if you talked about something sticking in a case gauge or other nonsense; that has nothing to do with it. I'm not going to debate your illogical foolishness.

I don't know you, and can only go off what I'm reading here. But what I'm reading indicates you're way out of your lane on this topic, and at this point are just trying to defend your pride and only looking foolish in the process.

The reason what you’re reading doesn’t make sense and seems irrelevant is bc you don’t understand it. To you the thread is about “the op’s brass is sticking in his gun”. But what the thread is really about is why and how cases stick in chambers. What you’re calling irrelevant is me attempting to explain this but you’re too focused on being the expert to digest it. Name calling and chest thumping might make you feel superior but it doesn’t change the fact that what I’m saying has flown right over your head.

 

[Precision Underground]

While you guys argue I'll go off topic here.
The AR15 drawing for 5.56, and copied to the most part for the 6.8SPC/224V (6mmHAGAR/NOSGAR) gives a somewhat narrow range for bolt headspace contribution.
I don't have a bolt that is more than 0.0005" from 0.154", bolt face to rear of lugs.
Drawing range is 0.156" -0.003, or 0.156 to 0.153
This is NOT the same as the 0.136" bolt face dimension often quoted for the 6.5G/6ARC.
I carry an extra .154 bolt in both case head types and pins for matches, just in case.
My "guess" is most quality bolts will be somewhere near the middle of this range. Is that what you get when you get an accuracy guaranty from a barrel maker but ONLY if you buy their JP bolt? What is the measurement range for a JP bolt?
Do bargain bin bolts fall outside this range?
View attachment 7973023

I’ve never measured the actual bolt I just measure headspace. I don’t typically use super high end bolts but also don’t buy bargain bolts. I’ve never had an issue with headspace or accuracy at the bolt. I’m curious what mine would measure though. Guessing you have to pull the extractors to check? I’m not sure I’m curious enough to pull the extractors lol.

 

[Rocketvapor]

0-1" depth gauge and micrometer will do.

 

[Precision Underground]

0-1" depth gauge and micrometer will do.

Are you measuring the lugs and then subtracting the depth? I didn’t know if that would stack errors.

 

[Rocketvapor]

A couple tenths for 0-1" depth mic, a couple tenths for a 0-1" micrometer.
Both measurements can be taken with the depth mic if desired.
Across the lugs bolt on a flat and into the face.
Using the 0-1" depth rod, and a 0-1" mic, zero is pretty good, measurement could be checked with blocks but I see no need.
Starett 445 spec is Accuracy (in): Mic head +/-.0001"; Rods (over 1") +/-.0002"

I'm getting close to 2000 rounds on my bolt. Maybe I should check it again?


Have rounds loaded for both rifles for the 600 match Saturday. Had to load about 10 to 15 at a time between A/C cycles.
Ran it down to 73F and managed to keep the humidity around 55-57%. About the best it gets here.
Since it's a match, every finished round will get a fit check in the upper.

Look, a lot of this stuff we are talking about doesn't matter one bit for most AR shooters.
I'm trying to set up ammo and rifle for the best I can. One day when I'm a good shooter it will make a difference (if I don't pass due to old age)

 

[SMTGWKD]

Was actually pushing the 18" ARC. Does really well to 1100...1200 not so much

Goal with the ARC was to replace my Grendels while adding a 6mm to the stable as I didn't yet have one. Since I live and shoot in Utah and surrounding areas, temperature swings are huge and I dislike temp instability. As a result, I've tested more temp stable powders - xbr8208 and Varget, specifically.

105 Hybrids over 26.8 Varget for 2564 fps and SD 14, .545" @ 100 (5 shots)
108 ELDM over 26.8 Varget for 2540 fps and SD 6, .497" @ 100 (5 shots)

I shoot the same loads out of the 12.5" ARC to 800+ with great success (5 for 5 of full size IPSC at 825).

Here are the culprits...

 

[SMTGWKD]

What your favorite load for the 6ARC?
I assume you are using the Creedmoor for 1200yd steel, not the ARC.

My reply is in the post above this one

 

[Rocketvapor]

The new range I joined has steel out to 800yds. Been focused on 600 for now, the longest I've ever been.
I might give the plates @ 800 a try, don't know the size offhand.
My (our) goal is to Master @600 then try 1000yd F-Class match in Pascagoula, Ms.
Our rifles, hers is a little less than 20 pounds (with the bipod) and mine just a little over (more lead).

 

[SMTGWKD]

Look, a lot of this stuff we are talking about doesn't matter one bit for most AR shooters.
I'm trying to set up ammo and rifle for the best I can.

This is where I ended up and backtracked - I have one sub 1/4 minute load for my DTA SRS (literally one hole groups half the time) that took quite a bit of time to perfect, but I ended up scrapping it as it's 41.3 RL 17 under 143 ELDx and RL 17 proved to be terribly temperature sensitive.

I realized the more I scrutinized groups the greater expectation of success and the less time/fun I had out shooting. If I can find a load that is 1/2 minute in precision bolts and barely under 1 minute in semis I call it good and go shoot. Typically takes a bunch of online research and one OCW ladder of 15 loaded rounds (5 3-shot charge weights at .3 each) to get close enough.

Time out shooting with family and friends trumps my time spent tinkering/ perfecting these days... wish I had more time for all three!

 

[Rocketvapor]

We are both retired and time is FREE.
Shooting is now our 'Bonding time' (other than Netflix ).

and since you showed one of your 'ornaments' here area couple of hydraulically deprimed 6.5x55 Swede Berdan primed cases for the wife's other
little girl gun

 

[SMTGWKD]

The new range I joined has steel out to 800yds. Been focused on 600 for now, the longest I've ever been.
I might give the plates @ 800 a try, don't know the size offhand.
My (our) goal is to Master @600 then try 1000yd F-Class match in Pascagoula, Ms.
Our rifles;

That F-Class barrel is artillery! Gorgeous rifles. You need to come to our neck of the woods to stretch their legs. We typically set up steel at 600, 1000, 1200, and 1800 yards when we head out.

Fun to bring friends who hunt but don't shoot as much and ask them how far they think the 600 yard target is when we're setting it up.

 

[SMTGWKD]

We are both retired and time is FREE.
Shooting is now our 'Bonding time' (other than Netflix ).

and since you showed one of your 'ornaments' here area couple of hydraulically deprimed 6.5x55 Swede Berdan primed cases for the wife's other
little girl gun
View attachment 7973457

Ha! Like a lava lamp!

In the end - stuff like this makes it all worthwhile. My son out prepping before heading to some P-Dog towns...

8-year-old at 600 Yards

 

[Rocketvapor]

That video is a keepsake.
You'll realize that 30 years from now.
I'll sign in and like it tomorrow.

 

[Joe1978]

I just had this problem in my ar 6mm arc and I solved it by vigorously ramming the case in to the die 5 or 6 times and it doesn't stick, must be no room for forgiveness!