There is a .003” difference in rim thickness between that case and another brand.
- Thread starter Rockhurr
- Start date
I don’t think the extractor grabs the rim as you’re suggesting and there is actually clearance between the rim and extractor. If there wasn’t it wouldn’t accommodate different types of brass and would be hung on the side of the rim on thicker brass.
I use a zero press, Lapua brass, and Redding dies. With a mitutoyo caliper I can get a measurable difference in shoulder dimensions. I think you’re way overthinking this.
I use a zero press, Lapua brass, and Redding dies. With a mitutoyo caliper I can get a measurable difference in shoulder dimensions. I think you’re way overthinking this.
Ever shoot a seating depth ladder at distance? If so, were you using .010 or .005 increments? That tells you your question is inconsequential. OAL also doesn’t matter because the only thing the bullet tip touches is the target.
The other issue with all your arguments is how are you measuring all this? How do you know your calipers are calibrated correctly, I don’t care what brand or how much was spent. The same thing applies to how we measure cbto, you’re not actually measuring the true depth of your throat (thats what she said), but rather a reference or datum to base off of. Do you really think pushing something with your fingers and then measuring it is a precise procedure? How strong is your thumb? Go pose all this stuff to a machinist and prepare to be schooled.
Also, I bet you’re fun at parties.
I’m exactly on subject. Or did you change the argument after your original arguments were proven inconsequential?
The results of a seating depth ladder prove OAL or cbto change in that small of increment is inconsequential. Can you shoot the difference?
The hornady comparator tool is a great little thing to have, but isn’t a precise measuring instrument. Measuring stuff correctly with calibrated tools is kind of a fine art. Again pose these questions to a machinist, its a revelation.
The only thing I shit on, is your trolling attitude.
I’m not trolling.. you’re just not answering the I question I asked… and yes I’ve done seating depth ladder and it does matter… you can’t be serious when say your rifle shoots the same regardless of seating depth… that’s bs right there if that’s what you’re saying… I’m tired of your nonsense too bruhhhh… go ride someone else’s dick.
When did I say that? Seating depth absolutely matters. Differences of .002 don’t, unless you’re riding the edge of the node. Accounting for the firing pin pushing your brass .002 or whatever in your cbto is minutiae, you’re very likely in the same node anyways. Do you shoot your seating depth ladders in cbto of .002 increments?
But whatever bruhhhh, you do you.
You do you …. have fun.
If you saw it on YouTube it must be true.
I learned all my reloading via random peeps on the internet. I'd give em all two thumbs up.
If I had thumbs left.
Always Consider who you are listening too. What are their credentials.
Can they demonstrate the problem/issue and it's solution.
Also is it applicable to your current situation. Where are you 8n terms of shooting/reloading
I learned all my reloading via random peeps on the internet. I'd give em all two thumbs up.
If I had thumbs left.
Always Consider who you are listening too. What are their credentials.
Can they demonstrate the problem/issue and it's solution.
Also is it applicable to your current situation. Where are you 8n terms of shooting/reloading
Trying to understand the mechanics of what is going on, from your statement, in order for the case to be extracted the ejector plunger has to be depressed back far enough to allow the case rim to sit behind the extractor, and due to the strong tension of the factory plunger spring, the plunger is always pushing on the case such that it’s shoulder is up against the chamber shoulder. And the case headspace will always allow clearance between the extractor and case rim until the case shoulder is bumped back to the point where the extractor claw just barely catches the rim, correct? And, from this, can I assume that the case has no forward movement when the firing pin strikes the primer because the case shoulder is already up against the chamber shoulder? And, there is no use trying to find where the shoulder is bumped too far back where there is no longer any shoulder contacts because at the point we wouldn’t be able to extractor the case or there would be misfire because the primer is too far forward , correct?
Pull your bolt, insert a case on the extractor, press it up against the plunger. Buy a set of wire feeler gauges, see how much space is between bolt face and case head. If it's greater than 002-003(normal shoulder bump, your chamber is always going to hold the case in the same position against the plunger/extractor.
OP,
If you are setting your shoulders back .002-.003 and you think your plunger has enough force to cause your brass to sit crooked in the chamber, you have bigger issues.
Much bigger issues...
Yes, the plunger can or will push the case forward until the shoulder contacts, but if it's sitting crooked, you have one fat-assed chamber.
^^^^read that again.
Seriously, size a piece of brass as much as your dies will allow.
Drop that into your barrel that you removed from the action. Try to move the brass left to right. You can't. The only thing you'll be able to do is rotate it.
That's why SAAMI allows like .010 headspace variation on brass and ammunition. Just imagine how much the case body varies...
Anyway,
what is not being looked at is web dimension, among other things.
If you are sizing with normal dies, then you are most likely getting .0005-.001 resizing at the .200 line.
That tiny amount is not enough to allow your brass to be pushed into the chamber beyond the beginning of the extraction cut.
It takes three dimensional changes to allow brass to go forward of its intended headspace:
The one we all know and love to argue about is the datum line. AKA shoulder bump. That is where this "discussion" seems to be stuck on.
Number two is the diameter of the .200 line. If it doesn't change due to resizing, then the lack of resizing the web can cause false indications WRT shoulder bump.
Thirdly, the diameter of the body to shoulder dimension must also allow the brass to go freely into the chamber. If it doesn't, then again we get false indications of improper shoulder bump.
I should probably add in a fourth point which is overall length of brass.
Brass can be waaaaay too short in neck length and it will function fine. If it's too long, then it causes pressure spikes because the brass is literally crimping the major diameter of the bullet, because it runs into the front of the chamber.
Here's a solution:
The OP could let his brass grow to the maximum allowed by his chamber and trim exactly there. If done that way, then the base of the brass would always be against the bolt face. This would eliminate the source of the OPs stress over what actually amounts to a big nothing burger.
How fun would that be to try and figure out the exact length, down to the thousands his case length needed to be? The OP could spend his time doing that instead of pressing the issue that isn't an issue. He would lose his ability to tell us it's not on topic, and we would lose our source of entertainment for the weekend.
OP, this isn't a hotdog down a hallway issue. The allowable dimensions are just too minute to cause the issue you're stressing over.
Typical firing pin protrusion hovers around .055. There has to be a ton of excess headspace to prevent ignition. Where more issues come from are actions with weak firing pin springs, modified actions that have had firing pin fall modified either on purpose or by accident due to changes in dimension after manufacture.
The firing pin could be dragging on the bolt body. It could be a case of built up crud inside the bolt body, causing a slow down of the lock time.
It sure as hell isn't caused by an extra .003 of shoulder setback.
In regards to the dimensional change of bullet seating depth. As was pointed out above, if your load is that temperamental, then rework your load.
At this point, I could bring up carbon buildup on the throat which can and will change the seating depth of a bullet. It will also rapidly change the pressure curve.
But, I don't bring it up because I'd really hate to be admonished by the OP for straying 3° off topic. (Which is really still on topic)
If you are setting your shoulders back .002-.003 and you think your plunger has enough force to cause your brass to sit crooked in the chamber, you have bigger issues.
Much bigger issues...
Yes, the plunger can or will push the case forward until the shoulder contacts, but if it's sitting crooked, you have one fat-assed chamber.
^^^^read that again.
Seriously, size a piece of brass as much as your dies will allow.
Drop that into your barrel that you removed from the action. Try to move the brass left to right. You can't. The only thing you'll be able to do is rotate it.
That's why SAAMI allows like .010 headspace variation on brass and ammunition. Just imagine how much the case body varies...
Anyway,
what is not being looked at is web dimension, among other things.
If you are sizing with normal dies, then you are most likely getting .0005-.001 resizing at the .200 line.
That tiny amount is not enough to allow your brass to be pushed into the chamber beyond the beginning of the extraction cut.
It takes three dimensional changes to allow brass to go forward of its intended headspace:
The one we all know and love to argue about is the datum line. AKA shoulder bump. That is where this "discussion" seems to be stuck on.
Number two is the diameter of the .200 line. If it doesn't change due to resizing, then the lack of resizing the web can cause false indications WRT shoulder bump.
Thirdly, the diameter of the body to shoulder dimension must also allow the brass to go freely into the chamber. If it doesn't, then again we get false indications of improper shoulder bump.
I should probably add in a fourth point which is overall length of brass.
Brass can be waaaaay too short in neck length and it will function fine. If it's too long, then it causes pressure spikes because the brass is literally crimping the major diameter of the bullet, because it runs into the front of the chamber.
Here's a solution:
The OP could let his brass grow to the maximum allowed by his chamber and trim exactly there. If done that way, then the base of the brass would always be against the bolt face. This would eliminate the source of the OPs stress over what actually amounts to a big nothing burger.
How fun would that be to try and figure out the exact length, down to the thousands his case length needed to be? The OP could spend his time doing that instead of pressing the issue that isn't an issue. He would lose his ability to tell us it's not on topic, and we would lose our source of entertainment for the weekend.
OP, this isn't a hotdog down a hallway issue. The allowable dimensions are just too minute to cause the issue you're stressing over.
Typical firing pin protrusion hovers around .055. There has to be a ton of excess headspace to prevent ignition. Where more issues come from are actions with weak firing pin springs, modified actions that have had firing pin fall modified either on purpose or by accident due to changes in dimension after manufacture.
The firing pin could be dragging on the bolt body. It could be a case of built up crud inside the bolt body, causing a slow down of the lock time.
It sure as hell isn't caused by an extra .003 of shoulder setback.
In regards to the dimensional change of bullet seating depth. As was pointed out above, if your load is that temperamental, then rework your load.
At this point, I could bring up carbon buildup on the throat which can and will change the seating depth of a bullet. It will also rapidly change the pressure curve.
But, I don't bring it up because I'd really hate to be admonished by the OP for straying 3° off topic. (Which is really still on topic)
I was going to bring this up yesterday as well, but it's too much too soon for another ever changing variable to be thrown into this between a bolt and a headspace conundrum!
Or the fact a bushing die typically doesn't size all the neck, leaving a light flare that centers case in chamber no matter what and may also affect headspace! I've always used Alex Wheelers reloading principles(sizing/load development) but in a dumbed down simpler manner. He's built a ton a championship rifles and has held quite a few records himself prior to taking up gunsmithing full time VS shooting.If you're bored, you could always bring small based dies into the conversation...
Alex is a smart feller.
I do love my bushing dies, but I don't need or want them for everything.
OMG!!
Are we gonna get yelled at by the OP for "Not on topic" discussion?
Funny thing is, it's all on topic and relevant.
I do love my bushing dies, but I don't need or want them for everything.
OMG!!
Are we gonna get yelled at by the OP for "Not on topic" discussion?
Funny thing is, it's all on topic and relevant.
Correct
Correct
Correct.
I'm really not sure what the original question was, but it spawned me to measure some things on my own that might be beneficial to the conversation.
This is on an Impact 308 bolt face:
The ejector protrudes .151 from the bolt face
The extractor has .056 clearance from bolt face to inside of the claw
The Lapua brass rim is .050 thick
So as long as the shoulder setback is less than .006 (.056 total clearance-.050 rim thickness) the case shoulder contacts the chamber due to the ejector pushing it forward without any interference from the extractor. The case rim is captured by the extractor in this ideal scenario but not holding it back.
For fun, what happens when the case is bumped more than .006? Any bump from .007 to .056 will result in the extractor riding on top of the case rim right? This is because the push feed system would push the case forward until it contacts the chamber. At this point the extractor is still behind the case rim and hasn't captured it yet. The ejector (which has ample travel) would hold the case forward against the chamber and would compress to match the HS. The extractor would be the last to make contact and would ride up on the edge of the rim and set there during the shot. The case would then expand and move rearward to match the bolt face and the extractor would capture it at that point.
This is how I think it works with an ejector button. I'm not sure how a control feed would work.
This is on an Impact 308 bolt face:
The ejector protrudes .151 from the bolt face
The extractor has .056 clearance from bolt face to inside of the claw
The Lapua brass rim is .050 thick
So as long as the shoulder setback is less than .006 (.056 total clearance-.050 rim thickness) the case shoulder contacts the chamber due to the ejector pushing it forward without any interference from the extractor. The case rim is captured by the extractor in this ideal scenario but not holding it back.
For fun, what happens when the case is bumped more than .006? Any bump from .007 to .056 will result in the extractor riding on top of the case rim right? This is because the push feed system would push the case forward until it contacts the chamber. At this point the extractor is still behind the case rim and hasn't captured it yet. The ejector (which has ample travel) would hold the case forward against the chamber and would compress to match the HS. The extractor would be the last to make contact and would ride up on the edge of the rim and set there during the shot. The case would then expand and move rearward to match the bolt face and the extractor would capture it at that point.
This is how I think it works with an ejector button. I'm not sure how a control feed would work.
Finally someone understands the question and provides a professional, detailed description, of what’s going on and answers the question inquired. Thank you! Takes a @Halffull guy to get the question….
enough said. Last edited:
I think everyone actually got it a long time ago and was puzzled why it was so hard for one particular party…
Hell, the OP couldn't even figure out which sub forum to post his question.
Should have been in the reloading section, not bolt action rifles.
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