How to encounter a pressure spike by changing COAL:
1 - Seat the bullet so deep that your nominal load is suddenly a compressed load. Powder-dependent.
2 - Change the COAL so that your "fast high-pressure round" is suddenly jammed way into the lands.
3 - Change the COAL so that your "fast high-pressure round" is suddenly a quarter inch off the lands instead of 0.020" off the lands. The huge increase in throat time can result in pressure spikes.
I was aware of 1 and 2, but I had other ideas about 3. That is, I'd figured that the long throat time would allow some pressure to bleed by the bullet before it actually engaged the lands. We're talking about a very short duration of time involved for this to happen. I suppose during the time the bullet is freeboring, gas by-passing the bullet creates a pressure within the barrel itself, which the bullet encounters once it hits the lands. Which in turn would slow it down and raise pressure, however briefly. Is this the idea or is there some other explanation?

Very good information throughout the post.

What you really want is complete understanding of the finite and manageable variables you are confronted with.

Some of your comments suggest that you may not be there yet. No prob. We all were beginners at some point.

Remember: COAL at the lands differs between different bullets.

The VV 1.976 spec is irrelevant to D2L. Perhaps it is a saami spec, I don't know.

D2L is gun dependent and bullet dependent, and differs for each gun and each different bullet.

I already said a quarter inch jump can be safe. Figure yours out.

I not 100% sure what you are saying about ".308 in the brass."
Get a caliper and a loaded round, measure the diameter of the bullet immediately above the case mouth. If it is .308, then that's normal. If it is .298, then you have buried the entire base of the bullet inside the case, and you can't crimp because the case mouth is resting on the ogive, and the pressure will be weird, and its just wrong.
We don't seat bullets so deep that the diameter of the bullet at the case mouth is less than the bore diameter.

Everything you need to know about this particular issue is in my posts, and repeated by various other contributors.
Slow down. Read them again. When you no longer have any questions, then you have arrived at where you need to be.

Fastest road to a kaboom: the road you are on right now. Don't forge ahead without understanding.

Unless zombies are already at the door. Then you can rush.

Understand that when it comes to reloading, people are reluctant to tell other people, "Yes! Safe to shoot!"

If I read your data correctly, you have a minimum charge. Within bounds of reason, it is nearly impossible to create pressure risk when starting with minimum load, unless something else is terribly wrong.

If you look at a factory round, you can't really use that as a benchmark for seating depth unless you know the exact powder used in the round.
Some powders are bulky, some not.
The consideration here is case fill.
If you use a minimum charge of a very fluffy powder, it will fill the case as much or more than a maximum charge of denser powder.
Since commercial ammo is often made with powder that is not available to handloaders, this comparison is difficult or impossible.

That length is 70 thousandths shorter than VV data.
Shake the round by your ear. Can you hear the powder go chicka chicka chicka in the case?
If so, the powder is not compressed.

Use a sharpie to color the entire bullet, then carefully insert the round most of the way into the chamber, then gently close the bolt.
Then gently extract. If the lands of the barrel do not cut shiny copper marks into the black ink on the bullet, then you are not on or into the lands.

If you pass those two tests, then you have a minimum load, not compressed, and not into the lands. Very safe to shoot.

If you can't hear the chicka chicka, use a knife to score the bullet all around at the case mouth, then pull the bullet, then measure from score line to base of bullet. Then charge the case and measure from case mouth down to powder level. If the bullet measurement is greater than the case measurement, then you are compressing the charge.

It has been normal for decades to compress charges in rifle ammo. My 69gr .223 match load for a different bolt gun here is a compressed charge of 4895. Old school. Very accurate. 2800fps. Moderate pressure. No chicka chicka, ever.

However, we only compress charges intentionally. We don't do it by accident, and we don't do it with powders that are not intended to be compressed.

I can tell you that kabooms are rare and you really have to mess up pretty bad to create that kind of pressure.
However, I will tell you that everything you need to know about this round you just made, you can find out by doing the tests described above.
I get it, and you all have giving me a wealth of info.

Still everyone is dancing around the question at hand...
If ALL variables are met, and this round is measuring @ .60 shorter than load data. BUT is still in SAAMI specs......

I'll rephrase not to implicate anyone.. (No i wont sue you. i do Insurance for a living and deeply know liability issues...)

#1 SHOULD a round thats within SAAMI spec COAL that has A min powder charge, cases also in spec. FIRE IN A RIFLE.
#2 IF said round has a few that may be 0.60 shorter than the others, BUT also still in SAAMI spec COAL not touching lands nor compressing powder FIRE IN RIFLE.
OR
Should i just pull the bullets and start over.

First of all do you have a pair of calipers and a set of comparitors for ogive measuring accurately? You will probably want a pair going forward.

Its not critical to know your jam. But can be handy. Or in this case where your starting more info is better just to make sure you know. The more experience you get you will see its a background factor.
Really you just want it to be accurate. You could start where your at just fine (if you want) and then find your accurate load. Then next five take that load and seat 3 to 5 rounds +.005" and next group +.010" next set +.015" and so on.
Knowing the jam won't REALLY matter because you SHOULD see pressure signs if things get too crazy (to far into the lands) then you know to stop. Take the most accurate of those groups and use that seating depth.
After that you can play with the load again just a tad. Up or down a few tenths of a grain and then that should be it.
If you happen to shoot thousands and thousands of rounds You could load 5 again seated +.005" again and shoot those. If they are more accurate thats your new seating depth.

Again you can do all this without KNOWING your B2L base to lands or D2L which is really also base to ogive. But knowing jam won't hurt and is easy to figure out. I use the same method as @baker3gun it sounds like we subscribe to the same info sources.
yes on calipers the ogive comparator should be here by sat.

I not 100% sure what you are saying about ".308 in the brass."
He's stating this because I mentioned as a general rule of thumb you want as much bullet down in the neck (to grip the bullet with tension) as the diameter of the bullet and gave a few examples.

I should also mention for some cartridges they just aren't setup like this and you just get what you get. And often not as much as you'd like, that's the fault of the cartridge creator not yours. Generally competition shooters want more neck grip for better control, concentricity, neck tension etc.

I was aware of 1 and 2, but I had other ideas about 3. That is, I'd figured that the long throat time would allow some pressure to bleed by the bullet before it actually engaged the lands. We're talking about a very short duration of time involved for this to happen. I suppose during the time the bullet is freeboring, gas by-passing the bullet creates a pressure within the barrel itself, which the bullet encounters once it hits the lands. Which in turn would slow it down and raise pressure, however briefly. Is this the idea or is there some other explanation?

Very good information throughout the post.
Regarding #3, when it comes to most longer match bullets they have a bearing surface thats longer than .250" so it should bridge the gap from the case mouth to the lands thus sealing it by in large.
In sure there's a bit of gas blow by on all bullets regardless. Like the corners of the lands that's why there's gas checks right? Correct me if I'm wrong..

When starting you will find a lot of times you just get what you get. Such as 55gn bullets loaded to cannelure length. Or grip length of the neck like .223 is often shy of the size if the diameter (I often find range brass is shorter than SAMMI min.) Etc the more you learn the more you will select components to allow you more flexibility and sorting all this stuff out to your liking instead of you get what you get.

You aslo asked about the grooves, the top groove is much thinner that is your cannelure, the lower band I believe they call a driving band.

I was aware of 1 and 2, but I had other ideas about 3. That is, I'd figured that the long throat time would allow some pressure to bleed by the bullet before it actually engaged the lands. We're talking about a very short duration of time involved for this to happen. I suppose during the time the bullet is freeboring, gas by-passing the bullet creates a pressure within the barrel itself, which the bullet encounters once it hits the lands. Which in turn would slow it down and raise pressure, however briefly. Is this the idea or is there some other explanation?

Very good information throughout the post.

My 2 cents:

Example: .308 rifle.
The bore diameter, otherwise known as the grooves, is .307.
The diameter of the rifling is .299.

To seal, the bullet must be pushed into the lands far enough that the rifling is cutting into the surface, so that the bullet base can enter the true bore (grooves).

Bearing in mind that a squib load (primer only, no charge) can push a bullet halfway down the bore...

I'd guess that the actual outcome varies according to burn rate, bullet weight, length of jump, and neck tension.

In the bypass scenario you describe, I envision a point in time at which raging burning powder is discovering an ever growing tunnel in front of it, and then suddenly has the door slammed in its face.
I'd anticipate a spike at that point which may test the limits of the chamber and brass.
IOW - the bullet experiences two distinct acceleration events, and the 2nd one can be massive in certain circumstances.
I'd guess that this is how excessive jump can get you into pressure trouble.

However, in a "tamer" long-jump bypass scenario (perhaps slower powder and lighter bullet), I can envision a bypass sequence that doesn't have a significant pressure spike, but still really messes with your accuracy.

I would mildly disagree with your thoughts on pressure in front of the bullet. I understand what you suggest, but
1 - the muzzle is open. Without confinement, significant pressure is hard to build.
2 - the pressure behind the bullet is so much higher than whatever pressure might exist in front of it, it may be irrelevant for practical purposes.

Fun discussion.
I was supposed to be working.
Gotta get.

What you really want is complete understanding of the finite and manageable variables you are confronted with.

Some of your comments suggest that you may not be there yet. No prob. We all were beginners at some point.

Remember: COAL at the lands differs between different bullets.

The VV 1.976 spec is irrelevant to D2L. Perhaps it is a saami spec, I don't know.

D2L is gun dependent and bullet dependent, and differs for each gun and each different bullet.

I already said a quarter inch jump can be safe. Figure yours out.

I not 100% sure what you are saying about ".308 in the brass."
Get a caliper and a loaded round, measure the diameter of the bullet immediately above the case mouth. If it is .308, then that's normal. If it is .298, then you have buried the entire base of the bullet inside the case, and you can't crimp because the case mouth is resting on the ogive, and the pressure will be weird, and its just wrong.
We don't seat bullets so deep that the diameter of the bullet at the case mouth is less than the bore diameter.

Everything you need to know about this particular issue is in my posts, and repeated by various other contributors.
Slow down. Read them again. When you no longer have any questions, then you have arrived at where you need to be.

Fastest road to a kaboom: the road you are on right now. Don't forge ahead without understanding.

Unless zombies are already at the door. Then you can rush.
I do know COAL is different per bullets.
I do know VV 1.976 has nothing to do w D2L. it was the vv load data for COAL for the 123gr lapua im using which gave the 1.976 COAL.
I do know D2L is also gun/bullet dependent.
I used .308 in brass(neck) because was said that it should be seated at min depth as diameter of bullet. 300BO = .308 diameter, I WAS IN FEAR THAT GOING FROM 1.910 COAL to 1.976 would possibly put that bullet too high and not have min .308 depth?
"Fastest road to a kaboom: the road you are on right now. Don't forge ahead without understanding."
I am asking question before i even think about firing one of these. So why am i on a path to kaboom? am i missing something?
I've measure weighed inspected 100x and came across questions. I need no kabooms!
I think i will pull them all salvage powder brass and bullets and try again.
I am ok with maybe .020 difference on my COAL BUT right now 0.60 is just possibly more than im comfy with.

These two rounds loaded -.060 short are on the min load range. Correct?

If above is true, you can shoot them they will be fine.
You won't get any useful data from them.

You can however just pull them and reload them to match the others and then get useful data.

That is all.

I believe he is saying you should read and understand the manual. And that thought crossed my mind too, but I also read (several) manuals and had questions like this as well. Like you I would rather have an abundance of caution than no face.

I'd also get a chronograph when starting out just another helpful data point to refer to.

One more point. But the max loads in most books are usually somewhat conservative as well. But still should heeded somewhat. I do however sometimes go over saami. Such as 223 v 556. One has a much lower pressure limit even though they are basically the same. There is a ton of nuance in reloading and its vest to thoroughly investigate all this nuance before really even starting to build a new caliber you might reload for.

These two rounds loaded -.060 short are on the min load range. Correct?

If above is true, you can shoot them they will be fine.
You won't get any useful data from them.

You can however just pull them and reload them to match the others and then get useful data.

That is all.

I believe he is saying you should read and understand the manual. And that thought crossed my mind too, but I also read (several) manuals and had questions like this as well. Like you I would rather have an abundance of caution than no face.

I'd also get a chronograph when starting out just another helpful data point to refer to.

One more point. But the max loads in most books are usually somewhat conservative as well. But still should heeded somewhat. I do however sometimes go over saami. Such as 223 v 556. One has a much lower pressure limit even though they are basically the same. There is a ton of nuance in reloading and its vest to thoroughly investigate all this nuance before really even starting to build a new caliber you might reload for.
Yes tests Literally first 49 rnds i completed EVER. hence the Caution
These two rounds loaded -.060 short are on the min load range. Correct?
yes Every thing as far as powder at minimum. according to hodgdon lil gun data @ 125gr bullet except i was 18.0
Other than that all are within SAMMI . IM GOING TO DOUBLE CHECK THE SHORTYS TO MAKE SURE I HEAR POWDER SHAKE 1ST.
i have Lapua 123gr not a Nosler 125gr boat tail
i have mixed 223/556 and 300BO converted brass trimmed @ min1.350
same primer, same barrel length same twist.
this is Hodgdon below

Twist: 1:8.000"
Barrel Length: 16.000"
Trim Length: 1.363"

BULLET WEIGHT 125 GR. NOS BT
PRIMER REMINGTON 7 1/2, SMALL RIFLE MAGNUM

 Manufacturer Powder Bullet Diam. C.O.L Grs. Vel. (ft/s) Pressure Starting Load Maximum Loads Hodgdon Lil'Gun BUY NOW 0.308" 2.060" 17.8 2,210 42,700 PSI 21.0C 2,402 48,800 PSI

I THINK I'LL SHOOT MAYBE THE LONGEST OF THE BATCH TAKE NOTES AND DISASSEMBLE THE REST AND START OVER.
YOU GUYS HAVE GIVING ME A WEALTH OF INFO AND REASSURANCE.

JUST WANT TO MAKE SURE THE BANG GOES OUT THE MUZZLE END LOL

THANK YOU ALL FOR THE HELP

Here's hornady 10th ed. For that weight. Notice the grouped 125 to 130gn together.. Hence why theirs probably starts out so low at the min. You'll find a lot of sources vary. It also gives a COAL for each bullet all of which look "pointier" than yours = longer COAL.

Fwiw I had the Nosler manual and Gabe it away. Didn't find it as versatile. I heard the Lyman (or was it Lee, pretty sure Lyman..) manual had tons of loads. I find the books that aren't catered by a specific powder or bullet maker has more wide ranges loads that covers more "ground"

Anyway. Sounds like your covered. So good luck and enjoy. If it were me. I'd just shoot those off, and that will help ease your jitters down the road. Reloading is pretty safe as long as you pay attention. The fact that you know they are short means a lot. Its the ones that you don't know are short that are the problem.

Also not sure if I'd be spending big money on lapuas for 300bo. Not exactly a precision cartridge unless you got them for cheap or my *fav* free!

Anyway enjoy, stop back and let us know how it went after wards.

Here's hornady 10th ed. For that weight. Notice the grouped 125 to 130gn together.. Hence why theirs probably starts out so low at the min. You'll find a lot of sources vary. It also gives a COAL for each bullet all of which look "pointier" than yours = longer COAL.

Fwiw I had the Nosler manual and Gabe it away. Didn't find it as versatile. I heard the Lyman (or was it Lee, pretty sure Lyman..) manual had tons of loads. I find the books that aren't catered by a specific powder or bullet maker has more wide ranges loads that covers more "ground"

Anyway. Sounds like your covered. So good luck and enjoy. If it were me. I'd just shoot those off, and that will help ease your jitters down the road. Reloading is pretty safe as long as you pay attention. The fact that you know they are short means a lot. Its the ones that you don't know are short that are the problem.

Also not sure if I'd be spending big money on lapuas for 300bo. Not exactly a precision cartridge unless you got them for cheap or my *fav* free!

Anyway enjoy, stop back and let us know how it went after wards.

View attachment 1281110 View attachment 1281111
i have the 50th ed. lyman book and got a good deal on the lapuas. have some sierras as well but was using lapuas had same amount of lapuas as rem 7 1/2 primers seemed logical to load those.

thank you very much.

i have the 50th ed. lyman book and got a good deal on the lapuas. have some sierras as well but was using lapuas had same amount of lapuas as rem 7 1/2 primers seemed logical to load those.

thank you very much.
weird is my lee data calls for 17.8 starting for lil gun on 125gr with 21.0 max and lyman says 17.0 to 18.0 but only 125gr is the sierra hollowpoint?

i assume eack book has diff value. or they all be the same # right..

Yeah I think I said that. Every source is slightly different but pretty much all in the same balk park. And also worth repeating is some are more conservative than others. I typically don't use the book for max velocity but I go by the saami spec for max pressure and use +p etc where applicable say for 9mm or others. And .308 instead of 7.62x51 because .308 is higher pressure.
I typically don't pick the MOST accurate load. But if one is very close to it which one usually is, at a higher velocity. I use that one. But I also record them all so whenever I want I can just go back and load the lower velocity load.
I don't really want to load for target loads though I want decent longer range or tactical rounds therefore there is more than one factor.

Yeah I think I said that. Every source is slightly different but pretty much all in the same balk park. And also worth repeating is some are more conservative than others. I typically don't use the book for max velocity but I go by the saami spec for max pressure and use +p etc where applicable say for 9mm or others. And .308 instead of 7.62x51 because .308 is higher pressure.
I typically don't pick the MOST accurate load. But if one is very close to it which one usually is, at a higher velocity. I use that one. But I also record them all so whenever I want I can just go back and load the lower velocity load.
I don't really want to load for target loads though I want decent longer range or tactical rounds therefore there is more than one factor.
yes im starting low and safe for now to just hit steel. once i get a couple hundred down then ill start tweaking for accuracy @ range. Shooting is really my only hobby, outside of my kids and grandkids and football...
i dont compete or hunt as of now. I may think about competition later on but I am paralyzed in a Wheelchair and need a tripod to shoot so most comps are not wheelchair friendly comps. I may hunt in next couple of years. but for now its fun for me and reloading keeps my very busy mind actively engaged in an activity that involves thought and precision and mathematical numbers which im pretty good at. I am kinda a perfectionist..except typing in forums bad measurements LOL

Yeah I think I said that. Every source is slightly different but pretty much all in the same balk park. And also worth repeating is some are more conservative than others. I typically don't use the book for max velocity but I go by the saami spec for max pressure and use +p etc where applicable say for 9mm or others. And .308 instead of 7.62x51 because .308 is higher pressure.
I typically don't pick the MOST accurate load. But if one is very close to it which one usually is, at a higher velocity. I use that one. But I also record them all so whenever I want I can just go back and load the lower velocity load.
I don't really want to load for target loads though I want decent longer range or tactical rounds therefore there is more than one factor.
again thank you for all this as well as @baker3gun and others all were most helpful this afternoon while my office is dead.

I get it, and you all have giving me a wealth of info.

Still everyone is dancing around the question at hand...
If ALL variables are met, and this round is measuring @ .60 shorter than load data. BUT is still in SAAMI specs......
...

#1 SHOULD a round thats within SAAMI spec COAL that has A min powder charge, cases also in spec. FIRE IN A RIFLE.
#2 IF said round has a few that may be 0.60 shorter than the others, BUT also still in SAAMI spec COAL not touching lands nor compressing powder FIRE IN RIFLE.
...

I am asking question before i even think about firing one of these. So why am i on a path to kaboom? am i missing something?
Friday!!

Disclaimer - it's hard to keep up with fast moving threads, so I'll just comment on a few things.
Also, I liked gmerkt's comment, and I haven't even read to the next page yet, so maybe there will be more to that discussion.

However, the primary issue is this: OP hollister has concerns and good questions.

So. If an experienced loader reads this thread, and sees the hollister questions above, then the experienced loader may have some concerns. The comments give the appearance of care and caution and wise progression, and that's good, but they also give cause for concern.

IMO - Mr. Hollister would be well served by big picture perspective, and by a rational reminder: people will be happy to advise, but only one person on earth is responsible for the behavior of that round, and some of the questions you ask should not be asked. Instead of asking for certain approval from others, the safest path forward is to obtain adequate knowledge so that you can arrive at your own confident self-approval.

It seems unlikely to me that the rounds you describe are even marginally unsafe.
I don't think you need to rush to disassemble them.
I suggest that your time may be better spent acquiring the understanding that is needed to conclude that they are fine.

A few posters here are making the exact same points, with only slightly different language, and they were doing so before I jumped in.
So I still say, slow down a bit and wrap your head around the critical elements.

In response to the quoted items above, I will give an accurate answer: any round you make will "fire in a rifle". That's not a good benchmark for assessment.

If you aren't compressed,
and you aren't into the lands,
and you are loading on the low end of the charge range,
and your bullet isn't seated so deep that it's full-diameter section (bearing surface) is buried below the case mouth,
and your bullet isn't seated so shallow that you barely have any neck tension on the bullet,
and you are sure of your powder and the charge,
and you are sure of all of the above,
then those rounds are fine, and it is nearly impossible for anything to go wrong.
This paragraph is the answer to your questions about how much COAL can vary before something goes wrong.
It can vary a lot.
You will learn that large variations in COAL result in large variations in accuracy.

It's unwise to jam a bullet 30 thou into the lands,
and it's unwise to make a round that has a 1 inch jump,
but also recognize that for most cartridges and chambers, the case mouth of empty brass is usually less than 1 inch from the lands, so the only way to get in trouble with too much jump is to load a really weird round that has the bullet seated waay too far into the case.

I typed a lot of words on this thread. Long posts.
That's my reaction to wise questions asked by a wise new loader who doesn't seem to quite yet grasp the essential concepts.

It gets us back to saami.
SAAMI is a great guideline, but it is also safe to load non-SAAMI ammo that fits your gun. Just know where the limits are, and what can get you into trouble. You can find that in earlier posts by me and the other people who are helping you on this thread.

Hope this helps.

So. If an experienced loader reads this thread, and sees the hollister questions above, then the experienced loader may have some concerns. The comments give the appearance of care and caution and wise progression, and that's good, but they also give cause for concern.

IMO - Mr. Hollister would be well served by big picture perspective, and by a rational reminder: people will be happy to advise, but only one person on earth is responsible for the behavior of that round, and some of the questions you ask should not be asked.
Bingo! From reputable sources. Aka not online..
But its ok I forgive you.

He's stating this because I mentioned as a general rule of thumb you want as much bullet down in the neck (to grip the bullet with tension) as the diameter of the bullet and gave a few examples.
Ah.
Yep.
That is a common rule of thumb, and explained well.
Usually, it is not difficult to achieve,
but sometimes a guy will try something funny, like loading up 53gr Vmax .224 with a COAL that puts the bullet at the lands in a bolt gun.
In that scenario, you may not achieve .224" of bearing surface gripped by the case neck.
Usually, when I see that I have barely any bullet gripped by the case, I abandon that track and seat deeper.

SO QUESTION FOR ALL
IF I GET A D2L AND TAKE -.20 OFF AND CONFIRM MY LANDS MAX LENGTH IS X(1.970)

ARE MY ROUNDS PREVIOUSLY LOADED @ MAX LENGTH OF 1.910

IS THAT .60 DIFFERENCE ENOUGH NOT TO SHOOT THEM? EVEN THOUGH ALL OTHER ASPECTS OF THE ROUND(case length, powder) IN QUESTION IS STILL WITHIN SAAMI SPECS OF COAL?
you put the decimal in the WRONG place again: "take - .20 OFF AND", it should be: - 0.020".
If you shortened the D2L by 0.200" the bullet would fall into the case.
Way different...

.

Last Edited:
Friday!!

Disclaimer - it's hard to keep up with fast moving threads, so I'll just comment on a few things.
Also, I liked gmerkt's comment, and I haven't even read to the next page yet, so maybe there will be more to that discussion.

However, the primary issue is this: OP hollister has concerns and good questions.

So. If an experienced loader reads this thread, and sees the hollister questions above, then the experienced loader may have some concerns. The comments give the appearance of care and caution and wise progression, and that's good, but they also give cause for concern.

IMO - Mr. Hollister would be well served by big picture perspective, and by a rational reminder: people will be happy to advise, but only one person on earth is responsible for the behavior of that round, and some of the questions you ask should not be asked. Instead of asking for certain approval from others, the safest path forward is to obtain adequate knowledge so that you can arrive at your own confident self-approval.

It seems unlikely to me that the rounds you describe are even marginally unsafe.
I don't think you need to rush to disassemble them.
I suggest that your time may be better spent acquiring the understanding that is needed to conclude that they are fine.

A few posters here are making the exact same points, with only slightly different language, and they were doing so before I jumped in.
So I still say, slow down a bit and wrap your head around the critical elements.

In response to the quoted items above, I will give an accurate answer: any round you make will "fire in a rifle". That's not a good benchmark for assessment.

If you aren't compressed,
and you aren't into the lands,
and you are loading on the low end of the charge range,
and your bullet isn't seated so deep that it's full-diameter section (bearing surface) is buried below the case mouth,
and your bullet isn't seated so shallow that you barely have any neck tension on the bullet,
and you are sure of your powder and the charge,
and you are sure of all of the above,
then those rounds are fine, and it is nearly impossible for anything to go wrong.
This paragraph is the answer to your questions about how much COAL can vary before something goes wrong.
It can vary a lot.
You will learn that large variations in COAL result in large variations in accuracy.

It's unwise to jam a bullet 30 thou into the lands,
and it's unwise to make a round that has a 1 inch jump,
but also recognize that for most cartridges and chambers, the case mouth of empty brass is usually less than 1 inch from the lands, so the only way to get in trouble with too much jump is to load a really weird round that has the bullet seated waay too far into the case.

I typed a lot of words on this thread. Long posts.
That's my reaction to wise questions asked by a wise new loader who doesn't seem to quite yet grasp the essential concepts.

It gets us back to saami.
SAAMI is a great guideline, but it is also safe to load non-SAAMI ammo that fits your gun. Just know where the limits are, and what can get you into trouble. You can find that in earlier posts by me and the other people who are helping you on this thread.

Hope this helps.
thank you so very much. I really appreciate it, your knowledge is a great help to me. I did get all the answers i needed and so much more great info that will go to very good use. I do understand vastly more now and admit was being overly cautious on a conclusion i knew the answer to. just started overthinking instead of trusting the rules, numbers and process.
thank you

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