COAL and 95-grainers

[grayfox]

OK, this thread is for you better-shooters-than-me out there (and there are quite a few I know!!  lol).
I have a few hundred in quantity of various 95 grainers, but most of them seem to need a, kinda-sorta, short seating in the case.

95 Noslers mostly BT, 2.220 or 2.210 to the lands, depending on the rifle.
95 Berger classic hunters - 2.200 to lands.
95 SST, 2.203 lands (I have 'em and they shoot fine, but not really a preferred pill right now).

So for most of these I've been using the conventional wisdom of ~0.060 off of lands, which puts them all about 2.150-2.170 depending.

What do y'all think about seating them up a bit more, for a bit more room, but still have accuracy?

I also have some 95 SMK's and they have lots of room, lands are at 2.318.
And 90 TGK's, they go out to 2.338.

Anyway, I'm wondering if seating up to say 2.180 (~20 off lands) how would they all perform?
My main babies are a 20" faxon (gas) and my 22" uintah (bolt).

And during the current unpleasantness it would be nice to stick to the ones I have on hand... just sayin'.

[Dino11]

Seat a couple of dummy rounds until you get full bearing surface contact and then measure them, you can jump this round pretty far. Just make sure you use a comparater to check the seating depth with the bullet that you are measuring. I have a bunch of short bullets in my stash and have not had any issues with them. Other than the fact the ones I have are not match grade. I need to go to the reloading room and inventory it, I don't even know what I have exactly.

Hell I had guys tell me that I wouldn't be able to shoot Berger 115 gr bullets and they were the the best ones I used. I pushed them out to a mile this summer.

[r.tenorio671]

.....FWIW, over the years one particular aspect of reloading that has stuck with me was to ensure sufficient amount of bullet was seated in the neck of a cartridge to securely hold it to prevent setback, tilting, etc. Granted it may be an "old" concept borne back in the day before the advent of super long and super sleek bullets. This was reinforced during my foray into 300blk and flatbased bullets were the more common format for 100-130gn bullet weights used in supers.

...the other thing I've learned over the years is that the popular recommendations for seating depths and amount of jump don't always apply, it comes down to individual barrels/chamber and the only way to determine what is "best" for achieving ones objective is to test, just no way around it. Sometimes the objective itself needs to be reassessed, i.e., is it realistic.

.... to the OP, if the bullets in question aren't being jammed into the lands at their longest possible COAL, while having sufficient bullet retained in the case neck and don't exceed the magazines internal COAL allowance....then I'd just start at that longest allowable COAL length regardless of the amount of jump, test and work backwards as required.

...BTW, I'm a gasser only user/reloader so my remarks are based strictly on MY experiences loading for my gassers...

[Thelaststraw]

I've been running 95 VLDs at 20k and 30k jump with good results and both were just shy of mag length in ASCs. I mostly stick to the 20k jump for simplicity and it puts the bottom of the bearing surface right at the shoulder/neck junction (not measured, just eyeballed). If I was using a powder like LVR rather than bulky extruded powders I would probably seat deeper with the short 95s.

[Dgjr]

Ok, I will give you what I would do or one way to proceed that you might not have thought of and a little theory as well.  First, barrel vibration or harmonic nodes occur around every 0.006" or so.  This varies due to many things like barrel material, diameter, length, etc...  Hence, there is no magic number that you can just seat a bullet that will do good things except by shear luck.  There is a way to reach your intended working accuracy potential.  Here is one way, someone might proceed.

Here's the thing.  This all turns into a timing issue.  A barrel will vibrate when the cartridge is fired very much like a steel pipe if you strike it on one end with a hammer. This vibration runs up and down the barrel and diminishes over time, a very short amount of time.  Very good accuracy happens when the projectile exits the barrel  while the barrel is going through the zero plane during its ringing cycle.  If the bullet exits while the bore is pointed elsewhere, the bullet will go elsewhere.

One way to find the best a given bullet, powder and primer combo will perform is to fine a more stable combustion node and then tune the bullets timing with seating depth changes.  Here is a quick look into one such method.

Start with loading some cartridges with the same bullet at the same length and charge the cases with 0.3 grains of increasing powder charge from a safe starting load up to a max loading point.  Just one round each charge weight.  Shoot these over a chronograph and write down the charge weight and the velocity for each shot. When done, look at the data and look to see if you can find a place where increasing the powder only moved the velocity a small amount.  This might happen in several places in your data.  Something like: charge x = 2770, charge x+0.3 = 2800, charge x+0.6 = 2807, charge x+0.9 = 2832.  A stable combustion spot might be between the +0.3 and the +0.6 load.  Lets say x+0.4 or x+0.5.  This is where a little more or less powder during charging will have a small affect on your velocity.  Example: lets pick a powder charge of X +0.5 grains for the stable load.

Once a stabled combustion load for that powder/primer and bullet combo has been found, the seating depth tests can be done to find the seating where it all comes together.  Start at some point off the lands or away from sticking in or jamming into the lands by at least 0.010" maybe 0.020".  Load some rounds, each loaded with our example of X +0.5 grains of powder, at several lengths down from that point in 0.003" increments.  An example: lands at 2.200", start at 2.180", 2.177, 2.174,  etc. Load 5 rounds at each depth to test and shoot each seating depth group on paper.  The best group (depth) will point to the more correct seating depth. There is NO magic number for this.  It will be different in every rifle with every powder and every bullet and yes even every different brand of primer.   

Looking at this info, it can be understood why folks try to find the bullet that they want to shoot and the powder that they want to use and proceed through the testing to find the load that their rifle shoots the best, then try to stay with that same load.  This is not to say that one can't work up a different load with different powder/primer/bullet and put two, three or four recipes in their reloading book.  To change anything in the combustion timing sequence, and the projectile simply will not be at the right place at the right time on exit.  

I don't know how many want or need this level of potential accuracy.  ( potential, because this chosen powder/primer/bullet just might not shoot in the test rifle ). With the way components are these days, simply finding a good load might be good enough for most needs.  I know this is more info than the OP asked for, but there is a reason for testing primer/powder/bullet combos and moving the seating depth around.  I have simply tried to explain what I think it does and why it matters.  Since the OP looks to have bullets of the same weight, finding a good stable powder charge first, then a seating depth might be found that works well with all of them.  There is a difference, but good notes in a log would at least allow for keeping most things the same and only a small seating depth change when loading a different 95 grain bullet.  If I remember correctly, Velocity will move the bullets up and/or down on the paper, Seating Depth will open and close the group size. Or a tuner will solve the issue. Simply remember the setting number for each bullet you tune it for. Easy!

Enjoy and have fun!  Its all good.

[Thelaststraw]

Actually that is exactly how I found my seating depth by pure luck. I have been using the OCW method thinking the Optimal Charge Weight was about finding a velocity node that was found within a charge weight band. I just recently learned that the OCW is mainly about finding the timing of the barrel harmonics and having a fudge factor in charge weights is only a side benefit.

I got lucky and my seating depth worked good with my charge weight as far as case fill and velocity with just one morning of load development. Could it get better? Probably....for my needs though it has worked just fine so far.

[grayfox]

This is close to the "modified" Chris Long approach that I already use. Optimal barrel timing for the regular guy type of thing.
He also developed an empirical formula for predicting what MV will be that node, I find it pretty accurate although it does use several assumptions. None the less, it has been a useful approach for me.
The main reason for my original question is whether we can bump out the bullet seating enough to lower the pressure and increase powder room so as to get up to the (next) node, which has to be pretty close b/c we're not talking about much change in seating depth.
I might try some loads at the ~0.020 jump instead of my usual ~0.060 and see what happens.

[Dino11]

As long as the bearing surface reaches the bottom of the neck and your not jammed into the lands.

[grayfox]

Roger that, thanks.

[StoneHendge]

I jumped the 95 gr Berger Hybrid Hunters about 0.1" in my 243 LBC. They shot so well there there was no need to do a depth ladder. My guess is that they will shoot great anywhere from 0.001" to 1.000"

I jumped the 95 gr SMK/TMKs 0.03" which is where I normally start a bullet that might be picky. They shot extremely well there to 600 yards, at which point a large portion of them were randomly transported to another dimension.

I personally don't like to go closer than 0.03" given potential measurement error (calipers and the Hornady gauge) as well as the small amount of size error from the manufacturer, the potential for slight discrepancies between the ogive and the area where the die touches the bullet, etc. I can vouch that a bullet accidentally jammed into the lands can ruin your day along with your bolt.

[grayfox]

Thanks SH, I typically try to take those uncertainties into my specs... I haven't been going closer than ~0.050 for most all of my shooting, measure distance to lands and take off a bit of margin from that. I can't say they have been terrible at my current seatings of ~060.
The one thing I think I did back in the summer/early fall was to load them up too hot, so trying to find some more realistic MVs, for these 90-95ers I want to use some Varget, esp since it just came back into stock and I got some more powder... if I really wanted to bump the speed I'd stay with Lever, which I have plenty of too... thought this would be a good 6Arc mini-project.
Appreciate all the ideas guys, thanks.

[r.tenorio671]

...I tend to prefer semi versions of military style platforms over the years, pretty much down to AR platforms only now, 15's and 10's. For any bullet I might use, I start at the max allowable COAL by the magazine internal limitation. I'll start at .010-.020 off toouch point to find the particular bullet/powder in use to determine charge weight then adjusting seating depth modification backwards (if necessary). I don't ascribe to "chasing the lands" philosophy, never have in my shooting/loading endeavor over the years, primarily due my exclusive use of mag fed semis. Bullet technology has advanced to the point that greater flexibility in how close/far one seats to the lands is less restrictive than in the past, especially for AR platforms.

[Old Marine]

Grayfox, I will add my barrels measurements for 95 gr pills, just touching.
95 Berger classic hunter 2.190
95 Berger target 2.270
95 Horn. SST 2.170
90 Sierra TGK 2.250

[6mmNewB]

Ok, I will give you what I would do or one way to proceed that you might not have thought of and a little theory as well.  First, barrel vibration or harmonic nodes occur around every 0.006" or so.  This varies due to many things like barrel material, diameter, length, etc...  Hence, there is no magic number that you can just seat a bullet that will do good things except by shear luck.  There is a way to reach your intended working accuracy potential.  Here is one way, someone might proceed.

Here's the thing.  This all turns into a timing issue.  A barrel will vibrate when the cartridge is fired very much like a steel pipe if you strike it on one end with a hammer.  This vibration runs up and down the barrel and diminishes over time, a very short amount of time.  Very good accuracy happens when the projectile exits the barrel  while the barrel is going through the zero plane during its ringing cycle.  If the bullet exits while the bore is pointed elsewhere, the bullet will go elsewhere.

One way to find the best a given bullet, powder and primer combo will perform is to fine a more stable combustion node and then tune the bullets timing with seating depth changes.  Here is a quick look into one such method.

Start with loading some cartridges with the same bullet at the same length and charge the cases with 0.3 grains of increasing powder charge from a safe starting load up to a max loading point.  Just one round each charge weight.  Shoot these over a chronograph and write down the charge weight and the velocity for each shot.  When done, look at the data and look to see if you can find a place where increasing the powder only moved the velocity a small amount.  This might happen in several places in your data.  Something like: charge x = 2770, charge x+0.3 = 2800, charge x+0.6 = 2807, charge x+0.9 = 2832.  A stable combustion spot might be between the +0.3 and the +0.6 load.  Lets say x+0.4 or x+0.5.  This is where a little more or less powder during charging will have a small affect on your velocity.  Example: lets pick a powder charge of X +0.5 grains for the stable load.

Once a stabled combustion load for that powder/primer and bullet combo has been found, the seating depth tests can be done to find the seating where it all comes together.  Start at some point off the lands or away from sticking in or jamming into the lands by at least 0.010" maybe 0.020".  Load some rounds, each loaded with our example of X +0.5 grains of powder, at several lengths down from that point in 0.003" increments.  An example: lands at 2.200", start at 2.180", 2.177, 2.174,  etc. Load 5 rounds at each depth to test and shoot each seating depth group on paper.  The best group (depth) will point to the more correct seating depth. There is NO magic number for this.  It will be different in every rifle with every powder and every bullet and yes even every different brand of primer.   

Looking at this info, it can be understood why folks try to find the bullet that they want to shoot and the powder that they want to use and proceed through the testing to find the load that their rifle shoots the best, then try to stay with that same load.  This is not to say that one can't work up a different load with different powder/primer/bullet and put two, three or four recipes in their reloading book.  To change anything in the combustion timing sequence, and the projectile simply will not be at the right place at the right time on exit.  

I don't know how many want or need this level of potential accuracy.  ( potential, because this chosen powder/primer/bullet just might not shoot in the test rifle ). With the way components are these days, simply finding a good load might be good enough for most needs.  I know this is more info than the OP asked for, but there is a reason for testing primer/powder/bullet combos and moving the seating depth around.  I have simply tried to explain what I think it does and why it matters.  Since the OP looks to have bullets of the same weight, finding a good stable powder charge first, then a seating depth might be found that works well with all of them.  There is a difference, but good notes in a log would at least allow for keeping most things the same and only a small seating depth change when loading a different 95 grain bullet.  If I remember correctly, Velocity will move the bullets up and/or down on the paper, Seating Depth will open and close the group size.  Or a tuner will solve the issue. Simply remember the setting number for each bullet you tune it for.  Easy!

Enjoy and have fun!  Its all good.

Thank you for taking the time to share your knowledge. Excellent information!