Yesterday I received a comparator and used it to measure 20 cartridges that I had previously loaded,that proved to be accurate,but I believed could be better.well when I did the measurements there was quite a variation in numbers,but when you look to see how much the calipers move its miniscule.how much do you feel having them the same length effects accuracy.maybe I'm not a good enough marksman to see the difference,but say for a competitive shooter.
Seating depth and accuracy
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Using a caliper you can get a variation depending on how ham handed you are and how good your calipers are. A human hair is .0015”-.003”, a sheet of paper is about .004”.
When is set up my seating depth I soft seat a bullet into the case. Then close the round in the chamber. Once this is done I run the round back into the die with the ram up and turn the seating stem down until it touches the bullet, then turn it down another .020”. I know that the throat will advance or wear during the season but I leave this seating depth as is for the year.
When is set up my seating depth I soft seat a bullet into the case. Then close the round in the chamber. Once this is done I run the round back into the die with the ram up and turn the seating stem down until it touches the bullet, then turn it down another .020”. I know that the throat will advance or wear during the season but I leave this seating depth as is for the year.
Seating depth can make a difference accuracy wise for some rifles.
I would suggest that you neck resize only, leaving about .020 in of the neck at the shoulder junction the same size as the throat in your chamber.
If the throat of your rifle isn't to deep, the bullet should enter the leade/rifling before the neck is cleared by the base of the bullet. This ensures that your bullet is feeding consistently to the axis of the bore.
I have a few rifles with minimum spec throat diameters and they don't care how far the bullet is seated from the leade.
One is a Tikka T3 and the other is a Model 1935/98 Mauser. They're factory production rifles and shoot as well as custom rifles with custom made reamers.
I would suggest that you neck resize only, leaving about .020 in of the neck at the shoulder junction the same size as the throat in your chamber.
If the throat of your rifle isn't to deep, the bullet should enter the leade/rifling before the neck is cleared by the base of the bullet. This ensures that your bullet is feeding consistently to the axis of the bore.
I have a few rifles with minimum spec throat diameters and they don't care how far the bullet is seated from the leade.
One is a Tikka T3 and the other is a Model 1935/98 Mauser. They're factory production rifles and shoot as well as custom rifles with custom made reamers.
unfortunately when I started reloading I would search the internet for 223 and 99%of the traffic was for ar,most of all the conversation was geared towards mag length.there was not alot about refining a 223 load.i understand that most people use 308,6mm and 6.5 etc,I get that.but I would like to work my loads in 223 to the t.i just sent for some forster dies that have a bushing to bump the shoulders and orderd .245 bushing with it.a couple questions to your answers,so on my tika I might find that uneven seating depth has no barring on my accuracy.im in the process of ordering an extended mag that if I do find a load closer to the lands I can mag feed.im trying to limit how much I spend in the 223 reloading because I'm fairly far out from were I started and my gut tells me when I turn 65 I'm going to want a 6.5.i just feel thats the trajectory lol.i have been working on some load development for ruger ranch but I feel I will never be satisfied,so leaving that were it is.well in the next 3 months I will be doing all testing in my tika and savage 10 starting from the lands.quick question should you stick with separate brass for each rifle.thanks
Seating depth is huge! get it bang on. It will make a difference in all rifles. If you worked up a load with an Optimal charge weight, and an Optimal seating depth, then your load will be more forgiving. Some might not notice a huge seating depth change in accuracy, but it's probably because they got lucky when they set up a load.
I would keep each batch separate because you're going for consistency, and it also reduces wear on your brass, esp if you find the chamber lengths are different between the two.
I'm using a used barrel, and have the used brass from the previous owner. When I installed the barrel, I used brand new go/no-go gauges, and checked 4 times. My fired brass is about 8 thou longer than his, when I use the Hornady comparator to measure brass length from the base to the shoulder. I'm curious what you'll find with your rifles.
I have sneaking suspicion that a 69 sierra load i had a few years ago but abandoned because of a flier here and there will resurface,why.because it was range pickup brass,the scale to measure powder was well not great,and my seating was inaccurate.i think I wasted a barrel figuring that out.i shouldn't say wasted it was fun but frustrating.it will be interesting going forward with new instruments and slowly learning to use them.i have 75gr hornady bthp that is nice and will mess around with seating and proper shoulder alignment and see were it goes.i know I will need a new barrel by the end of summer.and then back to square one except with alot more knowledge.when I get the dies here and setup I know will have a few questions.
Right now hornady and sierra I'm wanting to try some vld Berger in the 80 gr once I have a follower,now that I can measure from the lands.I have read about people that stabilized the 80's with 1 8 twist.i was messing around until late last night with the calipers and the comparator learng to keep it straight.it takes getting used 2.
For VLDs, here is some info from Berger about seating depth.
https://bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/
...and Berger’s twist rate calculator:
https://bergerbullets.com/twist-rate-calculator/
For the calipers and the comparator, I apply gentle pressure to the base of the brass to help center it. It’ll feel right when you get used to it.
https://bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/
...and Berger’s twist rate calculator:
https://bergerbullets.com/twist-rate-calculator/
For the calipers and the comparator, I apply gentle pressure to the base of the brass to help center it. It’ll feel right when you get used to it.
The reason why I ask is because: ogive measurement will vary a minuscule, from one lot number to another, either longer or shorter, once seated. Some brand name manufactures may not have consistent ogive length, from shank to ogive. Something to checkout. You'll eventually get the knack to find the proper pressure (sweet spot) with
your calipers.
I was referring to measuring the brass alone. Values I'm using are:
1.455" or shorter: use for foulers where I can make hotter loads to expand the brass
1.456", 1.457", 1.458" are all lengths I sort by. I will make groups and choose brass only from one batch for consistency.
Max fired brass length in my rifle measured with the Hornady comparator is 1.4585"
Never measure warm brass that has been warmed up in an oven to dry if you wet tumble. It's longer compared to when it is at room temp.
I suppose this is part of the variance we all run into when you leave a round in the chamber of a warm barrel for any length of time. Not only may the powder be affected by the heat, but the brass will grow as well.I have no idea how much either of these matter on the target. I just know these are more variables.
You could buy a box to play with, and maybe some others might chime in with success with certain powders? You may turn into a velocity hunter with those though.
I really like that Berger published that. Shows they are listening to their customers and trying to figure things out.
If you load close to the lands, a .005 error can make a great difference in pressures etc. - and if you have more than one rifle to load special for, it just gets silly for a hunter that needs a few shells for his pocket to need special loads for each rifle. If we back off from the lands, there is less variation from rifle to rifle - and no chance of a bullet stuck in the chamber and powder in the action. When something needs shooting, dependability of function trumps extreme accuracy - Mrs. Whatif has a few questions. Whatif you grab the wrong box of bullets? Whatif someone needs a couple of your bullets? Whatif your gun is sighted for some peculiar load and you borrow a few bullets? Whatif you get your bullets from one box and put them in another box - meant for a different rifle? Whatif you have more pertinent things to think about as you pull the trigger?
For target, we are looking for little problems to solve - and this is likely your case, but for hunting, we need a load which can solve every problem - change animals, change guns, change ranges, change temperatures, and this load will always do it's job faithfully - this is a better goal.
I have a hunch that there may be more important issues to spend the first years of handloading learning about - like neck thickness and tension and headspace - there really is no jump from caseneck to lands, the bullet is supported by the case long after it is in the lands - but if the neck is not concentric and held tight in the chamber, it can do a bad job of starting the bullet straight into the lands. A crooked lockup or casehead can slap the cartridge off to one side just as the bullet is getting it's marching orders. I wonder if we could put a wrap or two of masking tape around the neck so that it is held in center - the tape having just enough squeeze to allow the bullet to release when the pressures rise.
Old guy done babbling - off to the river.
For target, we are looking for little problems to solve - and this is likely your case, but for hunting, we need a load which can solve every problem - change animals, change guns, change ranges, change temperatures, and this load will always do it's job faithfully - this is a better goal.
I have a hunch that there may be more important issues to spend the first years of handloading learning about - like neck thickness and tension and headspace - there really is no jump from caseneck to lands, the bullet is supported by the case long after it is in the lands - but if the neck is not concentric and held tight in the chamber, it can do a bad job of starting the bullet straight into the lands. A crooked lockup or casehead can slap the cartridge off to one side just as the bullet is getting it's marching orders. I wonder if we could put a wrap or two of masking tape around the neck so that it is held in center - the tape having just enough squeeze to allow the bullet to release when the pressures rise.
Old guy done babbling - off to the river.
Your Tikka will not be the same as your Savage. Mainly because the Tikka will have a tight throat and chamber dimensions. Your Savage Mod 10 will likely be on the generous side all the way around.
My experience has been that seating depth is a pretty forgiving number, unless you're playing with no jump at all.
I tested a 243 Tikka a few years ago with jumps ranging from 0.005" to 0.120", 5 rounds at each length. From 0.005" to 0.040" of jump there was very little difference in group size, beyond that the groups opened up somewhat.
My advice would be, don't wear out a barrel experimenting with changing your jump by a few thou at a time, in most rifles there's a very good chance you won't see much difference at all until you move 20-30 thousandths or more.
I load for 0.015" jump in my target and hunting rifles, because some experimenting has shown me that being 0.010" closer or further from the lands really doesn't make
much difference.
I get reliable loaded round extraction, too.
I tested a 243 Tikka a few years ago with jumps ranging from 0.005" to 0.120", 5 rounds at each length. From 0.005" to 0.040" of jump there was very little difference in group size, beyond that the groups opened up somewhat.
My advice would be, don't wear out a barrel experimenting with changing your jump by a few thou at a time, in most rifles there's a very good chance you won't see much difference at all until you move 20-30 thousandths or more.
I load for 0.015" jump in my target and hunting rifles, because some experimenting has shown me that being 0.010" closer or further from the lands really doesn't make
much difference.
I get reliable loaded round extraction, too.
