seating depth starting point

[JFrank]

I’ve shot more than a thousand rounds jammed .030 without any issues of soft seating or bullets pulling out of the necks.
You just need enough neck tension ( bullet hold ) to do the job.
J

 

[BoydAllen]

These days, for any caliber that I want the finest accuracy from, I want to know were touch and jam are for each barrel and bullet. I think that the method for finding touch that Alex Wheeler demonstrates in the video on his web site is the most precise, and I measure jam with the neck tension that I plan on using for loading with cases that have been fired. As a review, classic jam is a particular seating such that if you seat it any longer the bullet will be pushed back to it when the round is chambered. For years I have used short marks, shorter than wide, for my starting, powder charge search, with .002 neck tension. Some powders like more but I can do the rough in work with .002, unless I have good information that something different works better with that particular powder. In the past, for my PPC if I seated .003 shorter than jam, I never pulled a bullet. I get the impression from reading posts that there are a lot of shooters who do not have precise information on how they are seating their bullets, relative to touch, or jam. Rather than saying that I am jamming bullets, I prefer to say that I am seating some distance into the lands or shorter than touch. Unless there is a magazine length issue, I see no reason not to seat into the rifling. Guys talk about excess pressure but since I do the entire test seated into the lands and start low, that is not an issue.

 

[marchx]

For PRS accuracy requirements somewhere between .020- .010 in the lands could do the job. Really. Their targets are big and usually at 300-600 m. if you could feed the BR case reliably from the mag, you should be ok.

 

[urbanrifleman]

I wouldn't shoot a lot of jam in PRS because of the bolt drop. The 105 Hybrid should shoot well beyond PRS requirements jumped 20 or 30.

But I wouldn't get in a twist either way. I usually shoot 20 in from touch on most everything. But that's not action shooting.

 

[Clancy]

@Ruger15151 after 25 years of loading I don’t really need a lesson in terminology. I do appreciate the Erik Cortina wisdom you found on YouTube though.

To be clear, when you say “I’m jamming 10” everyone and their dog knows what you meant.

To be completely transparent. From the moment a bullet first contacts rifling, any seating depth forward or longer than that measurement introduces a chance of extracting a live round and leaving the bullet in the barrel.

Yes, by all means, it’s much more likely to happen in a dirty rifle than in a clean one, and even more likely in well worn, fire cracked barrels. Low neck tension, or interference, makes it even more likely.

We can argue all day about where my lands actually are, but I think the wheeler method is pretty fool proof if you have decent hearing and relatively good dexterity. I’ve tested it against both the hornady tool and a stub gauge and came out with the same number, so I’m good with that.

Telling a guy that’s going to fire 10-15 rounds strings with 200 rounds between cleanings that it’s fine and dandy to seat into the lands is poor practice, in my opinion.

 

[JFrank]

To be clear, when you say “I’m jamming 10” everyone and their dog knows what you meant.

yep

 

[Jeff Porter]

I have run the Berger 105’s from 10-25 off in different 6BRA barrels with good results. Sling shooter shooting 70-120 shots in a day , 22 shots in a string of fire so I don’t want to jam if I can help it. Chamber full of powder when a cease fire is called is not a good day.

I do a 0.005” sweep from 0.005” off of touch back until I get a 0.2-0.3” group and continue until it opens up again. Depending how wide that spot is I may fine tune inside but as a sling shooter that usually works well enough.

 

[Jeff Porter]

I have run the Berger 105’s from 10-25 off in different 6BRA barrels with good results. Sling shooter shooting 70-120 shots in a day , 22 shots in a string of fire so I don’t want to jam if I can help it. Chamber full of powder when a cease fire is called is not a good day.

I do a 0.005” sweep from 0.005” off of touch back until I get a 0.2-0.3” group and continue until it opens up again. Depending how wide that spot is I may fine tune inside but as a sling shooter that usually works well enough.

I did a quick scan using 109 Berger Hybrids. I have dropped down to 2830 fps and set 10-20-30-45 off touch point. 3 shots each.

Clearly did not like 10 or 45 off but both 20 and 30 off were indicative of a good seating depth. I will use 0.020” off for a string in a 600 yard sling match this weekend. I may look at 0.015, 0.025 off and see if it gets better or if this is just a good “ flat spot” in seating depth.

 

[Liven The Dream]

I did a quick scan using 109 Berger Hybrids. I have dropped down to 2830 fps and set 10-20-30-45 off touch point. 3 shots each.

Clearly did not like 10 or 45 off but both 20 and 30 off were indicative of a good seating depth. I will use 0.020” off for a string in a 600 yard sling match this weekend. I may look at 0.015, 0.025 off and see if it gets better or if this is just a good “ flat spot” in seating depth.

View attachment 1651097

Are you shooting at Aurora ?

 

[Jeff Porter]

Are you shooting at Aurora ?

Atterbury

 

[Eric Leonard]

I use .002 neck tension and start as far in the lands as I can that the bullet won’t stick if I have to extract a loaded round.from there I shoot 3 shot groups and seat the bullets .003 shorter at a time until I find a spot where 2 depths in a row are knotting up well and then I’ll fine tune it from there.
I’m no good at finding the exact point where the bullet touches and don’t really ever measure anything. I just go by the marks on the seater die.

 

[ELR LVR]

I use .002 neck tension and start as far in the lands as I can that the bullet won’t stick if I have to extract a loaded round.from there I shoot 3 shot groups and seat the bullets .003 shorter at a time until I find a spot where 2 depths in a row are knotting up well and then I’ll fine tune it from there.
I’m no good at finding the exact point where the bullet touches and don’t really ever measure anything. I just go by the marks on the seater die.

Try this method, very easy to do:
Stick a blunt point cleaning rod down the barrel until it hits the boltface,
---Then Mark this point exactly at your muzzle.
Next, Stick a bullet through the chamber and lightly tap it against the rifling
Again Stick your cleaning rod in the front of the barrel and mark this second point at the muzzle.
Measure between the 2 points
This is the exact touching point of the bullet stopping at the rifling
Use this measurement as your starting OAL of "Touching" for a loaded round.
...then you can work back from there.

 

[Eric Leonard]

Try this method, very easy to do:
Stick a blunt point cleaning rod down the barrel until it hits the boltface,
---Then Mark this point exactly at your muzzle.
Next, Stick a bullet through the chamber and lightly tap it against the rifling
Again Stick your cleaning rod in the front of the barrel and mark this second point at the muzzle.
Measure between the 2 points
This is the exact touching point of the bullet stopping at the rifling
Use this measurement as your starting OAL of a loaded round then you can work back from there.

I’ve tried a bunch of different ways and if I do any of them twice in a row it’s always different. Not a lot but enough I don’t trust the numbers, as long as I can find the spot it shoots best and functions 100% I don’t really care what the measurement is, my seaters have micrometer tops and I just record the settings in case I need to make changes later.

 

[ELR LVR]

I’ve tried a bunch of different ways and if I do any of them twice in a row it’s always different. Not a lot but enough I don’t trust the numbers, as long as I can find the spot it shoots best and functions 100% I don’t really care what the measurement is, my seaters have micrometer tops and I just record the settings in case I need to make changes later.

Just thought I'd offer, I used to gauge rifle engraving on the bullet which was never very consistent
until I learned this method, it gives a pretty accurate starting point anyway

 

[BoydAllen]

@Ruger15151 after 25 years of loading I don’t really need a lesson in terminology. I do appreciate the Erik Cortina wisdom you found on YouTube though.

To be clear, when you say “I’m jamming 10” everyone and their dog knows what you meant.

To be completely transparent. From the moment a bullet first contacts rifling, any seating depth forward or longer than that measurement introduces a chance of extracting a live round and leaving the bullet in the barrel.

Yes, by all means, it’s much more likely to happen in a dirty rifle than in a clean one, and even more likely in well worn, fire cracked barrels. Low neck tension, or interference, makes it even more likely.

We can argue all day about where my lands actually are, but I think the wheeler method is pretty fool proof if you have decent hearing and relatively good dexterity. I’ve tested it against both the hornady tool and a stub gauge and came out with the same number, so I’m good with that.

Telling a guy that’s going to fire 10-15 rounds strings with 200 rounds between cleanings that it’s fine and dandy to seat into the lands is poor practice, in my opinion.

In the past, with the usual bullets I shot in my 6PPC short range group rifle, as long as I was .003 short of jam, with .003 neck tension, I never stuck a bullet. I do agree that many do not seem to have much of a handle on just where they are in the range between touch and jam. Granted I was shooting the cleanest powder that I know of, 133, and I never went more than 25 rounds between cleanings of some sort.

 

[Fuj]

On any of my new cats, I always start at touch. From there, I only go in.
If it's a hunting rifle with magazine, I start at mag length and then work
back.

 

[R.Morehouse]

For powder charges, I start at jam, use a 2-shot ladder until pressure, take the best of that, and work my way back with seating. I believe that starting at jam will show me pressure sooner, theoretically keep the load safer as I seat further into the case, and also give me a little better window when the temperature increases through the day. I let the target dictate where I go, but it seems I usually end up shooting the upper node in the lands when all is said and done. I like using the little Garmin during the whole process, it's SO easy to take advantage of and fun.....

Regards
Rick

 

[Jeff Porter]

I did a quick scan using 109 Berger Hybrids. I have dropped down to 2830 fps and set 10-20-30-45 off touch point. 3 shots each.

Clearly did not like 10 or 45 off but both 20 and 30 off were indicative of a good seating depth. I will use 0.020” off for a string in a 600 yard sling match this weekend. I may look at 0.015, 0.025 off and see if it gets better or if this is just a good “ flat spot” in seating depth.

View attachment 1651097

It works at 600 . The 8 was me turning the knobs the wrong way ‍.

This 197 was followed by two strings with .223 and 80.5’s in the same wind of 189 and 193

 

[JEFFPPC]

As long as you have a process that is repeatable to give you a reference point that is all you need. This is such a simple operation that gets butchered by people trying to sound smart.

 

[CharlieNC]

While it would be desirable to start with a short jump like 0.005, your length may be limited by the max magazine length. Look up the Berger seating depth testing recommendation with initial screening at several very long jumps, which surprisingly yield good results at times.