How far off the lands?

[ricky5042]

Hi all how far off the lands do you start testing at?

I don't have a Hornady O.A.L Gauge so I used a sized shell and just pressed a head into it and them put it in my rifle a few times while turning the shell then I measured it and it came out at 2.928" not ideal I know but its all I have to work with, this measurement I presume is right up to the lands, I then measured it with the bullet comparator and from the ogive it measures 2.358" and a friend recommended coming back 15 thou off the lands 2.343 this is where iv set my die at the moment and I would like to know what you guys think or do your selves.

Thanks

 

Rick

 

[DaveT]

There is no single 'right' answer as multiple other factors also come into play...EG

 

• Are you restricted to mag length rounds or willing to single feed longer ones?
• Are you loading your powder to max or beyond...watch out for raised startup pressures if ON the lands.
• Is your chosen bullet a VLD type or one more tolerant of 'jumping'?....look at Berger website recommendations for jump or jam with their bullets.

 

Speaking only for myself.... I generally try to load as long as I can to either ON or just barely off of the lands (.002") and see if I get good accuracy as I load test through the powder range that I select.

 

If no good there then I back of a few thou at a time BUT usually find that I don't need to.

 

Conversely / Interestingly enough I load my sons 260 rem with 139g Scenars to a good 20 thou OFF of the lands and it shoots great (jump tolerant bullet ogive)

 

My best advice would be stay away from the lands (especially jamming) by 10 thou unless you are a confident reloader and have worked your load up carefully ....also stress same if you do not have a reliably accurate set of tools for checkking your chamber max COL.

 

Also check your bullet type for Secant (probably better close to the lands) or Tangent (jump tolerant) design.

[ricky5042]

There is no single 'right' answer as multiple other factors also come into play...EG

 

• Are you restricted to mag length rounds or willing to single feed longer ones?
• Are you loading your powder to max or beyond...watch out for raised startup pressures if ON the lands.
• Is your chosen bullet a VLD type or one more tolerant of 'jumping'?....look at Berger website recommendations for jump or jam with their bullets.

 

Speaking only for myself.... I generally try to load as long as I can to either ON or just barely off of the lands (.002") and see if I get good accuracy as I load test through the powder range that I select.

 

If no good there then I back of a few thou at a time BUT usually find that I don't need to.

 

Conversely / Interestingly enough I load my sons 260 rem with 139g Scenars to a good 20 thou OFF of the lands and it shoots great (jump tolerant bullet ogive)

 

My best advice would be stay away from the lands (especially jamming) by 10 thou unless you are a confident reloader and have worked your load up carefully ....also stress same if you do not have a reliably accurate set of tools for checkking your chamber max COL.

 

Also check your bullet type for Secant (probably better close to the lands) or Tangent (jump tolerant) design.

Hi Dave thanks for that at present I am single loading so length not a problem my first load test with the N540 I went to 1/2gn above max 43.5gns and that gave the best group next highest was 40.5gns then 41.5gns so the next step would be to load them 15 thou off the lands and see if I can close the groups up a bit more, as new to loading compared to most would 15 thou be a good starting point or do you think come further off then work back the other way getting closer?

The bullets I was using were sierra 175gn HPBT Match im trying to develop a load which will be good for out to 400 at east holme then be good out to 1000 at bisley.

Thanks

 

Rick

[DaveT]

To me the logic of starting near the lands means that I only have to worry about going in one direction (ie OFF the lands) if I need to seek more accuracy.

 

I also like the idea that I am increasing the effective cartridge capacity by that approach which enables me to either insert a greater load or keep pressures down.

 

Either way i usually find accuracy close to the lands but in two cases out of five rifles have had to forfeit mag loading.

[DaveT]

Just to add to my previous post........ long COL (>SAAMI/CIP) & keeping pressures down is only the case until you get really close to or on the lands when starting pressures can / will increase significantly because the bullet has no 'run up' to engaging the riflings (its like trying to bump a car up over a kerb when you are already resting the tyres against the kerb) ....so watch out for increased pressures and only increment powder in small steps (.2 or .3 grains no greater) as you approach the lands.

[Andrew]

I start with the parallel sides of the bullet to the base of the neck then work out in increments to magazine length. This allows for optimal alignment, optimal pull weight (neck tension) and optiomal use of the combustion chamber. I have abandoned worrying about how far off the lands I am. I concentrate now on seating depth. Sounds like the same thing but it's really not. Not a 'popular' way to do it these days, but it was how I learned many ages ago and it works.~Andrew

[DaveT]

Many ways to skin the cat

[ricky5042]

Thanks for the replies guys I have yet to see whether it will go in the mag lol but I will and if it doesn't fit I may seat it deeper so I can still use the mag.

Rick

[foxing2night]

My advice would be to seat your bullet just kissing the lands or just off them, keep away from in the lands until you really know what you are doing,,

Follow Dave's advise and you will not go far wrong,,

 

Find a good powder bullet combination and primer

 

and go and play in the wind and get some good hard data,,

 

Darrel

[Chris-NZ]

There's an assumption there Darrel that guys know exactly where the lands are. Modified cases created from fired cases out of the particular rifle strike me as far better than SAAMI cases the gauge outfits supply.

 

If you're out on your measurement, you could end up with some touching the lands and some off which is worse situation than all touching or all not touching.

[Shootist]

Hi all how far off the lands do you start testing at?

I don't have a Hornady O.A.L Gauge so I used a sized shell and just pressed a head into it and them put it in my rifle a few times while turning the shell then I measured it and it came out at 2.928" not ideal I know but its all I have to work with, this measurement I presume is right up to the lands, I then measured it with the bullet comparator and from the ogive it measures 2.358" and a friend recommended coming back 15 thou off the lands 2.343 this is where iv set my die at the moment and I would like to know what you guys think or do your selves.

Thanks

 

Rick

 

I have found that a very good way to measure COL is to use a cleaning rod. First push your chosen bullet into the lands just enough to make it want to stay there. Put a cleaning rod down the barrel from the muzzle until it touches the bullet. Mark the rod. I use insulating tape, but a felt marker will also serve. Then tap the bullet out, remove it from the chamber, put the bolt in and close and de-cock it. push the cleaning rod in until it touches the bolt face and mark the rod again. Measure the difference between the two marks, and that's the COL to the lands. I've used this method alongside a Hornady COL gauge and never got more than a couple of thou' difference, which is what you are likely to get with a few measures of the gauge.

[DaveT]

I confess to being a little 'anal' about reloading measurements but the cleaning rod method is a bit too 'vague' for me.

 

I use a Hornady OAL tool and comparators but am probably going to convert to Shooting Shed equivalents to seek that bit more precision.

 

Opinions will differ but these measures can be critical to your safety (I am not that pretty but still value my face) so I will spend the cash for the peace of mind it brings me!

[MadSpaniel]

I start with the parallel sides of the bullet to the base of the neck then work out in increments to magazine length. This allows for optimal alignment, optimal pull weight (neck tension) and optiomal use of the combustion chamber. I have abandoned worrying about how far off the lands I am. I concentrate now on seating depth. Sounds like the same thing but it's really not. Not a 'popular' way to do it these days, but it was how I learned many ages ago and it works.~Andrew

 

My thoughts exactly. I used to sweat about how close to the lands I could load. Now I start as Andrew does with at least a full bullet diameter seated. My current 6.5x55 is what seems like a country mile (120 thou) off the lands, and she shoots as sweetly as any other rifle I have ever owned.

[jcampbellsmith]

 

My thoughts exactly. I used to sweat about how close to the lands I could load. Now I start as Andrew does with at least a full bullet diameter seated. My current 6.5x55 is what seems like a country mile (120 thou) off the lands, and she shoots as sweetly as any other rifle I have ever owned.

At a slight tangent to the initial post. Do you test for doughnuts on a regular basis or not? Regards JCS

[Tony.H]

At a slight tangent to the initial post. Do you test for doughnuts on a regular basis or not? Regards JCS

do you mean when you have neck turned the brass, and then after firing a few times, you get an internal doughnut, in the base of the neck where it meats the shoulder?

 

tony

[nitewatch]

it may be just coincidence but no load I have developed yet has been most accurate any closer than 10 thou off the lands. talking to mike Norris he reckons that more important is to have a bullet diameter length inside the case and I reckon he has a point atb tony

[foxing2night]

Consistency is the most important thing

Darrel

[ricky5042]

Thanks guys I will try 15 thou off to start and see what that does, if 15 thou is no better do I go to 20 thou off or 25 thou? what do you guys go up in? 5s 10s or higher?

Thanks

 

Rick

[Tony.H]

go to 20thou then 25thou, less chance of missing your accuracy node if you go 5thou at a time

 

tony

[Andrew]

My thoughts exactly. I used to sweat about how close to the lands I could load. Now I start as Andrew does with at least a full bullet diameter seated. My current 6.5x55 is what seems like a country mile (120 thou) off the lands, and she shoots as sweetly as any other rifle I have ever owned.

I'm glad to see I'm not considered a crack-pot!

I have a couple of younger friends that are absolutely beside themselves that I don't measure the distances off of the lands when I reload. One guy in particular gets really worked up about it. During one of our frequent arguments I proposed two scenarios for his consideration:

 

: A buddy says to him that he loads his 6mm to .010" off of the lands.

 

or

 

: A buddy says to him that he seats his 6mm's .050" into the neck.

 

I asked which scenario did he think had the greatest impact on potential accuracy.

 

He said it was a stupid question but I told him I had a 7-08 once that with one particular bullet gave me this exact option. I seated deep and the accuracy was all I could hope for.~Andrew

[jcampbellsmith]

Thanks guys I will try 15 thou off to start and see what that does, if 15 thou is no better do I go to 20 thou off or 25 thou? what do you guys go up in? 5s 10s or higher?

Thanks

 

Rick

 

Lower, I move 4 thou at a time when fine tuning. Regards JCS

[jcampbellsmith]

I'm glad to see I'm not considered a crack-pot!

I have a couple of younger friends that are absolutely beside themselves that I don't measure the distances off of the lands when I reload. One guy in particular gets really worked up about it. ....

 

Andrew. Wind him up further by reminding him that every shot fired will slightly erode the start of the lands. Callum Ferguson showed me the start of the lands on my freshly re-barrelled 260 Rem and they were nice and sharp and distinct as the rifle had fired about half a dozen rounds. If I was to look now, the picture would not be so pretty and the start of the lands is further away from the bolt face.

 

I use the Hornady OAL gauge to establish a consistent seating of the bullet. I'm not overly concerned where the bullet sits with respect to the start of the lands.

 

Regards JCS

[MadSpaniel]

At a slight tangent to the initial post. Do you test for doughnuts on a regular basis or not? Regards JCS

 

I always visually inspect my cases when I clean them, and never noticed any doughnuts.

[ricky5042]

Thanks guys il start moving in 5s until I find my change point then il go 2 either side to fine tune it.

Rick

[onehole]

Consistency is the most important thing

Darrel

Agree with this,,,,,,,I single load for my rifles,,,,I use threaded once fired cases to find touching land measurement to confidently load sorted heads to a known 5 or 10 thou off.Generally I prefer to go 5 thou this also gives maximum potential powder capacity per given case.I have never ever not found an accurate node or two using this regime.The threaded fired case is a "key"component,,,you must get yours done,,,, modified off the shelf cases will take you down the wrong road unless you potentially want to be plus or minus up to 10 thou in error.

VLDS can be stonking accurate but my best VLD oads were when stuffed hard in,,,,,,,,or shall I say the easiest way to get them to shoot was stuff em in to get good marks on the head without setting the head back on bolt closure.This was generally obtained with a known 15 thou over touching measurement.

I also agree with others who find accurate loads with other infinite types of loading regimes even down to book or saami spec,,, if it works for you then carry on.

Yes consistency is the most important thing,,,I dont really know why but I decided to use 15 thou off in my 308 and worked up a mild and stupid accurate load that has worked in 7 known to me 308 rifles to date,,,,,,pretty sure I wouldn,t get away with this in some other calibres but I,ve said it before ,,,,308 is just well yeah 308 isn't it?