• If you are being asked to change your password, and unsure how to do it, follow these instructions. Click here

coal and being .005 off lands issue

Bigeclipse

Well-Known Member
Joined
Aug 10, 2012
Messages
1,972
I finally am able to measure my rifles coal to lands so I can start loading at .005 off the lands. For 3006 Nobler says 3.340 is max coal. However, I am getting 3.489 for accubonds and 3.454 for partitions. To be .005 off the lands that would mean accubonds would be 3.484 and partitions would be 3.449. These both are longer than Nosler's max. I loaded up a dummy accubond with noowder...it even looks rather funny sticking out so far compared to factory loads. Is this normal? What am I doing wrong?
 
This is normal in a factory chambered rifle, the COAL listed in the book is to assure ammunition is standard for magazine length. If you are intending to seat 0.005" off the lands, you may or may not be able to use the magazine. As far as safety is concerned you can fire a round that is over max length, however it is recommended to start at a reduced powder charge and work up checking for pressure signs. Seating near or on the lands can create increased pressure.
 
This is normal in a factory chambered rifle, the COAL listed in the book is to assure ammunition is standard for magazine length. If you are intending to seat 0.005" off the lands, you may or may not be able to use the magazine. As far as safety is concerned you can fire a round that is over max length, however it is recommended to start at a reduced powder charge and work up checking for pressure signs. Seating near or on the lands can create increased pressure.
I did not know about the extra pressure so thank you. It is a Remington mountain SS rifle. I wanted to load .005 off lands to try and get good accuracy and heard this is a good place to start. Not worried about magazine as it has a floor plate... so no magazine.
 
Loading very close to the lands can lead to pressure spikes. Pressure will decrease as you seat deeper

seatingdepthvpressure_zps55dce562.jpg

pressuregraph.jpg


Read the sticky at the top of this forum

http://www.longrangehunting.com/forums/newreply.php?do=newreply&noquote=1&p=915883

where Berger recommends trying seating at much greater depths than you are talking about

It is very difficult to have a seating depth consistency of +-.002" (IME maybe its just me). If you are seating at .005" off then some could be .003" off and some could be .007" off, if you are very good at keeping seating pressure consistent. If you don't sort your bullets by bearing length, outside neck turn if you are using bushing dies, use expander mandrel, Lee Collets and have a very good hand on exactly consistent neck ID's, then you will have some that wind up touching the lands and some farther off.

For a benchrest competitor with lots of experience, .005" off is completely doable. For a hunter looking for accuracy and safety, not necessary to seat that close.

JMHO
 
Loading very close to the lands can lead to pressure spikes. Pressure

Read the sticky at the top of this forum

http://www.longrangehunting.com/forums/newreply.php?do=newreply&noquote=1&p=915883

where Berger recommends trying seating at much greater depths than you are talkinag about

It is very difficult to have a seating depth consistency of +-.002" (IME maybe its just me). If you are seating at .005" off then some could be .003" off and some could be .007" off, if you are very good

JMHO

I am not in competition but I do want to get the most accurate loads o can achieve, within reason. if .005 is going to be that difficult or wrong, then where should I start? I don't measure everything you stated above but I do measure every round after bullet seating and with my first loads... they were all within + or - .003 of eachother so for example the shortest was 3.332 and the longest was 3.335. this was with partitions. I just read that most factory rifles like a bullet jump of .020-.050 off the lands. Now I'm even more confused. I am just trying to get a load that is at least under 1moa. I shot factory corelokts in this rifle and they shot very nice at right around .75MOA so I know the rifle can do it but the first loads I made were 1.5moa. They were the ones I stated coal for. They were with rl22 powder and h4350. I made several loads with the rl22 but only one load so far with the h4350. Everything has shot around 1-1.5moa which is disappointing so far. I tried mostly partitions and a few loads of sierra game kings both 180grains.

PS I have loaded for my browning Xbolt with great results and consistency so I think my process so far has been ok.
 
Last edited:
This is normal in a factory chambered rifle, the COAL listed in the book is to assure ammunition is standard for magazine length. If you are intending to seat 0.005" off the lands, you may or may not be able to use the magazine. As far as safety is concerned you can fire a round that is over max length, however it is recommended to start at a reduced powder charge and work up checking for pressure signs. Seating near or on the lands can create increased pressure.

Agree! Playing with seating depth can help accuracy, but start with a reduced load and work up.
 
So your rifle shoots .75moa with simple factory loaded corelokts? Why not start your seating depth around factory with a good hand load, and start stretching it out from there? Increase in .010's" and move towards the lands. .75 is awesome for factory loads, so there is something there. Rather than run the risk of massive pressure spikes against the lands, why not try where its known to work and see if you can't find a seating depth that will produce .5moa and better.

I've found accubonds are rather easy to work with, I've gotten amazing results in my $300 mossberg .30-06 all the way up to 200gr accubonds and 4831 at 3.340" for a moose load.

Just my $.02 though..
 
if .005 is going to be that difficult or wrong, then where should I start?

I tried mostly partitions and a few loads of sierra game kings both 180grains.

PS I have loaded for my browning Xbolt with great results and consistency so I think my process so far has been ok.

Normally I would start most bullets around .025" or .030" off, monometals like the Barnes TSX's at .050" like they recommend. My load for the 30-06 is .030" off

300yd.jpg

IF YOU USE THIS LOAD START LOWER AND WORK UP IN YOUR GUN, LIKE I DID

Nosler Partitions are great performers in the field but NOT known for their accuracy. The Nosler substitute, the Accubond, can be made to shoot well much easier

Your PS says a lot. Rifles vary and while one may be accurate, another may not be. Some rifles will shoot almost anything well and others take a lot of work.
 
Your PS says a lot. Rifles vary and while one may be accurate, another may not be. Some rifles will shoot almost anything well and others take a lot of work.

Thanks for the info. The weird thing is I tried several factory loads with my 3006 before I started reloading. I shot federal fusion 165s, nosler accubond 165s, winchester super x 180s and remington corelokt 165s. The corelokts shot .75MOA or slightly better, the other three were in the 1MOA realm...I think the noslers were more like 1.25MOA. Now this is where it gets funny/weird, my XBOLT would not shoot ANY factory ammo under 1.5MOA. I tried like 6-8 different types of ammo...well my very first reloads for it shot .5MOA-.75MOA(I made 3 different batches with different charges) THIS got me REALLY excited!!! I figured dang, that gun shot like crap before so the remington mountain shooting so well with factory ammo is going to shoot as well or better with reloads...so far it has been the opposite. I have tried I think 5 different loads with two different types of bullets and NONE of them shot below 1.5MOA. My next step is to try the different bullet seating depths with the current weight bullets and powder I have. If that doesnt work, I will order up some new bullets(Easier than trying to find other powder around here). These two bullets are both 180 grains so maybe the rifle simply hates 180s???
 
So are you trying to find the magic pill for two separate rifles? Is the twist rate the same between the remmy and the xbolt? Its hard to expect two rifles to shoot sub 1/2 moa with the same exact ammo. Start with one and figure it out, then move on to the second. Its always "tough" when you have too many rifles to get to work out! Very lucky there.

How large of a swing were the changes you made in your batch of three? Are you changing more than one thing at a time? Do you have a chrono so you can see what kind of swing you are seeing in your velocity? How do you weigh each charge? If you keep changing things after only one trip to the range, it can be difficult to pin point the node you are looking for.

Last ditch, if your range is far, you may want to look at a hand press to be able to make changes on the bench while testing loads. I have seen this before, yet don't like to do it myself.

Always be safe, keep everything labeled, and get behind the glass every chance you can.
 
So are you trying to find the magic pill for two separate rifles? Is the twist rate the same between the remmy and the xbolt? Its hard to expect two rifles to shoot sub 1/2 moa with the same exact ammo. Start with one and figure it out, then move on to the second. Its always "tough" when you have too many rifles to get to work out! Very lucky there.

How large of a swing were the changes you made in your batch of three? Are you changing more than one thing at a time? Do you have a chrono so you can see what kind of swing you are seeing in your velocity? How do you weigh each charge? If you keep changing things after only one trip to the range, it can be difficult to pin point the node you are looking for.

Last ditch, if your range is far, you may want to look at a hand press to be able to make changes on the bench while testing loads. I have seen this before, yet don't like to do it myself.

Always be safe, keep everything labeled, and get behind the glass every chance you can.

The two rifles I am currently loading for is xbolt 300WSM and Remington 3006. I did not expect to use the same type things for both which is why I bought the 2 powders available(which work for both) and 3 different bullets. I have nosler accubond 200s (which is the only thing I tested in the xbolt so far and it loved those) and I have 180 partitions and 180 sierra gamekings which I have tried both in the remmy. I have not tried all powder weights or seating depths yet. I use a mechanical scale which is well calibrated and a powder trickler for each charge. I DO NOT use the powder throw as I want almost perfect consistency there. I have used the same promers (winchester large rifle standard for remmy and magnum for 300wsm). When I loaded the first couple batches for the remmy I used the same seating depth but varied the powder load by half grain from just under mid all the way up to max "book" charge. I loaded 4 of each...to try and ensure at least a decent 3 shot group (just incase I throw a flier by mistake). I cannot reload at our range so I have to do these before I go. I recently read maybe you should try staying with the SAME powder charge while trying different bullets depths first so I cam going to try that next. I am thinking that the rifle may like a farther from the lands approach since it shot the factory rounds well and all of those were pretty far off the lands.
 
Warning! This thread is more than 11 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.
Top