Max OAL, SAAMI vs actual.

[3006Sprng]

I have a question around seating depth, hoping someone could help.

Seating depth has been something I have been researching, so I started to take to the bench to experiment.
I will be looking to load up some 180gr Hornady SST's for my savage 110 30-06, so I figured now will be the time to look at seating depth and make a dummy round to test.

I wanted to figure out this cartridge/bullet max OAL for this particular rifle, not that I'm chasing the lands, but I want to know this information.

I loaded up a dummy seated to the max I can fit in the mag, turned out to be 3.475" (30-06 max saami = 3.340").
I attempted to chamber it, not even close to getting the bolt closed (with out smashing it). Had to use a cleaning rod to tap the round out since I didnt close the bolt.

Then I seated the bullet to max SAAMI for 06, 3.340", still couldn't easily close the bolt, so I didnt. Still had to use a cleaning rod to tap the round out. I guess i could have just smashed with bolt closed, but i figured id keep seating deeper.

Seated the round to 3.300", put a tiny bit of case lube on the bullet, chambered it, found I had to push the bolt all the way forward as it wouldn't fully close with light pressure, but I then was able to close it, and extract the round. The bullet did not rip out of the case, I re-measured this seating depth and it stayed at 3.300". This OAL seemed to JAM, but not hard enough it pushed the round deeper into the case, or get ripped out.

Next I went to 3.250" to verify, and the round feeds all the way in and doesnt get stuck in the rifling when the bolt isnt fully closed (extractor not pulling it out). This seems to not be crammed into the rifling since the round falls out freely.

So I guess what I am trying to figure out as I learn more about seating depth is,
-Does MAX OAL drastically change depending on bullet design being that the OGIVE could be pushed further forward (hornady SST's?)?
-Could my rifle have a shorter than SAAMI throat or is what I asked above the answer to this?
-Anyone have any tips for max seating depth measuring? OAL tool? Smash the bolt closed method?

Up until now I have just been using bullet manufacturer tested OAL since I do not have experience yet pushing bullets further out.

Disclosure, I load for hunting and feed reliability, but the more I can learn the better.

 

[marksjeep]

MAX OAL will be a function of bullet design (ogive) and chamber/leade characteristics as you observed. But the rifle should have been cut to somewhere within the specification.

Hornady OAL gauge is pretty cheap and easy to use.
https://www.hornady.com/modified-cases#!/

 

[Wind Gypsy]

I have a question around seating depth, hoping someone could help.

Seating depth has been something I have been researching, so I started to take to the bench to experiment.
I will be looking to load up some 180gr Hornady SST's for my savage 110 30-06, so I figured now will be the time to look at seating depth and make a dummy round to test.

I wanted to figure out this cartridge/bullet max OAL for this particular rifle, not that I'm chasing the lands, but I want to know this information.

I loaded up a dummy seated to the max I can fit in the mag, turned out to be 3.475" (30-06 max saami = 3.340").
I attempted to chamber it, not even close to getting the bolt closed (with out smashing it). Had to use a cleaning rod to tap the round out since I didnt close the bolt.

Then I seated the bullet to max SAAMI for 06, 3.340", still couldn't easily close the bolt, so I didnt. Still had to use a cleaning rod to tap the round out. I guess i could have just smashed with bolt closed, but i figured id keep seating deeper.

Seated the round to 3.300", put a tiny bit of case lube on the bullet, chambered it, found I had to push the bolt all the way forward as it wouldn't fully close with light pressure, but I then was able to close it, and extract the round. The bullet did not rip out of the case, I re-measured this seating depth and it stayed at 3.300". This OAL seemed to JAM, but not hard enough it pushed the round deeper into the case, or get ripped out.

Next I went to 3.250" to verify, and the round feeds all the way in and doesnt get stuck in the rifling when the bolt isnt fully closed (extractor not pulling it out). This seems to not be crammed into the rifling since the round falls out freely.

So I guess what I am trying to figure out as I learn more about seating depth is,
-Does MAX OAL drastically change depending on bullet design being that the OGIVE could be pushed further forward (hornady SST's?)?

Yes, coal “to touch the lands” varies greatly by projectile and how long the nose or ogive is in front of the bearing surface.

-Could my rifle have a shorter than SAAMI throat or is what I asked above the answer to this?

Yes, and it sounds like a good possibility although I’m not well versed in 30-06 throat config or how long the nose is on a 180 SST. I wouldn’t expect one to be jammed at SAAMI COAL with a 180 sst though!

-Anyone have any tips for max seating depth measuring? OAL tool? Smash the bolt closed method?

Hornady OAL tool is easiest to get ballpark IMO and what I always use. Otherwise Eric cortina and Alex wheeler have good videos with more precise methods that don’t require the OAL tool if you search for them.

 

[Sheltowee]

Another vote for the Hornady OAL gauge. They’ll even thread a custom piece of brass for you if you’re shooting a nonstandard cartridge.

 

[Dan-06]

Ya same opinion as all the other guys. Remember that when you get a measurement it will be different for every weight and type of bullet. I usually find the average of 3 same weight and type bullet then subtract 30 thousandths. Good place to start.

 

[mtmuley]

Another vote for the Hornady OAL gauge. They’ll even thread a custom piece of brass for you if you’re shooting a nonstandard cartridge.

Some don't like the Hornady system but it works well for me. mtmuley

 

[Forkyfinder]

Some don't like the Hornady system but it works well for me. mtmuley

Most hornady products do

 

[mtmuley]

Most hornady products do

Except for their bullets. I bought my comparator stuff 20 years ago. It was all that was out there. Works for what I need. mtmuley

 

[44hunter45]

I have a question around seating depth, hoping someone could help.

Seating depth has been something I have been researching, so I started to take to the bench to experiment.
I will be looking to load up some 180gr Hornady SST's for my savage 110 30-06, so I figured now will be the time to look at seating depth and make a dummy round to test.

I wanted to figure out this cartridge/bullet max OAL for this particular rifle, not that I'm chasing the lands, but I want to know this information.

I loaded up a dummy seated to the max I can fit in the mag, turned out to be 3.475" (30-06 max saami = 3.340").
I attempted to chamber it, not even close to getting the bolt closed (with out smashing it). Had to use a cleaning rod to tap the round out since I didnt close the bolt.

Then I seated the bullet to max SAAMI for 06, 3.340", still couldn't easily close the bolt, so I didnt. Still had to use a cleaning rod to tap the round out. I guess i could have just smashed with bolt closed, but i figured id keep seating deeper.

Seated the round to 3.300", put a tiny bit of case lube on the bullet, chambered it, found I had to push the bolt all the way forward as it wouldn't fully close with light pressure, but I then was able to close it, and extract the round. The bullet did not rip out of the case, I re-measured this seating depth and it stayed at 3.300". This OAL seemed to JAM, but not hard enough it pushed the round deeper into the case, or get ripped out.

Next I went to 3.250" to verify, and the round feeds all the way in and doesnt get stuck in the rifling when the bolt isnt fully closed (extractor not pulling it out). This seems to not be crammed into the rifling since the round falls out freely.

So I guess what I am trying to figure out as I learn more about seating depth is,
-Does MAX OAL drastically change depending on bullet design being that the OGIVE could be pushed further forward (hornady SST's?)?
-Could my rifle have a shorter than SAAMI throat or is what I asked above the answer to this?
-Anyone have any tips for max seating depth measuring? OAL tool? Smash the bolt closed method?

Up until now I have just been using bullet manufacturer tested OAL since I do not have experience yet pushing bullets further out.

Disclosure, I load for hunting and feed reliability, but the more I can learn the better.

HT knows I absolutely nerd out on these types of questions.

-Does MAX OAL drastically change depending on bullet design being that the OGIVE could be pushed further forward (hornady SST's?)?
YES
-Could my rifle have a shorter than SAAMI throat or is what I asked above the answer to this?
YES
-Anyone have any tips for max seating depth measuring? OAL tool? Smash the bolt closed method?
There are many methods to find the Max COAL for a particular rifle and bullet. YouTube is your friend. I'm in the "Hornady is overrated" camp. You do not need to spend a bunch of money to measure your chamber and leade (throat). I use a variation of the "whiteout" method to get close and then I use black ink or blue Dykem to know exactly where my loads touch the rifling. You also do not need to be all that precise if you plan to adjust seating depths for accuracy at a later step. Just safely off the lands. Sometimes I use the "Loctite" method, but I hate cleaning up from it.

YouTubes of the Loctite and Whiteout methods have demostrated results less than .003" different than those performed with a Hornady tool on the same rifle.

First thing to answer is whether these are bench rest loads made on high end dies or hunting loads made on basic dies. There is no need to be too precise on COAL measurements for hunting loads other than to make sure your loads are far enough off the lands to feed and extract properly. Then go straight to pressure testing.

These things get really fun when you are using micrometer type seating dies. Sadly, it is not always possible to get them for every cartridge.

No fancy tool and mathematics can do more than get you close enough to physically measure. When someone says they used a tool and set their COAL .030" off the rifling, that is safe enough, especially if they intend to do their pressure testing and then tweak the seating depths to find an accuracy sweet spot.

When the bolt closes easily on a dummy round and there are no marks in the ink or Dykem, you have found the "no contact" point. At that point I make a few more dummy rounds at that seat die setting. I run those through a feed cycle from the magazine and check them for contact marks. You will get some feed ramp contact, you have to learn to differentiate between those marks and rifling contact marks. After I'm happy with these, I can back away from the lands whatever I desire for my starting loads. The guys using tools are skipping this step because of what I wrote in the last paragraph. That is just fine. Once you've figured out your desired charge weight, you may play with this seating depth to find an accuracy sweet spot.

In the end you are looking for a safe pressure testing seat depth clearly off the lands. After pressure testing is done, you may or may not tweak the seating depth. That's your call. I like my hunting loads to finish at least .020" off the lands to assure good feeding and extraction of live rounds.

Magazine boxes can definitely limit your options. I have some rifles that simply cannot get close to the rifling and still feed well. I have others where the freebore is the limiting factor.

Keep in mind that measurements taken off lead meplates are rarely consistent due to the nature of the swaging process. This is why some use a comparator. There are tools for serious bench rest competitors that will uniform all the meplates on a batch of bullets.

If I am using the new(er) polymer tipped Hammer HHT bullets, I do all my max COAL measurement before I put the tips in the bullets. Then I check for magazine lengths. For me, Hammers often max out the magazine before they hit the lands. Especially the heaviest ones. Copper displaces more powder capacity from the case than lead core, so you MUST reduce your powder charge when substituting the same weight monoliths in a load. I find monoliths usually like a faster powder than lead core bullets anyway.

I used to be obsessed with stuff. (Who would believe that?) I even made a tool to trim the meplates off my 180 Speer Boattails to get closer to the lands in my magazine box of my Ruger M77 .30-'06. In hindsight, I was destroying their wonderful BC, so what did I gain? Eventually you will reach a point where the actual number of COAL is not important, but how your seating plug and your rifle work together to get you in the right starting place.

If you are making compressed loads and they are not crimped (That's perfectly OK if they feed and are at a safe pressure!) they may "stretch" on the shelf over time. Keep records of the COAL of all your finished loads. I DO use a comparator at this point. The next time I make a batch of a certain load, I make a couple dummies to the recorded COAL and perform the black ink check on them. If they chamber without the ink being marked, I proceed with loading up new ladder test loads if the powder lot is different. If I am still in the same can of powder I just start cranking them out.

Not a big deal on .30-'06, but over-bored calibers are going to erode the rifling away and this will invalidate your recorded COALs over time.

At this point, do not worry about crimps. Most cannelures are in the wrong place for your perfect load. They are placed based on a variety of formulas surrounding recommended bullet diameters of bullet shank in case neck and other variables. I use them if they are where I can use them, I don't sweat it if they are not. I will sometimes play with the case trim length to make this work out.

 

[3006Sprng]

HT knows I absolutely nerd out on these types of qustions.

-Does MAX OAL drastically change depending on bullet design being that the OGIVE could be pushed further forward (hornady SST's?)?
YES
-Could my rifle have a shorter than SAAMI throat or is what I asked above the answer to this?
YES
-Anyone have any tips for max seating depth measuring? OAL tool? Smash the bolt closed method?
There are many methods to find the Max COAL for a particular rifle and bullet. YouTube is your friend. I'm in the "Hornady is overrated" camp. You do not need to spend a bunch of money to measure your chamber and leade (throat). I use a variation of the "whiteout" method to get close and then I use black ink or blue Dykem to know exactly where my loads touch the rifling. You also do not need to be all that precise if you plan to adjust seating depths for accuracy at a later step. Just safely off the lands. Sometimes I use the "Loctite" method, but I hate cleaning up from it.

YouTubes of the Loctite and Whiteout methods have demostrated results less than .003" different than those performed with a Hornady tool on the same rifle.

First thing to answer is whether these are bench rest loads made on high end dies or hunting loads made on basic dies. There is no need to be too precise on COAL measurements for hunting loads other than to make sure your loads are far enough off the lands to feed and extract properly. Then go straight to pressure testing.

These things get really fun when you are using micrometer type seating dies. Sadly, it is not always possible to get them for every cartridge.

No fancy tool and mathematics can do more than get you close enough to physically measure. When someone says they used a tool and set their COAL .030" off the rifling, that is safe enough, especially if they intend to do their pressure testing and then tweak the seating depths to find an accuracy sweet spot.

When the bolt closes easily on a dummy round and there are no marks in the ink or Dykem, you have found the "no contact" point. At that point I make a few more dummy rounds at that seat die setting. Then I can back away from the lands whatever I desire for my starting loads. They guys using tools are skipping this step because of what I wrote in the last paragraph. And that is just fine. Once you've figured out your desired charge weight, you may play with this seating depth to find an accuracy sweet spot.

In the end you are looking for a safe pressure testing seat depth clearly off the lands. After pressure testing is done, you may or may not tweak the seating depth. That's your call. I like my hunting loads to finish at least .020" off the lands to assure good feeding and extraction of live rounds.

Magazine boxes can definitely limit your options. I have some rifles that simply cannot get close to the rifling and still feed well. I have others where the freebore is the limiting factor.

Keep in mind that measurements taken off lead meplates are rarely consistent due to the nature of the swaging process. This is why some use a comparator. There are tools for serious bench rest competitors that will uniform all the meplates on a batch of bullets.

If I am using the new(er) polymer tipped Hammer HHT bullets, I do all my max COAL measurement before I put the tips in the bullets. Then I check for magazine lengths. For me, Hammers often max out the magaine before they hit the lands. Expecially the heaviest ones. Copper displaces more powder capacity from the case than lead core, so you MUST reduce your powder charge when substituting the same weight monoliths in a load. I find monoliths usually like a faster powder than lead core bullets anyway.

I used to be obsessed with stuff. (Who would believe that?) I even made a tool to trim the meplates off my 180 Speer Boattails to get closer to the lands in my magazine box of my Ruger M77 .30-'06. In hindsight, I was destroying their wonderful BC, so what did I gain? Eventually you will reach a point where the actual number of COAL is not important, but how your seating plug and your rifle work together to get you in the right starting place.

If you are making compressed loads and they are not crimped (That's perfectly OK if they feed and are at a safe pressure!) they may "stretch" on the shelf over time. Keep records of the COAL of all your finished loads. I DO use a comparator at this point. The next time I make a batch of a certain load, I make a couple dummies to the recorded COAL and perform the black ink check on them. If they chamber without the ink being marked, I proceed with loading up new ladder test loads if the powder lot is different. If I am still in the same can of powder I just start cranking them out.

Not a big deal on .30-'06, but over-bored calibers are going to erode the rifling away and this will invalidate your recorded COALs over time.

At this point, do not worry about crimps. Most cannelures are in the wrong place for your perfect, load. They are placed based on a variety of formulas surrounding recommended bullet diameters of bullet shank in case neck and other variables. I use them if they are where I can use them, I don't sweat it if they are not. I will sometimes play with the case trim length to make this work out.

Thanks for the input, pretty much exactly what you highlighted, I am developing hunting loads but trying to have a better understanding of my rifles as well as optimize case capacity for slower burning powders.

 

[grizzly63]

A redneck method of measuring coal for any given bullet is to drop a bullet into an empty chamber, hold it there with a cleaning rod section while placing another cleaning rod down from the muzzle end. Mark it. Take the bullet out of the barrel, put the bolt back close the chamber. Measure down the barrel again with the same rod, mark it, measure the distance between the two marks = COAL for that bullet touching the lands. Some bullets like a big jump, some like to be touching. That is for you to figure out. Watch for pressure.

 

[kodiakisland]

A redneck method of measuring coal for any given bullet is to drop a bullet into an empty chamber, hold it there with a cleaning rod section while placing another cleaning rod down from the muzzle end. Mark it. Take the bullet out of the barrel, put the bolt back close the chamber. Measure down the barrel again with the same rod, mark it, measure the distance between the two marks = COAL for that bullet touching the lands. Some bullets like a big jump, some like to be touching. That is for you to figure out. Watch for pressure.

Another cheap way is to load a dummy cartridge with the bullet seated out long. mark the ogive on the bullet with a sharpie. Chamber the round. If it's too long the rifling will mark the sharpie area. Continue seating the bullet a little more until no marks on the sharpie area.

Sharpies are also good for setting proper headspace with new brass.

 

[44hunter45]

Another cheap way is to load a dummy cartridge with the bullet seated out long. mark the ogive on the bullet with a sharpie. Chamber the round. If it's too long the rifling will mark the sharpie area. Continue seating the bullet a little more until no marks on the sharpie area.

Sharpies are also good for setting proper headspace with new brass.

This is exactly what I do.

I used to take an old cleaning rod in from the muzzle against the seated bullet and mark the rod at the muzzle with tape. Then I would remove the dummy round and measure to the closed bolt face and tape again.The difference being my COAL. If you are really OCD like me than you get that measuring off a lead tipped bullet is not very reliable.

I eventually dispensed with the cleaning rod and micrometer. I just keep seating my dummy round deeper until I no longer get a mark in the ink. No comparators or measurement needed. Just turn the seating plug in a little more and I know I'm clear. Then I do magazine feed tests a mag full of those those dummy rounds. They should all feed, chamber, and extract easily with no rifling marks in the ink.

 

[std7mag]

While yes, there are instances where COAL is shorter than SAAMI length, they are specified in the loading manual.
These are due to bullet length and ogive shape.

Although I've never had one that was shorter than SAAMI length in my experience, yet.

As far as the Hornady comparator or anyone else's comparator, bear in mind that any measurements you get will only have meaning to you.
Who's to say that the comparator is the exact same length and opening size and fits the ogive the same as anyone else's?

COAL is usually within 0.005".

 

[Ought Six]

I don’t reload (yet), but very interested, so I’ve been reading and watching lots of videos. Idk if this helps:

 

[3006Sprng]

Gotta run into the city on tuesday, one of the shops has the OAL gauge and the modified cases available. Guess I will add it to the reloading supply collection.

 

[jwatts]

You can also modify your own case. I do this with several different calibers. I use a once fired piece of brass that I threaded to work with the Hornady OAL gauge. Push out the primer, drill the primer pocket with a size M or 19/64 bit, then tap 5/16-36 threads. Just be sure the hole you drill and trap is good and square with the case so the gauge threads in straight.

 

[Jbotto]

Another vote for the Hornady OAL gauge. They’ll even thread a custom piece of brass for you if you’re shooting a nonstandard cartridge.

You can buy the tap for like $10 I think and thread your own too. That’s the route I took so if a friend brought me a project I wouldn’t have to wait for Hornady or finding one locally.

@jwatts beat me to it. I should have read further

 

[N2TRKYS]

Finding the distance to the lands is a waste of time. Thusly, equipment to obtain such useless measurements are a waste of money. If you are hellbent on gaining this useless measurement, use your cleaning rod. At least it won’t cost you any extra money.

I seat them to the tested COAL and have never had to adjust seating depth. Adjusting seating depth is yet another waste of time.

I also find measuring base to ogive to be pointless, as well.


I don’t know or care how far off the lands I am.

 

[Sheltowee]

Finding the distance to the lands is a waste of time. Thusly, equipment to obtain such useless measurements are a waste of money. If you are hellbent on gaining this useless measurement, use your cleaning rod. At least it won’t cost you any extra money.

I seat them to the tested COAL and have never had to adjust seating depth. Adjusting seating depth is yet another waste of time.

I also find measuring base to ogive to be pointless, as well.


I don’t know or care how far off the lands I am.

Respectfully disagree with this. Not all chambers are cut the same or to SAAMI
spec. My Tikka 6.5 Creedmoor is exceptionally long and I’d have a crazy amount of freebore if I loaded to standard spec.

Not all projectiles are sensitive to seating depth but I’ve encountered some that are (Barnes, Hornady RDFs, ELD-Ms to a lesser extent) and some that don’t seem to care much at all (Hammer, most cheap soft points).

If you’re going to get engaged in something as esoteric as handloading, why not get freaky with it and collect all the data that you can in order to optimize performance? Otherwise, just shoot factory loads.