Another dumb newby question

[modlaw]

Ok. I have been trying to find an answer to this on my own but have not had any luck. I have reloaded about 5 times now. I usually fire about five factory rds and then about 10 reloads. I started with the lowest charge of Retumbo listed in the Nosler book. and proceeded to about 1gr less than the recommended max load. I am reloading 25-06 with 120gr Partitions using Win LR primers. I notice that I have 2 continuous conditions: 1) the primers ALL show a flattening compared to the factory rds. There seems to be no difference in the flattening from the lesser load to the largest load. Should I be concerned? 2) The neck of my reloads all show powder residue extending down nearly to the shoulder of the case. This is pronounced compared to the factory rds. I used the Hornady Lock n Load system to measure the jump and OACL. I did this about 6 times and came up with (I think) is an accurate OACL for the Partition of 3.168. The jump is about .050. Does anyone have any ideas?

Oh, and my shiney new ProChrono shows 3000s @ my max load of 56.5 and about 2800s @ 53.5.

 

[throttletony]

tell us a bit about the gun?
new, used, well-used? (could it have any throat erosion)
If it's had a life of firing hot 25-06 rounds, erosion could be an issue.

 

[kludge]

0.050" jump isn't to bad, but I like to start out at about 0.015" to 0.020" off the lands, if it will fit in the magazine and is not less than the stated COL in the manual for that bullet.

1) Flat primers are not always an indication of pressure. Some primers are softer than others.
2) Some dies resize more than needed. The sizing die has to be small enough to ensure proper feeding from a minimum chamber. Sometimes the die will size the brass to smaller than factory ammo.
3) #2 means you could have more headspace in your chamber than needed and be causing both of the issues you see (flat primers and soot on the necks). Upon firing the primer has time and space to be pushed out of pocket, then the expanding brass pushes the case back against the bolt, but in the mean time the primer has also expanded and you have a flattened primer with a bit of a mushroom.

So, flat primers do not necessarily mean excessive pressure, but it's something you have to pay attention to.

Questions: Is the bolt hard to lift after firing a round? Can you rechamber your fired brass?

Try this. Screw in you sizing die until it touches the shell holder, then back it off one full turn. Pull the expander out of the die. Run a piece of brass into the die. Check it in your chamber. Screw the die in 1/16th to 1/8th of a turn. Run the piece of brass into the die. Check it in your chamber. Repeat until the brass JUST chambers and lock the die down in that position. Put the expander back in and run all of your brass. Now your die is set for minimum full-length sizing, and could increase the life of your brass a bit and help accuracy.

You can do the same with bullet seating. (Do this with a dummy round, no primer or powder.) Turn in your bullet seating stem 1/16th of a turn at a time and when the round just chambers, measure the COL and then screw in the bullet seating stem 1/16th of a turn (or less) until you get a COL that is 0.015" to 0.020" less than the first measurement. This is a good starting place to be for best accuracy. Make sure this is not less than the COL in the manual for that bullet.

 

[modlaw]

tell us a bit about the gun?
new, used, well-used? (could it have any throat erosion)
If it's had a life of firing hot 25-06 rounds, erosion could be an issue.

I

I got the gun for Christmas last year. It has less than 200 rds fired (mostly factory). It is a Savage 11/111 25.06

 

[modlaw]

0.050" jump isn't to bad, but I like to start out at about 0.015" to 0.020" of the lands, if it will fit in the magazine and is not less than the stated COL in the manual for that bullet.


3) #2 means you could have more headspace in your chamber than needed and be causing both of the issues you see (flat primers and soot on the necks). Upon firing the primer has time and space to pushed out of pocket, then the expanding brass pushes the case back against the bolt, but in the mean time the primer has also expanded and you have a flattened primer with a bit of a mushroom.


Questions: Is the bolt hard to lift after firing a round? Can you rechamber your fired brass?

Try this. Screw in you sizing die until it touches the shell holder, then back it off one full turn. Pull the expander out of the die. Run a piece of brass into the die. Check it in your chamber. Screw the die in 1/16th to 1/8th of a turn. Run the piece of brass into the die. Check it in your chamber. Repeat until the brass JUST chambers and lock the die down in that position. Put the expander back in and run all of your brass. Now your die is set for minimum full-length sizing, and could increase the life of your brass a bit and help accuracy.

You can do the same with bullet seating. (Do this with a dummy round, no primer or powder.) Turn in your bullet seating stem 1/16th of a turn at a time and when the round just chambers, measure the COL and then screw in the bullet seating stem 1/16th of a turn (or less) until you get a COL that is 0.015" to 0.020" less than the first measurement. This is a good starting place to be for best accuracy. Make sure this is not less than the COL in the manual for that bullet.

No, the bolt is not hard to lift. I just purchased a headspace/length gauge. I notice that the head of my fired brass seems to be even with the lowest level on the gauge. I new factory rd is raised a little between the levels on the gauge. I will try to follow your instructions to test this out. Thinking of what you said seems a logical cause. What do you mean "not less than the COL in the manual?" The only thing I paid attention was the SAAMI max COL. Thanks for the help.

 

[kludge]

Loading manuals will list COL (aka OAL) based on the type of bullet you are using.

Example: Lyman's 49th, under .25-06, a 100gr jacketed SP bullet has a OAL of 3.155" and the 110gr Accubond OAL listed at 3.250". When using the loads in the manual, don't go under 3.250" for the Accubond or the load data they list will be over-pressure. Being longer that 3.250" is fine if it chambers and fits in the magazine. 3.250" is SAAMI max length, but the .30-06 SAAMI length (which is what the magazine length is based on) is 3.340" so you should have some room to play with.

You also don't want the bullet to be too long and be touching or jammed into the lands. That can raise pressure too. Benchrest shooters do it for maximum accuracy, but they have VERY specific chambers for the bullet (not bullets) they are shooting and they are very aware of what they are doing.

Gun manufacturers, as a rule of thumb, put a little more freebore in the chamber because they don't know which bullet you will use and so they are making room for the biggest one, plus some. And they know that extra freebore will lower the max chamber pressure, regardless of what it does to accuracy.

I load my .308 Win (Savage 110FP) to 2.900" with the 168gr SMK bullet, even though SAAMI COL for the .308 is 2.800"

 

[modlaw]

Loading manuals will list COL (aka OAL) based on the type of bullet you are using.

Example: Lyman's 49th, under .25-06, a 100gr jacketed SP bullet has a OAL of 3.155" and the 110gr Accubond OAL listed at 3.250". When using the loads in the manual, don't go under 3.250" for the Accubond or the load data they list will be over-pressure. Being longer that 3.250" is fine if it chambers and fits in the magazine. 3.250" is SAAMI max length, but the .30-06 SAAMI length (which is what the magazine length is based on) is 3.340" so you should have some room to play with.

You also don't want the bullet to be too long and be touching or jammed into the lands. That can raise pressure too. Benchrest shooters do it for maximum accuracy, but they have VERY specific chambers for the bullet (not bullets) they are shooting and they are very aware of what they are doing.

Gun manufacturers, as a rule of thumb, put a little more freebore in the chamber because they don't know which bullet you will use and so they are making room for the biggest one, plus some. And they know that extra freebore will lower the max chamber pressure, regardless of what it does to accuracy.

I load my .308 Win (Savage 110FP) to 2.900" with the 168gr SMK bullet, even though SAAMI COL for the .308 is 2.800"

Well, I thought I was on my way to understanding this hobby, but now I am confused. My Nosler manual list the "maximum SAAMI" as 3.250 for 120 gr Partition. The "tested" load was 3.200. I thought the max SAAMI was never to be exceeded. So, if I am reading you right, you are saying never to load UNDER 3.250. I tested with the Lock n Load device and it indicated that the Partition touched the lands at 3.218 so I backed off .050 to 3.168. Are you saying this is wrong? The Nosler 85gr BT also indicates a max SAAMI of 3.250 yet the bullet is much shorter. If I loaded the 85gr to 3.250 it would barely be in the brass. Thanks for your patience.

 

[Broom_jm]

For bottle-necked rifle cartridges, there isn't really a "maximum" length established by SAAMI. If your LnL gauge says 3.218 is where the bullet you're using touches the lands, you can adjust from there. In fact, you can even exceed that length, in a process called "jamming the lands", but you have to back off the powder charge and really know what you're doing. The advice Kludge gave in his first response really couldn't be better...each rifle/bullet combination is a little unique, so you just go with whatever works in your gun.

How accurate were the loads you mentioned earlier? If you're getting 3,000fps from a 120gr Partition, and the accuracy is 1.5" or less, sight in 3" high at 100 and then practice at longer range.

 

[modlaw]

For bottle-necked rifle cartridges, there isn't really a "maximum" length established by SAAMI. If your LnL gauge says 3.218 is where the bullet you're using touches the lands, you can adjust from there. In fact, you can even exceed that length, in a process called "jamming the lands", but you have to back off the powder charge and really know what you're doing. The advice Kludge gave in his first response really couldn't be better...each rifle/bullet combination is a little unique, so you just go with whatever works in your gun.

How accurate were the loads you mentioned earlier? If you're getting 3,000fps from a 120gr Partition, and the accuracy is 1.5" or less, sight in 3" high at 100 and then practice at longer range.

Thanks. My accuracy with 54gr @ 100 is about 5 inches. HOWEVER, I am using a Aimpoint Hunter Red Dot scope (no mag). I use the gun for hogs in Florida in the winter. @ 100 even the 2 moa dot covers the center of the target. I am thinking of purchasing a Vortec 2.5-10 to replace the Aimpoint, just not sure what would be best on hogs. I have to get the loading issue solved first.

 

[Broom_jm]

Thanks. My accuracy with 54gr @ 100 is about 5 inches. HOWEVER, I am using a Aimpoint Hunter Red Dot scope (no mag). I use the gun for hogs in Florida in the winter. @ 100 even the 2 moa dot covers the center of the target. I am thinking of purchasing a Vortec 2.5-10 to replace the Aimpoint, just not sure what would be best on hogs. I have to get the loading issue solved first.

I used to have an Aimpoint dot scope on my 30 Herrett barrel, but replaced it with a 2-6X LER. The Aimpoint is now on my son's 9mm carbine, where it's much better suited.

For your needs, I would suggest a 2-7X32, or something along those lines. At 2X, you can make quick shots on hogs that show up a lot close than you expected, but you can still shoot sub-MOA with the 7X setting.

 

[kludge]

I don't have a Nosler manual but I would be interested in a pic of the page in question. Is this it? 25-06 Remington ? Nosler

Typically the load data will list the bullet, min and max load, pressure, and COL for the loaded round when it was tested. If I were a testing lab the test barrels would have SAAMI minimum chambers, so as to have the highest chamber pressure possible for the pressure measurements.

If the link I pasted in is the one you are referencing, here is an explantion... "Tested OACL" is the COL (overall catridge length or cartridge overall length, same diff) used when gathering the load and pressure data for the manual. So in other words, don't go below 3.200" or the max load will be overpressure.

The "Maximum SAAMI OACL" is just that , it is exactly what is listed on the SAAMI drawing for the cartridge. It's what ammo manufacturers go by to make sure THEIR AMMO will fit in EVERY .25-06 rifle with a chamber that is in spec (between the minimum and maximum SAAMI chamber specs).

If you are touching the lands at 3.218", then 3.200" would be a perfect starting place for you, IMO. 3.168" might raise your chamber pressure too high. I say might because there are a lot of of things happening very quickly.

Your flat primers may indeed be a pressure sign. But you say that this happened even at the start load. Which is why we always start at the start load and work our way up (0.3 to 0.5gr increments in a .25-06 size case works fine) then stop if we see any signs of high pressure.

I would go back and run it again at 3.200" resizing your cases as I described to eliminate primer push back as the cause of the flat primers.

Any "craters" around the firing pin dimple? (a sign of excess pressure where the primer is flowing back into the firing pin hole)

By the way, there are flat primers and then there are FLAT primers...



P.S. major kudos to Nosler for putting load data up on their web site... other bullet manufacturers take note!

 

[modlaw]

I don't have a Nosler manual but I would be interested in a pic of the page in question. Is this it? 25-06 Remington ? Nosler

Typically the load data will list the bullet, min and max load, pressure, and COL for the loaded round when it was tested. If I were a testing lab the test barrels would have SAAMI minimum chambers, so as to have the highest chamber pressure possible for the pressure measurements.

If the link I pasted in is the one you are referencing, here is an explantion... "Tested OACL" is the COL (overall catridge length or cartridge overall length, same diff) used when gathering the load and pressure data for the manual. So in other words, don't go below 3.200" or the max load will be overpressure.

The "Maximum SAAMI OACL" is just that , it is exactly what is listed on the SAAMI drawing for the cartridge. It's what ammo manufacturers go by to make sure THEIR AMMO will fit in EVERY .25-06 rifle with a chamber that is in spec (between the minimum and maximum SAAMI chamber specs).

If you are touching the lands at 3.218", then 3.200" would be a perfect starting place for you, IMO. 3.168" might raise your chamber pressure too high. I say might because there are a lot of of things happening very quickly.

Your flat primers may indeed be a pressure sign. But you say that this happened even at the start load. Which is why we always start at the start load and work our way up (0.3 to 0.5gr increments in a .25-06 size case works fine) then stop if we see any signs of high pressure.

I would go back and run it again at 3.200" resizing your cases as I described to eliminate primer push back as the cause of the flat primers.

Any "craters" around the firing pin dimple? (a sign of excess pressure where the primer is flowing back into the firing pin hole)

By the way, there are flat primers and then there are FLAT primers...



P.S. major kudos to Nosler for putting load data up on their web site... other bullet manufacturers take note!

Here is the Nosler manual that I am using 25-06 Remington ? Nosler. Scroll down to the 120 Partition. My understanding of what you are saying is NOT to go shorter COL than 3.200. Am I correct. I am going to re-adjust my die tomorrow and do some experimenting with my brass. I will load some @ 3.200 and go to the range first chance. Here is a pix of my brass.

 

[Broom_jm]

To the untrained eye, both of the pictures above might appear to be "flattened primers". Where they are remarkably different is around the rim of each primer: The picture of two 22-250 cases show the primers flattened all the way to the edge of the primer pocket, with no gap whatsoever between the primer edge and the edge of the pocket. The metal has flowed outward to fill it in, completely. Close examination of the picture of the 25-'06 cases shows a distinct gap between the primer and the pocket. Yes, the primer surface has flattened somewhat, but none of the ones pictured suggest over-pressure, IMHO.

 

[kludge]

I agree. The two on the bottom you're GTG. The one on the top I would start paying attention.

Correct, I would not go shorter than 3.200" without starting over at the min and working up, watching for pressure signs all the way. In my experience the first one I see on a bolt rifle is the bolt gets harder to lift... and here is the explanation why...

Brass has a little bit of "spring" to it. If you move it slightly it will move back to it's original shape. If you move it beyond a certain point it will stretch and can't go back to it's original shape. Although it will still spring back a little. When fired in the chamber, the brass will expand to fill the chamber and seal off the chamber. After the bullet leaves the barrel the pressure drops and the brass springs back a little -- not all the way to it's original shape, but enough to get it out of the chamber. Maybe it's obvious but this is why we have to run it into a resizing die to reload it, the brass might be a little too tight to feed nicely into the chamber and the neck has expanded and will no longer hold a bullet. So far so good.

The brass is not the only thing that expands -- so does the steel in the chamber. And steel is much better than brass at returning to its original shape (hence springs are made of steel and not brass). As we work up a load we continue to increase the pressure and we increase the amount that the chamber expands -- and thus the amount that the brass expands to fill the chamber. At some point we increase the pressure beyond the point where the brass can spring back enough to be easily removed from the chamber. i.e. the steel chamber is back to the original shape but the brass isn't; it's now larger than the chamber and the brass will be hard to extract. Usually this comes on fairly quickly... in 0.5 to 1.0 grain increase in the powder charge. If I think I notice a hard to lift bolt I make a notation in my log book (fancy name for a $0.20 spiral notebook from WalMart that I keep for each rifle) and then fire one more round at the next higher charge and this usually confirms it - and that's when I stop and back it off 0.5 to 1.0gr and call that the max for that load in that gun... regardless of what the book says.

This is usually my first sign of pressure, and is usually where I also just start to see a hint of a "crater" around the dimple left by the firing pin.

Some good reading... Pressure Signs - Shooters Forum

 

[modlaw]

What a great forum. Filled with people willing to help someone get started with excellent advice. I am going to incorporate all these tips at the bench and start over with my die adjustments and loads. I will post back here when I have a chance to test out at the range. A couple of things: Am I correct that the photo of the 22-250s also show signs of incipient case head separation? Also, I have experienced a split case neck (about 3/8 inch) which was on a FACTORY round. I labeled it and saved it as an example. Thanks to all. I will post back in a few days.

 

[Broom_jm]

What a great forum. Filled with people willing to help someone get started with excellent advice. I am going to incorporate all these tips at the bench and start over with my die adjustments and loads. I will post back here when I have a chance to test out at the range. A couple of things: Am I correct that the photo of the 22-250s also show signs of incipient case head separation? Also, I have experienced a split case neck (about 3/8 inch) which was on a FACTORY round. I labeled it and saved it as an example. Thanks to all. I will post back in a few days.

Good eye! Yes, the case on the left certainly does show what may very well be an incipient CHS.

 

[Fishersjohn48]

In before scooter