Need help with 308 load, struggling

S

Shadow9mm

New member
Helping a friend, he only loads handgun. I load 30-06, he shoots 308. He provided the supplies.


Federal brass trimmed to 2.005 per hornady
Hornady 150g sst bullets
Cci standard large rifle primers
H4895 powder

We tested start to max with no pressure signs loaded just below max col at 2.810. I used the hornady bullet seat Gauage, I don't remember the measurement but it was around 0.030 off the lands

Looking today hornady recommend seating that bullet at 2.735. I tried it but got compressed load at 40.0g and I struggled to get consistent seating depths. Also the cannalure is below the neck and not visible at all seated to this depth.

My plan is to go back to the 2.810 seating depth tomorrow and see how case fill is and where compression starts. Since I know I have ok jump.

I don't mind compressed loads. But if it's messing with my seating depths I don't want it.

I feel like a beginner. Something seems odd. Is this a bad powder choice? Could hornadys data be off? The cannelure being below the neck and not visible seems wrong.. What am I missing?
 
If the rifle shoots the ones seated longer, better, shoot them. But I've got a bit of a different view about load data, and cannalures.

Load for the rifle, PRUDENTLY(that will come in handy for what I'm about to say next) load to the gun, not to a book. Book data is ball park. Developed in a controlled environment with a certain set of equipment, components and gun. Especially in a bolt gun, is easy to just be observant and watch for signs of pressure, and go by that and use the book numbers as a reference.

Completely ignore the cannalure. The only practical application I see them having is holding the jacket to the core (I know, I know, people will say they're to crimp in to help hold the bullet, and I call bull spit, but that's beside the point and my opinion)

Sent from my SM-G996U using Tapatalk
 
I haven't checked the Hornady manual...too lazy to go downstairs. 2.735 may be the minimum COL for the 308 Winchester. Alliant has data for the 150 gr. Hornady GMX and indicates 2.735 is minimum COL.
 
COAL is about whether or not the bullet will feed through a magazine and then not jam into the lands. Other than that you can use any length your rifle shoots best.
 
On canneure: Its possible to place a cannelure in a specific location to be used for a crimp,but that would have to be for a specific cartridge application,such as 7.62 NATO ball.
I consider an "ideal" to be the base of the cylindrical diameter of the bullet to be seated to the base of the cartridge case neck.I let a boat tail protrude into the case body.
Thats not a hard and fast rule,it just seems "proper". Of course,its not possible with all bullet weights in all cartridges, and other factors like distance off the lands weigh in. A heavy bullet may get deep seated into the boiler room.
Consider the variation in cartridge case neck lengths in 30 caliber. 30-30 ,30-40 Krag,30-06,300 Savage,300 Win Mag all have different neck lengths.

The bullet manufacturer just can't put the cannelure in the right place for all those cartridges if its to be at the case mouth.

Unless you are creating ammunition you are determined to crimp,there is no reason to worry about the cannelure.

Cannelures are used in cup and core bullet manufacture to lock the core.

I agree with the suggestion to ignore the cannelure.

I'd expect 308 ammo loaded to a max COAL of 2.800 to fit the magazine.

Beyond that,riflng erodes. Where your bullet contacts the lands and how much jump shoots best for you must be determined.

Or pick a number like .015 or .030 and just go with it.

Unless you are in a competition ,the deer won't notice.

Loading excellent ammo does not have to be so overthought and technical.
 
Bullet touches the lands at 2.875, so with a 2.280 it has 0.075 jump, quite a bit really. I was a touch tired and frustrated last night. I still find it odd that the recommended col is 2.735. Every bullet I have had with a cannelure, the recommended seating depth is generally right at the ogive.

I'm gonna seat at 2.800 and do seating depth tests back from there in 0.003 increment
 
what will the purpose of this rifle and what accuracy do you expect? What type of groups does it get with factory ammo?
 
Shadow9mm,

Something seems to be off. You say 2.735" is compressing a 40-grain charge of H4895. Hodgdon shows a maximum of 45 grains for charge weight with an even longer Nosler 150-grain BT bullet, putting you below their starting load when you get compression. They use Winchester cases and the military 2.800" max COL. But even at 2.735", in QuickLOAD I have to reduce case water overflow capacity to below 56 grains to get 100% loading density from 45 grains of the powder. I know Federal cases aren't that small because they hold 43.5 grains of the even bulkier IMR4064 under a 168-grain bullet. So this is a bit off.

I would check a couple of things, just to be sure.

Is the powder container one you opened or your friend opened, or did he get it from someone else and is unable to confirm the type on the label is the type in the container? Generally, faster stick powders are bulkier, so if neither of you witnessed the container seal being broken, I would want to take a bulk density measurement and check with Hodgdon about it. To do this, get one of those little one-ounce dosing cups with a 30 ml line at the top. Weight the empty cup. fill with the powder to that line and weigh it again. Divide the difference in the two weights 15.432 to convert grains to grams. Then divide by 30 to get grams per cc (milliliters are the same size as a cubic centimeter). As Hodgdon, if the result is in the normal bulk density range for H4895. QuickLOAD has it at 0.92, but that could be a little high.

Check your scale with a check weight, and then weigh one of your charges and one of your bullets to be sure they are what you think they are or that the box correctly says what they are.

Take the cup of a spent primer and seat it backward in one of the Federal cases to serve as a plug. Weigh the case and primer and then fill it with water level with the case mouth with no meniscus (flat) and no drops left on the outside or air bubbles trapped inside and weigh it again. I would expect the difference in the dry and wet weights to be about 57 grains. If it is much less, you have some sort of odd or specialty case or a case with something trapped in it messing with the loading.

I've seen all the above problems. A case with a slug of lead flattened in it. The wrong bullets in a labeled box. The wrong powder in a container bought at a gun show. You want to check you don't have any of these issues just because your numbers don't seem to be adding up and it could be a safety issue and because you said your friend supplied the components, which means you weren't there to witness their origin.
 
well there you go, the heavy lifting has already been done for you. Use the same bullet at the same COL as that match ammo then just match the velocity and you should be home free
 
You want to match the powder, too, though. For a given velocity, powders at the faster end will produce shorter barrel times than powders at the slower end, and you don't want the choice detune the load.

I'm still concerned about that compression at 40 grains of charge. Everything I can find published suggests that should not be happening, so it merits explaining.
 
all true Nick, however the COL and the bullet is there. A lot of 308 powder choices are out there. BTW 2.735 is what Hornady's 10th recommends. with H 4895 they use 37.7 as starting up to 46.4 maximum
 
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Unclenick said:
Shadow9mm,

Something seems to be off. You say 2.735" is compressing a 40-grain charge of H4895. Hodgdon shows a maximum of 45 grains for charge weight with an even longer Nosler 150-grain BT bullet, putting you below their starting load when you get compression. They use Winchester cases and the military 2.800" max COL. But even at 2.735", in QuickLOAD I have to reduce case water overflow capacity to below 56 grains to get 100% loading density from 45 grains of the powder. I know Federal cases aren't that small because they hold 43.5 grains of the even bulkier IMR4064 under a 168-grain bullet. So this is a bit off.

I would check a couple of things, just to be sure.

Is the powder container one you opened or your friend opened, or did he get it from someone else and is unable to confirm the type on the label is the type in the container? Generally, faster stick powders are bulkier, so if neither of you witnessed the container seal being broken, I would want to take a bulk density measurement and check with Hodgdon about it. To do this, get one of those little one-ounce dosing cups with a 30 ml line at the top. Weight the empty cup. fill with the powder to that line and weigh it again. Divide the difference in the two weights 15.432 to convert grains to grams. Then divide by 30 to get grams per cc (milliliters are the same size as a cubic centimeter). As Hodgdon, if the result is in the normal bulk density range for H4895. QuickLOAD has it at 0.92, but that could be a little high.

Check your scale with a check weight, and then weigh one of your charges and one of your bullets to be sure they are what you think they are or that the box correctly says what they are.

Take the cup of a spent primer and seat it backward in one of the Federal cases to serve as a plug. Weigh the case and primer and then fill it with water level with the case mouth with no meniscus (flat) and no drops left on the outside or air bubbles trapped inside and weigh it again. I would expect the difference in the dry and wet weights to be about 57 grains. If it is much less, you have some sort of odd or specialty case or a case with something trapped in it messing with the loading.

I've seen all the above problems. A case with a slug of lead flattened in it. The wrong bullets in a labeled box. The wrong powder in a container bought at a gun show. You want to check you don't have any of these issues just because your numbers don't seem to be adding up and it could be a safety issue and because you said your friend supplied the components, which means you weren't there to witness their origin.
Click to expand...


1. Powder was bought at local reputable gun shop, it was sealed, I opened it. It is several years old, according to the lot number 11-25-2014. but it was stored in a climate controlled environment.

2. Powder volume, I felt like this was imprecise however I gave it a go, took couple tries to not compact the powder when leveling and eyeballing the measurement. Best I could do was 425.0g, giving a density of 0.918.

3. I don’t have a check weight, I will be ordering one today. It’s a RCBS balance beam. I used a 169g SMK as a check weight. I weighed it on cheap pocket scale and got 169.1g. I preciously measured all the bullets in the box on check weight calibrated Hornady scale that I no longer have, and all were between 169.0 and 169.1g so I believe that is valid. On my balance beam it is coming in at 169.2g, so off my 0.1g s near as I can tell.

4. I measure one of the 150g sst Bullets, it weighed in right at 150.0g

5. Case capacity measured 54.1g of water
 
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Just a check. Are you using the book figure for measuring to the tip (COAL) or Ogive being crossed into that?

Not to be insulting or insinuation (this is from the guy who put 13 x 270 bullets into 6.5 cases)

COAL with micrometer is from the base to the tip, not to the Ogive.

Ogive readings are only good for your adapter (they are not precision, I have a two x 270 that don't agree at all) and your gun.

Cannelure should never be below the neck.

My Hornday manual confirms the COL value, SST is a cannelure bullet and should be plastic tip and a boat tail.

Normally any cannellure bullets I have, the fit is closer to the bottom of them or below the bullet cannelure does not even go down to the neck (.020 off lands for a given gun)
 
Other than it being a rifle, I didn't see any mention of what gun you are shooting .308 Win from.

I think you need to talk to someone at Hornady, to get their take on what they are doing.

One point to consider, is the COL a recommendation, or just what they got for length when they seated the bullet to a certain spot? Like cannelure at the case mouth??

I note that they show a different COL for their RN bullet, the SST bullet and the AMAX bullet.

Another point to consider is that the listed COLs are not requirements. Your gun determines that.
 
RC20 said:
Just a check. Are you using the book figure for measuring to the tip (COAL) or Ogive being crossed into that?

Not to be insulting or insinuation (this is from the guy who put 13 x 270 bullets into 6.5 cases)

COAL with micrometer is from the base to the tip, not to the Ogive.

Ogive readings are only good for your adapter (they are not precision, I have a two x 270 that don't agree at all) and your gun.

Cannelure should never be below the neck.

My Hornday manual confirms the COL value, SST is a cannelure bullet and should be plastic tip and a boat tail.

Normally any cannellure bullets I have, the fit is closer to the bottom of them or below the bullet cannelure does not even go down to the neck (.020 off lands for a given gun)
Click to expand...
Measured from the point of the bullet. I do use an ogive comparator but I didn't even take it out. I only use that once a load is finalized since it's generally more consistent measurement when I want to work that load up again, but I record both measurements in my data book.
 
44 AMP said:
Other than it being a rifle, I didn't see any mention of what gun you are shooting .308 Win from.

I think you need to talk to someone at Hornady, to get their take on what they are doing.

One point to consider, is the COL a recommendation, or just what they got for length when they seated the bullet to a certain spot? Like cannelure at the case mouth??

I note that they show a different COL for their RN bullet, the SST bullet and the AMAX bullet.

Another point to consider is that the listed COLs are not requirements. Your gun determines that.
Click to expand...
It's a tc compass. While a budget rifle, he has been able to consistently shoot sub moa, even with red army steel case, thing is a shooter.
 
I seat the bullets as long as possible to just fit the magazine. Then I check to see if they chamber without hitting the lands. If they fit I go to the range and shoot. If they hit the lands I seat them a tad deeper until they don't, then I go to the range and shoot.

I can't remember ever not getting accuracy that met my requirements with that method and I can't even tell you the OAL. If I ever felt the need to tweak the loads I can always experiment by seating them a little deeper, but since I can't possibly go any longer it eliminates a lot of guesswork trying to find best OAL.

Most of the bullets I use don't have a cannelure, but if it does I ignore it.
 
quick update. I got to the point where I can load, but I still don't understand Hornady's recommended COL.

So when we shot the pressure test loads we went from start to max. He prefers to go by how the recoil feels when he works his loads up. He has never loaded bottle neck, only straight wall for handguns so I can kind of understand this. He liked 1.0g under max so 43.0g. we had no pressure signs at 44.0g so this seemed fine to me.

In may case, I did a charge seating test. I put his preferred 43.0g in the casing. I started the bullet high to see where compression started. my target range was 2.800 to 2.780 based on where I wanted to do my seating depth testing. I was able to get down to 2.780, the shortest I planned to seat, and still hear he powder moving when shaking the cartridge, although it was sounded like it barely had any room to move.

Got 6 sets of 4 loaded. Starting at col 2.800, working back in 0.003 increments. Will see how she does.
 
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