Brass measurement Not to avoid.

[swampratt]

I went shooting the other day at 200 yards..I have a new .308 with a very tight chamber.
Luckily my die almost matches the chamber to my liking only sizing the case .001 to .002" anywhere.

Now I was running my die in the press all the way to the shell holder and then added another.
1/12th of a turn..This is with the ram up of course.

I sized some cases and loaded them.
My chamber is tighter than I thought .IN ONE AREA.

The shoulder Ogive area.
I had to turn my die in another 1/12 if a turn..Think of a clock with 12 numbers.

Ok so I shot the stiff to chamber rounds and the others with the shoulder .003" farther back.

The groups were much different with the tighter group going to the longer shoulder that was hard to chamber.

Maybe it was not the shoulder at all that made the groups tighter.. maybe it was the new gun getting more fouled. shot 10-14 vs the shots 15-20.

More testing today.

Here is a clincher: When Full length sizing the cases I found some cases were a tad harder to size..a very small tad mind you.
This was due to the amount of lube in the neck.. Those cases would measure .002" different from base to the shoulder ogive ..Or middle of the shoulder.

No way to wring out all the accuracy you can muster if you do not have the same case dimensions.
I polished my die and it does much better this morning and I went back to my old way of lubing necks inside .
Q-Tip and some Hornady sizing wax or Imperial wax.
Then clean it all out with another Q-Tip and brush the necks.
Before I was just running my finger over the mouth of the cases with the lube on my fingers.

All the shoulders now measure the same.
Gun shot very well .450 MOA stiff seating to .750 MOA with shoulder pushed back .002" and easy to chamber. This was at 200 yards

Have fun and shoot straight.

More testing today.

 

[slas]

I like these post as they not only educate me but also give me plenty to think about when reloading....keep em coming....

 

[Pokinfun]

I normally clean my brass after I size it to remove the lube. For the inside of the neck, I roll my neck brush on a lube pad and brush the inside of the neck. I do not think I need to clean the inside of the neck, but I am not trying to shoot .5 moa at 200 yards. If I was trying to punch holes that size, I would make sure everything was exactly the same down to the amount of lube used in each case.
If you are worried about the chamber size, why don't you just use a neck die?
If you are setting up your press to cam over, I am not sure turning it in or out a 1/12 of a turn makes a difference. it could be your press flexing. The 1/12 turn could be letting you bump the shoulder back if you are not cam over on the press.
You know more than I do about reloading. I guess I am asking why you do not just neck size your used cases?

 

[lasher]

i only shoot AR platforms and bump the shoulder back on everything,,,.002 to .003

 

[Calamity Jake]

What are you using to measure that base to shoulder length?
Do you have s special fixture that rests on against the shoulder?

 

[Pokinfun]

What are you using to measure that base to shoulder length?
Do you have s special fixture that rests on against the shoulder?

 

[swampratt]

Very good Pokinfun.


Many ways to get there but you must have precise tools. Mitutoyo or like your Brown and Sharp.
I have some 27 year old claipers that were 75 bucks back then and they are dead nuts on.

I have tried RCBS and Oter 45 dollar ones and a couple Harbour freight ones and .002" accuracy plus or minus is the best you will get , at least with the ones I played with. Just too much play in the gear sets.

My press does not cam over it is Lee classic cast iron O press.
The .002" is flex not in the press as I checked that with a dial indicator. It is the threads in the die and press taking up that small amount of slack.

I shot more today only to be scratching my head more.
I set them all the same to Ogive and shot groups at 100, 200 and 300 yards.
I only shot 200 yards yesterday. The 200 yard 178 load looked the same. But it looked like crap at 100 and 300.
Much more drop than the 168gr load.. which shot like crap at 300.. it was ok at 100 and 200.

I had some ammo that needed used up. just for kicks I shot it at 100, 200 and 300 yards.
155 A max with 8208XBR. 1.7" 3 shot at 300 yards and .550" at 200
Ok now we are getting somewhere..Much much less drop at all distances and good groups.

Could be I am pushing the 168 and 178 too slow and the wind is pushing them around 4.5" groups or larger at 300 for them.

Drops look like this.
168 drops 5" at 200 yards and 14.5" at 300 yards vs where the 100 yard hits were.
178 drops 7" at 200.................21" at 300.
155 drops 2.5" at 200...............9" at 300. That has been a good load in my other .308, in fact those were built for the other gun. All the bullets are A-Max.

I can't put enough powder in the Lapua case to play with high speed 178 loads.
I usually pull out the winchester cases.. but I wanted to play with these Lapua cases in this gun.
Fun with numbers.

 

[beastep]

You are making my head hurt. Hell sometimes I dont even check my headstamps.

 

[Pokinfun]

Very good Pokinfun.


Many ways to get there but you must have precise tools. Mitutoyo or like your Brown and Sharp.
I have some 27 year old claipers that were 75 bucks back then and they are dead nuts on.

I have tried RCBS and Oter 45 dollar ones and a couple Harbour freight ones and .002" accuracy plus or minus is the best you will get , at least with the ones I played with. Just too much play in the gear sets.

My press does not cam over it is Lee classic cast iron O press.
The .002" is flex not in the press as I checked that with a dial indicator. It is the threads in the die and press taking up that small amount of slack.

I shot more today only to be scratching my head more.
I set them all the same to Ogive and shot groups at 100, 200 and 300 yards.
I only shot 200 yards yesterday. The 200 yard 178 load looked the same. But it looked like crap at 100 and 300.
Much more drop than the 168gr load.. which shot like crap at 300.. it was ok at 100 and 200.

I had some ammo that needed used up. just for kicks I shot it at 100, 200 and 300 yards.
155 A max with 8208XBR. 1.7" 3 shot at 300 yards and .550" at 200
Ok now we are getting somewhere..Much much less drop at all distances and good groups.

Could be I am pushing the 168 and 178 too slow and the wind is pushing them around 4.5" groups or larger at 300 for them.

Drops look like this.
168 drops 5" at 200 yards and 14.5" at 300 yards vs where the 100 yard hits were.
178 drops 7" at 200.................21" at 300.
155 drops 2.5" at 200...............9" at 300. That has been a good load in my other .308, in fact those were built for the other gun. All the bullets are A-Max.

I can't put enough powder in the Lapua case to play with high speed 178 loads.
I usually pull out the winchester cases.. but I wanted to play with these Lapua cases in this gun.
Fun with numbers.

I use MAHR digital calipers, they are great. I do have a cheap set of digital Harbor freight calipers, and they have always been accurate as well, but they have not been used much.
Speed and wind can have an effect at 200 meters.
For 308 I have over a thousand LC11 cases. I keep reusing the same 200 cases. I reamed the primer vent hole and swaged the primer hole on them. I always FL size them and trim them.
For 243 I use Hornady brass with the same process.
MY 7mm Remington Mag, I use what ever brass that is in the bag or I can trade for.

 

[beastep]

I use MAHR digital calipers, they are great. I do have a cheap set of digital Harbor freight calipers, and they have always been accurate as well, but they have not been used much.
Speed and wind can have an effect at 200 meters.
For 308 I have over a thousand LC11 cases. I keep reusing the same 200 cases. I reamed the primer vent hole and swaged the primer hole on them. I always FL size them and trim them.
For 243 I use Hornady brass with the same process.
MY 7mm Remington Mag, I use what ever brass that is in the bag or I can trade for.

Do you like the Hornady 243 brass? I need to buy some 243 and was thinking about those.