Newbie neck tension problems loading TTSX for .308

[Technologist]

Hi there,

I've been loading a box of 150 gr TTSX bullets for my .308 Winchester. I've had some issues during loading and I strongly believe that they are the cause of the poor accuracy I've been getting with this batch of handloaded ammo.

I'm asking you guys for a second opinion on my troubleshooting.

Two weird things are happening when I seat the bullet:
1) The bullet often gets stuck to the seater. I've tried greasing the seater and working it with a fine file. This causes uneven COAL.

2) As I insert the bullet, the contact between the TTSX ring cuts and the brass neck is violent. The noise and uneven resistance as I push the bullet in doesn't inspire any confidence with regards to accuracy. I also get quite a lot of shavings falling off the bullet.

I thought I could fix this by resizing without the expander. I figured the increased neck tension would hold the bullet better against the seater, and also generally keeping the bullet in place. This kind of worked. The COAL was much more even and I didn't have to mess around getting bullets out of my bullet seating tool. However, the COAL is still uneven and I still get brass shavings. After accuracy testing I got suspicious of the ammo and I noticed that some of the bullets aren't firmly held in place in the neck.

I have a feeling that I should try changing the brass, or trim and chamfer the case mouths instead of just shoving once fired brass into the resizing die.

 

[CVCOBRA1]

You need to chamfer the inside and outside of the brass even if it is new, once fired or any time you reload it. You also might have to get a new seating stem. How old are your dies? Some seaters do not like the long slim ogives on these newer style bullets.

 

[Satterlee Scott]

Chamfer and Debur. Additionally I anneal every other firing and use a mandrel to expand the necks back out instead of the expander button inside the stock die

 

[Oi.223]

I've got best accuracy when resized case mouth diameters are about .0005" smaller than bullet diameters.

This is easiest for me when the die's neck is about. 001" to .002" smaller than loaded round neck diameter. It compensates for brass springback properties.

Forster will hone their die necks for $12. Then the expander ball is not needed. Case necks are straighter and can be reloaded more times.

Neck tension has several meanings. It's often expressed as the difference in die neck diameter and loaded round neck diameter. Sometimes the difference between sized case mouth and bullet diameters, called interference fit. Other times by the force needed to push the bullet out of the case neck.

 

[birdiemc]

All the above, plus clean your seating die. I was having problems with mine sticking slightly, and cleaning it helped. As for the contact issue, pull the die apart and set the seating plug on top of a bullet, see where it's making contact. That should clear it up for you if you need a different plug for longer vld style bullets

 

[ShtrRdy]

If you're measuring the length from the base of the brass to the tip of the bullet then this dimension will likely change from cartridge to cartridge.
Measure the length of 10 to 20 bullets to get an idea of how much this varies.

 

[lancetkenyon]

I never measure COAL. I always measure CBTO (Cartridge Base to Ogive). You will get more consistent results this way.

Like others have said, chamfer the case mouth inside.

 

[ronstone09]

Hi there,

I've been loading a box of 150 gr TTSX bullets for my .308 Winchester. I've had some issues during loading and I strongly believe that they are the cause of the poor accuracy I've been getting with this batch of handloaded ammo.

I'm asking you guys for a second opinion on my troubleshooting.

Two weird things are happening when I seat the bullet:
1) The bullet often gets stuck to the seater. I've tried greasing the seater and working it with a fine file. This causes uneven COAL.

2) As I insert the bullet, the contact between the TTSX ring cuts and the brass neck is violent. The noise and uneven resistance as I push the bullet in doesn't inspire any confidence with regards to accuracy. I also get quite a lot of shavings falling off the bullet.

I thought I could fix this by resizing without the expander. I figured the increased neck tension would hold the bullet better against the seater, and also generally keeping the bullet in place. This kind of worked. The COAL was much more even and I didn't have to mess around getting bullets out of my bullet seating tool. However, the COAL is still uneven and I still get brass shavings. After accuracy testing I got suspicious of the ammo and I noticed that some of the bullets aren't firmly held in place in the neck.

I have a feeling that I should try changing the brass, or trim and chamfer the case mouths instead of just shoving once fired brass into the resizing die.

sounds to me like theres something wrong with your seater ! also try chamfering the case necks inside and out and usea little graphite on the neck to help seat the bullets

 

[crkckr]

You might also take some 600 sandpaper and make sure there are no sharp edges on the inside edge of the seater plug that might be "grabbing" onto the bullet. If there were, it will usually leave a thin line around the bullet where it contacts the plug. This could be why the seater is grabbing the bullet.
Cheers,
crkckr

 

[Technologist]

Got 27 cases through the resizing die before I broke the stem on a berdan primed case that somehow got into the mix. Might take a while before I post results.

 

[okie man]

You can use a vld inside chamber tool too put a nice bevel on your seating stem too help with seating vld style bullets. That and a nice bevel on the inside of your case neck should help your problems

 

[LoneTraveler]

Technologist, Those 7.62X51 NATO cartridges loaded in Europe with Berdan Priming are a pain in the tosh. Check the decapping rod close, It may be bent too. Safest thing, Just order a complete rod for a spare so if it happens again. Or this one is bent beyond use.

Once you get the seating stem smoothed up, To eliminate that problem. You need to chamfer the inside of the case mouth so the bullet will not catch on entry of the case mouth. If you are wet cleaning the cases, You may need to lightly lube the case necks for easier seating of bullets. With Graphite or Mica.
Good Luck on this project.