Thread: Neck tension

Originally Posted by distant stalker

I think the answer to your question vc is no...

no the answer is actually 42 :0



Apologies in advance I couldn't help myself

if you develop your load with the neck tension your dies give you does it matter as you just keep using the same die.
then the other thing would be the brass, how soft or hard it is, changing the neck tension using that same die, but that would come under annealing.

so if you can measure how much neck tension a round has, what are you going to do with that knowledge? develop loads with different neck tensions rather than, powder weights or seating depths etc...
or maybe just try to have more consistent neck tension...
interesting though.

Originally Posted by veitnamcam

Also 2 thou on say a 17 cal would be a lot compared to say 2 thou on a 50 Cal yes?

I don't load stuff that small or big so I don't care

Originally Posted by ebf

Abe, the problem with that is that the OD of a loaded round may or may not have any relation to the chamber.

Shoulder bump, you're looking at a fire formed case, and sizing relative to that... With a fixed diameter projectile, but variable neck thickness and variable chamber dimensions it all gets a bit random. If you are using a high-end barrel, and can specify how tight you want the neck in terms of the reamer, then turning the necks, and using a known size bushing makes sense.

Also, .002 bushing on very thin brass won't give you the same tension as on thick necks. So to get consistent tension, you pretty much have to turn the necks, which can cause a whole other set of problems with an average "loose" neck chamber...

All my brass is neck turned to .013 so again .002 works mint for me. Use no expanding balls just size them with correct bush.

I have .005 clearance on my loaded rounds so .0025 each side clearance, all mine are hunting guns in have no need to go super tight neck

Tried less and they move still. Try more and what's the point is holding them so tight.




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For ultimate long range consistency think case neck annealing

I made up 12 dummy 303 rounds to dry fire with and forgot to crimp, they lasted over a month of dry firing each night before 3 or 4 worked lose, so I'd suggest a light crimp is all you need for something thats going to be in a mag and chambered only 1 or 2 times max.

Lee suggests crimping is beneficial to accuracy, Ive not tested that yet but intend to.

Originally Posted by tui_man2

Bushing dies

Measure loaded dummy round neck diameter
Use correct bushing .002 smaller

Job done

Some of the recent comments Ive seen from Reading and Lee say 1thou as the bullet just expands the neck anyway and getting the bullet to do it isnt a good idea.

At the moment Im using the Lee neck sizer (and I think its doing well) but I have a Reading S comp neck die to try, I just need some new privy brass, the 1943 stuff I have varies hugely so I cant use a bushing die on those.

regards

Originally Posted by LJP

For ultimate long range consistency think case neck annealing

Every palma/TR shooter I have talked to so far, doesnt anneal, but they only neck about 1/4 to 1/3 of the neck with a bushing die so work hardening is minimal, or use the Lee neck die, good scores either way.

regards

Originally Posted by steven

Every palma/TR shooter I have talked to so far, doesnt anneal, but they only neck about 1/4 to 1/3 of the neck with a bushing die so work hardening is minimal, or use the Lee neck die, good scores either way.

regards

Wouldn't that increase the odds of encountering bad run out issues with only a fraction of the projectile being held in a parallel within the case neck? I've heard of guys doing this, but its never made absolute sense to me?

Originally Posted by kimjon

Wouldn't that increase the odds of encountering bad run out issues with only a fraction of the projectile being held in a parallel within the case neck? I've heard of guys doing this, but its never made absolute sense to me?

Wouldn't the un sized portion hold the round perfectly concentric(in a tight neck chamber) and the projectile held straight in the bore?

Would also mean effectively a lot less neck tension.

Originally Posted by veitnamcam

Wouldn't the un sized portion hold the round perfectly concentric(in a tight neck chamber) and the projectile held straight in the bore?

Would also mean effectively a lot less neck tension.

I can see the unsized section working to hold the brass concentric in the chamber, that makes perfect sense to me.

But the 1/4 sized neck (bearing surface) on the case is all that really touches the projectile if the bullet isn't jam seated. its just cantilevered out there in free bore and this could cause issues with concentricity?

You often hear of wild-cats like the 7mm-300WSM when there is already a 7mmWSM, so it seams pointless...but its done to get the longer neck, which aids in concentricity. It comes at a slight cost in capacity (internal capacity is lost by having the longer neck, so its a little slower than the true 7mmWSM), but some consider it important for accuracy.

Originally Posted by veitnamcam

Wouldn't the un sized portion hold the round perfectly concentric(in a tight neck chamber) and the projectile held straight in the bore?

Would also mean effectively a lot less neck tension.

Redding bushing dies leave about 1mm on there type s dies that don't size the neck to line it up in the chamber also
Compertition bushing dies let you adjust the amount of the neck you size so you can play with it if your that way inclined.

What's your method Mr Veitnamcam?

Whack it threw a full length die

Originally Posted by kimjon

I can see the unsized section working to hold the brass concentric in the chamber, that makes perfect sense to me.

But the 1/4 sized neck (bearing surface) on the case is all that really touches the projectile if the bullet isn't jam seated. its just cantilevered out there in free bore and this could cause issues with concentricity?

You often hear of wild-cats like the 7mm-300WSM when there is already a 7mmWSM, so it seams pointless...but its done to get the longer neck, which aids in concentricity. It comes at a slight cost in capacity (internal capacity is lost by having the longer neck, so its a little slower than the true 7mmWSM), but some consider it important for accuracy.

Yeah mate on the money.

And the longer neck aids throat life some what also.

The little it lets down in speed if any depending is nothing

So for the most consistent 'neck tension' we should be neck turning all brass and using the appropriate bushing/bushing die to size the neck?

Bushing Selection | Redding Reloading Equipment: reloading equipment for rifles, handguns, pistols, revolvers and SAECO bullet casting equipment

The shoulder of the case will not be bumped back by using only the neck bushing die, this will sort the concentric bullet issues in the bore? am I correct?

I see Redding do a body die and state: "Body Dies are designed to full length resize the case body and bump the shoulder position for proper chambering without disturbing the case neck. They are made without internal parts and intended for use only to resize cases which have become increasingly difficult to chamber after repeated firing and neck sizing".

interesting thread in the never ending search for accuracy.

Originally Posted by Baz

So for the most consistent 'neck tension' we should be neck turning all brass and using the appropriate bushing/bushing die to size the neck?

Bushing Selection | Redding Reloading Equipment: reloading equipment for rifles, handguns, pistols, revolvers and SAECO bullet casting equipment

The shoulder of the case will not be bumped back by using only the neck bushing die, this will sort the concentric bullet issues in the bore? am I correct?

I see Redding do a body die and state: "Body Dies are designed to full length resize the case body and bump the shoulder position for proper chambering without disturbing the case neck. They are made without internal parts and intended for use only to resize cases which have become increasingly difficult to chamber after repeated firing and neck sizing".

interesting thread in the never ending search for accuracy.

That's the idea, the main body of the case isn't sized by a neck die, so your fire-formed cases should be a perfect fit in the chamber. The neck is sized to hold the projectile only. Some go as far as putting a mark on the case and always feeding it into the chamber with that mark facing the same way up...

The theory V's reality are often governed by the shooters and/or rifles potential. Some people waste a lot of time doing really anal things that will never eventuate in any accuracy gains as either they or their rifle will never realise the difference.

I've gone full circle with my reloading and now do my brass prep, then just shoot and full length size until the brass fails. I'm finding that my accuracy out to 600y isn't suffering for it. Maybe beyond 600y these little subtleties will show up(?), but I don't shoot beyond 600y very often myself.

I am looking into building an annealing machine mainly to extend brass life (but it will improve neck tension, as a side effect) - I can see merit in this approach...but its kind of slipping down my ''to do'' list at the moment with more important things to make before that one.

kj