Can a crimp serve same purpose for neck tension?

[Bayourambler]

I’ve found that Sierra bullets tend to like more neck tension than others but when I trim many times I think the pilot on my case trimmer loosens the tension up. What if I put a light crimp on them? Wouldn’t this make things more consistant? I’ve never crimped, any of you tested this?

 

[USSR]

A crimp is never a substitute for neck tension. I would suggest you get a good case trimmer such as the L.E. Wilson which doesn't use a pilot in the neck.

Don

 

[ArchAngelCD]

I agree, a crimp will never replace good neck tension. As a matter of fact too much crimp could reduce neck tension.

 

[Walkalong]

Agreed, no amount of crimp can make up for poor neck tension. A good roll crimp helps neck tension. A taper crimp should be minimal because the auto cases it it used on headspace on the case mouth. It isn't used to help hold the bullet.

 

[Bayourambler]

Ok. I use a old Lyman universal case trimmer, I hate it. I just watched a video on the L E Wilson trimmer, that thing looks precise. Might have to get one of those! Thanks!

 

[Walkalong]

What if I put a light crimp on them? Wouldn’t this make things more consistant? I’ve never crimped, any of you tested this?

What caliber etc?

A crimp can help get more better start pressure and a more consistent burn in some applications.

 

[Bayourambler]

What caliber etc?

A crimp can help get more better start pressure and a more consistent burn in some applications.

Mostly load for 308 and 300 wm. Bolt action

 

[Dwb1957]

I never crimp rifle bullets with out crimp groves I have tried crimping rifle bullets with crimp groves and it always seemed to hurt accuracy for me. You could try cleaning the inside of the neck with alcohol and a q-tip that seems to help the bullet crip the case better and if that don't work you could remove about a .0005 off of your expander ball to in crease neck tension.

 

[Walkalong]

A crimp shouldn't be needed. A tighter sizer in the neck area, or polish the expander ball down, or use a bushing die to get better neck tension.

 

[Bayourambler]

I was thinking a crimp might help in slower powders

I never crimp rifle bullets with out crimp groves I have tried crimping rifle bullets with crimp groves and it always seemed to hurt accuracy for me. You could try cleaning the inside of the neck with alcohol and a q-tip that seems to help the bullet crip the case better and if that don't work you could remove about a .0005 off of your expander ball to in crease neck tension.

i did polish an expanded ball down the other day , I haven’t loaded and tried it yet.

 

[Walkalong]

I was thinking a crimp might help in slower powders

It might with the big boomers and slow powders, but I have no experience with those. My big boomer is a .458 Win Mag, a straight walled caliber using medium or faster speed powders.

 

[Dwb1957]

Something else that seems to help neck tension that you could try is I always clean my brass after sizing to remove the lube from inside the neck and outside of the case. In doing so you get some dust from the media in the case which I think increases neck tension a little.

 

[rg1]

A case trimmer especially a partially dull one can and does roll up a burr on the inside of the case mouth. I find a standard case neck deburr tool does not remove this rolled up burr totally. The raised neck mouth burr will prevent maximum bullet tension. Check very closely the inside neck mouth for a raised burr not completely removed. You can use a sharpened wire to feel for a burr here. I highly recommend a VLD case mouth deburr tool as it will completely clean burrs on the inside neck mouth. These burrs if present will scrape copper from bullet also. That's all I can imagine that your Lyman case trimmer might do to loosen neck tension by rolling up a burr from a dull cutter or from brass buildup on your pilot or a cutting edge. If your pilot is tight or has a problem with brass build up it could be scratching the inside neck. The standard 45 degree deburr tool you have to remove too much material to clean up the inside case mouth burr often leaving a sharp knife edge mouth. The VLD inside tool will remove the burr without sharpening the case mouth.

 

[murf]

if you think trimming reduces neck tension, size the case again. if you don't have enough tension, polishing the expander button should work.

luck,

murf

 

[azjohn]

Could use these after trimming. https://www.titanreloading.com/lee-.../lee-rifle-reloading-dies/lee-collet-die-only

 

[jmorris]

If you think holding the bullet in the case for more pressure to build before it moves is going to help, seat thebullet out to touch the lands. That will do more than neck tension or any crimp.

 

[fguffey]

I agree, a crimp will never replace good neck tension. As a matter of fact too much crimp could reduce neck tension.

Too much crimp reduces bullet hold if we are talking about bottle neck cases. Because the seating die does not have case body support too much crimp can bulge the case below the crimp. Seating and crimping with the same die is considered a bad habit by some die manufacturers. I use a lock out die in the 550B, that means I crimp after loading all of my cases or I use the same station for seating and crimping, I do not crimp bottle neck cases. I go for all the bullet hold I can get.

F. Guffey

 

[Slamfire]

I’ve found that Sierra bullets tend to like more neck tension than others but when I trim many times I think the pilot on my case trimmer loosens the tension up. What if I put a light crimp on them? Wouldn’t this make things more consistant? I’ve never crimped, any of you tested this?

Find a smaller pilot. Crimping is not conducive to best accuracy. When you crimp, you deform the soft lead core of a jacketed bullet. You also create a gap between the jacket and the core because the jacket materials will spring back (modulus of elasticity) differently from lead. Swaging the lead core will shift the center of gravity of the bullet and shift it unpredictable. If the center of gravity is moved outside the axis of rotation the bullet will oscillate unpredictably. The further out you go the more pronounced this will be.

 

[Sunray]

"...think the pilot on my case trimmer loosens..." If it does, it's the wrong pilot.
Neck tension is something that is not and cannot be measured. The bullet doesn't like it or dislike either.

 

[Walkalong]

Simply not correct.

 

[fguffey]

"...think the pilot on my case trimmer loosens..." If it does, it's the wrong pilot.

Depends on what trimmer; I have old trimmers that have pilots that fit the neck very tight, a reloader has to go into mortal combat to install the case onto the pilot and it is no easier removing the case after trimming so when I use that trimmer I trim the case before sizing, I understand all other reloaders trim after sizing. I also have trimmers that do not use pilots meaning it does not matter if I trim before and or after sizing.

I am the only reloader that can not bump the shoulder back meaning I when I size a case the shoulder does not move, it becomes part of the neck and part of the shoulder becomes part of the neck. If my sizing dies did not have case body/shoulder support I could bump/move the shoulder back but that would cause an upset at the case body/shoulder juncture.

F. Guffey

 

[Rule3]

I’ve found that Sierra bullets tend to like more neck tension than others but when I trim many times I think the pilot on my case trimmer loosens the tension up. What if I put a light crimp on them? Wouldn’t this make things more consistant? I’ve never crimped, any of you tested this?

If the pilot is hard to insert into the case neck, then perhaps just "hone" down the pilot with some wet dry paper.??

Some guys actually trim before sizing (not the most preferred method but if they are all the same, why not?

 

[Bayourambler]

"...think the pilot on my case trimmer loosens..." If it does, it's the wrong pilot.
Neck tension is something that is not and cannot be measured. The bullet doesn't like it or dislike either.

Well I sure can tell a difference when seating bullets. Some slide in easy , some require more force . I can promise you they shoot different, I've set the ones that I felt more tension seating aside, they shoot better. Now, the bullet diameter could be varying a little. It's the correct pilot, it's very snug on some. I even tryed running them through a a bushing die right before I load, still they don't all feel the same when seating bullets.

 

[jmorris]

Some guys actually trim before sizing (not the most preferred method but if they are all the same, why not?

Because if you want the final lenght to be the same, you don't want to cut them until you have finished moving metal around by sizing them.

 

[murf]

If you think holding the bullet in the case for more pressure to build before it moves is going to help, seat thebullet out to touch the lands. That will do more than neck tension or any crimp.

be careful with this as pressures can get out of hand if you are already at the top end of the reloading data. some bullets are very accurate when loaded this way, some are not (berger usually recommends seating bullets a ways off the lands for best accuracy).

luck,

murf