Cracked necks in 6.5 x 55 brass.

[Parashooter]

Seems to me some of the sizing advice here is intended for conventional neck-sizing dies. In the initial post, Aprayinbear says he's using a Lee collet-style neck-sizer. With this design, you don't normally get a choice about how far to size the neck (that's built into the die, but see below for a workaround) - only how tight you squeeze it onto the mandrel. Back off just slightly too far and the collet doesn't compress at all. Screw it down too much and the collet can compress the neck dead hard against the mandrel, at which point more pressure simply stresses tools and deforms brass without making the neck any smaller.



Info from Lee's website FAQ section -

Collet die pressure exertion

All of the sizing in the Collet die takes place at the very end of the stroke, when the ram/shell holder appears to bottom out against the base of the die. If you lean into the handle at this point, you will force the collet up into the die body, and cause the collet to squeeze the case neck down against the mandrel (the very end of which pops out the spent primer). About 25 lbs. of force is sufficient to resize most cases. If you are sitting in front of your press, just leaning your upper body weight into the lever is about right.

A good way to determine how much is necessary is to start the case into the die and feel the die remove the primer. Start using pressure and work up to what you think is about 25 lbs. Remove the case from the die and attempt to place the intended bullet in the case neck. If there is little or no resistance, repeat the process with slightly more pressure. When you have reached a point where there are vertical striation marks on the outside of the case neck or the intended bullet does not fit easily into the case neck, the correct amount of pressure has been achieved.

Partial neck sizing with collet die

If you want to resize just a part of the neck, find a washer at your local hardware store the has an inner diameter large enough to fit over the case, and an outer diameter large enough so that it contacts the collet sleeve that protrudes from the bottom of the die. Slide this washer over the case after the case has been inserted into the shell plate. Now when the ram is raised, you can still close the collet by applying force at the top of the stroke, but the case will not go up as far into the collet, and the neck will be sized less an amount equal to the thickness of the washer.

[JBS]

The two types of neck splits in the photos are from the same cause. The neck is tempered and too hard, work/heat hardened. The correction is to anneal it and work the brass less or anneal more often. The difference in appearance is that in the first photo the split has been flame cut. This split existed as a hair line crack prior to the loading that it showed up as a flame cut split. The other photo shows a split that was large enough to be discovered after the firing that caused it, an thus was not reloaded and fired again resulting in a flame cut.

[Patrick Chadwick]

Thanks to Parashooter, I now know how the Lee collet dies work!

I use the washer trick myself for repeatable changes to die settings.
Example: sizing/expanding/seating the .455 Webley/Eley MkI and MKII cases with the same die set. Eternal changing of the die settings is unreliable, so I have a spacing ring that is as thick as the difference between the MkI and MkII case lengths, and move up the dies by this amount when sizing the MkI case.

Getting back to 6.5x55: I have a classic Carl Gustaf M96, and a Schultz & Larsen match rifle. Both have barrels in top condition. But cases fired in the M96 cannot even be forced into the S&L, which is very tightly chambered to CIP dimensions. I now have two die sets, and use different manufacturers cases, so that I am in effect treating the two rifles as if they had different calibers.

As to the load with light bullets (120gn or thereabouts) - I have no experience, but intend to try it a.s.a.p. It seems plausible that a certain length of the parallel section of the bullet should be inside the neck, but in this case I would like to pass the question on to Gunner, who (I believe) uses such a load.

Gunner, you may have done this before, but being myself too lazy to search it out (excuse: I want to help aprayinbear!) perhaps you could repeat the details of your light Swede load, including seating depth.

Patrick

[aprayinbear]

The washer fix works like a charm. I tried it out on several of the poor cases. I was worried that with the washer I might have trouble getting enough change in the neck size to firmly hold the bullet..... not the case. It worked just fine

All The Best

[gunner]

Patrick,

my favorite load for the Swede is as follows:

139grs Lapua Scenar, 34.5grs VV N140, CCI BR-2, OAL 78.1mm ( 3.0748" ), Cases are PRVI ( Case length 50mm / 1.968"), neck sized only.

It is a mild an accurate load wich holds 1.5" at 100 yards out of my M38.

Regards

Gunner

[gunner]

Now i´m really getting old!

I forgot my "Soft Load" It is 107grs Sierra Matchking, 25.3grs VV N110, CCI BR-2, OAL is 78.2mm ( .3,0787") Cases are PRVI ( CL 50mm/1.968"). Best group was 5 rounds, diameter 17mm with scoped M38 at 100 yards.

Regards

Gunner

[aprayinbear]

I'm happy to say that I purchased some PRVI brass and have had no problems since. Brass shows no problems and I'm a happy camper. I'm only neck sizing after firing once and using the washer trick to keep the sizing die off the shoulder. Works like a charm. Great suggestions everyone. Without your help I could have easily headed to the local gunsmith and spent way too much cash trying to figure out the problem.

All The Best To Everyone