TIGHT NECK CASE PREPARATION
The items highlighted in ‘blue’ are the only tasks that are usually necessary with new Lapua 220 Russian Brass
PREPARATION
1 – Weigh cases and batch to 1/10 grain (use minimum of 100 cases and use cases from same batch with same serial number)
The very heavy and very light cases at either end of the spectrum can be used as experimental set up cases, the largest batch can be used for the pre-loaded competitions and the smaller batches for reloading on site.
2 – Inspect cases for debts and flaws, is case flash hole central.
3 – Check neck wall thickness and discard where excessive variations (can be .001 to .006 variations)
4 – Expand the Case Neck (lubricate mandrel).
Best not to use oil based lubricant on the inside of the case neck (use Lee resizing lube or a dry lube). Expander mandrels are 0.0008 to 0.001 larger than the neck turner mandrel. Use the expender mandrel and neck turner from the same manufacturer as mandrels do vary in size.
5 – Full Length Size to bump Neck (remove any central expander mandrel in the die).
This allows one to cut back sufficient of the neck to prevent a doughnut forming on the inside of the case.
6 – Uniform internal Flash Holes – Carry out once only when new (7 light turns in same direction).
Even the drilled European brass has small burrs. The punched American brass has larger burrs. Tools can be purchased with stops to prevent one from cutting too deep.
7 - Uniform external Primer Pocket Hole – Carried out on new and used cases.
Primer depth can vary with new brass. It is more usual to fire form the new case and then use the uniformer tool after this first firing.
8 – Cut cases to same length + chamfer inside and outside of case neck.
1.500 inch recommended max length (can usually go up to 1.525 inch). Trim 1.485 inch.
NECK TURNING
9 – Neck Turn to 10 thou with first cut (use feeler gauge to set).
Note – Best to use 2no pre-set Neck Turners. Case wall thickness on new Lapua 220 Russian is 14 thou.
10 – Fine Neck Turn 8.8 to 9.0 thou with second cut.
8.8 thou is a popular second cut to give a minimum 1 thou total clearance. This equates to half a thou each side of the bullet. Berger bullets usually require a 9.0 thou cut to give 1 thou clearance. The majority of American bullets are slightly larger and require an 8.8 thou cut for 1 thou clearance. The final fine cut gives a smoother finish.
Note – Approx 200 rpm is the best speed for any drill attachment. Cut into the shoulder just a little. There will be a small doughnut formed just inside the shoulder rather than in the neck which will not be a problem.
11 – After turning it may be necessary to lightly chamfer the inside and outside of the case neck. Avoid this process if you can as it is difficult to chamfer each bullet by exactly the same amount
Note – Weigh bullets and batch before loading
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Only neck turn new brass in batches and at the same time and in exactly the same way using exactly the same processes and procedures. Whatever you do to one piece of brass then make sure you do exactly the same thing to every other piece of brass in that batch. When shooting use this brass together and do not mix with previously prepared batches.
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GENERAL NOTES
Trim Length
As a general rule trim a minimum of 10 thou shorter than the chamber length. Chamber length range from 1.500 to 1.525. Some trim as close as 5 thou shorter than the chamber which is very tight and will need constant checking. Cases can grow up to 1 thou per firing.
Fireforming will reduce the case length by 3 to 5 thou. It is not possible to cut cases much longer than 1.500 after the first Fireforming therefore with the longer 1.525 chambers there will be 25 thou clearance.
A recommended trim length of 1.485 is often quoted. This could be excessive especially with a longer 1.525 chamber which would give you 40 thou clearance.
Doughnuts
We are told that there is little evidence to suggest that doughnuts do actually reduce accuracy. The problems that I have found with doughnuts is they are never exactly the same size and never in exactly the same position and this will definitely affect accuracy.
Doughnut Removal – Use expander mandrel and then neck turn the outside of the case. This usually reduces the doughnut but may not completely remove.
Headspace – Set headspace with bolt dissembled as this gives a much finer feel.
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Neck Tension
Using V133 powder you need a fairly tight 0.003-0.0035" net size reduction. Using 8208 or H322 you can get by with about 0.0015-0.002" less
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TYPICAL REMINDER SCHEDULE for NECK TURNING new LAPUA 220 RUSSIA
NECK TURNING (262 Henriksen Reamer)
(220 Brass - 14 thou neck start thickness, 1.515 inch)
1 - Weigh cases and batch
2 – Sinclair neck Expand
Expand
Bump
Expand
Bump
3 – Sinclair neck turn 10 thou approx
4 – K&M neck Expand
Expand
Bump
5 – K&M neck turn 9.3 (or 9.0 for 1 thou)
243+9.5+9.5=262 neck
FIREFORM
6 – Uniform Primer Pocket
7 – Possibly Uniform inside of flash hole
(7no light twists in same direction)
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NECK TURNING (263 Boyer lll Reamer)
(220 Brass - 14 thou neck start thickness, 1.515 inch)
1 - Weigh cases and batch
2 – Sinclair neck Expand
Expand
Bump
Expand
Bump
3 – Sinclair neck turn to 10 thou
4 – K&M neck Expand
Expand
Bump
5 – K&M neck turn 9.8 (or 9.5 for 1 thou)
243+10+10=263 neck
6 – Cut Case to 1.498
Will reduce by approx 5 thou after Fireform
7 - Lightly cut inside of neck with Wilson case trimmer, hand hold brass (2no turns)
8 - Trim outside of neck with K&M cutter
(DO NOT CUT INTO SHOULDER)
9 - Clean top of neck with steel wool
FIREFORM
10 – Cut Case to 1.490 (or 1.485)
11- Lightly cut inside of neck with Wilson case trimmer, hand hold brass (2no turns)
12- Trim outside of neck with Lyman hand tool
13– Uniform Primer Pocket
14 – Possibly Uniform inside of flash hole
(7no light twists in same direction)
Note – Weigh Bullets and batch before loading
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TYPICAL BATCHING SCHEDULE of WEIGHTED BRASS
EXAMPLE OF CASE WEIGHING & BATCHING
110.3 1 Set-up brass
110.4 Nil
110.4 10
110.6 31 Total 41no
110.7 Nil
110.8 12 Total 12no
110.9 Nil
111.0 24
111.1 37 Total 61no
111.2 Nil
111.3 23
111.4 18 Total 42no
111.5 Nil
111.6 9
111.7 6 Total 16no
111.8 Nil
111.9 3
112.0 5 Total 8no
112.1 Nil
112.2 Nil
112.3 1 Set-up brass TOTAL 182no
