New brass prep?

[TrxR]

For you guys shooting F open or F/TR what are your New Brass Prep procedure? I will be using Lapua .308 without neck turning. My question is should I run an expander mandrel through these (if so whose mandrel) and run them through the FL bushing sizing die ( button removed) before I load them? I assume I should also chanfer the inside and outside of the mouth. What about deburing the flash hole?


I am new to all this so sorry for all the questions

Thanks

 

[ShootDots]

I will give you MY procedure:
1.) I run the brass into an expander mandrel to "iron out" any case mouth imperfections;
2.) I then turn the necks (only enough to get the "high spots" off>>and not really ALL of them>>>about 85-90 percent of the neck is turned;
3.) I then find the shortest piece of brass and trim (really "true-up") the rest to that length;
4.) I then chamfer the outside and inside of the case mouth;
5.) I then run the cases into a die with a bushing that gives me 1.5k to 2.0K neck tension...

I do nothing with the flash hole or primer pocket>>>as ALL of my brass is either Norma or Lapua and I have found that "improving" the brass by "deburring the flash hole and cutting the primer pockets" amounts to zero gain. Now to "quailify" that last statement, I used to do both of those procedures ALL the time BEFORE I got into "accuracy shooting" with Remington and Winchester brass I used for varmint hunting. It DID make a difference with that brass. However, with the use of Lapua / Norma I have found ZERO benefit to it... I did it for about a year with no increase in accuracy! So I quit doing that, without any loss of accuracy>>>that noted, I don't do those things. However, I am quite sure others will take exception to that>>so it becomes a personal choice!

I hope all this helps..

 

[TrxR]

Thanks Who's expander do you use?

 

[ShootDots]

I use, almost exclusively, Sinclair products. I use a stainless steel mandrel for the expander and a carbide one for the neck turning tool... Sinclair makes the best stuff...

 

[brian427cobra]

All new brass in my comp rifle(260 Rem, I shoot in Tac Matches) gets the same treatment.

1 Full length resize with expander ball installed
2 Trimmed and deburred to a a uniform length
3 Primer pocket uniformed
4 Flash hole deburred
5 Neck turned to .0135

 

[CanusLatransSnpr]

Quick question, what if the length of your virgin brass is shorter than minimum trim length? .243 Win. brass max trim length is 2.045" and I read somewhere that min trim length is .010" less than max. My new Norma brass is measuring somewhere around 2.032-2.033" and I want to trim it all same length but, it's shorter than min trim length already! Is it ok to go shorter than .010" shorter than max trim length? Sorry to hijack the thread!

Thanks,
Mike

 

[Turbulent Turtle]

For Lapua virgin brass, I simply run a Sinclair expander die through each case to round out the mouths and uniform the neck tension, then I load it and fire it.

On each subsequent loading, I run the brass through a Redding S/B F/L bushing die adjusted to push the shoulder back between .001 and .002 from the fired case; this brass stays with this rifle. I do nothing to the flash hole as Lapua drills the flash hole; there is no chad to remove.

When the cases have been fired five times, I trim them all to 2.005, chamfer and deburr.

I get upwards of 8 firings from these cases and by that time the primer pocket is fairly loose.

 

[TrxR]

Do you guys use any sort of lube when running the expander through? If so do you use a dry lube or a wax? I plan on using the Imperial wax for sizing but was wondering if I should use graphite for the neck interior for when using the mandrel?

Thanks

 

[CanusLatransSnpr]

For any kind of sizing I've used Hornady One-Shot spray lubricant! Good stuff and they say you don't have to worry about cleaning it off your cases afterward but, I always do! Works great for just neck sizing too!

Does anybody know if I can trim case necks under min trim length and get away with it?

Thanks,
Mike

 

[Turbulent Turtle]

I do not use any lube when I use a mandrel on virgin brass.

 

[Cleftwynd]

Most of my dies have carbide buttons and require no lube, but I usually use a film canister 3/4 filled with small lead shot and powdered graphite. Dip the necks in then size the necks, it helps prevent pulling the shoulder back when retracting due to friction and causing the size of the brass to be longer than I want for the rifle.

 

[BaconFat]

Quick question, what if the length of your virgin brass is shorter than minimum trim length? .243 Win. brass max trim length is 2.045" and I read somewhere that min trim length is .010" less than max. My new Norma brass is measuring somewhere around 2.032-2.033" and I want to trim it all same length but, it's shorter than min trim length already! Is it ok to go shorter than .010" shorter than max trim length? Sorry to hijack the thread!

Thanks,
Mike

I have some .308 virgin Norma brass from 1990 and some of the cases measured 1.997". The shortest I have ever read anyone trimming their brass to was 2.000". Since I can't do anything about them being short, I figured I'd just load 'em up and shoot 'em a few times and see if they won't stretch out a little.

 

[K22]

The two functions I perform which I consider essential for new brass prep are:

1. I chamfer the inside and outside of the necks of new case to eliminate the ridges on the lips that you sometimes find on new cases.

2. I run all new case through the sizing die to assure that they are straight and the necks are not deformed which you sometimes encounter with new cases.

Although I also uniform the primer pockets and debur the flash hole, I'm not sure this is essential because I've never detected an improvement in accuracy by doing it. I do it primarily because it make me feel good and the "experts" say you should do it to optimize accuracy.