Case prep - 300wm

[Deleted member 107666]

I have the Redding comp 3 die set... What's the proper order for new brass (ADG). Should I run it all through the body die first, then turn necks, then neck sizing die? Do not have my .300 chambered yet, just getting tired of waiting and figured I'd do what case prep I can ahead of time.

New to this, have the Lyman and Berger manual, but they dont really get into that...



Am I correct to...
Neck turn just enough to get them consistent
Then run through neck sizing die for neck tention
Then trim case to OAL and chamfer/debur?

Forgive the ignorance, i only confused myself with the many different opinions on Google.

 

[ar10ar15man]

yes...
neck size to something smaller than the expander that came with neck turning kit.
( you did buy an expander from the same people than make the turner,,,right ??)
expand, turn..you pick how much from a 50% contact cut to a 100% cut.
you did not say 300 what
you did not say hunting or target, nor distance.

 

[Deleted member 107666]

Sorry, .300wm

I have the k&m neck turner in the mail. I have the .30 cal pilot for it, but read NOT to get an expander mandrel?

One gun for hunting and range fun. Would like to shoot (not hunt) out to a mile. Being chambered for Berger 215s at Mile High. I've only previously fired factory FGMM from my other range gun, just a nice shooting .308 built by Mr. Gradous. Wanted to venture into reloading the .300wm, but soo much to learn.

I have more questions on shoulder bump as well, and not sure where that falls into the process for case prep either, assuming I need the exact reamer dimensions first and I bump the shoulders .002" from that?

 

[Bang4theBuck]

You wont probably be able.to bump.the shoulders until after at least one firing. The new brass will be sized to saami spec, or very close, which will probably be a touch shorter than your actual chamber. You can use a comparator to measure the dimension from base to shoulder datum, and then set you die to bump.the shoulder back, a small amount. I go .0015 bump to ensure clambering, and reduce the stress on the brass. Also not mentioned was the minimum neck thickness. My experience is that if you get much below .015" of neck wall thickness things can start to get wierd. I am using the ADG brass, and the necks were so consistent, right out of the box, I opted to not turn them. Good luck

 

[SealT5]

@Vandy321 you have to have the KM 30cal expander in order to use the turner. The expander irons out the inside of the neck pushing the majority of imperfections to the outside to be removed. It also gives you the proper fit on the pilot

 

[dok7mm]

The necks of new brass are pretty tight, so you'll definitely need the 30 cal. mandrel to expand the necks for a good fit on the turning mandrel. Also, depending on the brass you get, you may need to uniform primer pockets and debur flash holes. On good brass, I just expand the necks to .002" under caliber and shoot 'em.

For every cartridge I use, I get the K&M turning mandrel and .001, .002, .003 under caliber mandrels. You will also need a neck micrometer to get exact numbers on case neck thickness, if you're gonna turn necks. If you have a factory chamber, neck turning may not be beneficial.

 

[Deleted member 107666]

The necks of new brass are pretty tight, so you'll definitely need the 30 cal. mandrel to expand the necks for a good fit on the turning mandrel. Also, depending on the brass you get, you may need to uniform primer pockets and debur flash holes. On good brass, I just expand the necks to .002" under caliber and shoot 'em.

For every cartridge I use, I get the K&M turning mandrel and .001, .002, .003 under caliber mandrels. You will also need a neck micrometer to get exact numbers on case neck thickness, if you're gonna turn necks. If you have a factory chamber, neck turning may not be beneficial.

I dont see the undersized expander mandrels. All I see is the K&M .30cal expander mandrel and the press adapter to use it with.

Would I just run them through that expander, then neck turn, then run them through the Redding neck size with bushings for .002 under?

I had a previous post on neck tension questions and it seemed the answer was to take a loaded round and start with a bushing .002 under that load round neck diameter.

Do I still need a case neck micrometer if I'm going to use the neck sizing bushing die?

 

[wildcat455]

OP, that ADG Brass is pretty consistent straight from the factory.

I'm not sure what you are hoping to gain over that, when it doesn't seem you know the steps to take to get you there? I would calm down and back away until your chamber is cut and you have a chance to at least shoot your rifle.

 

[Deleted member 107666]

OP, that ADG Brass is pretty consistent straight from the factory.

I'm not sure what you are hoping to gain over that, when it doesn't seem you know the steps to take to get you there? I would calm down and back away until your chamber is cut and you have a chance to at least shoot your rifle.

Why not learn the correct steps right off the bat? Gotta learn it sometime, right? Have read the Berger and Lyman manual, still obviously have some questions. With no local mentor, I'm at the mercy of forums to learn. Thank you for the input, but I'd prefer to learn all I can on the correct processes and procedures the first time around.

 

[wildcat455]

Then go pick you up some range brass to learn on, if that's what you want to do.

What if the correct step is to leave it alone and just run it?

Turning necks on a no turn neck chamber is not a correct step.

You go learn what you feel you have to, I was just trying to save you some time and effort in the wrong direction.

Carry on..

 

[ar10ar15man]

not always correct.
uniform neck tension from turned necks and bullets seated near the lands .or long bearing surface can bypass the issue of excess neck clearance.

Then go pick you up some range brass to learn on, if that's what you want to do.

What if the correct step is to leave it alone and just run it?

Turning necks on a no turn neck chamber is not a correct step.

You go learn what you feel you have to, I was just trying to save you some time and effort in the wrong direction.

Carry on..

 

[ar10ar15man]

i think a post above has you confused
a neck turner has an expander mandrel and a turning mandrel.
expand then turn pretty simple.
when done and close to ready to load, the neck tension can be adjusted after sizing by using an expanding mandrel like a 305,306,307 instead of setting with a neck bushing. i shoot several of my competition rifles with only -.001 interference for tension.

 

[Deleted member 107666]

It's starting to slowly make more sense, thos post really helped clarify some burning questions, thanks all!

 

[dok7mm]

If you don't know what the diameter of your chamber neck is and/or the neck thickness of your brass, you'll just be spinning your wheels.

I would suggest you use a die set that has a conventional FL resizer and a micrometer seater. Take the expander ball assembly out of the FL die. When resizing your fired brass, this will usually reduce your nks .004 to .005" + under caliber. You can then use the the K&M under caliber mandrels to expand the necks for your best neck tension. I would, for the 300wm, suggest getting mandrels in .3060", 3055", and .3050".
This would give you options of .002, .0025 and .003 neck tensions. Then experiment to find which gives you best accuracy.

This is a far simpler method than trying to turn necks for unknown dimensions and will produce excellent results. It is cheaper and less time consuming than neck turning.

To get good results with bushing dies, you need to turn necks to an even thickness, as you are changing case ID by a bushing on outside of neck. A mandrel sizes the neck ID the same regardless of case wall variances, so you get consistent neck tension.

This way, you won't have to buy a turner set-up or a neck micrometer.