Neck Sizing Questions

[rebelracer79]

Been reloading for a while now and I'm wanting to try and improve my accuracy and case life by neck sizing. I have a couple of questions before I dive in tho.

If you are only neck sizing is it nessicary to trim your cases? I read that the cases get longer from the shoulder being moved back and forth during sizing, so if only neck sizing do I need to trim?

My other question was, I read in my Hornady manual that it is possible to neck size with a full length sizing die, just back it off a little, has anyone had any luck with this?

Thanks
Reb...

 

[Shadowrider]

Yes you still have to trim. But not near as often if ever. Trim after first firing and you might not have to again if your are loading hot because the case might last that long. If loading mild you may need to trim again at some point. The cases grow from repeated sizing of the body. They stretch and get longer. Since you aren't sizing them they grow much slower but still do with each firing. You should always keep your eye on case length. Too long can lead to higher pressures and other issues. If for no other reason you should to keep the neck tension on the bullet uniform.

 

[criticalbass]

I have found that with a Lee factory crimp die that case length is less critical for most of my rifles. I just seat the bullet slightly deeper in stretched cases to get the overall length down to where I want it. The crimp die will hold it in place regardless of how long the case is, where it would probably get crushed in the other kind of crimper.

Eventually I do trim cases, but not often. CB

 

[Ksmirk]

With my 308 I wanted the best I could produce so the necks are turned and trimmed. The best thing I can say about making accurate loads is to be sure each case is the same length! I have found in my years of trying to make the wheel better this was the most helpful. I normally trim .010" shorter than the max length so I don't have to trim each time.

If you take a sharpie and mark the neck you can back off your FL sizer and while watching the neck screw in the FL sizer raise case into then see where the die has made contact, keep doing this until you get the die to the point you want the neck sized too. I'd show you pictures but I'm in Patterson, La I hope this makes sense to you? Later,

Kirk

 

[1mathom1]

With my 308 I wanted the best I could produce so the necks are turned and trimmed. The best thing I can say about making accurate loads is to be sure each case is the same length! I have found in my years of trying to make the wheel better this was the most helpful. I normally trim .010" shorter than the max length so I don't have to trim each time.

If you take a sharpie and mark the neck you can back off your FL sizer and while watching the neck screw in the FL sizer raise case into then see where the die has made contact, keep doing this until you get the die to the point you want the neck sized too. I'd show you pictures but I'm in Patterson, La I hope this makes sense to you? Later,

Kirk

+ Exactly. I have also used a match to "smoke" the neck when I could not find my sharpie. Kids!! If you use once fired factory brass, you'll likely find the first trimming to be the worst. Then once you've neck sized, trimming will be much less on subsequent firings. You'll quickly learn how often a case can be fired before it needs trimming again. Cases will last longer too. My FIL shoots a SMLE .303 Brit. When we first started loading for him we had not learned the tricks of neck sizing. Were triming a lot! Couple firings and we were seeing the dreaded bright ring just foward of the base indicating an imminent head separation. Then we went to neck sizing. Stopped having to trim as often and the cases were lasting several more firings before needing to be tossed.
Couple notes. 1)If you are loading for two different rifles in the same caliber keep the cases separate and dedicated to the same gun. Chambers are never exactly the same from gun to gun. I load .270 for both my son's Winchester M70 and my Ruger M77. Cases fired in the M70 then neck sized are tight in the Ruger....difficult bolt closing.
2)My old .30-30 doesn't like neck sized only cases. I have to full length size. Difficult to close the lever. You don't have the same chambering force like you do with a bolt "camming" shut in the event the cases are at the ragged edge of acceptable shoulder-to-base length. I have never loaded for a semi-auto but I have heard the same about them. Luckily the .30-30 is not too expensive to feed so an occasional box of shells doesn't hurt too bad.