Couple of reloading questions

[Dodger2]

Need some help/advice if possible. I'm fairly new to reloading, and got a couple questions/problems...

 

1. Neck resizing vs. full length resizing: I've recently been neck resizing only lately, but used to only full length resize. When do you need to do one vs. the other?

 

2. Today I went and shot two batches of reloads. Both were neck re-sizing, trimmed to the specs, and under my recommended COAL...the only difference was one batch was Federal brass the other was Winchester. The Federal batch chambered without a problem. The Winchesters wouldn't until after I shot the Federals.

 

What causes rounds not to chamber? Is it the re-sizing or bullet depth? I measure each of my rounds, but still get some that chamber fine, need a little convincing, or won't chamber at all...

 

Thanks

[firstcoueswas80]

2. This one has me puzzled. I do not know why the Winchester would chamber ONLY after the Federal did. That is strange. 300 wsm by chance? Screw your sizing die down just a touch until empty, resized brass chambers no problem.

 

My suggestion for the brass:

Trash or sell one of the other. They are different, and the thickness will give you different pressures, speeds, neck tensions etc. I recently did this with my 300 wsm, trashing all Federal, going only to Winchester.

[Dodger2]

Its not a 300wsm...its a 7mm WSM. I thought it was weird too, and also knew there would be a difference since the two types of brass are different. I only have about 20 Federal brass and can only find Winchester brass (which is what I have the most of anyways). But wanted to see how the two would shoot (not chamber) differently.

 

Just thought it was weird that one would chamber and the other wouldn't. And they were all loaded at the same time/session.

[ctafoya]

My wifes 7mm did the same thing. My 300wsm dont care it eats anything.

[nralifer]

Interesting problem. One potential reason is that the chamber, after shooting the Federals, was warmer and therefore slightly larger. Neck sizing is supposed to improve accuracy, but when he brass is subjected to 50,000 t0 60,000 + psi, the brass adopts the shape and size of the chamber. With heating the chamber size enlarges as it heats up, so brass shot in a hot chamber are going to be ever so much larger than brass shot in a cold chamber. I have gone to loading all my hunting loads with full length sized brass especially if I am hunting in cold temperatures.

[bradne]

Were both brands of brass new or previously fired? If they were previously fired in another rifle, then they could have been "fire formed" in the chamber of the other rifle. No two rifles are exactly the same. So if the original rifle had slightly looser tolerances, and the current rifle has slightly tighter tolerances, previously fired brass may not chamber easily. As mentioned above, once the chamber gets warmed up, it expands and the round may chamber while its warm.

 

Personally I full length every time, usually out of habit and the fact that I tend to pick up a lot of brass and dont always know its history.

[MULEPACKHUNTER]

Winchester brass is known for being thicker as well and may be part of the issue, definately heated barrel helped them load. I would start measuring diameters on the loaded rounds. I would guess your Win brass is larger at the neck than the Fed. Look into neck turning also if your going to be neck sizing, the thickness varies as you check around the neck so when you neck size you will get different internal diameters and your bullet press will be different. This can cause the neck outer diameter to be larger after putting the bullet in. I neck turn my important long range rounds and then neck size but I still pin check every round for a press of .001 and under. I leave my bullets long and let the chamber set the depth.

Military brass is thicker as well and messes with your case capacity so you get less air space so this is why guys weigh brass into lots after all prep work is done, it is figured you get the same wall thickness if they weigh the same.

I use K&M shooting supply Turner by the way. Works great. I make my own cutters so I can bump the angle right and eliminate any doughnut issues.

[nralifer]

Neck resizing theoretically is supposed to yield more accuracy because the casing more accurately aligns the bullet to the rifling. Alignment is theoretically assured because the case is essentially a fire formed cast of the chamber. Although true, accuracy is not necessarily improved if the bullet itself is not seated within the case perfectly straight. Also, variability in chamber size as the chamber heats and cools can cause chambering problems for neck sized cases previously fired in hot chambers, and then chambered in cold chambers. I have found that more consistent groups are obtained when a competition bullet seater die is used, because bullet/case alignment is much more consistent. For hunting loads I have gone back to full length resizing and using a competition bullet seater die because in cold weather I have to be assured that the round will chamber properly every time.

[308Nut]

I've personally never have seen any improvement in accuracy neck sizing only versus FL sizing. Depending on the chamber dimensions, I might neck size only simply to save the life of the brass and to get a specified neck tension without the use of an expander ball. Expander balls are from the devil. They often cause the necks to become misaligned.

 

The less the brass is worked, the less it gets work hardened and the less they stretch. Both of which are bad. when they get work hardened they can be annealed but that can be difficult to do right. When they stretch in the chamber and then get pushed back by the die, the case head gets thinner and after a few firings they seperate. For larger factory chambers I try to neck size most of the time. All my custom barrels have as small a chamber as possible with '0' head space and tight 'no turn' necks. The necks only expand .001-.002" and the shoulder area expands .001" as well. The head doesn't expand and the shoulder actually gets set .0005" back from factory after the first firing. Since they don't expand much, I run them through a bushing neck sizer/FL combination die. This allows me to use a given bushing for a given neck tension and FL size the case in one shot versus using a body die for FL and seperate neck die which is what I have done in the recent past but I like the combo die better. This ensures flawless feeding with extremely long brass life.

 

ALL of the rounds I take hunting are either fire formed and FL sized or virgin. I never hunt with neck sized only loads.

[PRDATR]

Its not a 300wsm...its a 7mm WSM. I thought it was weird too, and also knew there would be a difference since the two types of brass are different. I only have about 20 Federal brass and can only find Winchester brass (which is what I have the most of anyways). But wanted to see how the two would shoot (not chamber) differently.

 

Just thought it was weird that one would chamber and the other wouldn't. And they were all loaded at the same time/session.

 

So. Have you made any changes to the way you reload? I just buy one brand of new brass and go from there. I just neck size, trim to spec after three loads and toss them at six.

Biggest thing I have come across since I began reloading in the 70's is everyone wants Benchrest accuracy with a factory rifle but even with todays optics and better rifle manufacturing tolerences less than 1/2% of shooters are consistently capable of meeting the mark which is tough to do if you are only shooting 30 rounds from a rifle every three of four months. Not that I'm saying that is you.