.308 - Need shoulders bumped after one firing?

[darkvibe]

Gun is a Remington 700 in .308, factory barreled action.

Ammo is Winchester brass, CCI Benchrest primer, varget, 175gr sierra match king, chrono at 2660fps out of my 26" barrel.

The brass was virgin when I started. Full length sized, loaded and it ran great. I loaded the brass a second time and it was really tough to close the bolt. I had to give it a good smack on some of the rounds to close it.

I tried neck sizing with a lee collet die as well as FL sizing with the die going down the neck but not touching the shoulder, same result.

I bought a Redding S die and bumped the shoulders back .002" and they chamber fine again.

So my question... Anyone ever had to bump shoulders back after firing brass one time? I've heard its not needed until you fire it a few times.

[dauntedfuture]

You just don't have your FL die set up correctly. You need adjust your FL die properly so that the shoulder is set back. This is far different from bumping the shoulder and there is lots of confusion. When you FL size you size the neck, set/ bump the shoulder back and size the body of the case.

IN THE OLD DAYS we had Neck and Full length Dies:

If neck size (NS) you are only sizing the neck. Depending on your rifle and brass you can usually go a few time until you have to Full length (FL) size your brass again.

Most HP shooters FL size all their brass each time you shoot it. Provided you set up your dies correctly you are only sizing the brass just enough. Most of the time the Primer pockets open up before the necks split.

NOW

we have shoulder bump dies that will size the neck and set the shoulder back and will not touch the body of the case. We also have body dies that only touch the body and not the shoulder of the case or the neck. In short we have created lots of options that have niche uses. 99% of shooters are well served with a standard FL die, remember that most shooters are not shooting competitions. Even with that said, unless you have a custom rifle you will likely not see an accuracy improvement between fancy dies and standard dies provided they work properly. Bushing dies are another matter all together.

In your specific case: the first time you fire a new stick of brass it grown the most as there is plenty of room between the case and the chamber. After you FL size it again and shoot it, it will grow less and I suspect you will not have an issue NS the brass.

If you are running hot loads you will need to FL/ bump brass more. Most Neck sizing of brass is done within the BR crowd and they are shooting mild to moderate loads out of cases with thick webs and rims. If you are hammering a .308 then the brass will grow more.

If you are in a position where you have inconsistent bolt close on a bolt rifle you need to size your cases so that bolt close is consistent. If I'm closing the blot on a loaded round in competition and its tough to close i'll remove the loaded round and try another. Typically "tough" to close cases shoot high in my Palma gun.

Your factory rem chamber is HUGE compared to a custom rifle with lots of freebore. I don't think you will see a difference in how you size your brass for that gun until you get a new barrel. If anything I think a proper FL case will shoot better. Remember that 3 round groups don't count and you need to shoot more then one group to confirm. If you have access to a chronograph you will also see more consistent results with FL sized ammo.

[darkvibe]

What's the best way to set up a FL sizing die? Just crank it down until it touches the shell holder or do I need to get more detailed and blacken a case neck and keep adjusting until it just touches the shoulder?

[Graham Smith]

There should be no need to FL size new brass for a factory bolt action rifle. And there should be no need to FL size brass that's been fired in your rifle unless it was over pressured and hard to remove (in which case I wouldn't use it at all).

My guess is that you don't have the sizing die setup correctly and are going to have to get that fixed and possibly trim the brass. Different dies are adjusted differently. Follow the MFG directions.

BUT, once you have correct brass and have fired it, don't FL size it again. You should only need to neck size and, perhaps, bump the shoulder back a tiny bit.

[dauntedfuture]

Ok, it is easy to set up your FL die. Start by cleaning your chamber and bolt face and action well, you will get a better reading and ensure you don't have crud in there.

Method 1.

- Take 10 fired cases and measure to a datum point 1/2 way down on the shoulder. You can use a .40 s&w case flipped over so the neck of the .308 is inside the .40 case and the mouth of the .40 case rests on the shoulder of the case and obtain a measurement, it does not matter what it is its just a reference. Most of the cases should be the same, 1-2 might be short .001-002 and one or two might be long.

-Adjust your FL die so its just touches your shell holder, lock die. Size a case. Measure again with same .40 case. Keep adjusting until you set the shoulder back .002. You need to size a "new" fired case each time you adjust your die down a little bit.

-Once this is set, size and attempt to chamber 5 other five cases. If they all chamber easily with about the same force, your dies are all set.

Method 2.

- Size a case fired case and try to chamber it.

-Adjust die.

Size another fired case and try to chamber it.

- keep doing this until case easily chambers.

- Size 5 cases to verify setting.

The only down side is that you might crank the die a little too much and be setting the shoulder back a little more then necessary.

You can also apply a small piece of masking tape to the shoulder of a fired case and try to chamber it. It should chamber. the tape is .001-002 thick.

Both methods work just as well. There are specialized tools and inserts to measure to the shoulder as well. Its quite hard to oversize cases and much as to do with your dies and shell holder combination. Hornady dies are on the very tight side. On a custom min-spec barreled rifle you might have to machine down the die a little so you can screw it down enough. Redding has special shell holders to allow .001 adjustment as well.

[Religious Shooter]

After one firing... I've never had to bump the shoulder with a bolt gun.

What charge weight did you use with the Varget?

If the COAL is too long for the bullet and chamber it will also result in a hard to close bolt. Next time it happens to you, jack the round out and look at the bullet. If there are heavy rub marks the COAL was too long.

[Religious Shooter]

Also the brass can grow when you fire it and when you neck size it. Measure the length of the case and see if it is over. Try and chamber the sized and unloaded cases and see what it does.

[darkvibe]

Ok, it is easy to set up your FL die. Start by cleaning your chamber and bolt face and action well, you will get a better reading and ensure you don't have crud in there.

Method 1.

- Take 10 fired cases and measure to a datum point 1/2 way down on the shoulder. You can use a .40 s&w case flipped over so the neck of the .308 is inside the .40 case and the mouth of the .40 case rests on the shoulder of the case and obtain a measurement, it does not matter what it is its just a reference. Most of the cases should be the same, 1-2 might be short .001-002 and one or two might be long.

-Adjust your FL die so its just touches your shell holder, lock die. Size a case. Measure again with same .40 case. Keep adjusting until you set the shoulder back .002. You need to size a "new" fired case each time you adjust your die down a little bit.

-Once this is set, size and attempt to chamber 5 other five cases. If they all chamber easily with about the same force, your dies are all set.

Method 2.

- Size a case fired case and try to chamber it.

-Adjust die.

Size another fired case and try to chamber it.

- keep doing this until case easily chambers.

- Size 5 cases to verify setting.

The only down side is that you might crank the die a little too much and be setting the shoulder back a little more then necessary.

You can also apply a small piece of masking tape to the shoulder of a fired case and try to chamber it. It should chamber. the tape is .001-002 thick.

Both methods work just as well. There are specialized tools and inserts to measure to the shoulder as well. Its quite hard to oversize cases and much as to do with your dies and shell holder combination. Hornady dies are on the very tight side. On a custom min-spec barreled rifle you might have to machine down the die a little so you can screw it down enough. Redding has special shell holders to allow .001 adjustment as well.

Thank you. I am going to re-read this when I am at my reloading bench and can be more hands on.

After one firing... I've never had to bump the shoulder with a bolt gun.

What charge weight did you use with the Varget?

If the COAL is too long for the bullet and chamber it will also result in a hard to close bolt. Next time it happens to you, jack the round out and look at the bullet. If there are heavy rub marks the COAL was too long.

44.5gr varget. 2.860" OAL. Resulted in 2660 fps. These are loaded magazine length for AICS mags. The bullet is a long way from the lands in the factory barrel.

Also the brass can grow when you fire it and when you neck size it. Measure the length of the case and see if it is over. Try and chamber the sized and unloaded cases and see what it does.

The brass is not over length. I trimmed it on a Giraud trimmer to 0.008" under the max after firing it once. The thought was it is not a critical dimension and going short would mean I would not have to trim again before I throw the brass out.

[Religious Shooter]

44.5gr varget. 2.860" OAL. Resulted in 2660 fps. These are loaded magazine length for AICS mags. The bullet is a long way from the lands in the factory barrel.

So you checked? With the 175 SMK what's the COAL to the lands of your rifle?

With both of my factory .243's R700 I can't load it to AICS mag length. For example on one of them I can't load past 2.75" using 90 grain E-Tips or 80 grain TTSX. That's way before the ~2.9" AICS max dimensions.

[427Cobra]

The most accurate ammo comes from brass that is FL sized, including Benchrest, the most consistent ammo is FL sized every time, the most reliable ammo is uses brass that is FL sized, I had some Win 7-08 brass that I resized to 260 with over 30 reloads(annealed every 2-3 filings) so with a .001-.0015 shoulder bump brass last forever, primer pockets are the life limiter.

While a SIZED 40sw case can be used on these 308 family of cases I recommend getting the Hornady Headspace Gauge with .400 insert, now take all your cleaned fired and most importantly Decapped cases, I like to use at least 50, and none with ejector swipes, use the Hornady HSG to measure all the cases, use the case with the longest measurement as your reference case, set your FL to size your cases .001-.0015 shorter, now I like to fire the 50 cases again and repeat the process, this ensures that the brass is being properly sized and not oversized. Do not over lube, and no lube on the shoulder

[dauntedfuture]

Yes, the Hornady gauge is better and that is what i use. In a pinch a case will work!

[Graham Smith]

The most accurate ammo comes from brass that is FL sized, including Benchrest, the most consistent ammo is FL sized every time, the most reliable ammo is uses brass that is FL sized, ...

For a semi-auto, yes. But I just can't agree with that for a bolt gun. And I know a number of long range shooters who will agree with me. There's no reason to overwork the brass like that.

[darkvibe]

I did measure the OAL for my bullets touching the lands when I first got the gun. I have the length written down but don't remember it off the top of my head. I am going to play with the FL sizing die tonight and see if I can get my brass to chamber easily after adjusting that. I will post back when I try that.

I think the root of my problem is that I was under the impression that a FL sizing die should come down the neck to the shoulder but NOT touch the shoulder. Seems I was mistaken.

[dauntedfuture]

A Neck sizing die will come down to the shoulder and should not touch the shoulder. For what its worth most all NRA LR shooters that I know FL size their brass, do what you want. Try a test with FL vs NS brass and see what happens. When you do this make sure you run them onto a target and over a crono. About the only advantage of NS is that you can get away with not lubing the case and the cases don't grow as much.

[Powder Finger]

I did measure the OAL for my bullets touching the lands when I first got the gun. I have the length written down but don't remember it off the top of my head. I am going to play with the FL sizing die tonight and see if I can get my brass to chamber easily after adjusting that. I will post back when I try that.

I think the root of my problem is that I was under the impression that a FL sizing die should come down the neck to the shoulder but NOT touch the shoulder. Seems I was mistaken.

when you size with a FL as the diameter gets smaller the brass gets longer. So to just neck size you need a neck size die.

you can see this happen if you size a little - measure - size - measure. you will see the brass get a little longer then stay about the same then of coarse shorten when you get on the shoulder.

[darkvibe]

Moved my fl sizing die down so it contacts the shell holder. Seems to work OK. I think I'm going to load a few and try it. I bang steel and shoot modified f class for fun with a factory barrel and action so minor differences in my reloading setup aren't going to be noticeable.

[Graham Smith]

For what its worth most all NRA LR shooters that I know FL size their brass, do what you want.

And the long range people I know and shoot with say just the opposite. Neck size 3-4 times then bump the shoulder, but never FL size.

Sometimes I think that this stuff has become a crazy mix of old and new ideas and should really involve chicken entrails and some guy in a feathered mask mumbling chants as you load your ammo. People find something that works and that's what they swear by.

[twodownzero]

For what its worth most all NRA LR shooters that I know FL size their brass, do what you want.

And the long range people I know and shoot with say just the opposite. Neck size 3-4 times then bump the shoulder, but never FL size.

Sometimes I think that this stuff has become a crazy mix of old and new ideas and should really involve chicken entrails and some guy in a feathered mask mumbling chants as you load your ammo. People find something that works and that's what they swear by.

Federal GMM is loaded in the softest brass, fits in every chamber, and if it won't shoot MOA or better from your gun, your gun is trash.

What does this indicate? All that matters is good bullets and powder. The rest is either snake oil/voodoo or if anything, makes a minor difference.

The only ammo I sort by headstamp is that which I load with expensive match bullets.

Edited March 12, 2015 by twodownzero