[Peakbagger46]

Just started loading .308 a week ago, so I am continuing to ask dumb questions. The loads (165 and 168 grain) are shooting inside an inch and I see no signs of high pressure.

My concern is the bolt is a bit hard to close, not bad, but not as easy as factory loads. I measured the OAL my gun (custom 700) will take by inserting a bullet just into a case and chambering it. It came to 2.810". My reloads with the same bullet are at 2.750", and the bolt is still a bit hard to close on most of them.

Is this a problem? I'm worried about seating the bullet deeper as it seems it would increase the pressure of the round.

Once again, thanks in advance for the help.

[hokeyplyr48]

Well I went through the same thing and you have to push the shoulder back. It's not just the OAL that's the problem. Someone else from here who is much more knowledgeable can give you a better explanation.

[Peakbagger46]

Guess I need to cut the (once-fired) brass...

[hokeyplyr48]

Yup you also need to trim them. Not sure about the OAL case length for .308 but i'd be checking that

[The Bushmaster]

Check empty resized case for length. If it's too long the case mouth enters the barrel where the bullet is and jams things up and when fired cases a pressure spike. Also bump the shoulder back a bit and see if that is the problem. It will be one or both of these...

[JimKirk]

Peak,
Take a sized empty case and chamber it. If the bolt is hard to close you need to move the shoulder back more. I don't think you would have problems with your cases being too long if they are only once fired, it will not hurt to trim them. Get the case to close with just slight(I mean slight) pressure, then worry about seating a bullet and OAL only after getting the sizing right.

Jimmy K

[Peakbagger46]

What does "moving the shoulder back" mean?

[NCsmitty]

Chances are good if you screw your die down another 1/8 to 1/4 turn and try the resized empty case in the rifle, the bolt should close properly.
You can measure your brass but I doubt that they need trimming, being once fired.
Set your COAL to fit the magazine. If your bullets actually touch the lands at 2.810, I would set the COAL at 2.790 if it clears in the mag. See if they shoot any better like that. Just be sure of your dimensions.
Your jumping .060" to the lands at your old COAL, which may be more than necessary.


NCsmitty

[Chawbaccer]

Most likely the cases are undersized. The press should knuckle over when resizing. You can hold a cartridge in a candle flame to get it all sooty and then chamber it to see exactly where it is too big at.

[dardascastbullets]

Hi Peakbagger,

With everything else assumed to be 'up-to-snuff', I can suggest that your problem is with the case headspace. You need to know the headspace of your chamber. To acquire this information, you will need to obtain a case gauge (RCBS, Stoney Point, etc.). I can only speak of the RCBS as I had one for every caliber that I shot. Using a case gauge is the only way to properly set your full length die in your press to obtain the correct headspace. Your bolt is hanging up due to the case binding in the chamber. Obtain the correct headspace and your problem will go away and your cases will thank you!

[WNTFW]

"Most likely the cases are undersized." Meaning they are not sized enough.

It can be hard to feel if a case is sized correctly. On a 700 the firing pin can fool you. If you are getting brass deposited on the bolt face or scratching & galling on the case head that is a sign the case is still too big and in need of more sizing. If your brass is mixed you may get some that don't size as easily as others.

[Peakbagger46]

How do I do "more sizing"? Do I need to run the cases through the die more than once, or just lower the die a bit? It seems to be low enough, but I can try to bring it down a bit more I guess.

I guess I'll have to acquire a case gauge as well.

[JDGray]

If using Lee dies, you must run the sizing down untill it touches the shellholder in the raised ram, then you have to give it another 1/4-1/3 turn to bump the sholder. If you don't, the cases wont fit, and if you do manage to close the bolt, getting it open again will be very hard to do. You may end up removing skin off your knuckle when you hit your scope, when you do get it open:o

[Walkalong]

How do I do "more sizing"? Do I need to run the cases through the die more than once, or just lower the die a bit?
Just lower the sizer a tad at a time until the case is easy to chamber.

[Horsemany]

Walkalong is correct. The way you set your FL sizer up is to chamber a sized case in your rifle. Gradually lower the die by 1/8 turn increments until you cannot feel resistance when you lower the bolt handle. If you are only feeling slight resistance now you are very close. You just need to try 1/8th turn and possibly 1/4 to have clearance.

This is the technique I've been using for years even with benchrest stuff. I've never had a need for a headspace gauge.

On a side not most rifles will shoot better with far less than .060" jump to the lands. .020" to .005" jumps produce the best accuracy in my non-benchrest guns. Remember as the jump decreases the pressure increases so you need to reduce powder charge when you play with seating depths. Work your way up with a few spare cartridges.

[Sam1911]

If using Lee dies, you must run the sizing down untill it touches the shellholder in the raised ram, then you have to give it another 1/4-1/3 turn to bump the sholder.

Maybe I'm misunderstanding what you wrote. If you bring the resizing die down all the way until it firmly bottoms against the shell holder in the raised ram, turning it farther doesn't increase the amount of resizing. That's all you get.

If the shell holder stops firmly against the die, there is no possible way to push the case farther into the die than that. If you move the die lower in the press all you'll do is change how far up the ram goes. It will still go all the way up to the base of the die -- and no farther.

To push the case farther into the die, you'd have to machine metal off the bottom of the die!

Did I misunderstand you?

-Sam

[The Bushmaster]

Resize a case and note as to whether the die touches the shell holder. If it doesn't. Turn the die in 1/4 to 1/2 turn and resize the case again. Noting if the die is touching the shell holder. Repeat this until the die is touching the shell holder with the case in the die...This procedure will allow and adjust for press flex...

[JDGray]

Sam,

You didn't missunderstand me:) If you dont give the sizing die a 1/4-1/3 turn more, it will not bump the shoulder. Its all in the dirrections;)

[rcmodel]

You have slack in the press linkage and press frame flex during resizing.

The extra 1/4 to 1/3 turn past touching the shell holder is necessary to take out all the slop & slack.

rc

[Sam1911]

I agree with that. I guess I was reading that there was further "bumping" to be gained the farther you go.

So, we're agreed. Once the press is bottomed (hard) against the lower edge of the die, that's all you get. Maximum resizing.

-Sam

[Walkalong]

Once the shell holder is against the die bottom. ;)

Yes, that is all you get. If it won't size to spec then you have a bad die, or very work hardened brass that has not been sufficiently sized all along.

[Zeke/PA]

Read the instructions that came with your Reloading Press and dies regarding full length sizing.
Then try a re-sized case or two.
The case SHOULD chamber with no problem.
Load the same cases with your powder/bullet and try again.
If problem is present, it is of course the bullet seating depth.
In a bolt action rifle, cases fired in THAT rifle don't REALLY have to be full length sized.

[Bart B.]

I caution folks about turning down a sizing die 1/4th or 1/8th of a turn. 1/4th moves the die about 18/1000ths of an inch; about 9/1000ths for 1/8th of a turn. (Dies have 14 threads per inch; do the grade school math.) Half a turn moves the die about 36/1000ths of an inch.

If the fired case shoulder's set back more than 3 to 4 thousandths, accuracy goes south. As much as 10 thousandths back from the fired position can start incipient head separation.

Get a case headspace gage such as the RCBS Precision Mic. Read its directions for measuring case headspace both before and after full length sizing. You'll no longer have problems and if the fired case shoulder is set back only 2 thousandths, best accuracy and long case life typically happens.

[JimKirk]

You don't need no case gauge ...hundreds of thousands of Reloaders have been loading for years with out them and can do so today! Sure they are handy, but not needed 98% of the time. I remember a time when only real big time gunsmith had headspace gauges! Get off it ....if a guy does not know how to set a sizing die....do you think he can use a gauge? Speaking of bolt actions ...almost any amount of headspace can be corrected with a sizing die. If headspace is too long ...back out the die....if it is to short... tighten the die down ...if that is not enough grind the base of the die on a grinder or carry it to someone who can...or send it back to the maker that is what they'll do!

Jimmy K

[Peakbagger46]

I believe I got it now! I was using the sizing die like I do with the pistol rounds, I DO have a bit more I can crank her down. Plan on trying it later this morning and seeing what happens.

Went and shot the loads I have made earlier today and averaged around .8" for 3 shots at 120 yards. This is the best I've ever shot any rifle!

Once again, thanks for the wisdom everyone.

[Peakbagger46]

Messed with the die this morning and found out it had more adjustment than I thought, the brass now chambers properly, and I am anxious to get out and shoot the perfected rounds!

Once again, thanks. I am not very mechanically inclined, and I appreciate all the help.

[counterclockwise]

http://i255.photobucket.com/albums/hh133/counterclockwisester/bulletmodel.jpg

It means moving the conical section of the case (top arrow) straight back, or in this diagram, straight down toward the case head (bottom arrow).

A properly sized, bottleneck, rifle case will register the assembled cartridge lengthwise in the chamber by contact at the case head surface against the bolt face when locked--and at the shoulder or conical surface of the case in the chamber.

The fit should be a slight clearance fit. In other words, there should be some rattle space between case, chamber, and bolt face. Most reloaders try to keep that rattle space down to a few thousandths of an inch.

When the round is fired, the case stretches lengthwise and closes that rattle space to zero. After firing, the case should spring back to almost the original length.

There are one or two exceptions to this lengthwise relationship--purposely driving the bullet into the start of the rifling before firing, or belted magnum registration, IIRC.

[JimKirk]

In the above drawing, the shoulder(angled) is the area from the upper black arrow to the beginning of the neck. The body is what that is between the two black areas. Thus if you shorten the case body it will move the shoulder back, but it is the shoulder that has to be moved.

Jimmy K

[Riss]

Now if you check and properly locate the bullet off of the lands, somewhere between .015 and touching and you just might close up those groups a little.

[Bart B.]

counterclockwise claims:A properly sized, bottleneck, rifle case will register the assembled cartridge lengthwise in the chamber by contact at the case head surface against the bolt face when locked--and at the shoulder or conical surface of the case in the chamber.Well, almost correct. You're forgetting the forces applied to the chambered round. Consider the chambering of a rimless bottleneck cartridge.......

First, the ejector. If you bolt's got a straight line ejector near the edge of the bolt face pushed forward by a spring, than spring's gonna push the chambered round as far forward as the chamber shoulder allows. For example, if the chamber has exactly 2.000 inch headspace (bolt fact to shoulder datum) and the case has 1.995 inch headspace, the case head will be .005 inch away from the bolt face with its shoulder pressed against the chamber shoulder. The front of the case is perfectly centered in the chamber by the coned case shoulder mating with the coned chamber shoulder

Second, the extractor pushes the case body's back end against the chamber wall. Extractors are spring loaded, too, as the press against the extractor groove. This ever so slightly cocks the loaded round at a tiny angle in the chamber. How much is determined by the diameter differences between chamber and case body.

And third, when the firing pin smacks the primer, that drives the case forward a few thousandths setting the shoulder back. The case now has less head-to-shoulder headspace than it originally did. But the case stretches back when pressure peaks pressing its head against the bolt face.

[counterclockwise]

That is true. By the time the primer ignites, the rattle space has shifted to the rear and shows up between the case head and the bolt face. Also, the fact that the body of the case gets cocked slightly is a function of the fit between case body and chamber wall. Lose fit, short neck, large jump-to-land assemblies, will usually not be as accurate as those that present the longitudinal axis of the bullet to the lands dead center and colinear with the bbl centerline.