308 reloading problem

diver1

I am having a problem with my reloads for the 308. I have checked the measurements and they seem to be in tolerance with the book that I use. The problem is that the rounds will feed into the chamber but I can't turn the bolt closed. I do not reload much so each time I try to follow all the steps as outline in my book. I did not crimp these test bullets is that the problem? Please advise any help thanks Vince

jonk

A crimp or lack thereof shouldn't prevent it from chambering. I don't crimp a lot of my rifle ammo, no ill effects.

Is this brass fired from the rifle previously? Or fired from another? Or new?

What type of rifle is it? Does it have a tight match chamber?

The things I'd look for first are overlength brass, inadequately resized brass, bullet seated too far out so that it is touching the rifling, a brass/bullet combo that results in too thick of a neck, a tight rifle chamber and/or a dirty chamber, etc.

Will regular ammo chamber in the gun from the factory? That will help us narrow the problem to the gun or the load.

diver1

700 remington and the brass was fired from another rifle. factory ammo will chamber and the oal is less than the established factory min. I checked the brass and it's the same as the factory ammo. Thanks I was hoping it was the crimp.

bassassassin007

I would think that your case over all length is too long for your chamber. (The reloading manual is just a guide and may not be right for your gun. I have had some data from a Sierra manual that wasn't right for one of mine) What I would do is make some rounds without powder or primers and close the bolt on them slowly. If you do this to a few rounds and measure them you should have an idea how long the over all length can be. Then using the shortest of these rounds as a guide I would make live rounds at least a tenth of an inch shorter and increase the length in 1/100th increments up to 2/100ths from the rifling. If your groups get better the longer the cases gets then your done. If they were better when they were shorter then make them shorter in 1/100 increments until you find the length the gun likes.

Dave

perry shooter

Hello diver 1 the OAL might be in specs but the shoulder of the case fired in another gun may be longer to the shoulder. Before going to the trouble of loading a round just resize the cases and see if they will chamber I suspect you might not have the sizeing die screwed in as far as it needs to be . If you have a mis match between shell holder and dies some times you cant get the die to size the case shoulder correctly. and then you need to take some STONE/FILE some off the end of the die.

Tailgunner1954

Before you go through a bunch of hoops with changing the distance to the lands (OAL), we need to get your bolt closed.
Will a unsized fired case (from the other rifle) allow the bolt to close?
Will a sized case (from the other rifle) allow the bolt to close?
Measure the diameters of a new factory case, a case fired in the other rifle, a case fired in your rifle, and a sized case from each rifle. Compare the following measurements:
Base diameter (just above the extractor groove)
Expansion ring diameter (about 1/4" above the groove)
Shoulder diameter.
Base to body/shoulder junction (this one can be a little tricky to see)
Base to neck/shoulder junction.

diver1

Those are great ideas. I will try to resize the cases and see if it's the shoulder, all of the other measurments seem to match the factory ammo that will cycle in the chamber. Thanks Vince

B17-P51

You must set the size die so that the press cams SLIGHTLY over center. This should cure all your problems if the cases are the right length.

diver1

Thanks again, I resized the brass and it seems to be ok know. I knew
that the brass was the right lenght, but must have done a poor job sizing the brass the first time.

bpost

quote:Originally posted by diver1
Thanks again, I resized the brass and it seems to be ok know. I knew
that the brass was the right lenght, but must have done a poor job sizing the brass the first time.


The CRITICAL measurement is from the base of the case to the shoulder. That sets head-space. Ideally you want about .002 clearance on the case shoulder as you close the bolt. To get this take a fired case and start the resizing process with about 3/8" clearance between the shell holder and the base of the die.

If you size a case, wipe the lube off and it chamber back in your gun (it probably won't) then you are OK. The idea is to close the gap between the base of the die and the shell holder until the desired clearance is attained to just size the brass enough to chamber reliably. In real world guns that set point plus 1/4 turn down more is about right. The extra 1/4 turn will allow for brass that has been work hardened by firing and springs back more during sizing to still work OK.

If you set the die to cam over on the shell holder you are going to shorten the brass life considerably. Setting a proper head-space on the sizing die will help accuracy and extend brass life. No two chambers are alike.

Properly sized brass seldom needs trimmed and has a long firing life. Some 6BR cases I have have been shot 10-15 times with no sign of fatigue.

The OAL is important for feeding from a magazine but will seldom cause difficult bolt closure.

badlandsbutch

Use a Wilson case guage to set your sizer die. I had the same problem, trim your cases to min specs.

dcs shooters

diver1, just full lenght size the used brass, then fire it in your rifle. Then you can just neck size it.

375H&H

quote:You must set the size die so that the press cams SLIGHTLY over center. This should cure all your problems if the cases are the right length.

+1 [:)]

GUNFUNCO

If you are using a mauser-style rifle it may be because you are not loading the ammo from the magazine. Then you have to force the extractor over the rim. If using a mauser-style rifle, put the ammo into the magazine first and let the bolt pick them up and move them into the chamber. This way the rim of the ammo gets under the extractor. If you don't understand what I am talking about, ask again and maybe someone here can explain it a little better.

HandLoad

+1 on the rimbase to Shoulder length check...cases elongate over time if only neck sized and reloaded a few times. Full length resize all my not for accuracy loads.

SteveWag

The things they don't tell you in the off-the-shelf reloading manuals. A fundamental tool is the case headspace gage. OAL means very little, it's the distance from the rear of the case to the "spot" on the case that limits forward movement in the chamber, in the case of the 308, midway on the slope of the shoulder.

Check out this link:

http://www.gswagner.com/bigreloading/resizing/casemic.html

Steve Wagner