Author Topic: The bolt wont close . . . how come? (Read 986 times)

longwinters · « **on:** May 25, 2003, 08:47:13 AM »

Recently I have had 2 occaisions where the bolt would not close on the rifle with reloaded ammo. The 1st time was with a box of 30-06 shells where 14 out of 20 shells were great (one inch groups no problem). But 6 of the shells would not allow the bolt to close. I did not reload these , a friend did, but what would cause this? The second time was just yesterday while helping a friend set up his Lyman kit. It is different than my RCBS but I figured a die is a die etc... We loaded a few shells for his 7mm and I said lets ck them in your gun to be sure everything is all right. This was with once fired brass out of that gun and they would not allow the bolt to close. We measured everything against shells I had reloaded myself at home and the measurements seemed to be the same. My shells would load fine but his wouldnt. We reset everything according to the book (for neck size only) and redid them. This time they worked just fine. I cannot figure out what went wrong?

Loader 3009 · « **Reply #1 on:** May 25, 2003, 02:51:33 PM »

Longwinters. did you trim your brass after re-sizing? Was this with a bolt gun or auto-loader? What weight or type bullets were you loading vs. the weight or type of bullets you were using in your comparisons? Were the empties fired in the gun you were reloading for? Knowing the answers to these questions would help.

chk · « **Reply #2 on:** May 25, 2003, 03:07:08 PM »

The first thing I can think of is you've set the shoulder back and caused a slight bulge in the case. I smoke the neck on a case that's been fired in my rifle and then set the die so it stops resizing just as it touches the shoulder. I now use a RCBS X die for my .243 and it's easy to cause a slight bulge and get hard to chamber rounds with this type of die. Dave

Graybeard · « **Reply #3 on:** May 25, 2003, 04:13:46 PM »

I believe the most common reason for what you experienced is failure to properly size the case. If you fire a case in one chamber and then neck size or partially full length size it sometimes will not fit another chamber. If fired in same chamber this is seldom the cause of failure to fit.

Next most common I've seen is if the case is too long because you failed to trim before loading and it has grown is the case will buckle slightly when you try to seat the bullet. This can happen even if the case is NOT over the trim to length IF you have the dies set up wrong. If you use a trimmed case rather than a max length case when setting up the die and then later try to seat a bullet in a case longer than you set the die up for it can cause the case to buckle a bit and not want to chamber.

I'm sure there are other reasons but those are the two I've most commonly heard of and encountered.

GB

longwinters · « **Reply #4 on:** May 25, 2003, 07:16:46 PM »

Ok, what you are saying makes good sense. The 30-06 shells were never fired in my sons 06 . . . so perhaps they were not full length resized before my friend reloaded them for him. The 7mm shells were not trimmed before we loaded them, although the length was under the book max length. No doubt the problem, at least with the 7mm was that the bullet seating die was not set up just right. It must take very little to cause the case to bulge because we could not see a difference with our eye, although we are both just beginning. But here is a follow up question. How close do the cases have to be in length? 10ths, hundredths, thousandths? ie.. 3.25 versus 3.30 or 3.256.

Loader 3009 · « **Reply #5 on:** May 25, 2003, 10:37:10 PM »

longwinters,

Your cases should be the SAME length...no variation. A good case trimmer will accomplish this. Keep your cases below max OAL.

Trim your cases AFTER resizing as the resizing operation will often stretch them.

NEVER neck size a case fired in another gun to be used in your gun as chamber dimensions vary and the case will take on the dimensions of the chamber it was fired in.

Different bullets have different shapes. A heavier bullet may contact your rifling where a lighter or different bullet didn't. You must determine the max OAL for your chamber. A 200 gr. bullet may not allow your bolt to close where a 150 gr. set to the same OAL would. Should you force this 200 gr. to chamber you could experience VERY high pressures.

Graybeard · « **Reply #6 on:** May 25, 2003, 11:22:54 PM »

Regarding the question of bullet seater die set up. Generally the directions tell you to put a case in the shell holder and raise the ram all the way. To then screw in your bullet seater die until it touches the case if no crimp is to be applied which is normally the case with rifle rounds.

I like to do this with a case that is at the MAX case length listed in reloading manuals. Then any case shorter than this will allow you to seat the bullets fine without putting a buldge in the case. If you adjust the die with a case at the "trim to" length in the manuals and you ever let the case grow at all it might buldge the case when seating bullets. Normally you can feel this as you seat the bullet once you know what you are looking for. With the die adjusted as mentioned above this tells you instantly you messed up and failed to trim that case before loading it.

GB

IronKnees · « **Reply #7 on:** May 26, 2003, 02:27:32 AM »

I read through the other replies rather quickly, so I hope this was not already hit upon... Actually, it was in a way, but I want to bring this up. A different bullet of the same weight can cause this problem, and I have had it happen. Even the same bullet using a different type seating die can. The shape of the bullet in my case was different, and the bullet was actually touching the lands before the bolt was closed. Turned out two things had happened. One, even though the weight of the bullet was the same, the shape of the nose and curvature (there are more technical terms) were different enough that the bullet ended up seated just to a slightly longer COL. This added to the fact that the bullet did not taper as fast as the one that did fit caused the bullet itself to need to be seated deeper to avoid actually contacting the lands. Just a thought. Check the overall length between the two carefully. The others have covered absolutely all the other points that I can think of... BTW, you can take a magic marker and blacken the bullet and other areas of the entire case and then find out which area has a "scuff" mark on it... That will confirm where the problem is... Dave

longwinters · « **Reply #8 on:** May 26, 2003, 03:54:37 AM »

This has all been very helpful. I will be sure to ck my cases regularly before seating the bullets. Here is a (hopefully) final question then. When measuring a specific rifle for a specific bullet I have tried taking one of my once shot brass, pinching the end down a smidge and then putting a bullet in it etc... With my 7mm it seemed to work ok but each time I did it the measurement was not exactly the same. I will confess however that I did not do the magic marker thing but rather just took the cartridge out and measured it with my caliper.How do you guys take that measurement. And again, do your cartridges actually measure out exactly the same to the thousandths . . . every one of them?

Stan M. · « **Reply #9 on:** May 26, 2003, 04:30:49 AM »

Longwinters,
I think I can answer you last question. If you are measuring from the base of the case to the tip of the bullet, you will get different measurements. I don't know exactly why ,you would think they would all be the same. (Maybe someone can clue me in here)
When you close the chamber on your dummy round the bullets ogive is hitting the lands, not the point. With that in mind, I would seat the bullet a few thousandths away from the lands and try it out. If you smoke a bullet or color it with a marker you can see the lands imprint on the bullet.
On a hunting load make shure the bullet is not in the lands hard enough to leave the bullet in the barrel when the case is extracted. Been there done that on my varnit rifle.
Also before going hunting, chamber each round to make sure each round will chamber properly. You don't want to go for a follow up shot and the bullet not chamber.
Go to the range and learn your loads and rifle before hunting and everything should then work in your favor.
Good Luck

Mikey · « **Reply #10 on:** June 11, 2003, 04:04:05 AM »

Longwinters: I had a similar problem with a 308 I once owned. It seemed that I had to jump through the hoops and put each case through a 4 step resizing process. It didn't matter if it was military brass or commercial, I had the same problem of the bolt not wanating to close. I never had that problem with new commercial ammo, just reloads.

Sometimes it was the primer not being seated deeply enough. Sometimes it was a shoulder not being set far enough back. I never had a problem with overall cartridge length with loaded bullets so I figured it was the case. I put mine through a 308 die, a 308 trim die, a 307 die and then finally a 30-06 die before the dang things would chamber and the bolt would close. One fella told me my chamber was too tight. Another told me to use small base dies. But no matter what brass it was, resizing it was a chore going into the first resizing die.

I think the others are correct about the shoulder being set back far enough. That was my most consistent problem with that 308 and one of the reasons I got rid of it. Hope this helps. Mikey.