Stiff bolt after reloading

[buck52]

Hi Guys
I have a problem with reloads in 6.5X55:

Full length sized Norma Cases
Trimmed to 2.155"
120 grn Nosler BT

The rifle is a Tikka M595 with a Border (Archer) barrel chambered for 120 grain bullets and has been well cleaned.
The resized, trimmed & cleaned empty case fits pefectly with the bolt closing easily, the problem is that after a bullet is seated the bolt becomes tighter to close, not too tight but tight none the less, I have tried all seating depths from 20 thou off the lands to exactly the same length as a Norma factory round (which is not tight)
Once fired the case ejects easily and there are no signs of pressure.
The outside case neck diameter is the same after seating the bullet as it is before.
Anyone got any idea of what the problem may be please?

Thanks in advance

 

[Long Trang]

The resized, trimmed & cleaned empty case fits pefectly with the bolt closing easily, the problem is that after a bullet is seated the bolt becomes tighter to close, not too tight but tight none the less, I have tried all seating depths from 20 thou off the lands to exactly the same length as a Norma factory round (which is not tight)
Once fired the case ejects easily and there are no signs of pressure.

The outside case neck diameter is the same after seating the bullet as it is before.

The underlined text indicates the casing is fine. If there is a problem, it's likely the bullet. However, you're using the same brand of bullet as your factory loads...which aren't tight.

Are you using the same type and weight of bullet? Are you using a bullet comparator or going by COL? Is the 'stiffness' of the bolt that severe, or could it be just normal resistance but, you may be being a little overconcerned?

Good luck.

 

[buck52]

The underlined text indicates the casing is fine. If there is a problem, it's likely the bullet. However, you're using the same brand of bullet as your factory loads...which aren't tight.

Are you using the same type and weight of bullet? Are you using a bullet comparator or going by COL? Is the 'stiffness' of the bolt that severe, or could it be just normal resistance but, you may be being a little overconcerned?

Good luck.

The bullet is a Nosler 120grn BT, it is the identicle bullet used by Norma in his factory round
I am measuring (digital calipers) by COL which is fairly acceptable as the bullet has a polymer tip so does not deform like lead.
The bolt is too stiff to be acceptable
Regards

 

[buck52]

Reply to Chris-NZ
I should have said that the cases are once fired factory Norma, they eject perfectly, and chamber perfectly after FL sizing with no bolt stiffnes.

 

[RDM416]

Measure a loaded and a sized but unloaded round at the junction of the case body and shoulder. If you have excessive neck tension your case may be bulging at this junction due to the force of pressing the bullet in. Is this a compressed load? It is possible to make a case swell when seating bullets over a compressed load.

 

[buck52]

Measure a loaded and a sized but unloaded round at the junction of the case body and shoulder. If you have excessive neck tension your case may be bulging at this junction due to the force of pressing the bullet in. Is this a compressed load? It is possible to make a case swell when seating bullets over a compressed load.

Done that, measures 0.436 on both, the tension felt when seating the bullet is noticable but normal in my opinion, its not a compressed load, powder is below neck.

 

[RDM416]

The only other thing that comes to mind is maybe you need to bump the shoulder a bit more. Just for fun, take decapper/expander out of your die and resize a loaded round. This will tell you if something is happening during seating process.

 

[buck52]

The only other thing that comes to mind is maybe you need to bump the shoulder a bit more. Just for fun, take decapper/expander out of your die and resize a loaded round. This will tell you if something is happening during seating process.

Thanks willl do
Just so I know, what will that do/show me?
What will it tell me?
Regards

 

[Reloader222]

The only other thing that comes to mind is maybe you need to bump the shoulder a bit more. Just for fun, take decapper/expander out of your die and resize a loaded round. This will tell you if something is happening during seating process.

Check for the correct AOL - not too near to the lands. Go to this site for making you own device to measure the guns maximum AOL: Innovative Technologies - Reloading Equipment

Second test is to check if a sized case chambers easily. If not, I agree that you need to bump the shoulder a bit more. With the ram up, lower the sizer dies until it touches the shell holder. Then lower the ram. Turn the dies in another 1/4 turn and lock it. Size and case, clean it and then chamber it again in the rifle and see what it does. If it still does not chamber nice, you could try another 1/4 turn. You would feel the ram woud over-cam. However, be caucious that you do not bump the necks too far back as this might influence headspace and cloud lead to case seperation.

Lastly I would check the position of my seater dies. If turned in too much it could deform the case. Raise the ram with a case in the shell holder. Then turn the seater dies in until you feel it touches the case. The back off at least 1/2 a turn or a full turn.

 

[RDM416]

Thanks willl do
Just so I know, what will that do/show me?
What will it tell me?
Regards

This is just to make sure you do not have just a little swelling of the case around the shoulder. I know you measured for that, but running it back through your sizing die will make sure.

I did notice one thing you said earlier, that there was not a difference in the neck size before and after seating a bullet. There must some difference or you would have no neck tension. You should be seeing anywhere from .002 to .005 larger neck size after you have seated a bullet.

Take a black magic marker and color the neck and shoulder area of a loaded round, then chamber it. You may be able to see where contact is being made by the marker rubbing off. I still suspect it is either the neck or the shoulder needs bumped.

 

[buck52]

Thanks for all the help, I am going to adjust the die and run all them through again, will let you know if it solves the prob, been reloading for a few years and never come across this before!

 

[RDM416]

Weird stuff happens to all of us. I've been at this a long time as well and had similar thing happen to me loading 308s for my AR. I was loading a slow powder and 190 grain Bergers and having to seat them deep to fit the mag..... a compressed load. When I started shooting them I would have about 1 out of 20 that would not chamber all the way. I finally figured out that the case was expanded slightly just below the shoulder from the compressed powder. I had loaded 250 rounds and was not looking forward to having to pull all the bullets and resize the cases. That is when I came up with the idea of running them back through the sizing die. Worked like a charm. I'm going to change that load up next time and use a different powder and bullet combo, and I would not do that with my long range rifles, but I just use the 308 for playing around and short range stuff.

 

[buck52]

I understand now, so taking the decapping pin out and running the loaded round through the press allows you to just bump the shoulder back a little more, I would never had thought of that, I assume thats a safe thing to do with a charged round ?

I still dont understand what went wrong tho, the charge was well below the neck so no compressed charge and the dummy (no powder round) cycled ok, I have adjusted the die now and run all the cases through again, the problem has gone away, I am using an RCBS FL die and originally backed it away from the shell holder a full turn, it was obviously (now!) not setting the shoulder back enough, funny it only did it on a few cases though.
Thanks again

 

[lever-hed]

The Archer barrel, was this work that you had done to the Tika? or did you purchase the rifle as is?

You could possibly have a custom reamed chamber, and thus be the cause of your bolt binding... I would seriously take another look at it.