I am stumped and need help

[taxman]

I have 15 years of general reloading experience, rifle, handgun & shotgun. Reasonably successful.

I have recently purchased a new in the box stainless Remington 700 2007 vintage.

A new Krieger 6mm barrel chambered in 243 AI. with a .268" neck

I have shot the same 5 lapua cases 10 times for consistency.

The cases are new to start, Full length sized in Redding Bushing die, Run over a 6mm Sinclair expanding die, trimmed to length, chamfered, neck turned to .267"

Loaded and shot 3 times, then trimmed again and the shoulder bumped once.

In between firings the cases are necked sized only with a .266" sizer in Redding Neck die.

At about the 8th firing I noticed that 2 cases seem to have more resistance when chambering.

With the firing spring mech out of the bolt, the bolt falls closed, no resistance.

The 3 cases that chamber easy, initially there is a slight little resistance when the case is chambered, then the bolt closes very easy.

On the two that do not chamber easy, initially there needs to be much more force used to get the case chambered, and the bolt closes with some difficulty. When the cases are removed, the bolt requires a bit of forces to open, when it cams open, there is a loud click, then the bolt opens.

I have used a body die on these two pieces of brass, full length re sized, and they are still difficult to chamber.

Have I exceeded the life of the brass? I am perplexed.

The load is 46.0 grains of H-4831, 87 gr hpbt with WLRM primers.

Sorry for the long post.

Thanks,
Tony

 

[FALPhil]

With the firing spring mech out of the bolt, the bolt falls closed, no resistance.

SOunds like you may have a bolt timing issue. Not unheard of, but relatively rare in a Remington. Timing problems are much more common on Savages.

When an action is out of time, it is typical that the bolt operation is stiff, bolting or unbolting. This is caused by several things, such as the cocking ratio being out of balance, and the sear engaging too early or too late. Another geometry problem is that the lead-in ramps and the primary extraction are not synchronized, but are actually in conflict with one another.

A decent gunsmith knowledgeable about Remington tming issues should be able to straighten it out in short order.

 

[DonL]

Hi Taxman,
I'd almost bet you may have some work hardened brass. You may want to try anealing those two stubborn cases, bumping their shoulders and see what happens. And having something to measure to the datum line like gunamonth advised will definately help you measure whats happening.
Good Luck! DonL

 

[BigJim]

That loud click you are hearing could be the case finally getting into the extractor on your bolt, does sound like a mismatch between the case size and your head space. Check your sizing with unloaded cases and see if you have the same problem extracting them. Then load some dummy rounds,no power or primer) and try them. When all else fails, take it to a good gunsmith.

 

[CatShooter]

With the firing spring mech out of the bolt, the bolt falls closed, no resistance.

SOunds like you may have a bolt timing issue. Not unheard of, but relatively rare in a Remington. Timing problems are much more common on Savages.

When an action is out of time, it is typical that the bolt operation is stiff, bolting or unbolting. This is caused by several things, such as the cocking ratio being out of balance, and the sear engaging too early or too late. Another geometry problem is that the lead-in ramps and the primary extraction are not synchronized, but are actually in conflict with one another.

A decent gunsmith knowledgeable about Remington tming issues should be able to straighten it out in short order.

If it were timing issues, it would show itself on all the cases, and right from the beginning - there is something about these two cases that is different, and that has not been explained.


.

 

[SooStan]

I agree with Catshooter. Not a timing problem. I would take an empty 38 case and place over the neck area of the brass and measure the overall leanth. This will give you a reading off of a make shift datam line. I would compare it to the brass that does chamber. My guess is that it will be a .001 or .002 longer. Also check the over all length as you may have a long neck stopping against the end of the chamber. Not all cases grow equally.

 

[taxman]

Thank you for all of the ideas.

I think I am having problems with the base of the necks swelling in diameter. I have a Redding full length sizing die with bushing. The sizer will not size the entire length of the neck? Is this typical?

One other situation, I may not be turning my necks far enough into the shoulder. This is the first rifle with a tight neck.

Thanks again!
Tony

 

[CatShooter]

Thank you for all of the ideas.

I think I am having problems with the base of the necks swelling in diameter. I have a Redding full length sizing die with bushing. The sizer will not size the entire length of the neck? Is this typical?

One other situation, I may not be turning my necks far enough into the shoulder. This is the first rifle with a tight neck.

Thanks again!
Tony

Bushing FL dies often leave a slight part of the neck unsized.

That alone should not be the problem...
... unless that is the section of neck that you didn't turn.

You MUST turn the entire neck in a tight neck riffle - otherwise, the unturned section of neck gets wedged between the bullet and the chamber wall of the neck - a VERY BADD THING,so says Martha Stewart!!)

This would account for the difficulty in chambering you are having.

Turn the necks all the way to the base of the shoulder...


.

 

[MSwickard]

It sounds as if you are not getting the shoulder pushed back or the bases have swelled. You can always try a different FL sizing die.

As for turning necks, make the cut slightly past the shoulder neck junction. Not a lot but this will remove brass that forms the dreaded doughnut.

Mike

 

[rayjay]

Keep them bolt lugs greased !!!!

 

[BoydAllen]

Do you have a tool to measure shoulder bump? If you do not, get one and use it,and ignore the set it by feel crowd). The back of your chamber is probably too small for the FL and body dies that you are using. I know, I said it backwards, but it did get your attention. The die is probably to big to size the back of the body of the brass from your chamber. You need a different die. That is one reason for small base dies. Not all chambers are the same, and, as you have learned brass is not so identical that it all gets tight on the same firing. I predict that if you set aside the tight cases and keep shooting the rest, with the same loads, eventually it will all be tight, even with proper shoulder bump after each firing.

 

[Eddie Harren]

Here we go!

 

[rayjay]

On the main site there is an article about the Harrell's FL sizing die. In the article there is described a method of measuring how much sizing your die is doing to the brass. It is possible to see if your die is reducing the dia of the case at the shoulder and farther down.

 

[BoydAllen]

Lynn,
With the base of the die too large, the die will have to be adjusted so that the shoulder is bumped too far back to get the desired feel. Without a gage to measure bump this will go unnoticed. Bumping the shoulder too far back will eventually lead to incipient separation,bright line above the head with corresponding thinning inside the case in the same area, detectable with a bent paper clip) and if that is ignored, a separation of the case, just above the head...not what we want. You can't adjust a die that is the wrong size to do the job properly; you need another die.

 

[SooStan]

I read that bad dies can be easily fixed by throwing into the nearest lake.

 

[taxman]

Thanks guys for all of the info.

2 culprits were found. One issue with the neck not being turned properly completely my fault in understanding the turning process. That issue is sleeping now.

2nd issue as I believe Lynn stated, I was assuming that I was bumping the shoulder. My gunsmith modified a shell holder to give a few extra thousandths and I can now just move the shoulder. All brass chambers nice & easy.

Thank for pointing me in the right direction. Excellent info here.

After 15 years of general reloading, I thought I was perty smart on it. Got a lot to learn.

Tony

 

[BoydAllen]

Taxman,
Do you have a way to measure how far back you are bumping your shoulders when FL sizing?

 

[taxman]

Boyd Allen - Not specifically. I have vernier calipers and micrometers, but nothing specific for head space gauges. What gauges do you recommend? I have no problem buying what I need to be safe.

Lynn - Some of my fired cases still close easily with just slight resistance on the bolt at bottom of bolt throw, with no click at top of ejection stroke. I can take that case put in my full length sizer or bump die and make it harder to chamber and a very audible click at the top of the stroke. I believe I am moving things too much at that point.

My current load is 108 Berger BT match, 45.5 grns of R-25, Lapua Brass Fed 210m. I can shoot them under .3 easily and occasionally smaller at 100 yards. 46.0 grans give slight ejector marks. Seems like a mild load unless I am missing something. I will have to get the details on the reamer. I may just have a short throated chamber?

Thanks for all the help guys.

Hopefully this info will help other guys out!!

 

[rayjay]

Look at post 8 in this thread:

http://www.websitetoolbox.com/tool/post/6mmbr/vpost?id=2806790

 

[taxman]

After an afternoon of measuring and comparing my dies, I believe I have found the culprit to my problems.

I started with a 38 case to measure casehead to shoulder lengths on different pieces of brass. Ones that would chamber, ones with slight resistance and some with more resistance to chambering.

I can move the shoulders with the bump die about .0055". Which when done makes the case nearly impossible to chamber. After trying numerous cases, I just could not get rid of the click at the top of the bolt stroke.

For grin & giggles, I pulled out a regular RCBS .243 win FL die. I ran my AI brass into the old die a little at a time, being very careful to not changes the profile of the AI shoulder.

Low and behold, the brass chambers like new with out any click or difficulty in chambering.

I started measuring die diameters. My new Redding AI dies are at minimum .0025 larger than the older dies.,This includes my full length bushing die and the body/bump die) I would not think this is a huge difference, but obviously it is.

Now, I am wondering, should I have a custom sizing die made from fire formed brass? If so, who is the better die grinders.

Thoughts and ideas?

Thanks,
Tony