6.5X55 always needs trimming - why?

Scott Bear

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Just wondering my 6.5X55 always needs trimming when reloading. I have a .308 and all I have to do is neck size it and it chambers fine.

I'm guessing the throat is really long before the rifling starts to accommodate the 160 grain bullet or is it a head space problem?

This is the last time I will have to punch out live primers and from now on will always measure the case length before resizing and repriming.

Any help in satisfying my curiosity would be greatly appreciated,

Scott
 
Scot, you are a bit sketchy with details, but I will see if I can figure it out.
For starters, the shape of a 6.5x55, quite a large volume and small diameter bullets, indicates it will stretch cases more than will the 308 Winchester, which is more of a balanced, volume to bore size.
However, I think you are being too fussy with case length. What are you going by for length, to decide you must trim the case? To relate figures to real world distance, look at it this way. The thickness of a sheet of copying paper in your computer copier is about .008" thick. That amount is an absolute nothing when it comes to when a case is too long to shoot. So, unless they have considerable longer growth than that, just shoot them and trim next time, if you want. You haven't said, so I am doing some guessing here.
Bruce
 
from now on will always measure the case length before resizing and repriming.

Measure the case length after resizing, not before, it may change with sizing.

I use Lapua brass, and a neck bushing die, and I go at least four to five firings before trimming.
 
More details:

I bought 50 pieces brass once fired. When I started to reload my rounds I resized and primed the brass. Half way through the operation I decided to measure the case length. I thought that with the full-length resizer die I would be fine using brass from another rifle. The OAL was out of spec so I tried a piece of brass in my rifle and the bolt wouldn't close. After resizing the rest of the brass and trimming it it chambered fine. I loaded up 20 rounds for my ladder load test and went to the range. The rifle shoots like a laser.

Now I thought that I had brass fire-formed to the chamber so I didn't think that I would need to trim it again (except for the brass that needed the live primers taken out and resized from the first part of the operation that I screwed up). I decapped, sized and reprimed the 20 pieces of brass. Once I was done I thought that maybe I should check the case length just in case (I've had to pull bullets before and I thought about the first 30 rounds I screwed up). I tried one of the pieces of brass in my rifle, and once again, the bolt wouldn't close. Now I had 50 pieces of brass with live primers that needed to come out.

This morning I decided to do something about the brass. Having more time than money I put a drop of water into each piece of brass, put on ears and eyes, and went to work. I decapped and resized the brass. After cleaning out any moisture inside the case and in the flash hole with Q-tips I trimmed the brass with a Lee case trimmer. I then let the brass dry in the sun to make sure all the moisture was out of the cases (it's very hot even in the early morning these days in Kamloops).

So now I'm wondering why the neck of the case always seems to stretch so much that the bolt won't close after firing in the same rifle?
 
Something else besides the length of the neck is stopping the case from going full into the chamber.
 
First off, you didn't need to remove the live primers, you just needed to adjust the deprimer so it was short enough so as not to touch the primer.

Second, trim to at least .010" short so you don' t have trim every time.

Third point, if your rifle is military surplus the chamber may be oversize so that it can chamber dirty cartridges. So even tho you are "neck sizing" you may in fact be reducing the diameter by some amount which would cause the brass to flow forward resulting in more case trimming than you might expect.

Good luck sorting it out! It's all part of the fun.
 
This is up to you but you don't need to remove the live primers before you resize again. Back off the decapping pin so it won't touch the primers and all will be well.

Obviously your OAL is ok or your other loads wouldn't have worked.

You also don't give what the length of your brass is after resizing.

I have a 308Win and a very early 257 Roberts that have a similar issue to what you describe. Both of these rifle have minimum spec chambers. The 308Win requires a small base die for reliable chambering. It's an easy issue to detect. Just take a Sharpie felt pen and mark the back half of the case before chambering it. The color will be marked or slightly removed in the area the case is binding.

The 257Rob has another issue. Because the chamber is so tight I had to make up a special forming die with the shoulder slightly shorter. The RCBS forming die I had couldn't be set down enough to bump the shoulder back enough. I didn't want to trim the base of the die and I had another die, made of malleable steel that I could cut with an undersized finishing reamer then harden. It fixed my problem.

One other issue I have encountered is with partial resizing, which some rifles really like. This can leave a slight shoulder on the neck which can cause some difficulty when the expanded neck enters the neck portion of the chamber.

I didn't notice witch dies you are using and it just may be a simple case of setting your die down a bit closer to the shell head holder if in fact you do have a very tight chamber.

The 308Win I have with the issue is a Tikka T3 and it to shoots like a lazer.
 
If you are only neck sizing.. perhaps it is that you have a slightly eccentric chamber causing fired brass to be difficult to re-chamber - due to now having slightly elliptical casings?

just a shot in the dark.....
 
I don't think it is a trim length issue, I am willing to take yet another shot in the dark and guess that your using a Lee full length sizing die and do not have it set up in the press so that the ram is fully camming over......read the manual for your dies and report back
 
After a FL size of fired brass you need to trim, which you learned already.
After the first fireforming from FL sized brass, you need to trim on the first neck sizing.
Subsequent firing and neck sizing should not need any trimming for several firings.
This is assuming you are using a collet type neck sizer and not and FL die to neck size your brass.
 
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You could be possibly bumping the shoulder back to much when you resize and causing a head space issue . set your resize die up shallow on the piece of brass that will not chamber .then adjust it down in very small amounts just until the piece of brass will chamber .I had to do this for a 22 250 I had at one time . if I set the die per the instruction it would be hard to chamber after fire forming .as the shoulder was moving forward .out of spec chamber on the rifle I assume .
 
I am not using a neck sizing die. It is a LEE full length. I'll check it to make sure I'm using it correctly.

The primers need to come out for the trimming tool to fit in the flash hole so I needed to remove the live primers to trim the case.

The bolt closes after trimming.

The rifle is a sporterized Carl Gustav Swedish Mauser.

Thanks for the help guys. I'll try and figure it out and let you know.
 
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I am not using a neck sizing die. It is a LEE full length. I'll check it to make sure I'm using it correctly.

The primers need to come out for the trimming tool to fit in the flash hole so I needed to remove the live primers to trim the case.

The bolt closes after trimming.

The rifle is a sporterized Carl Gustav Swedish Mauser.

Thanks for the help guys. I'll try and figure it out and let you know.

Buy a collet die from higginsons....neck sizing with FL die is not ideal. You will never go back.
 
Do you know if the bolt and reciever match? Have you had the headspace checked?
I have found most Swedish Mausers have decent headspace, but still on the generous side.
I recently got a new m38 and my old reloads won't chamber.
I had to fiddle with the die, also a Lee full length, to get the brass to chamber. I had to set the die down to the point that the handle just barely cycles over when sizing. Using Prvi brass from the 90's.
Do you lube the inside of the neck a bit? Sometimes if you're really pulling it hard over the expander it could strech a bit, especially with annealed brass.
 
Do you lube the inside of the neck a bit? Sometimes if you're really pulling it hard over the expander it could strech a bit, especially with annealed brass.

This a good point often overlooked.
Pushing a barrel cleaning brush in and out the case neck usually makes resizing
much easier with rough inside necks.
 
What are the case lengths? If the chamber is generous in your Swedish Mauser it still should not require trimming every time. Even if your FL resize. Trimming isn't going to fix a headspace issue either.
 
It does feel a little tight on the down stroke. I do lube the inside of the neck, but it is still rough when the brass is coming out of the die.

The next time I'm at the range I'll check to see if the brass rechambers after firing. If it does it has to be something with the die.

I use a Lee neck sizer on my .308. It is less time consuming and the loads are really accurate. You can get a full set of dies from Lee with the neck sizer, but not for the 6.5X55 for some reason. Usually you have to settle between the collet crimp die and the neck sizer die in the set. Not sure why they just don't offer a set with the FL resizer, neck sizer, bullet seater and collet crimp die.

Thanks for your help guys.
 
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