chambering problem

[Guest Stacka]

Ok, so iv made my first batch of home load ammo.

 

Iv been so so careful to get the measurements spot on.

 

Yet when i did a run of cambering, some where much stiffer than the others? And causing a burr on the ejection rim.

 

Iv measured some Norma stuff i had, and the over all length of that is much shorter than the 2.130 advised on the loading manual.

 

Im using sierra varmint 50 GR

 

Fully sized brass

 

any one any ideas.....is this safe to fire?

[DaveT]

Stacka

 

This is normally caused by either brass that has not been sized sufficiently in an overall sense ....IE the body etc is still too tight a fit radially OR (more usually) it is either just too long measured from the Base to the mouth of the neck and the case mouth is jamming at the end of the chamber OR it has not had its head-space reduced enough (IE Shoulder setback .001" or .002" from fired dimensions.

 

Can you reliably eliminate any of the above?

 

Check brass length (Case base to neck mouth is less than what it shows in reloading manual)......or at the very least not greater.

 

How did you resize?...I will assume Full Length Size with standard die?

 

Did you measure headspace using something like a Hornady Lock & Load tool after sizing....you can actually make the case grow in length when FLSizing and so prevent it rechambering due to insufficient headspace.

[DaveT]

In addition to previous post.....it is impossible for someone on the forum to remotely quantify what you describe as stiff to chamber BUT ........if you have ANY doubts then don't fire them until after investigations concluded...its not worth risking your face.

[Guest Stacka]

Dave,

 

I resized using the lee full resizer and decaper.

 

The dimensions all seem to be really the same, from what i can make out. The brass has all been fired before.

 

Iv measured every single one with a set of calipers and the over all lenght seems to be perfect, id argue a little short

[DaveT]

Trouble is that if you are measuring base of case to tip of bullet you are wasting your time with regard to reliability & accuracy......the bullets will vary in length significantly so the measure is pretty useless.

 

You need to check the case base to headspace datum on the brass itself using a comparator and the same for the overall cartridge length which is measured from case base to the bullet Ogive using a comparator.

 

I am not saying that this is definitely the problem but it needs checking with the right tools to eliminate it.

 

Is there any chance it was simply a dirty case (picked up some grit or something) that struggled to chamber?

 

I have no ideas on the burr on your rims unless the ejector / extractor is damaged in some fashion?

[Guest Stacka]

you mean using one of these?

 

http://www.dauntseyguns.co.uk/products.php?cat=53300

[DaveT]

That's the job....you need at least three tools ideally......A Lock & Load gauge (pushrod) and a dummy brass cartridge threaded to fix to that tool, a headspace comparator and a bullet comparator....its also useful to have the anvil fitment.

 

Together these allow you to measure the max overall length that your specific chamber can accommodate for a given bullet, check your finished cartridge length has the jump or jam to the rifling that you wanted and also check your headspace is correct on the brass.

 

Together they are quite costly ...but needed.

[Guest Stacka]

ill get one next weekend, put problem solved thanks to oaken....the primer was pretuding ever so slightly enough to make the bolt stiff

[DaveT]

Brill......well done Rup!

[DaveT]

Just in case.....don't try to seat them any deeper in a loaded round!

[Chickenthief]

I think your problem is to "long" brass.

If a cartridge is fired in another veapon than yours then i will guarantee you it wont have the exact same chamber as your rifle.

It might be longer and then it will be almost impossible to chamber the same piece of brass in your rifle.

 

Take 1 piece of empty brass and FL size it, whipe of any lube.

Chamber the brass in your rifle, if the bolt closes just fine then on to another solution.

If not then your brass is still not sized short enough and the FL die needs to be adjusted deeper.

 

Bear in mind that i have experienced the same thing using Hornady dies with a Lee case holder.

In fact the Lee case holder is higher than the Hornady one and the brass cant go fully into the FL sizer. (I had to grind a smidgen of the bottom of the die for it to work).

 

In this pic you can see the length that i suspect is to long for your chamber:

 

If you still have problems then please cone on again and well deal with it.

[baldie]

The picture is incorrect.

 

The headspace measurement is from the base of the case , to an imaginary line, HALF WAY UP the shoulder.

[Tony.H]

I think your problem is to "long" brass.

If a cartridge is fired in another veapon than yours then i will guarantee you it wont have the exact same chamber as your rifle.

It might be longer and then it will be almost impossible to chamber the same piece of brass in your rifle.

 

The picture is incorrect.

 

The headspace measurement is from the base of the case , to an imaginary line, HALF WAY UP the shoulder.

 

But Dave, are you talking about the same VEAPON as he is.... :D

 

[DaveT]

Just stick with the Hornady headspace comparator toolset and you will be on the right track regarding this particular measure.

 

There are other headspace checking methods such as that used by benchrest shooters whereby they use a 'feel' for the amount of resistance to the bolt closing (with firing pin mechanism removed) to get the proper adjustment on the sizing dies but I have always been more comfortable with a hard measure obtained via a tool.

[fizzbangwhallop]

Bear in mind that i have experienced the same thing using Hornady dies with a Lee case holder.

In fact the Lee case holder is higher than the Hornady one and the brass cant go fully into the FL sizer. (I had to grind a smidgen of the bottom of the die for it to work).

 

A Lee case holder with an inaccurate deck height caused me headspace problems with my first batch of .20Prac ammo...switched to an RCBS and problem solved..... apart from what to do with a box of Lapua brass.

 

cheers

 

Fizz

[DaveT]

Wow ...love the jigglies Fizz!

[The Gun Pimp]

Stacka - we seem to get this 'problem' on the Forum on a regular basis - "I've loaded my rounds and they won't go in my rifle, is the headspace wrong?"

 

Firstly - don't use brass that's been fired in another rifle.

 

As I've said before - your chamber is YOUR chamber and it's up to you to use re-sizing dies to make your brass fit YOUR chamber. Whether it's a thou. longer or shorter than some reloading manual number is irrelevant - it's got to fit your chamber.

 

No need to actually measure anything - just strip the firing pin/spring assembly out of your bolt and size your brass until it fits the chamber - i.e. the bolt-body closes with the lightest of effort. When all your cases will chamber in this way, you can prime, powder and seat the bullets.

 

What's hard about that?