burnt power on bolt face and case

[AzMaN 0]

I took my new 6.5 x 55 up the range on sunday (well its new to me) with some loads the previous owner had made up (44gr n160 on 123gr heads).

 

anyways most of the ejecting cases had powder burn markings round the base of the case (round the ejector ring) and on the actual bolt face. what would cause this???

[riohog 5,701]

sounds like its coming from around the primer socket , !!

[jonher 0]

I took my new 6.5 x 55 up the range on sunday (well its new to me) with some loads the previous owner had made up (44gr n160 on 123gr heads).

 

anyways most of the ejecting cases had powder burn markings round the base of the case (round the ejector ring) and on the actual bolt face. what would cause this???

 

AzMaN,

 

I had the same problem with my 6.5x55 using N160 and found it was due to low pressure, I have experieced it in three different ways:

 

1) When working on a new load the cases on the lower charges were coming out covered in soot right back to the bolt face, this stopped as the powder loads increased.

 

2) When experimenting with OAL I also had the same issue, rounds loaded too long/ bullets not seated deep enough had cases covered in soot, this also stopped as the seating depth was increased.

 

3) Colder temperatures create lower pressures, I worked up an ideal load during the summer with 44 grains of N160 when the temperature was 30 degrees celcius, groups were excellent with no powder residue on the cases. However, when I fired these round during winter -15 degrees celcius all cases were coming out covered in soot.

 

Hope this helps!

 

Don't let this put you off, 6.5x55 is an excellent caliber, we use it on eveything from roe deer to moose over here in Norway

 

Jonathan

[SNAP SHOT 194]

it does indeed sound like low pressure, And should go with a heavier load as stated, also check the primer pockets to make sure the primer is not too loose a fit, when seating it.

 

 

Snap.

[AzMaN 0]

hmmmm see now i thought it would be more hight pressue, i forgot to add in my first post i had 3-4 flattened primers out of 50 rounds.

 

Im going to see if my local shop will measure my chamber for the correct OAL.

 

Other than the dirty cases its a superbly accurate round and im rearly pleased with it.

 

 

[jonher 0]

hmmmm see now i thought it would be more hight pressue, i forgot to add in my first post i had 3-4 flattened primers out of 50 rounds.

 

Im going to see if my local shop will measure my chamber for the correct OAL.

 

Other than the dirty cases its a superbly accurate round and im rearly pleased with it.

 

AzMaN,

 

Using primers to determine high pressure is not accurate, primers of different brands react differently at varying loads, so therefore they are not a clear indicator of high pressure!

 

An indicator of high pressure is when the bolt handle becomes difficult to lift up when extracting the fired case. Remember safety first work from the lowest and gradually up in small steps, when the bolt handle becomes stiff you've gone too far so back off on the load!

 

44 grains N160 for a 123 grain is not the highest listed in the VV reloading manual, as Snapshot mentioned, check when your reloading that the primers are seated nice and snug, if the primer goes in with little or no resistance the brass has been stretched in the primer pocket and is no good!

 

What OAL are you using?

Edited April 20, 2010 by jonher

[dicehorn 38]

I took my new 6.5 x 55 up the range on sunday (well its new to me) with some loads the previous owner had made up (44gr n160 on 123gr heads).

 

anyways most of the ejecting cases had powder burn markings round the base of the case (round the ejector ring) and on the actual bolt face. what would cause this???

 

You said you were given some loads from the previous owner - do you know how many times these cases had been reloaded? All cases have a limited life, even if you are annealing them. Cases from different manufacturers have a different life span.

 

After several loads just neck sizing, cases need to be full lengthed or better still to give better longetivity shoulder bump them.

 

As said (provided the blackened cases have no neck splits) this is sometimes a sign of under power. Having said that, I use 44 gr of N160 behind a 120gr Nosler in my 6.5 but I do seat the bullet well in the case (222 thou off the lands) to mitigate the lack of pressure and the only time I have the problems you are experiencing is due to a split neck.

 

Peter

[AzMaN 0]

I shall measure the OAL that they are currently at when i get home later today and report back.

 

I have no idea how many times the brass had been used but they were full sized each time (they were the dies that came with it) and i was given a full box of 100 new lapua brass when i brought the rifle.

 

The fitting of the primers i cant comment on yet, i havent got round to reloading them myself, i was supplied with 50 123gr's and about 30 139gr's although suprisingly the load data that was written inside the cases for both loads state he used 44gr of N160.

 

Ive got a feeling im going to have to start from scratch on these loads to see what performs best.*** OAL is 3.15in ***

Edited April 20, 2010 by AzMaN

[jonher 0]

*** OAL is 3.15in ***

 

Well your OAL is what the VV manual suggests, so I guess as long as the brass has been resized properly in the neck, OAL is not the issue.

 

So next steps are to try increasing the load slightly to see if this works and also to check the primer seat to see if it has been stretched to the point where it's not holding the primers securely enough!

 

Let us know how you get on?

 

Jonathan

[dicehorn 38]

*** OAL is 3.15in ***

 

Well your OAL is what the VV manual suggests, so I guess as long as the brass has been resized properly in the neck, OAL is not the issue.

 

So next steps are to try increasing the load slightly to see if this works and also to check the primer seat to see if it has been stretched to the point where it's not holding the primers securely enough!

 

Let us know how you get on?

 

Jonathan

 

 

My advice would be to bin your old brass - especially as you have no idea how many times it has been loaded. Get some new brass - Lapua is very good.

 

 

If you continue to use this 'old' brass especially if you plan to increase powder weight, this could cause case separation which is not a pleasant thing for your rifle. Be safe - buy new brass and then you can be sure when to neck size and when to full length them from the records you will keep.

[provarmint 25]

A few things to look for regarding high pressure aswell as hard bolt lift

pressuresigns.bmp

[AzMaN 0]

A few things to look for regarding high pressure aswell as hard bolt lift

pressuresigns.bmp

 

 

damn i de-primed and cleaned them the other day. I still have 30 or so left, i'll inspect them closely after i go to bisley again next month.