Intermittent bulging primers

[garyb]

Chaps,

 

After some help with an issue I sometimes face.

 

When sizing and decapping my brass, sometimes the primers are very hard to remove. Infact some wont move at all.

 

What I notice is that these primers appear to have "bulged" the strange thing is, I dont see this all of the time maybe one case in 8 from the same load, fired by the same rifle? All the others are fine!

 

Is this a pressure problem? Too high... Too low perhaps?

 

Some pics to show the problem - Sorry for the size, but you won't see the problem them if I size them as small

 

A primer I could only remove 80% of the way

 

Normal on the left - Bulged on the right

[al4x]

its odd only some are doing it bearing in mind the consistency of the loading, I guess it could be worth putting some through my rifle at some point to exclude anything there.

Edited June 8, 2010 by al4x

[MC]

This may be a really silly question but as I don't reload for rifles I don't know the answer but,

 

Why were you bothering? That case looks shagged out.

[garyb]

This may be a really silly question but as I don't reload for rifles I don't know the answer but,

 

Why were you bothering? That case looks shagged out.

 

It is indeed, it was the only way I could free it from the shellholder.

 

Now in the bin.

[webber]

From the little that I know about re loading, and its not much, bulging primers are early signs of too high pressure problems.

 

If you PM me your full spec I'll run it past my friend who is a reloading wizzard.

 

webber

[BRYAN3]

Hello mate.

Is it the act of decaping that swells the primer or are they leaving the rifle like that?

The three primers to the left look slighly over pressured.

Are all the cases from the same batch and had the same treatment the same number of times?

 

Bryan.

[garyb]

Hello mate.

Is it the act of decaping that swells the primer or are they leaving the rifle like that?

The three primers to the left look slighly over pressured.

Are all the cases from the same batch and had the same treatment the same number of times?

 

Bryan.

 

They appear slightly swelled whilst still in the case.

 

Hmmm maybe it's the photo - but the ones on the left are just like any other primer I've ever seen - I don't have any other pressure signs either

 

The load is 26.0grn of Varget with a 55grn Head - book says max is 27.5grn

 

All cases are the same batch twice fired.

Edited June 8, 2010 by garyb

[10WM]

It is indeed, it was the only way I could free it from the shellholder.

 

Now in the bin.

[10WM]

It is indeed, it was the only way I could free it from the shellholder.

 

Now in the bin.

 

 

LIke Bryan. I would quess its your reloading press causing the bulging primers, If they are coming out of your rifle like that,

 

Then you have some very serious issues with the Rifle load combination, Is it the right bolt for that rifle for instance ??

 

 

What calibre is it? what powder and grainage did you use? also what make/ type of bullet tip and grainage did you use? Do you use a scoop or scales

 

with the powder measuring.?

 

There are very slight early indications of pressure, as Bryan says on the primers in the left picture. a little cratering around the ridge of the firing pin

 

hole.

 

I would recommend you buy a Primer Pocket Uniforming tool, they are not that expensive and are used by the "Bench Rest" boys to uniform the cases

 

primer pockets to the same dimension's, this may give tiny advantages, as the initial primer flame front burn into the powder is then all equal.

 

 

It is important to clean the primer pockets of any previous burn residue **** each time the cases are reloaded.

 

Are you using the correct decapping tool ? You must be because you said it is only some that are this way?

 

 

Be intrested in the information as above before going down the over-pressuring route?

 

 

Best wishes. 10WM

[Harnser]

Looks like to me that your decapping die is not set down deep enough to pop the primers out . Also some primers are crimped in and can be harder to de-cap . The de-capped primers dont look like they have been subjected to high pressures to me . In extreame pressure they would be flat and not show the dent were the the striker has struck them .

 

Harnser .

Edited June 8, 2010 by Harnser

[garyb]

The load is...

 

26.0 grn of Varget

55 grn Sierra Spitzer BT (1365)

CCI 400 SR Primer

Lapua Match Brass

 

Will shoot a .2 @ 100 yards

 

Calibre is 223Rem

 

All charges are thrown with either an RCBS uniflow, or now a RCBS chargemaster 1500 digital scale and dispenser combo

 

The sizing die is a Redding Competition Neck Sizer, with TiN bushing

[al4x]

just as a slight addition mine also come from this set up only difference being Norma brass and 26.5 of varget and to my knowledge don't do it though Gary has cleaned up my cases

[Dougy]

what size is the bushing die, if you have problems getting the case stuck in the die its another sign of pressure, i am no expert but i could imagine if you had a bushing thats too small it will increase the pressures,

does the bolt lift easy or do you find it hard,

do you check your scales now and again to check its throwing the correct amount

 

just another thought the brass i am sure will have less capacity that most others, being lapua i am sure its a thicker brass.

 

my bushing are i am sure 47 & 48 & 49

Edited June 8, 2010 by Dougy

[OCD]

It is possible to get this from a poor batch of primers some will have soft or thin cups,primer pockets tend to be very consistent in lapua brass but I have found that their can be inaccuracies in the flash hole consistency and even burrs on the inside of the case.Have the primers and powder been stored correctly and is it possible that the inside of the case could have been damp before you reloaded them.

 

How many times have the cases been reloaded and did you notice poor accuracy or different noise signature when fired are you sure that all cleaning media was removed before reloading and that no flash holes where obscured by cleaning media .

[Graham M]

Are you lubricating the cases?

G.M.

[BRYAN3]

Hello Chaps.

There are many things that can cause problems for reloaders even when all components are correct.

Do not exceed overal cartridge length because if the bullet is touching the rifling as the round is loaded you will get excesive

pressure buildup.

Headspace is also a concideration on older rifles.

Over greasing of the bolt can cause massive pressure buildup. Do not get grease on the face of the bolt.

Also overcrimping causes overpressure.

Primers must be seated flush or slightly recessed but never proud of cartridge base.

 

Sorry if I am boring peeps or repeating what folks already know,but this is serious stuf and is important.

 

ATB-Bryan.

[garyb]

OAL to ogive is 1.875

 

No lube used for neck sizing.

[10WM]

The load is...

 

26.0 grn of Varget

55 grn Sierra Spitzer BT (1365)

CCI 400 SR Primer

Lapua Match Brass

 

Will shoot a .2 @ 100 yards

 

Calibre is 223Rem

 

All charges are thrown with either an RCBS uniflow, or now a RCBS chargemaster 1500 digital scale and dispenser combo

 

The sizing die is a Redding Competition Neck Sizer, with TiN bushing

 

 

Hi again Gary,

 

The above according to my reference books is a quite warm load allegedly, but should not be doing the stuff that you have.

 

Check the overall case length it should be no more than 1.760" and has a trim to length of 1.750" If it get too long it impinges on the bullet when

 

chambering and has the effect of a severe crimp that can put pressures up to dangerous levels. Also check that the chamber throat is completly clean

 

and free from any oil or other contaminations.

 

Do you notice any tightness when closing the bolt?

 

Its a bit of a mystery because all signs of pressure have the immediate effect of loosening the primers and growing the pocket dimensions?

 

yours appears to be going the other way?

 

Forgive me for searching for the reason, Are you quite sure you have not got any .222 Magnum brass mixed up? as it looks just the same but the .222

 

Mag. is longer. check the head stamps on the brass?

 

If the resizing bush is too tight? I would think you will be having problems getting the tip to go into the cases in the first place, does it take a lot of

 

press effort to seat the tips? are you distorting the finished round forcing the tip in?

 

Other things to think about has the powder been stored in a hot area as this can make for very hot rounds.

 

Any chance the powder could have got mixed with other faster powder?

 

Have you check weighed the tips to make sure they are the correct weight?

 

Have you measured the bullet to chamber throat touch point, as an engraving round can increase pressures by lots.

 

Does your Rifle have a special bench rest competition tight cut chamber,? that will require the case necks to be turned to a certain

 

thickness to allow for a few thou clearance.

 

 

 

 

Pressure signs to be aware of,

 

(1) Slight cratering lip of the firing pin hole in the primer. (2) flowing of the primer into the gap between the primers edge and the case edge,

 

(filling in / flat primers) (3) primers becoming loose / pockets growing, (4) Cases starting to get marked, case head inscriptions starting to blend.

 

(5) bolt getting stiff. You are now close to blowing the rifle up. If you get sign 1 or 2 you need to back off the loads.

 

Always start at well below the recommended loading tables, try a few shots into a sand bank. and inspect the cases, then work up by half a grain

 

increments, watching all the time and inspecting for pressure signs, and don't ever exceed the reloading manuals max load.

 

Something is well out of line with your set up just need to narrow it down to find the reason.

 

Hope some of this is of help to you, Best wishes and stay safe 10WM

[garyb]

Hi again Gary,

 

The above according to my reference books is a quite warm load allegedly, but should not be doing the stuff that you have.

 

Check the overall case length it should be no more than 1.760" and has a trim to length of 1.750" If it get too long it impinges on the bullet when

 

chambering and has the effect of a severe crimp that can put pressures up to dangerous levels. Also check that the chamber throat is completly clean

 

and free from any oil or other contaminations.

 

Do you notice any tightness when closing the bolt?

 

Its a bit of a mystery because all signs of pressure have the immediate effect of loosening the primers and growing the pocket dimensions?

 

yours appears to be going the other way?

 

Forgive me for searching for the reason, Are you quite sure you have not got any .222 Magnum brass mixed up? as it looks just the same but the .222

 

Mag. is longer. check the head stamps on the brass?

 

If the resizing bush is too tight? I would think you will be having problems getting the tip to go into the cases in the first place, does it take a lot of

 

press effort to seat the tips? are you distorting the finished round forcing the tip in?

 

Other things to think about has the powder been stored in a hot area as this can make for very hot rounds.

 

Any chance the powder could have got mixed with other faster powder?

 

Have you check weighed the tips to make sure they are the correct weight?

 

Have you measured the bullet to chamber throat touch point, as an engraving round can increase pressures by lots.

 

Does your Rifle have a special bench rest competition tight cut chamber,? that will require the case necks to be turned to a certain

 

thickness to allow for a few thou clearance.

 

 

 

 

Pressure signs to be aware of,

 

(1) Slight cratering lip of the firing pin hole in the primer. (2) flowing of the primer into the gap between the primers edge and the case edge,

 

(filling in / flat primers) (3) primers becoming loose / pockets growing, (4) Cases starting to get marked, case head inscriptions starting to blend.

 

(5) bolt getting stiff. You are now close to blowing the rifle up. If you get sign 1 or 2 you need to back off the loads.

 

Always start at well below the recommended loading tables, try a few shots into a sand bank. and inspect the cases, then work up by half a grain

 

increments, watching all the time and inspecting for pressure signs, and don't ever exceed the reloading manuals max load.

 

Something is well out of line with your set up just need to narrow it down to find the reason.

 

Hope some of this is of help to you, Best wishes and stay safe 10WM

 

Hi.. thanks for the reply.

 

Brass is always trimmed to 1.750

 

Bolt is never difficult to lift before or after firing either!

 

I've now reamed the brass, but to be honest bullet seating was never difficult anyway

[garyb]

I'll prime an empty case, fire and compare it with one of my "normal" loads

[al4x]

I had a quick look at my fired ones this morning Gary and can't see anything suspect, these just have half a grain more varget in and different brass on the same reloading gear. I can bring some over next time to pop the primers out if this might help discount anything

 

 

and versus factory remington

 

[garyb]

Ok...

 

Primer is bulged on a primed case after firing (no powder or head)

 

So I guess the issue is low pressure, more than High..

[al4x]

or a duff load of primers, or something gun related,

 

Try one in mine next time I'm over if you want, whatever its a bit of a pain in the backside bearing in mind how well they shoot

Edited June 9, 2010 by al4x

[hyflier]

Anyone else think this might be a "cartridge headspace" fault? :blink:

[Doggone]

Anyone else think this might be a "cartridge headspace" fault? :blink:

 

Sounds like excessive head space doesn't it, however the primer may have bulged in the case with no powder, if the case was resized, because there would be no pressure to expand the shoulder of the cartridge up to the chamber shoulder, so allowing the head to leave the bolt face and allowing the primer to bulge. Since he only neck sizes, maybe he bumps the shoulder a bit too much. Strange one isn't it. Maybe try an unsized case with just a primer to see if it still happens.

Andy

 

Edit

Another thought, this doesn't explain the decapping difficulty. That sounds like poorly adjusted decapper

Edited June 9, 2010 by Doggone