blown primers

[Willoughby]

I had my 1st 2nd and 3rd blown primers today , shooting a 270 win with 130 Sierra flat base spitzers, and H100 -and once fired ww brass , and when I hand prime the cases if it feels a bit loose I toss them, powder range is 61 to 64 grains 2 were 61 grains and one at 62 , several others 61 & 62 grains were ok - the 3 that blew out also had ejector marks - I use a rcbs 1500 electronic powder measure on all the rounds , I dont understand what happened -if I didn't know better I would say overcharged. but in all calibers I shot 98 rounds today , all powder charges thrown on same machine & when it is off a few tenths like it is sometimes I dump it back in and let it try again til its right ,any help appreciated . I have been handloading for about 12 years , but I am still eager to learn

 

[Thud]

Check for carbon ring in throat area. and clean it out.

 

[rsmithsr50]

not enough info to tell.
what primer
oal
case vol
have you done this load in these cases before
get a magnifying glass and inspect the top of the firing pin.
three in a row..maybe burnt/damaged

 

[243winxb]

When primers fall out of the pockets on firing, pressure is to high.

To much powder-Scale issue?

Case volume reduced- Tumbling media let in case, then loaded?

When seating the bullets, did any act like a compressed powder charge?

H100

Wrong powder. Do you mean H1000?

 

[Willoughby]

When primers fall out of the pockets on firing, pressure is to high.

To much powder-Scale issue?

Case volume reduced- Tumbling media let in case, then loaded?

When seating the bullets, did any act like a compressed powder charge?


Wrong powder. Do you mean H1000?

yes

 

[Willoughby]

cci lr primers , brass wet tumbled in stainless media ,cleaned inside and out - I pulled down the rest of the rounds in the ladder test and inspected inside of cases they are very clean cant feel any ring with bent wire then I weighed each one and every one weighed what was written on case , measured firing pin protrusion , it was .051 I adjusted it to .040
I reloaded my ladder test and Im going to try it again -I just cant figure out how I had 3 HOT loads at the bottom of a ladder test ! and that's what it had to be looking at the case with the ejector witness mark well at least the gas ports worked thank GOD

 

[243winxb]

Check case weight or internal volume, blown vs ok empty brass.

A case with less volume & heavier may produce high pressure.

 

[Willoughby]

I had a thought but it dont hold water, I was also loading 3006 that day with H4350 and for a 270 it is exactly 10 grains less powder min to max - but if I had a senior moment and done this horror , why did the rest of the rounds fire ok with no pressure signs ?-total was over 50 as I was working with 2 different 270;s that day at the range all fed from the same ammo box loaded at same time , like I said it dont hold water . I meticulously label all loads date= powder -bullet , and when doing ladder test each case is marked with charge weight , Im out of ideas , this a 1st for me , never had a issue with my hand loads till now . I am dumping the powder in cases and bottle and starting over -only idea I have at the moment

 

[243winxb]

use a rcbs 1500 electronic powder measure on all the rounds

Could some clumps of H4350 remained in the measure when changing over to H1000?

Interesting.

 

[Willoughby]

as I was using the charge-master today when I changed powders I tipped it as I normally do to remove all powder - then I decided to hold it vertical and low and behold 3-4 grains worth was hiding in the tube - -
this may have been the culprit -I've read mixing powders can cause severe pressure spikes -going forward I will run dispense and hold the charge-master completely vertical to clear tube in the future , thanks for all the help guys

 

[Uncle Ed]

Buy some canned air and a long handled 1/2 inch paint brush and you will not need to tilt or turn your chargemaster upside down. Use the brush to clean off the sides and bottom of the storage hopper. And the canned air to blow out the feed tube and any remaining powder in the base. I also use the paint brush to tap on the hopper and shake any sticking powder loose.

 

[Old Navy]

Buy some canned air and a long handled 1/2 inch paint brush and you will not need to tilt or turn your chargemaster upside down. Use the brush to clean off the sides and bottom of the storage hopper. And the canned air to blow out the feed tube and any remaining powder in the base. I also use the paint brush to tap on the hopper and shake any sticking powder loose.

I use the canned air also. I drilled a hole in my bench and built a little platform underneath to set the powder container on. On top is a funnel with a short piece of hose that extends into the powder container. I never more the scale.

 

[Iowa Fox]

Just to be sure, you're using H1000 correct?

 

[Willoughby]

Just to be sure, you're using H1000 correct?

yes sir , that's what I had on hand , and it has the lowest pressure with good velocity but some loads are compressed

 

[Bill Rodolph]

Couple of cases too long?

 

[gman47564]

yes sir , that's what I had on hand , and it has the lowest pressure with good velocity but some loads are compressed

Willoughby you say but some loads are compressed.. is that some loads with the same powder charge are compressed and some aren't?

 

[MagnumManiac]

There is a common phenomenon with once fired brass...The pressure at, or near max changes as the brass is not expanding like once fired cushioning the pressure peak.
Therefore, the max tolerated load LOWERS.
This does not happen with EVERY load or cartridge but certain bullets/powder combos.
Have had this happen myself.

Cheers.

 

[JMayo]

Jammed bullets cause spike in pressure.
High neck tension on some and not others cause different pressures.

Why run so close to max when your not competing ?

 

[bozo699]

I use the canned air also. I drilled a hole in my bench and built a little platform underneath to set the powder container on. On top is a funnel with a short piece of hose that extends into the powder container. I never more the scale.

Frank,
Is it possible for you to post a picture of this please.
Wayne

 

[NorCalMikie]

Head space too short (brass) and when the round was fired, primer tried to back out then got pushed back into the pocket by the bolt face?

Why run so close to max when your not competing ?

Keep it as simple as you can.