Don't know why it's still over pressure!?

[Iceman]

Just couldn't work it out why my reload is still showing over pressure signs when shooting through SA Loaded in 9mm. I know we discussed some of this before but now I have downloaded to 3.7 grain of W231 with 131 grain SWC Lead but still have flattened primers. It's faar from max load and I shot someone else's ammo which worked fine in a Colt Series 70 but shot thru my Sa, the primer flattened again. Could WSP be too soft?

[AZ COLLECTOR]

would try a few other primer brands. is the primer loose to start with?

very light loads will sometimes produce the flatened primer. is the primer flowing into the firing pin hole?

are you using the right size bullets?

bore condition of firearm?

any other high pressure signs?

does the ammo do the same in another pistol?

how old is the brass?

not assuming you don't know all these things just a short and by no means complete check list. lord knows i have forgoten to check the little things every once in a while.

sean

[stans]

I find it hard to believe that it is an over pressure load. I shoot 4.6 grains of W-231 under a Remington 115 JHP ignited by WSP primers and I am still under max pressure.

[Iceman]

would try a few other primer brands. is the primer loose to start with?

very light loads will sometimes produce the flatened primer. is the primer flowing into the firing pin hole?

are you using the right size bullets?

bore condition of firearm?

any other high pressure signs?

does the ammo do the same in another pistol?

how old is the brass?

not assuming you don't know all these things just a short and by no means complete check list. lord knows i have forgoten to check the little things every once in a while.

sean

This is why I am so puzzled by this as the brass are new or once fired from the factory ammo I bought...

Firearm also new, probably 400 rounds fired...and I assume the bore is in quite good condition since I also clean it every 50-100 rounds.

The primer wasn't loose and didn't go back into the firing pin hole. The diameter is the new standard 9mm of 0.356". I might take a few and measure them by the venier caliper again and see if I can get a good average. These are coated and may be that's why...because I did find that the weight on the box says 128 grain but actually average 131 grain...

I just gave 50 rounds to another fellow club member and guess we will see how it goes next Sunday.

This is so confusing... :confused:

[Recon]

I can't help but wonder if the bearing surface on your SWC bullets is to close to the riflings or if the bullet is being pushed into the case during feeding. Either condition might result in higher pressures even if your using a "light" load.

What OAL are you using? Can you get the same high pressure results with other bullets in that weight?

[Iceman]

I can't help but wonder if the bearing surface on your SWC bullets is to close to the riflings or if the bullet is being pushed into the case during feeding. Either condition might result in higher pressures even if your using a "light" load.

What OAL are you using? Can you get the same high pressure results with other bullets in that weight?

Ok, just did a few experiment.

First, mesured all projectiles, they seems to be pretty uniform at 0.356".

Second, did the feeding the seating experiment. The projectiles after feeding doesn't seem to exihibit rifling cut nor did the OAl shortened, 2 out of 3 shortened by 0.002" which I think it's normal? However, those two also exihibit a scuffing mark from the feeding process where the third did not have a mark on the projectile and the OAL did not change.

I has another load with 125 grain conical and 4 grains of W231 and it also showed pressure signs on the primer.

[Recon]

Iceman:

I share your frustration. I use WSP and 231 all the time with a 125 TC without any problem.

Wish I had something else to suggest. Hope you get it figured out.

[Iceman]

UPDATE!

I think the new batch of WSP's are definitely softer than normal...I load up another batch with 3.5 grain now with some using an older WSp batch (silver ones instead of the new brass colour ones). You can definitely tell when you sit the primer that the silver ones sit firmer and harder where as the new ones sit easier and feels soft.

Range time tomorrow and will keep you posted.

[Iceman]

OK, had a great day at the range today. came first in centre fire pin comp! Hehehe...;f

But have a look at the pic, that's what I am talking about. Two batch of primers, same gun and the primer different after shooting. It seem the load is a lot better now. Do you think the primer still flatten a bit indicating over pressure? Someone from the club also commented that the firepin strike is a bit shallow/light, what do you guys reccon?

Thanks guys! :cool:

http://i4.ebayimg.com/02/i/03/39/44/60_1_sbl.JPG

[Recon]

Iceman:

One of my reloading manuals has a feature about pressure. In the article they use a pressure gun to measure the pressure and then take pictures of the primer as pressure was increased. Surprisingly, they were able to greatly exceed SAAMI pressure limits without the primer indicating anything other than normal.

Personally, the picture of the new WSP doesn't look like a concern. If the space around the primer and the pocket was filled in more I would agree the pressure might be high.

[Iceman]

Iceman:

One of my reloading manuals has a feature about pressure. In the article they use a pressure gun to measure the pressure and then take pictures of the primer as pressure was increased. Surprisingly, they were able to greatly exceed SAAMI pressure limits without the primer indicating anything other than normal.

Personally, the picture of the new WSP doesn't look like a concern. If the space around the primer and the pocket was filled in more I would agree the pressure might be high.

Thanks...

http://i2.ebayimg.com/03/i/03/3c/76/66_1_sbl.JPG

The one one the left was yesterday and the one on the right was from last week with 3.7grains and obviously the ones with 4.0 grains just fill the whole pocket.

I think it's probably the combination of projectile and seating depth that make this load has a higher pressure level compare with similar projectile with much more powder.

I think I am going to reduce the powder a bit further then it should be a very sweet subsonic load with lower recoil and accurate for up to 25m.

[brickeyee]

What do you think you are seeing? Neither of the primers in the picture looks flattened. The outside curve of the primer is still intact. Primers are soft, and they do change shape slightly after firing. The tool marks on the breechface arounf the fring pin hole are embossed into the metal (can be used to ID a gun). Primers are not a good indicator of high pressure due to variation between manufacturers, and the fact that by the time they do show signs in some firearms the pressure is way to high.

[Iceman]

What do you think you are seeing? Neither of the primers in the picture looks flattened. The outside curve of the primer is still intact. Primers are soft, and they do change shape slightly after firing. The tool marks on the breechface arounf the fring pin hole are embossed into the metal (can be used to ID a gun). Primers are not a good indicator of high pressure due to variation between manufacturers, and the fact that by the time they do show signs in some firearms the pressure is way to high.

So you think my latest batch of ammo is ok? Still need to dig out the chrono...

[brickeyee]

If you have a chrono run it over that and forget about 'reading' primers.

[Nathan]

I wouldn't consider either of those primers overly pressured. Both look ok. The flatter one looks about right.

[Iceman]

I wouldn't consider either of those primers overly pressured. Both look ok. The flatter one looks about right.

Cool...thanks... :) Feels much better, at leat not fearing of KB's anymore! :p

[AZ COLLECTOR]

what to look for would be if the primer started to flow into the firing pin hole.
that is almost a sure sign of pressure....unless you own a GLOCK lol they almost always do that. thinking its a geometry issue with glocks.
sean

[Iceman]

what to look for would be if the primer started to flow into the firing pin hole.
that is almost a sure sign of pressure....unless you own a GLOCK lol they almost always do that. thinking its a geometry issue with glocks.
sean

Hehehe...I also have a Glock and yes, they seem to always do that, I think it's the combination of retangular firepin hole and the firepin that's causing that. But then again, Glock always requires hotter loads to cycle the slide and they seem to fire anything you put in it...hehehe :D

[brickeyee]

A weak firing pin rebound spring will allow the primer to flatten out the indent, or an action that fails to keep the firing pin filling the dimple during peak pressure.

[Iceman]

A weak firing pin rebound spring will allow the primer to flatten out the indent, or an action that fails to keep the firing pin filling the dimple during peak pressure.

Thanks for that...

How to check and remedy the problem if any?

[TriumphGT6]

Those two in your pic look just fine to me. You want to see what overpressure looks like? Go check out the "Man, I've never done that before" thread in this same forum.... ;)

[neolithic hunter]

i see no pressue problems with this brass. the primer is not flattened at all, you don't even have enough pressure for the primer to flow into the machining marks on the face of the slide. how did you decide that there was a pressure problem to begin with? :cool: