454 casull squib question

[xkon]

Question for you guys. I recently purchased a SRH in 454 and loaded up some ammunition for it.

240gr Hornady XTP/MAG
28.2 gr AA 9
CCI 450 Small Rifle Mag primers
1.745" OAL

I checked a few manuals and this is a mid range load for this powder and bullet weight. The issue was, I fired one round and heard the dreaded pop with no recoil and instantly stopped firing to check it out. I opened the cylinder. The bullet went just into the forcing cone and throat of the barrel, almost flush as I was able to open up the cylinder. The powder was still in the case and most poured out and some looked very very partially burnt in a clump as it was a goldish color instead of the dark color of the AA9. And the primer, instead of flattening out, seemed to flow or bubble a bit instead.

What are your opinions on what happened here? I don't believe it was undercharged or no powder, clearly as powder was still in the case, and I hand weighed each charge several times for all my 454 loads. Could this have been a case of a defective primer?

 

[243winxb]

neck tension

Not enough neck tension. The primer moved the bullet before enough pressure was made to burn the powder correctly. Make sure the sizing die is doing its job correctly. Check the expander, should be .004" smaller than bullet diameter. On seating a bullet, the case should expand .002" or more. Try different brass if you think the case walls are thin. Maybe a different mag primer, or different powder?

 

[rcmodel]

Could this have been a case of a defective primer?

No.

If the primer ignited at all, it ignited.

For some reason, you failed to get enough initial bullet pull for full ignition of the powder to happen before the bullet left the case and the pressure leaked out the barrel / cylinder gap.

Without a chance for full chamber pressure to build up, the fire went out.

Insufficient case neck tension, and insufficient roll crimp are the usual suspects.

rc

 

[xkon]

Here are pictures of the fired case along with one of my reloads next to a round of underwood.


My reload is the one closest to the fired case in each picture, the Underwood being farther away. The crimp on mine seems tighter than the underwood. Or would you suggest crimping even tighter?

 

[243winxb]

Crimp again? Noooooooooooooo. Been covered a lot. Read this-http://www.thehighroad.org/showthread.php?t=469815&highlight=crimp+walkalong
Good Luck.

 

[xkon]

Will read through that thread now. After looking at the pictures would you still say that the squib was due to an insufficient crimp still tho?

 

[rcmodel]

Well, it looks crimped enough.

How was neck tension before you crimped it??

The only other thing I can think of is the powder got contaminated with excess case lube, or something.

rc

 

[243winxb]

If AA 9 powder is anything like Win 296 , near maximum loads are needed to keep from having squibs. I have not uses AA 9.

 

[56hawk]

CCI primers are notorious for doing this in the 500 S&W. Had it happen once with my 500 and H110 powder. Went back to Federal primers and that fixed that problem. I am using the same CCI primer as you in 454 though. Haven't had any problems with them yet, but I load to the max and use a very heavy crimp.

 

[243winxb]

AA 9 - 454 Casull - 240 gr Jacketed bullets

Accurate load data on there website shows starting 28.8 gr to 32.0 Max. Try increasing the powder charge. http://www.accuratepowder.com/wp-content/uploads/2011/01/accurate_load_data_3.5.pdf

 

[ngnrd]

I'm pretty new at this. But, since the powder was unburned, is it possible that there is a problem with the flash hole, either not opened up properly from the factory (new brass), or possibly plugged by tumbling media (used brass)?

 

[xkon]

This is brand new starline brass btw.

As for the load, I referenced Lyman Reloading Handbook 49th ed, Modern reloading 2nd ed, and Accurate Powders Edition 3.4

Lyman's had a load using the same 240gr XTP/Mag bullet. AA9, starting 27.5gr to max of 29.0gr. 1.745" OAL

Modern Handloading has 240gr Jacketed bullet. AA9, starting 25.2 to max of 28.0gr. 1.705" MIN OAL

Accurate Powders did not have a 240gr however had a 250gr XTP listing. Starting 25.2gr to max of 28.0gr

----


With this data, I felt 28.2gr would be sufficient for a starting load, not close to a starting load. With the link you provided, it seems Accurate has updated their manual with edition 3.5 now and list a 240gr. However their info is much different then the other manuals I have with a starting load of over max loads on my manuals

 

[rcmodel]

Thats the problem with Accurate powder.

It has been made in five different country's over the years.

What was right 10 years ago can't be trusted with what is right today, because the powder has changed manufactures and specs a couple of times since then.

And thats the reason I don't use Accurate powder.

rc

 

[xkon]

Also, if this load was undercharged, wouldnt the powder have still burnt instead of clumping and dumping out of the case. It looked like all the powder had remained in the case. I feel like the powder would have still burnt and sent the bullet farther into the barrel instead of just the throat.

 

[243winxb]

Thats the problem with Accurate powder

+1 Xkon, coatings on powder used to control burning rate & help flow, can make powder hard to ignite. Had H450 in 22-250 with mag primers, do the same thing. I would never use H380 or H450 (discontinued) ever again.

if this load was undercharged, wouldnt the powder have still burnt instead of clumping and dumping out of the case.

This goes back to "neck tension"

 

[Edarnold]

The appearance of the fired primer suggests you got a dud that had very little effective compound. If the the primer pocket flash-hole had been obstructed enough to cause this misfire, the primer would have been much more flattened. Weak primer + heavily coated powder = misfire. The way to determine the cause is to fire some more of this batch. Take along a sturdy cleaning rod and a mallet...

IMHO

 

[gamestalker]

Was the squib in fact the first shot you fired? If not, it is very likely that too light a crimp on that round, allowed the recoil from the previous round or rounds fired, to cause the bullet to partially dislodge, or in fact completely jump out. If this was what happened, it would almost deffinitely cause a squib.

I've seen this happen before at the range on other revolvers that produce high recoil. It's actually not all that unusual if the crimp isn't firm enough to hold bullets in the mouths of rounds that are making their way into battery.

GS

 

[xkon]

This was the very first shot, so I can't reference any other rounds until I take it back out and try it again with that load(did not have a brass hammer and rod with me at the range.)

As for the powder load being too light, accurate uses a cci 400 with loads, so i would have assumed a 450 (SRM) would be sufficient, even if this was a "light" load compared to their new manual.

Also I called AA about the new manual and the drastic change in powder charges, and they were not too informative.

 

[243winxb]

Try it again. Did you size the brass before loading?

 

[xkon]

Will be trying again as soon as I get a chance. Yes all the brass was sized. I also compared the outside diameter of the case neck of both my rounds to the underwood and the manuals and they were all in spec