gas blow back on Lapua 22-250 brass

D

DaveT

Member
I am shooting Lapua brass in my 22-250. I fired this brass in a club match today and experienced gas blow back on the neck and all the way down the case body. This is the 3rd firing of this brass and it has not been full sized yet and I have never had this problem with this gun before. Before anyone wants to say your load is not sealing in the chamber and load isn't hot enough to get good seal, let me say I have fired this same brass with same load, and the load is not a mild load. I am wondering if this new Lapua brass is harder? Is it already hardened after only 3 firings? Anyone had this problem with 22-250 Lapua brass? Any help would be greatly appreciated.
Dave T
 
Dave,
I'm curious to see what answers come in on this one as I have a box of Lapua .22-250 brass that I have not shot yet. This brass gets fireformed in a .22-250 A.I. chamber when I need it. I have used Remington brass and Norma brass in this chamber and never experienced what you are describing.
 
Before anyone wants to say your load is not sealing in the chamber and load isn't hot enough to get good seal, let me say I have fired this same brass with same load, and the load is not a mild load.
Click to expand...

You are most likely pushing the shoulders and obviously sizing the necks. You may also be FL resizing without knowing it. It doesn't take much.

The brass is thick, thicker than other brands in the body. That contributes to the seal. But, you not annealing the neck and shoulder is why you're having the trouble. As to not saying the load isn't sealing, well, you have blow by, I'd think that's pretty obvious then eh?

On the "Same Brass" statement, that also is wrong. You fired with no (or little and unnoticeable) problem with NEW brass. This isn't new brass any more, it's different. It changes every firing unless you have a perfect fit chamber. That is most likely not the case.

IFFF it sealed, your load would probably be fine. When it does not, it is not hot enough. But the cure isn't to add powder. You could change burn rates. You could buy a different brand of brass. You can anneal the ones you have every firing. You can use longer, heavier bullets. There's lots of stuff you can do. Bottom line is, the brass is rebounding, and your load leaks. Soon, you'll have crushed shoulders.
 
chino69,
I had this exact same problem with a Sako factory 6PPC varmint gun, blow back. I found the problem had to be brass becoming hardened from several firings because when I tried new brass the problem went away, but this took 5-6 firings. These Lapua 22-250 cases are doing this on the 3rd firing and this gun has never done this with Remington, Winchester or Federal brass. If it is because the brass has become to hard after just 3 firings to get a good seal, then as far as I'm concerned this brass isn't what it's hyped up to be and costly, but I will try other things. Oh one other point, I tried new Lapua (cardboard box) in the above Sako 6PPC and had blow back problems on first firing after I blew out the necks and now this brass is no good to me, another costly deal.
Dave T
 
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4Mesh,
Please take a moment a read my post again? I wrote, this is 3rd firing and this brass HAS NOT been full length sized yet and necks are sized in Wilson hand dies.
 
Having owned a 22-250 or two, and swifts, I can tell you that if you are not required to FL resize by the third firing, the load is too light, or powder too slow, or case sized improperly. If these do not fill the chamber after the first firing, you have a problem. If the brass is too thick, you can't fireform it properly in one firing. It almost has to be annealed.

As to Lapua brass being the be-all-end-all of brass. Personally, I think it's great marketing and that's about it. I've had as much trouble, or more, with that crap than any other brand. I hate it. And I'm not interested in paying a premium for more of it. Jmo...

In any case, please take a look at MY post, and anneal the shoulder on 5 pieces. Then see if the problem does not go away. Anneal the shoulder, not the neck. The neck is so thin it will get plenty soft just from conducted heat. For that matter, try with ONE case, just your worst one. It'll seal perfectly.
 
Well 4Mesh, not sure about your guns, but my 22-250 can go 2-3 firings and most times I can still just neck size, I don't wimp over a bolt that is a little hard to raise and I know what pressure signs are. All I am asking in this thread is, has anyone had this problem with Lapua 22-250 brass, that's it. Although I am starting to agree with you on the Lapua brass being a little overated.
Dave T
 
Dave,
I have not used Lapua 22-250 brass specifically. I have used Lapua brass, and have some for guns currently, even brand new boxes unopened. I have also had the issues you are talking about, and have seen others have the same issue. I have seen it solved and I have solved it, both for myself and for others. I have spent rather a good bit of time working on cartridge leakage. Like most shooters, I've discovered ways to avoid it and simply don't do the things that cause it anymore. If changing brands of brass for a particular caliber is the solution, I do it. If it were me, I'd be getting Winchester brass for that 22-250 and not looking back. But it's not me...

To answer the question then, no the problem is not uncommon. Well, it's only uncommon for anyone who already had the problem and solved it once.
 
The only times I've ever had cases smoke back to the extractor groove was with powder charges that were too light, and with the discontinued RL-12 powder that in at least one caliber I have smoked the cases back to the extraction groove up to a grain and a half below a max charge. Quit using RL-12 and never had it again that bad. Cases shouldn't be too hard after 3 firings.
 
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