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Cases rupturing when firing Matchguns MG2
Posted: Thu May 25, 2006 7:48 am
by Matchguns MG2-owner
Hi.
I have a another problem with the MG2: case-rupture at firing.
I have had this bad experience with all different brands of ammo in my MG2, and it is discomforting.
Some brands of ammo rupture more often than others. Geco pistol (green bok) ruptured most often.
At an average rupturing occurs about once in 50 to 100 rounds with the best ammo, once in about 10 to 20 rounds with the Geco ammo.
The chamber is neither very tight nor very sloopy. The case is rupturing at the extractor-recess cut into the chamber. Cases that do not rupture show a marked bulge of brass formed by the extractor recess at firing.
When a case ruptures, some gas is directed into the action, not only out of the gun to the right as could be expected.
Because of the loss of gass pressure when a case ruptures, action will often not cycle fully, and a jam occurs.
The breech-faces of my MG2 are kept reasonably klean, and I am very worried by the case rupturings.
(I have experiences ruptured cases by other pistols, but very, very seldom did that occur. Less than once in 10.000 rounds, I think).
I wish to learm from experiences of other troubled MG2-users of this forum.
Thanks
MG-2 Case Rupturing
Posted: Thu May 25, 2006 8:43 am
by Ernie Rodriguez
What you are experiencing is very well known to my MG-2.I suspect it occurs in shells that have a thinner base thickness.I solved the problem by using a brand that does not produce a pronounced bulge upon firing.In my pistol-CCI and S&K Pistol match work fine.There are others also.Federal 711b ruptures frequently. The bulge/rupturing comes from the unsupported area of the shell combined with a thinner shell construction in that area.Once you find the brand that minimizes this bulge the pistol should work fine.Hope this helps.Ernie
Posted: Thu May 25, 2006 12:12 pm
by Gort
I am also a MG2 owner, and that problem you describe is most likely caused by the cartridge is not fully chambered when the primer is struck and it is fireing slightly out of battery. Make shure that the chamber is clean and that the brand of ammunition that you choose drops fully into the chamber with no resistance. I think you will find that the breech is 1 or 2mm's from home when the round was fired. This problem is not unique to the MG2, many match chambers in an auto loaders with light slides and ammo brands on the large side of tolorance can produce this condition.
Gort
Re: Cases rupturing when firing Matchguns MG2
Posted: Thu May 25, 2006 8:21 pm
by Fred Mannis
Matchguns MG2-owner wrote: The case is rupturing at the extractor-recess cut into the chamber.
I am not an MG-2 owner and have never even seen one. But it sounds like a bad design to have the extractor groove actually cut into the chamber wall, so there is no support for the cartridge case at this point.
Re: Cases rupturing when firing Matchguns MG2
Posted: Fri May 26, 2006 4:35 am
by Matchguns MG2-owner
Fred Mannis wrote: . . . it sounds like a bad design to have the extractor groove actually cut into the chamber wall, so there is no support for the cartridge case at this point.
Well, yes. Depends on how large the groove cut into the chamber is. I have never seen any other match .22 with a groove cut this big.
And to "Gort": No, the cartridges are entering the chamber fully. The chamber is not very tight. The extractor groove cut into the chamber is surprisingly large.
Have you not had any case ruptures, Gort? How many rounds have your MG2 digested? Which ammo do you use?
And Mr. Rodrigez: I have had some ruptures of CCi "Standard" (blue/hvite box) of current production too. This is the ammo I would like to use for the bulk of my practise, du to the moderate cost.
And save less powerful and more expensive match ammo for serious target use. Regrettably, my MG2 was never able to cycle reliably with target-powered ammo. Neither is any of the MG2s that I know of in this country.
MG-2 Case Rupturing Issue
Posted: Fri May 26, 2006 6:59 am
by Ernie Rodriguez
Fred hit the nail on the head-the extractor groove is too wide and deep into the bbl chamber.IF Matchgun company is listening and responsive to customer input-a solution to this issue is to narrow the width of extractor as well as the extractor groove in the bbl.This would allow the MG-2 to use a wider variety of STD vel ammo and reduce the problem of rupturing of shells-as well as making the pistol more reliable.
Posted: Fri May 26, 2006 9:13 am
by Gort
I had one case rupture early on withh CCI standard, the cartrigde was clearly not fully seated. I have shot Lapua pistpl match, the lub was too waxy for the MG2, the rounds not chambering fully reliably. Win T22, Fed 711, Wolf match and SK. SK Proved to be the best in my MG2, the oily lub that SK uses has been very reliable in my MG2, I am into the second case of SK.
Gort
Posted: Fri May 26, 2006 2:36 pm
by Mark Briggs
Gort - just one quick note with respect to SK. We can't get it here in Canada, but we get the same thing in a different package, called Lapua Standard Club. This is indeed very oily. I enjoy shooting this stuff and it works well in the MG-2. EXCEPT in extremely warm temperatures (approaching 100F). Last fall I had an allowable malfunction in an international rapidfire match with this ammo, and not willing to take the risk of another malfunction, switched back to Eley to complete the match.
Not sure if this same problem has been encountered by others, but it is something to keep an eye out for.
(By the same token, my MG-2 eats everything you put in it, from cheapo Winchester Wildcat right up through to Tenex.)
Posted: Fri May 26, 2006 5:26 pm
by Fred
Mark Briggs wrote: with respect to SK. We can't get it here in Canada, but we get the same thing in a different package, called Lapua Standard Club. This is indeed very oily.
If the Lapua Standard Club you mention is the variety that comes in tins instead of boxes, supposedly it is the only Lapua/SK variety that has that "very oily" lube. Since it is apparently not available in the US (I've been unsuccessfully looking for it to try), I don't know for sure, but the lube on all the other varieties of Lapua/SK that I have seen is pretty normal looking. It's certainly more like a light grease than like the wax on CCI for example, but it would be a stretch to call it oily.
FredB
Case head blow out
Posted: Sun May 28, 2006 7:39 am
by PASA008
Not familiar with your gun, but what you describe could also be caused by excessive head space, or too weak a recoil spring. I assume this is a "blow-back" operated action. If the spring is too weak it will cause the action to open too soon and bulge the case head. If the head space is not mating up properly it will have too much space and cause the same thing.
MG-2 Issue
Posted: Sun May 28, 2006 8:01 am
by Ernie Rodriguez
According to Match Gun company-the issue of extractor,extractor groove/bbl/occasional rupture has been addressed and solved and has been incorporated into their production run for some time now.This should make the MG-2 even more reliable.Ernie
Re: MG-2 Issue
Posted: Sun May 28, 2006 4:28 pm
by MG2-owner too
Ernie Rodriguez wrote:According to Match Gun company-the issue of extractor,extractor groove/bbl/occasional rupture has been addressed and solved and has been incorporated into their production run for some time now.This should make the MG-2 even more reliable.Ernie
Hear that now! Where did you get that info, Ernie?
So the company has finaly admitted there was a problem? After two years of complains from customers. the response to the complans has been total silence from MatchGuns. They have continued spewing out useless guns to the customers, despite their knowledge of the engineering flaws?!
The faulty guns ought to be RECALLED! They are potentially unsafe in use, because shrapnel from blown cartridge cases can hurt bystanders.
Now I will take steps to force the MatchGuns company to replace my gun with a usable one, or return my money.
The importer keeps telling me the problem with my gun is related to the way I use my gun, and has until recently not been listening much to my complaints. (!)
MG-2 Issues
Posted: Sun May 28, 2006 6:29 pm
by Ernie Rodriguez
I am afraid I have mis-quoted something that I heard. You need to contact your dealer for more accurate information. I am sorry for any misunderstanding. I meant no harm. Ernie.
Posted: Sun May 28, 2006 11:33 pm
by Fred Mannis
Fred wrote:Mark Briggs wrote: with respect to SK. We can't get it here in Canada, but we get the same thing in a different package, called Lapua Standard Club. This is indeed very oily.
If the Lapua Standard Club you mention is the variety that comes in tins instead of boxes, supposedly it is the only Lapua/SK variety that has that "very oily" lube. Since it is apparently not available in the US (I've been unsuccessfully looking for it to try), I don't know for sure, but the lube on all the other varieties of Lapua/SK that I have seen is pretty normal looking. It's certainly more like a light grease than like the wax on CCI for example, but it would be a stretch to call it oily.
FredB
FredB - At the range today I saw a box of SK Jagd labelled 'Standard Plus'. It caught my attention becasue it was also labelled (in small letters) Lapua. You can find it at Champions choice for $5/box. I have just started using the SK Pistol Match, which differs from the Match and Rifle Match in that it uses a slightly faster burning powder better suited for pistols. It does not appear to be heavily lubricated.
FredM
Posted: Mon May 29, 2006 4:17 pm
by Fred
Fred Mannis wrote:
FredB - At the range today I saw a box of SK Jagd labelled 'Standard Plus'. It caught my attention becasue it was also labelled (in small letters) Lapua. You can find it at Champions choice for $5/box. I have just started using the SK Pistol Match, which differs from the Match and Rifle Match in that it uses a slightly faster burning powder better suited for pistols. It does not appear to be heavily lubricated.
FredM
FredM,
Thanks for the info. In fact I recently bought a case of SK Standard Plus, which is exactly the same thing as Wolf Match Target - it's good stuff for the price (usually much less than $5/box). However SK Standard Plus is not the same thing as Lapua Standard Club (I don't know which, if any, Lapua variety is equivalent to SK Standard Plus). While the SK, Lapua and Wolf variety names are very confusing, it seems pretty clear that the Lapua Standard Club comes in a tin, not a box, and I believe I've been told it is a tin of 500. Nobody in the US seems to carry it. Champion Shooters in Ohio used to stock it, but no longer does. I've been looking because I've been told that it might be the one ammo that could get my FAS 607 functioning reliably. Kind of the holy grail of FASdom? So far no luck.
Regards,
FredB