MGM contender barrel lock-up

[45r]

Got a used MGM 357 barrel and it has to be snapped shut hard or it won't hit the FP.Is that something to worry about.Haven't had any barrels other than stock T/C and they lock up easy.The barrel shoots real good.Half inch at 25 yards with holosight and 185GC boolits.

[gandydancer]

doesn't sound right to me if you have to slam it. I have 1 MGM bbl and a few others some custom some factory don't have to slam any of them. I would have it checked out. what is it for? a G2? contender? encore?

[45r]

I have 2 G1 contender frames and it does it with both if I shut it slow.I don't have to slam it but it wants to be snapped shut with a little more snap than my factory barrels.The previous owner said he didn't have any lock up issues with his Gen 1 frame.The quality and accuracy looks good.The EA brown base wasn't installed right,has spacers and a set screw in front probably because they didn't know how to shorten the screws to keep them from bottoming out.Base is bowed and had to put holosight on since rings would bend scope.Got it off E-bay to try MGM without paying top dollar and might have to go through the thing to get it right.At least now I know MGM makes accurate well chambered and throated 357mag barrels.My factory barrel got rechambered to 357max when I seen how bad the throat was.Should have got a MGM barrel.Haven't had much luck getting quality used stuff.OH well,he said it shoots inch and a half at 100 yards with corbon ammo.My rechambered max shoots that good with RE-7 and the 185GC boolits.I'm hoping this barrel can shoot sub loads accurately.It's shorter and lighter than my 12 inch scoped max set-up.

[gandydancer]

I just had a custom 357 match bullberry 21" re-cut to 357 max have not shot it as yet. work was done by M Bellm still don't know why I had it re-cut? I never shot the 357 mag?I know the contender bbl s will fit the G2 frames OK and the G2 bbl's will work on the contender frames but some times not all that well. do you know any one with a G2 frame to try it on?? GD

[stubshaft]

I have eight MGM barrels and none of them have to be snapped shut.

[dk17hmr]

My latest MGM barrel needed to be snapped hard to lock up. I made a slightly smaller hidge pin for it and the problem went away.

[leadman]

Use a marker on the locking lugs, then shut the action a couple of times. Inspect the locking lugs to see how far they extend when locked by the amount of marker removed. If the lugs are not going out very far you can polish them down a little. I like to use emery paper on a stick to use as a backing. Go slow and your problem should go away with a little polishing.

Or you could call MGM and ask for thinner locking lugs than what you have now. I haven't done this but have heard that they will do this.

[uscra112]

This could just be a headspace-too-tight problem. Does it happen with no cartridge in the chamber?

Is the barrel O.D. showing any "spots" that might indicate that it isn't seating in the receiver channel correctly? (A smaller hinge pin might appear to alleviate that problem, but it isn't the best solution by any means.)

Another problem I've had with Gen 1 is the spring on the hammer block slide being weak. If the slide can't clear quickly enough when the trigger breaks, the hamme hit is light or not at all.

I would not go honing on the bolts until you've exhausted all other possibilities.

[leadman]

The locking bolts have been the problem with most of the barrels I have encountered closing problems with. Good place to start checking.
Another area I have had issues with is the clearance, or lack of clearance between the end of the barrel and the breach. This is also easy to check with a look or a feeler gauge. If it is a blued barrel the bluing may be rubbed off. Or use a .001" feeler gauge placed between the barrel and breach, the gauge should slide out easily. Also you can close the action and hold it up to a light to check for clearance.
The proper fitting of your brass is also crucial. This is also checked easily with a feeler gauge. Best way is to remove the extractor as it can hold the brass to the rear. Place a piece of sized brass in the chamber, then hold a .001"feeler gauge on the end of the brass while the action is closed. The feeler gauge should slide out easily, if it doesn't the brass is either too long or the rim recess is not cut deep enough. The rim of most brass I have checked is thinner than SAAMI specs and creates other problems. It is possible for the bullet to hit the rifling and cause this problem also.
I have heard of an aftermarket barrel having a lug with a pin hole slightly off or the lug not the proper height and the barrel hitting the frame along the sides. Hopefully this is not your problem.

Pictures would help.

[45r]

Thanx for the replies,the seller said he'd take the barrel back if I wasn't happy with it so I sent it back and got a refund.He was a real nice guy and said a factory barrel opened up one time on him and the shell hit him in the chest so he understood my concerns.Better for the barrel to go on a frame that fits it better.I wish it fit and the base was installed right,it was super accurate.MGM barrel looked and shot good.I was told that a 300/221 rimmed would make a better sub-sonic barrel using 357 max brass with my dies and still be able to use 300 BLK or 300whisper brass.Might go that route since I have the NOE 247 grain BLK mold and the boolits shoot real good.I think MGM has that chamber available.