Author Topic: Uh oh....did I mess up my Contender? (Read 952 times)

Kivaari · « **on:** September 28, 2005, 11:53:30 AM »

Shot my contender at the range today testing some reloads and it started "opening up", the action that is, spitting the case at me. In other words, it's not staying locked up...

What's up?

karbo · « **Reply #1 on:** September 28, 2005, 12:10:23 PM »

It sounds like the locking lugs on the barrel aren't fully engaging the frame. I thought the design wouldn't allow the hammer to be cocked if the lugs didn't engage. At least it does on the G2. Use a marker on the tops of the lugs and open and close the frame a bunch of times. You should be able to see how much engagement there is based on where the marker gets rubbed off. If there's a problem, the safest bet would be to take it to a gunsmith or contact TC.

KN · « **Reply #2 on:** September 28, 2005, 12:14:56 PM »

What caliber and what hand load? KN

Kivaari · « **Reply #3 on:** September 28, 2005, 02:32:04 PM »

It's a 7-30 Waters using neck turned .375 Win cases with 34.6 grains of Varget at 2.815 OAL, 130 grain Sierra flat base, GM210M primer.

Using a chronograph today, at 33.5 grains the mean velocity was about 2180. At 34 grains, the mean velocity increased about 50 fps. Going to 34.3 and 34.6 the velocity change was only 30 fps or so respectively. I figure its a maximum load, but safe. At 34.3 grains the groups started going wild like something was loose somewhere so I stopped after 2-3 round of 34.6 grains. I also noticed my handguard had loosened a tad as well.

Steve P · « **Reply #4 on:** September 28, 2005, 03:48:02 PM »

Do you have an older frame, or a new G2?
If older frame, take off the barrel, and look from the top down. Do the sides of the frame look wavy or are they perfectly straight?

Locking lugs are not locking all the way. Several things can cause this: lugs that do not match your frame, sticking lugs, and stretched frame.

Stretched frame can be checked per paragraph 1 above. As the frame starts to stretch, you can see movement in the metal.

If you can move the locking lugs with your fingers and them move back, likely they are not too sticky.

I like to check the fit of my lugs by using a colored grease. The tetra gun grease is white, gorilla grease is purple, Hoppe grease is black. Open the action, put a little grease on the top surface of the locking lugs, close the action until you hear it click, then open it again. The grease should be pushed back nearly to the back of the half circle. The top of the locking lugs are surfaced (3 degrees i think) and come in different thicknesses due to the machining process at TC. Your barrel may work on one gun, and not on another. If you have just the tips clean, or grease moved back less than half way to the tip of that half circle, then your locking lugs are not locking all the way.

Greasing the lugs can help them to work better. open and close the gun a few times. Trying the barrel on a different frame may work. I have lots of my barrels id'd with nail polish on barrel lug. last 4 numbers of serial number from frame. That way they go on correct frame each time. If barrel locking lugs don't close all the way, and different frame wont resolve, I would send back to TC and have them match locking lugs to your frame.

Good Luck,

Steve

poule d'eau · « **Reply #5 on:** September 28, 2005, 05:40:53 PM »

Steve I have to disagree with your thoughts on grease on the locking lugs. Have seen that throw folks fits for years. I learned my lesson when the "moly" was the do all lube of the future. Put that stuff on everything, lugs included. It would auto eject every other round at least. :?

HL · « **Reply #6 on:** September 29, 2005, 07:20:34 AM »

I had this happen to me with my 6mm-223 and with my 222mag imp.

The cause was not have sufficient lock up. This occurred during fire forming and was caused by the bullets being too far in to the lands causing the base of the brass to not go fully in to the chamber. I looks completely closed but it in fact was not.

I never had brass to fly back at me. But I had the action open up several times.

Since I found the problem, I have had no more occurrences of this happening.

It may also be, if you are forming the cases, the shoulder may not be bumped back enough. Just a thought.

Steve P · « **Reply #7 on:** October 06, 2005, 07:33:54 PM »

Quote from: poule d'eau

Steve I have to disagree with your thoughts on grease on the locking lugs. Have seen that throw folks fits for years. I learned my lesson when the "moly" was the do all lube of the future. Put that stuff on everything, lugs included. It would auto eject every other round at least. :?

I am sorry you have had problems, or have heard of others having problems. It is likely something else with the gun. My experience with locking lugs came first hand from TC rep, I think his name is Ken French, and from Jim Henry, one of the few experts on TCs. I have spent hours watching Jim take TCs apart, repair them, and put them back together.

I have 6 frames and more barrels than I care to count. I have had a gun open once on me, and that was due to my improperly sizing the brass and being stubborn (and stupid) enough to try to fire it anyway. All of my barrels see use (I think around 3000 rounds thru TCs this year so far) and all have the lugs and frame properly lubed.

Steve