Mark III interesting behavior - ammo related(?) Help please.

JeepinCalifornia · Post by **JeepinCalifornia** » Sun Jan 04, 2009 10:20 pm

I took my Mark III (5.5 bull) out for a shoot today and while shooting Blazer, it was doing some odd things. (It was properly cleaned and lubed prior to shooting.)

Before today, the Mark III had 1k rounds through it; and it's had zero problems other than the occasional FTE or miss fire with cheap ammo. (Pre-VQ sear)

The first 200 rounds (of a brick of 500 rounds; ie: a box of ten, 50 round boxes) of Blazer shot fine a week ago. Essentially, the first-four, 50 round boxes, shot great.

Today (shooting it with a VQ sear for the first time) I shot another 200 rounds of the Blazer; I also shot 100 rounds of CCI Standard Velocity. Each of the 50 round boxes of the Blazer I opened today looked different than the boxes I shot last week. The lead and brass looked quite dirty, with chunks of wax throughout. I wiped down 40 rounds with a rag, but those shot the same: an average of 40% of my attempts to pull the trigger (shooting the funky Blazer) resulted in "nothing"...
If/when I had a positive fire, the bolt would cycle the brass, load another round, and when I would pull the trigger nothing happened, the gun did not feel like it had cocked (but it did cycle). I could manually cycle the round (which would come out with some noticeable shave marks half-way down the nose) and the next round would go bang; it would cycle the brass, and the gun would again act like it was not cocked. This was about average for the first 100 rounds I shot today (of the dirty-waxy Blazer).
But then I shot 100 rounds of CCI Standard Velocity without a single problem (so much for it being the same ammo). I then tried another 100 rounds of the Blazer but it did the same fire-no fire thing again (not feeling as if it was even cocked, when the trigger was pulled).
Each of the rounds I manually cycled had the same kind of shaved mark; hitting the feed ramp (gap?) probably...?
Trying the same ammo again (in the magazine) resulted in the same margin of error.

It's weird that the gun did not behave this way last week with the 200 rounds I shot then. But I really do think the 200 rounds I shot today looked a lot dirtier/waxier than what I shot last week. And the 100 rounds that is remaining looks rather nasty too. Is it possible that they changed lots of 50 round boxes while they were filling a bigger box of ten?
I could see a new sear doing weird things, but it shot fine with 100 rounds of CCI...?
I'll try some different ammo, but can this [already] be positively attributed to sear problems?

greener · Post by **greener** » Sun Jan 04, 2009 11:55 pm

Did you change the trigger to a VQ trigger when you put in the VQ sear. In part, it sounds my problems with the pre-travel screw on the trigger walking in and getting too much pretravel. If you did change the trigger, you need to add some blue loctite to the pretravel adjustment screw.

My problems with dirty or highly lubed ammo have usually resulted in the stuff just not feeding. A couple of times, I've had to clean the magazine. Give the pistol and magazine a good cleaning then try some different ammo and see if the problem goes away. CCI SV or the Federal Value pack ammo from Wally World always seem to function well. If you can pin it down to the CCI Blazer, give them a call and tell them you had the problem and the lot number.

I had a problem with Federal Automatch and ended up with a new box of ammo.

Post by **Bullseye** » Mon Jan 05, 2009 6:36 am

I agree with greener, if you installed an adjustable trigger it sounds like your pretravel screw has walked and the disconnector is not engaging the trigger. When this happens, can you push the trigger forward and hear a click sound? That is a sign of the disconnector not engaging the trigger. The trigger will feel as if there is no tension on it and it cannot release the hammer. If you don't have a trigger with a pretravel screw then your disconnector lever is not lifting up properly. This condition can be caused by dirt and grit getting caught behind the lever or by residue build up in the trigger plunger area.

Hope this helps.

R,
Bullseye

DancesWithSquirrels · Post by **DancesWithSquirrels** » Mon Jan 05, 2009 8:10 am

In the original post he said that the CCI SV shot without any problems but the Blazer acted up. This seems to indicate an ammo problem rather than a trigger problem. I am a big fan of the CCI SV myself. I almost went into shock this weekend when I had my first misfire with the CCI SV in over a year.

DWS

JeepinCalifornia · Post by **JeepinCalifornia** » Mon Jan 05, 2009 11:34 am

Thanks for the replies.
She's already clean again; and I'm eager to try some more [different] ammo.

I appreciate all your advice, and though I don't think it will change what you have to say, here's some clarification:
-The trigger is stock; when it was acting up, I could pull it back or push it forward and it simply felt like the trigger normally does when the gun is not cocked.
-When I installed the sear, I broke down the gun far enough to do only that; the stock trigger didn't come out.
-[When this happened] I shot 100 "bad" rounds of Blazer, then shot 100 "flawless" rounds of CCI, then another 100 "bad" rounds of Blazer.
-The behavior does suggest gun issues; but the problem did start, stop, and start again when I changed ammo. Come to think of it though, it did slowly get worse as I kept shooting the Blazer.
-I also just remembered that when I would slingshot the bolt after inserting a fresh magazine of Blazer, I would hear a "click" inside the receiver a half-second after racking the bolt...I did not try to pull the trigger before this sound, and it only did this with the Blazer, but not every time. The gun did fire the first round of each magazine.

Post by **Bullseye** » Mon Jan 05, 2009 5:18 pm

Another possible cause in a stock trigger is the trigger return plunger was clogged with residue. This is the part of the trigger that is exposed to ejected shells and tends to gum up with grit and soot. The return plunger lifts up the disconnector lever and causes it to engage the sear. If the hammer was cocked but the trigger was not connected then the problem was associated with the disconnector, trigger, or the trigger plunger.

R,
Bullseye

greener · Post by **greener** » Mon Jan 05, 2009 5:49 pm

Beginning to sound like dirty ammo problems.

bearandoldman · Post by **bearandoldman** » Mon Jan 05, 2009 8:47 pm

I must have shot up 3 or 4 bricks of that Blazer stuff last summer, I was gettinng it for about 20 bucks a brick before the price went up and I never had a problem Amazingly it shot very in my 10/22T, the first few groups hocke me they looked so good. Shot it in the 22/45's also and it worked well ther also.

JeepinCalifornia · Post by **JeepinCalifornia** » Sun Jan 11, 2009 12:08 am

I got back out to the range today. I shot lots of Federal 550, Federal 525, and Winchester 333. I also brought a 50rd box of the same Blazer I was shooting last time...

One round of the Blazer caused the same "acting like the gun is not cocked" behavior that was happening last time (in the original post), but just the one round of the 50. Through hundreds of rounds (350 or so?), all functioned fairly well for bulk rimfire: only one of those three (a 525 and two 333's) failed to fire after two strikes (the 525 failed the second), and three rounds of Winchester 333's had noses so disfigured I wouldn't even load them in the magazine. They were also the cause of the one jam I had during the shoot.

I also put a Millet red dot on her this week. After a few magazines of 525 to get it dialed in, the groups, even at 25 yards, quickly tightened. It was fun actually having a good sight picture and I quickly saw the key role trigger pull is in the grand scheme of things (in retrospect, considering this new sight picture, it also makes me think I may need to get my eyes checked

). The 525's seemed to shoot the straightest out of my gun - though I confess, the only difference I can see between the 525 and 550's is the copper on the 525's looked dirtier and the 550's seemed to shoot a little tighter. The 525's are a few dollars more a box which reads "Champion".

greener · Post by **greener** » Sun Jan 11, 2009 12:21 am

Sounds like you solved the ammo problem. Try some 40gr SV ammo (federal 510, or fed automatch). Mine have been very consistent with those although they did very well today with the 550 box of Federal and the Winchester 333 round box. I did ok with Win Xpert22, but the groups were a bit bigger.

Sounds like a fun setup with the pistol.

bearandoldman · Post by **bearandoldman** » Sun Jan 11, 2009 7:28 am

A couple not so readily available except by order from Midway USA that have worked very well for me as far as function and accuracy are : Eley Sport and Fiocchi #22CRN also marked LSP. Sorry but in most areas they are not stocked by the big retailers.

Post by **Bullseye** » Sun Jan 11, 2009 8:44 am

Well, perhaps some more rounds through the barrel are helping with the break-in. When you say, "acting like the gun is not cocked," do you mean that the hammer is not cocked or is the trigger not connecting with the sear? If the hammer is not cocking then the bolt may not be cycling all the way rearward. If the trigger is not connecting then the disconnector lever is sticking, or the trigger return plunger is not forcing the disconnector lever upwards properly. Sometimes the trigger can cause this problem if the disconnector pivot pin hole is too tight. Keep shooting it and lets see if the pistol just needs a work out to break-in more.

R,
Bullseye

tenex · Post by **tenex** » Sun Jan 11, 2009 9:00 am

I've had Rugers that were sensitive to ammo length. I believe I had issues with CCI std vel, but the Federal Gold Medal worked ok. I did recently buy a new Mark II that although it functioned correctly, was cutting a big dent in the nose of the bullets (if removed from the chamber after cycling). It also would hang up on loading the first round.

Turn out there was a burr/sharp edge on the very nose of the feed ramp that was catching the longer bullets. I scalloped out the burr and polished the ramp (don't try this at home, I'm not a gunsmith!), and now it works fine. I always thought the dents were from the round feeding high and hitting the top of the chamber.

I think I had this problem with an older gun that always has occasional failures to completely return to battery. I would find light hits & misfires with bullets with the same dent.

Just my experiences,
Steve.