Magnum hunter 44 magnum issues? Update

[7887mm08]

So i recently received this model 629. Cleaned it, looked it over dry fired it for a week every night (with snap caps). Mounted a holosun 507c reflex sight and finally took it to the range.
Shooting 240 gr swc from Lost river ammo.
Now the problem : seems as i fire (in single action mode) the trigger pull weight increases and the drawing back of the hammer gets harder with each shot. If i load up another cylinder full the first 2 shots the trigger pull is fine but each of the last 4 cylinders the trigger pull weight increases.
Any one have any suggestions? I shoot this same ammo in my model 69 with no issues. I plan on shooting some 44 specials this weekend to see if there is any difference.

 

[Tom S.]

If you feel comfortable disassembling it, you might want to take off the slide plate and give it a good cleaning and a light oil. It sounds like you might have some debris left over from manufacturing causing the problem and a good cleaning should take care of things. Also, check for burrs in machined areas. The last couple I took apart had some.

 

[Protocall_Design]

You don't say what ammo you're using. If the bullets are lead, it could be leading up at the forcing cone. This can be caused by an improper forcing cone, too close of a cylinder gap, endshake, etc.

 

[7887mm08]

You don't say what ammo you're using. If the bullets are lead, it could be leading up at the forcing cone. This can be caused by an improper forcing cone, too close of a cylinder gap, endshake, etc.

Yes coated and uncoated lead swc. I did check the cylinder gap and it's between .007" / .008". I'm not versed in checking end shake.
And to Tom S. shouldn't i have seen this problem with all the dry firing i did before hand?
Thanks for reponses.

 

[Yendor357]

Do you have a trigger pull gauge?

This is going to come across as crass, but “it seems” is not a standard unit of measure. Maybe giving us some numbers to work with might help.

Check under the extractor. I used to burn a lot of a certain type of powder called 2400. It wouldn’t burn completely. And once in a while I’d get a chunk of what looked like corn bread mix under the extractor. I used to bring an old toothbrush with me because it happened so often.

 

[7887mm08]

No i don't have a trigger pull gauge, but lets just say that i had a hard time keeping the gun on target to get the last few rounds in each cylinder to fire
This is shooting off sand bags. the trigger pull was harder in single action mode than when i was dry firing in double action mode. im not going to fire the gun with a trigger gauge! This does not happen when dry firing, only live firing.

 

[series guy]

When the trigger pull weight increases with use look at the face of the cylinder. Specifically look for scratch or rub marks in the black fouling on the face of the cylinder. This indicates that the build up on the cylinder face is dragging on the barrel and making the cylinder hard to rotate. Cleaning the cylinder face will be a short term solution. Shooting cleaner ammo (copper plated bullets) or opening up the barrel cylinder gap will usually negate the issue.

 

[s&wchad]

Any difficulty opening the cylinder after firing?
Have a look at the fired case heads/primers and see if looks like they're rubbing on the recoil shield.

You might also try different .44 Mag ammo.

 

[Nightowl]

With a .007-.008 B/C gap, you should not have a problem there, so that increases the probability of the back of the cylinder causing the issue. After cleaning under the extractor, check to see if the cylinder rotates freely, if so, insert some empty clean cases in the chambers. Do they seat all the way? Does the cylinder rotate freely? If so, then the ammo may be the problem. At the range, when the cylinder gets hard to turn, open it, remove cartridges, and clean under the extractor, reinsert and check to see if it fires normally.

Also, get a box of Federal or Winchester jacketed ammo and see if that hangs up.

You did not mention if this was a new or older model 629.

 

[Protocall_Design]

If it runs fine when dry firing, it's the ammo, not the gun. Something about the ammo is causing a problem. Try a box of jacketed ammo and see if it does the same.

There is one caveat about not being the gun. If the forcing cone is not done correctly, or if it's out of time, it could be the gun. At .007 to .008 cylinder gap, that's not it. A .006 gap is the minimum for lead bullets, so gap is fine.

 

[ruger 22]

Is it possible the primers are unseating a bit?

 

[7887mm08]

i will try to answer all remarks (which i appreciate). I did not notice any scratches or rub marks on the face of the cylinder.
I did not pay close of enough attention to see if the cylinder opened with more resistance. i will next outing!
Primers and case head look fine.
This is a new 629.
I am of the opinion that may be there was crud under one section of the star. Looks like rain this weekend but i have some pmc jacketed ammo i can try and some lead 44 special swc also. I will update, Thanks for all suggestions

ps: i loaded some new empty starline brass in the cylinder and all worked fine.

 

[stansdds]

Could be some debris beneath the extractor. Might be bullets pulling from the cases during recoil. Could also be recoil fatigue, which makes you feel like the trigger is getting heavier with continued firing.

 

[7887mm08]

So i finally had a chance to get out and shoot again. Pistol was cleaned beforehand. Fired 2 cylinders each of 3 different types of ammo, including the lead swc that i originally shot and had the problem with. All loads were of the magnum variety.
Results went perfect, issue did not return! I know 36 shots isn't alot, but thats all the time i had.
So i am a believer that something was under the extractor.
Thanks for all replies, shoot straight and shoot often.

 

[ken158]

Is it possible the primers are unseating a bit?

I would check for high primers before anything else

 

[7887mm08]

I would check for high primers before anything else

This was answered in post #12 above, primers were fine all seated below case head after firing.
This was the first thing i checked when problem arose.