trigger hanger, trigger timing eat......

S

scott mims

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trigger hanger, trigger timing ect......

to start off I have a BAT DS model LB/LP/LE serial number 84 also still has the brass bushing in it bought in 2004.

did a lot off searching on here and this thread seems to be the one i keep going back too....

http://benchrest.com/showthread.php?84430-Anyone-use-the-roller-bearing-on-their-2-lug-BAT-bolt

Joe on page 1 post 7 and 10 also page 2 post 20 paragraph 4 seems interesting to me..........

joes post on page 1 post 7 part of it reads.................

"I believe what makes the two-lug work smoother is having the action timed correctly so that there isn't excessive cocking on closing: along with having your dies properly match the chambering. This comes from having the firing pin travel somewhere around .220. More gives you cocking on closing of the bolt and less smooth bolt opening. Less than this gives you inconsistent ignition. I just had a new 1.370 Model M built that wouldn't shoot until I replaced the trigger hanger to give me 2.19 of travel and it now becomes a barrel-tuning exercise rather than a gun-fixing exercise. I believe that having the action correctly timed and having your dies properly fit the chamber make these actions the smoothest on the planet; with or without the roller bearing. Before you take your rifle out of service to have the cocking piece replaced, you may wish to try the timing on the action first. (I would also have a very competent gunsmith install the tungsten firing pin weight to remove any doubt about good ignition.)"

page 1 post 10 reads....................

"My newly-acquired under-acheiver was throwing shots at .239 of pin fall. It had noticeable cocking on close and was more resistant when opeing the bolt than when it got moved to the .219 fall. It had the Jewel trigger in the hagger with the .030 showing on the front of the left side of the hanger. I put the .010 hanger in showing the number on the front left side of the hanger and the gun started to shoot with no shot-pitching and the bolt lift was more smooth and much like my other well-performing rifles. It seems like the correct setting is with no cock on close for my rifles, which have the 7 1/2 bolt. Can't speak for the engineering behind it. What I see on the target is what guides my thought process. (I'm too mentally slow for all that engineering.)

I had other BAT rifles not shoot well with .195 to .210 of fall and became performers when it went to the .220 mark. That being said, other actions seem to also have a "relevent range" where the correct fall gives the best compromise of performance and bolt lift. The Pandas that I had worked best at .230 of fall. I once had one that was schizophrenic with another brand of trigger that showed .280 of fall. When I put a Jewel into the rifle and it showed .230 of fall, alll of a sudden it looked like the gun was on the correct amount of Prozac; go figure."

and last one i will copy/paste. page 2 post 20 paragraph 4 reads............

"I think that checking for cocking on close is as simple as watching closely if the cocking piece drops (not enough fall) or moves backwards (too much fall) as the bolt handle is closed. This is adjusted with either a trigger hanger or a different trigger. I check the amount of fall with a coarse measurement using a dial caliper (the skinny rod that comes out the end away from the dial) against the cocking piece and indexed against the back of the action. Zero the measurement when it is cocked and then see what the measurement is after you pull the trigger (on a EMPTY chamber). There are other aspects of action timing like how does the fired round get out of a microport (or IF it does), but that is more to do with the type of extractor, the ejector plunger extension and tension and even as simple as where the port is located. Too much technology for this thread (and my meager engineering knowledge)."


I'm wanting to know what does "cock on close" mean? i always thought your rifle "cocked on close" am i missing something? it sounds like they are saying you don't want cock on close or very little.

View attachment 17021 picture 1

View attachment 17022 picture 2

View attachment 17023 picture 3

1) I'm adding these pictures to see if i am checking what they are talking about right. picture 1, shows that the firing pin is sticking out and it measures around 0.220-0.230. picture 2 shows the bolt on the first "close/click" and the firing pin goes in the shroud more. picture 3 shows the firing pin sticks out again of the shroud but not as much as when the bolt is out of the rifle. is this telling me/you anything? is this what they are looking for. i have hanger "0" in on this.

2) now that being said. when i put hanger "10" in. picture 1 of course is the same, picture 2 does not go in the shroud as much and picture 3 would measure longer than picture 1 (bolt out).

have you found out for yourself that one will shot better than the other? (i have no where to shot other than matches or i would check this myself) been this way for 10-15 years :)

if i have anymore dumb question i will update the post. just bare with me on these questions......... or should i leave well enough alone? :)

again........ i did a rough measurement at each setting with a digital caliper and also did a visual inspection opening and closing the bolt watching the firing pin move like joe says in his post on page 2 paragraph 4. the ALL have movement but to me it looked like when using hanger 10 it might have been less movement maybe hanger 0... but i might be seeing things. in one of his post joe also said it seems to shoot better with a slight cocking on close.

i used hanger 0, 10, and 20 to see if i could notice that much difference in movement and again hanger 0 lost length on closing the bolt and hanger 10 gained length on closing the bolt.

on BATs web page under specifications it says the firing pin travel should be between 0.210-0.230 inch where do you find this info when doing your on measuring? is that the reading you get when you measure the firing pin sticking out of the back of the shroud when the bolt is out of the action?


thanks and please add comments and anything you have tried.
 
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As far as I am aware, the Panda has enough pin fall to allow for some timing adjustment without running into a problem. For other actions this may not be the case, and a different approach may be worth considering. For instance, typical firing pin protrusion is in the range of .055 but I remember reading that my friend Bob Greenleaf routinely set his Savages at .035 with no problems. (Savages have adjustable protrusion, and I am well aware that comparing 110's to pandas is apples and oranges.) We know that it is the primer that stops the firing pin, not its shoulder, which means that one might be able to shorten up a pin's tip a bit and by doing so increase effective fall as opposed to total fall which would remain unchanged. Obviously one would still need to maintain some clearance between the front of the pin shoulder and the opposing surface in the bolt, during firing. Similarly, there is supposed to be some clearance between the cocking piece and the bottom of the cocking cam notch. By thinning out the pins shoulder at the front, some of that might be converted into increased total, and then effective fall. We are talking about small differences here, but in this area, small differences have been shown to matter.

Related question: I believe that some smiths have added mass to BAT firing pins, and that those pins may have in the area of .200 total fall, depending on the trigger and how it is timed. How have those mass additions worked out? I seem to remember that Jerry Stiller wrote that there is no substitute for adequate pin fall. Perhaps adding mass is not as good as, but may nonetheless help. My Viper has a nominally .062 firing pin tip, and seems to require less energy to set off primers because of the concentration of force that the smaller tip provides. Previously I have been able to get away with a lighter spring AND pin without any noticeable ignition problems, and less cross hair disturbance when dry firing. My latest modification has been to switch to the Tubb dual spring which cuts down on vibration, and cocking effort, while at the same time having a full cocked weight of 25#. The cross hairs are virtually motionless when dry firing, and ignition seems to be just fine. Some time ago, I reversed my Viper's trigger hanger to pick up .020 total fall (.220 as modified), and a slight amount of cock on close which is much less noticeable if I operate the bolt rapidly.
 
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