Author Topic: Transfer bar and FTF (Read 7087 times)

gcrank1 · « **Reply #30 on:** October 01, 2011, 12:23:15 PM »

Fred, with the FTF I experienced it seemed to me that if the T-bar were held in the most forward and 'up' position behind the F-in that it could impart the hammer blow. Its unlikely the workers at the factory repeatedly tear down and reassemble to hand fit these parts, or only minimally, they likely just grab from a bin and assemble. By getting a little extra length I achieved that, yet the real solution is a T-bar with the taller Striker portion with less chamfer toward the pin. For whatever reason the factory redesigned that T-bar, or their contractor missed the tolerances and they installed a rash of bad ones. I understand they have rectified that, though I do not know just when. This site is the best trouble shooting/reporting network on serial codes to maybe define it, but really, the gun either works or it doesnt.
My 'lengthening the Trigger Ext.' was an experiment and expediant, and resulted in some success, though my new (old style) T-bar sits higher and better and FTF is not a concern now.
Slack, Unless one is quite the artist in small part welding I would not recommend trying it. Ive only known one guy who was good at it, and it wasnt me.
I think I described the cold forging on your post the other day. IIRC, I also said that I was quite sure your problem would be solved with the currently used factory T-bar. From your pics there Im 100% convinced of it.

quickdtoo · « **Reply #31 on:** October 01, 2011, 02:06:48 PM »

Here's a comparison pics of two trigger extensions, the one on the left was obviously modified, dunno if it was by the factory tho, I've seen others that have been modified the same way tho, the point has been ground flat, the other is a new extension.

Tim

Fred M · « **Reply #32 on:** October 01, 2011, 06:37:33 PM »

It is possible that H&R is farming out some of the small parts to different contractors. Resulting in slightly different different pieces. In my two Handi's I had never any issues with this extention. I would like to check but taking the action apart is not in my schedule since every thing is working well. Obviously my extensions are different than some in other Handi's and perhaps the newer long ones may not even fit my two rifles? Let the old dog sleep.

Sprint · « **Reply #33 on:** October 02, 2011, 03:20:28 AM »

Tim,

The extension on the left of your photo was probably done at the factory. This modification was made to ensure the trigger returns fully forward on some SB2 frames.

Note that only the high point was ground and not the lifter engagement area.

Sprint

gcrank1 · « **Reply #34 on:** October 02, 2011, 04:20:03 AM »

It was not a huge amount of lengthening (I believe the amount is in a the detail posts previously), and was able to hold the too short Striker just high enough to get it off the chamfer facing the F-pin, thus not get squeezed out when hit. And it was futzy, but Im futzy.........
The thing is that once the sear trips and hammer falls the T-bar assembly is intended to fall, this being a micro-second timing and the safe, proper function of the T-bar idea.
If it aint broke, dont fix it; if you dont know what you are doing, dont mess with it; KISS; sleeping dogs; et al.......but maybe the most apt, fools rush in where angels fear to tread.

quickdtoo · « **Reply #35 on:** October 02, 2011, 05:37:06 AM »

Quote from: Sprint on October 02, 2011, 03:20:28 AM

Tim,

The extension on the left of your photo was probably done at the factory. This modification was made to ensure the trigger returns fully forward on some SB2 frames.

Note that only the high point was ground and not the lifter engagement area.

Sprint

Thanks for the input, we appreciate it!

Tim

Mink WV · « **Reply #36 on:** October 20, 2011, 06:57:34 AM »

Howdy, another "new guy" here. Great forum with a lot of good info. I have a SB2 I am trying to repair and need a striker assembly, preferably the "old style" and cannot find one. Brownells discontinued them and Numrich is out of stock and probably won't get any more. This striker is getting squeezed under the firing pin when the hammer hits it and causing a FTF. Don,t know if the current production striker is any longer or taller than this one or not, but this is a newer rifle made in the last couple of years, doesn't matter as Remington won't sell them anyhow, other suggestions ?
Thanks, Mink WV

quickdtoo · « **Reply #37 on:** October 20, 2011, 08:11:15 AM »

Welcome, Numrich has the old style replacement.

Tim

http://www.gunpartscorp.com/catalog/Detail.aspx?pid=1139220B&catid=8099

gcrank1 · « **Reply #38 on:** October 20, 2011, 08:48:35 AM »

The nomenclature thing is a problem with the Lifter/Striker (T-Bar).
As I understand it, they had one style, then changed it to the 'new and improved style', which seems to have had the majority of issues, then went back to the 'old style' upon the recommendation of their gunsmith dept. ( and that is what they are using on new builds and fixes of those returned with FTF).
In trying to order the 'right one' you may have to trust they have the current style, but from a used parts dealer you may get a bad one from a pulled down action. Im sure they dont keep up with what are problematic factory parts.

Mink WV · « **Reply #39 on:** October 20, 2011, 12:49:55 PM »

Thanks for the replies and the link to the part at Numrichs'. Is that the same lifter as the SB2 or Buffalo Classic? Says it's for an SB1 ? Probably a lot of different versions of the part over the years, but here is a pic of the one that works (bottom or left), and the one that is too short (top or right)......I measured both and the older style is approx. .200 longer than the newer one... Thanks again, Mink WV..........

quickdtoo · « **Reply #40 on:** October 20, 2011, 01:15:28 PM »

I've use the Numrich replacement, internal parts are all the same for the SB1 Pardner and SB2 rifles(Handi, BC, doesn't matter) with the exception of the firing pin, frame construction is the only difference.

Tim

Mink WV · « **Reply #41 on:** October 21, 2011, 04:14:24 AM »

Thanks for the info Tim, I ordered the part. Guess I'll find out next week which one it is........
Mink WV ......

Mink WV · « **Reply #42 on:** November 01, 2011, 11:56:25 PM »

Well I am back to square 1 on this repair. I got the part from Numrich and it was actually smaller than the factory t-bar/lifter by a few thousands. Tried to weld it and turned it into a blob of slag. Appeared to be an injection molded part and welding that material is beyond my abilities if possible at all. Since I can't find an "old style" t-bar I guess the next step will be to try and make one.
Mink WV........

quickdtoo · « **Reply #43 on:** November 02, 2011, 03:30:04 AM »

I'm thinking Numrich has changed what their sending out since another member said the same thing about the one he got. $:-\$ PM Brian56, maybe he can help.

Tim

Mink WV · « **Reply #44 on:** November 02, 2011, 09:16:51 AM »

Thanks Tim, will do....
Mink........

44 Man · « **Reply #45 on:** November 03, 2011, 05:00:12 AM »

I guess this is a good time to check back in here. After having the same FTF issues with my old Topper 30-30, I went through all of the above fixes and thought I had it cured once and for all. Then I took it back out last week at the range and had another FTF! On closer inspection, I find the rim cut is too deep on the barrel and sometimes the ejector would hold the case against the firing pin long enough to fire, and sometimes it would not. I'm going to try a shim behind the ejector to force the case against the breechface in a more consistant manner. I also think this may be a good time to convert it to 30-30 AI that I have always thought about. Then the case can just headspace against the shoulder and we'll be all set. This has been a frustrating journey, but I love the handling of the old barrel contour so it is well worth it. (And this one really, really shoots good too!) 44 Man

quickdtoo · « **Reply #46 on:** November 03, 2011, 05:11:59 AM »

Be careful shimming the ejector, I was once an advocate of that until Bobby brokes his extractor, it may work better on an ejector tho, but old style ejectors are no longer made, Numrich has none, Brownell's has the early NEF style in stock tho which may work in the Topper barrel.

My best idea to cure a deep rim cut was to make a disc of shim stock that fits the rim cut, epoxy or solder it in place, then carefully remove the center leaving a thin "washer" in the rim cut, but I haven't done it yet on my 45-70 Ultra which has the same problem.

Tim

http://www.brownells.com/.aspx/pid=7094/sku=427-401-215/Product/Ejector-1987-98

bucmeister · « **Reply #47 on:** October 30, 2012, 10:34:21 AM »

Quote from: gcrank1 on February 20, 2011, 10:16:05 AM

Thanx Tim!
Update: I decided that I had nothing to lose; I took the 'trigger extension' to the anvil and, on the horn, cold forged it to lengthen it (the horn does this, not an anvil flat) a bit on the contacting tip end. That is, the end which contacts the transfer bar and locks it in place when you pull the trigger.
I made this whole operation easier by having a slave pin for the trigger group assembly and a pair of slip fit test pins to replace the small front trigger guard retaining pin and the thru pin for the trigger group proper (quick assembly/disassembly compared to the factory splined pins).
I know a half dozen shots is far from definative, but, 6 shots without a bobble after 50%+ FTF is very encouraging; enough for me to be confident that this is the culprit and I can fix it!
When I can get a couple 'virgin' parts I will test my theory that they need to be long enough to lock the t-bar right after the sear trips out of the hammer notch, and no shorter.

gcrank1, I am trying to picture the procedure in my mind of what you have done to lengthen the part because I am convinced this is what is happening with my gun. If I squeezed the trigger the sear releases and the t-bar drops out of position before the hammer gets there, whereas if I use a quicker twitch of the trigger finger the t-bar stays up in place and the f-pin protrudes as it should. Leading me to conclude that the timing of the t-bar drop needs to be delayed for a couple more milliseconds. Have you by chance made a video showing the process? It sounds like you are placing the concave side of the extension on the horn of the anvil and striking the opposing flat with the hammer, is that a correct interpretation?

bucmeister · « **Reply #48 on:** October 30, 2012, 11:16:33 AM »

Scanned a picture of the extension then colored it in a bit. The yellow is the anvil horn, the blue and red blocks represent the hammer, with the blue and red arrows indicating the direction the hammer blows would be expected to lengthen the part. I am wondering if you are forging the red side in order to lengthen in the direction of the red arrows or the blue to lengthen in that direction.

gcrank1 · « **Reply #49 on:** October 31, 2012, 03:36:41 AM »

It was primarily the blue area above I lengthened, again as an experiment and expedient, with some success. For reference in particular see page 1 of this thread, posts #11 &12 for a good example and illustration of function and page 2, posts 31 &33. Basically, whatever it takes to get 'more reach' to hold the lifter/striker assembly into place is what I wanted to achieve.
It should be noted that the real easy solution ended up being a replacement striker which is taller, thus does not need the extra lift imparted by my experiment, and it does not squeeze out on hammer blow. If a guy was desperate and can weld a bit on top of a too short striker and file/grind it to shape, etc. it would likely be as good as the replacement I eventually got.
FWIW, although I had success with the lengthening I it was futzy to do and I did not use the rifle extensively. Once I got the new lifter/striker in hand I installed it as I wanted this rifle to be fail-safe. It would have been better, in terms of experiment, to have used it over many rounds and time........perhaps someone else can?

bucmeister · « **Reply #50 on:** October 31, 2012, 07:07:40 AM »

Went to Numrich Gun Parts and see that they list two different "Striker & Lifter assemblies", one original and the other replacement, so which one did you find was the longer version?

Part # 280500B Striker & Lifter Assembly Original $17.20 Which looks like mine and seems more likely to "squirt" out like a watermelon seed.

Part # 1139220B Striker & Lifter Assembly Replacement $21.20 Seems to be more squared off on top giving more chance for it to be hit.

gcrank1 · « **Reply #51 on:** October 31, 2012, 08:02:57 AM »

Sorry to say I didnt get mine from Numrich so I dont know; perhaps someone else has that info.
Your visual check of their offerings is likely right, but I have to wonder if whoever 'pick the bins' will send you one that matches the pic!

bucmeister · « **Reply #52 on:** October 31, 2012, 09:01:25 AM »

The two listings I have in blue are hyperlinks to the two individual listings with pictures. Did you happen to open them? I'm thinking it is the higher priced one based on what I interpreted from your description of the part design since the lower priced item is beveled on the side toward the hammer.

Buster95 · « **Reply #53 on:** October 31, 2012, 12:09:34 PM »

Instead of using the hammer directly on the extension why not use a flat steel bar, just place the steel bar on the area and hit the steel bar with the hammer, more control, I've used this method for more than 20 years at work (sheet metal).

bucmeister · « **Reply #54 on:** October 31, 2012, 03:25:07 PM »

Well, honestly I'm still trying to get straight in my mind the procedure that gcrank1 used to lengthen the piece. At first I pictured the curved inner portion of the piece on edge on the horn of the anvil with the hammer blow represented by the blue block striking the surface which would seem to the piece to lengthen in the direction indicated by the two blue arrows. However, I am now wondering if maybe the piece is laid flat on the horn and forged along the leading flat edge facing the blue block and arrows.

Guess it would help if I saw an animated model representing the motions and timing involved in firing the gun. I think I have it figured out pretty well but it would help to see it. As best I can figure when the hammer is cocked the front edge down in the action contacts the bottom of the t-bar mechanism holding it in position, then I think that as the trigger is pulled and pivots forward the trigger extension moves to take the place of the hammer in holding the t-bar up so that when the trigger is released the t-bar drops back down allowing the f-pin to retract. Where this timing issue results is in the lack of overlap of the motions of the hammer releasing the t-bar and the extension then blocking the fall. In the misfire situations there is a window where neither is holding the t-bar up, by lengthening the extension a bit it reduces the window size so that the speed of the trigger movement get the extension under the t-bar before it can drop past the point where it catches the t-bar. With a high trigger pull weight the springy momentum stored in the compressed tissues of the trigger finger causes the follow through on the pull to be speedy enough to get the extension under the t-bar holding it up in firing position whereas with a light trigger that jump due to pressure is not there and the t-bar falls through the to wide of gap that results from no overlap of function.

At least that is how it seems to me it would function given the way it does when I pull the trigger and I can replicate this with my action. A slow squeeze will release the hammer and the t-bar will fall before the extension can block the fall giving a fail to strike the t-bar and firing pin, whereas if I quickly pull the trigger the hammer releases and the t-bar stays up in place causing the firing pin to pop out as it should.

Hope all my rambling makes sense. Going on gcrank1's work it would seem that the extension is getting into position just a bit late. I believe that if the tolerances were closer and it were set up properly there should be no way for the t-bar to fall through the gap as there should be no gap.

gcrank1 · « **Reply #55 on:** October 31, 2012, 05:12:01 PM »

I think you pretty well have a grasp of the fine tuning aspects of this approach, and I do not think that the factory is working to such fine tolerances to accomplish it. The action of the trigger being pulled and the extension moving forward to hold the lifter/striker sorta in place is likely all they want, but if that striker is beveled too much or a bit too short it squirts out. The quickest and easiest for them to put together is the taller striker and I think they may only file the tip of the Trig-Ext. to get the release and drop timing right.
As to the cold forging; it was done flat, alternating sides as it will want to curl, and with hammer blows to draw the length of the forward part longer so it would have a closer/sooner contact on the lifter and prop it up into place better. That top section after the belly curve is the forward reaching part that I wanted 'longer' to hold the lifter/striker just to the edge of being tight to compensate for that too short striker. IIRC, if you make it hold too tight it wont allow the drop after hammer fall, so just shy is best.

bucmeister · « **Reply #56 on:** November 01, 2012, 02:12:47 AM »

Actually, on my gun once the extension makes it forward enough to catch the striker assembly, holding it up in place, the assembly will not fall until the trigger is released no matter what the hammer does. This can be verified by holding the cocked hammer while you depress the trigger into the full fire position then lowering the hammer, the t-bar/striker will make no move to drop out of the "fire" position. If the extension does its job then the longer striker is not needed. The only advantage of the longer striker is that there is still enough of it in the way so that a sufficient impact is transferred to the f-pin. If you cock the hammer then snap the trigger back quickly the slowly release the pressure on the trigger you will hear the click of the striker falling as the trigger returns to its' forward position allowing the extension to move out from under the t-bar. If the timing is correct the t-bar/striker should not or could not drop out of position, period, because there would be no gap in the support holding the t-bar/striker up in position. It is because of the window created by the small timing gap between the hammer releasing and the extension taking over the support of the t-bar/striker that is causing these misfires.

As others have stated, we should not have to deliberately snap the trigger quickly in order to overcome either a poor design or sloppy timing workmanship.

Think I am going to order a new striker assembly and spare extension to see if I can get this timing issue corrected. I am also now wondering if the stub on the edge of the striker assembly that the extension engages with is also a bit different profile on the longer striker assembly, because a different profile there could also make up for the short trigger extension.

gcrank1 · « **Reply #57 on:** November 01, 2012, 04:21:03 AM »

You have certainly stated it better than I did with my abbreviated 'hammer fall'. You seem to be at the same place I was for the original post; ie, troublesome misfires? If the striker is still being held well up behind the F-pin upon hammer fall it should be going off, right? That would indicate that your T-Ext. is doing its job and your lifter/striker assembly is of the correct dimensions. Mine were not and upon misfires, in spite of my still having the trigger held back, the striker was below the F-pin even though it had been behind it before my attempted shot. If yours is still there behind the F-pin you have something else going on; ie, weak hammer fall, inadequate F-pin protrusion, etc.