Author Topic: Latch shelf repair (Read 3050 times)

trotterlg · « **on:** August 27, 2009, 06:19:52 PM »

For a re-chamber to 22 Hornet and some dies (which I still have to deliver) I aquired a .270 extractor barrel that someone had filed the latch shelf so far that it would not lock up and had also changed the angle about 15 degrees. This barrel was hosed up for sure. I've been thinking about this for a while, so this is what I did: I milled the latch shelf flat withoug regard to angle, just cleaned it up and made it flat. Next I cut a key way across the face of it. Next I made up a thick shim with a male key built in that fit in the key cut in the latch shelf. I used some barrel steel for it. After I fit it in I soft soldered it in place. I put the key in to keep the latch from shearing off the shim (about .100 thick). All I have left is to machine the latch shelf to the proper angle and height now, just got too late to finish tonight. Took a couple of pictures after I got it soldered together. Think I should be afraid to shoot it? Larry

LaOtto222 · « **Reply #1 on:** August 27, 2009, 06:33:52 PM »

Larry - you continually amaze me. What an innovative idea. I think that once you machine in the proper angle and it locks up tight, you have a winner. I see no reason that it would be just as safe as one that was not "modified". In fact it might be better, as the barrel steel is more than likely a better quality steel than the lug itself (less wear anyway). As always, Good Luck and Good Shooting.

dpe.ahoy · « **Reply #2 on:** August 27, 2009, 06:41:41 PM »

That's what you were talking about, now I understand. Just got back into town tonight, will try to get those barrels sent off to you Monday, after being gone from work this long, I'm sure I won't get out of the office to get them mailed Friday. Good news is, cabin is done on the outside. Huntin camp is gonna be much nicer this year. Canvas tents are good, but it's pretty windy at camp, and that canvas can sure wake a guy up when ya think the thing is gonna take off and leave ya!

Don't care how tight ya think ya get it, that wind can sure make it pop and crack sometimes. DP

quickdtoo · « **Reply #3 on:** August 27, 2009, 08:06:48 PM »

Good work Larry, looks good to me, I'd shoot it!

Tim

canon6 · « **Reply #4 on:** August 28, 2009, 03:17:03 AM »

Count me with Quick on this, I would not hesitate to shoot it.

Jimbo47 · « **Reply #5 on:** August 28, 2009, 04:16:34 AM »

No reason seen why I wouldn't shoot it!

If you are concerned that the solder may not hold, I'd just find an arc welder and tack it on each side where the keyway is.

AtlLaw · « **Reply #6 on:** August 28, 2009, 06:08:37 AM »

Quote from: LaOtto222 on August 27, 2009, 06:33:52 PM

Larry - you continually amaze me.

+1

trotterlg · « **Reply #7 on:** August 28, 2009, 08:35:37 AM »

Here it is finished and it does lock up nice and tight. Larry

LaOtto222 · « **Reply #8 on:** August 28, 2009, 08:58:00 AM »

I think you are ready for a range session

trotterlg · « **Reply #9 on:** August 28, 2009, 10:46:55 AM »

Do you guys think it would be ethical to sell this if I told about the repair? I have absolutly no use for a .270, I have a 25-06 and a couple of30-30's. I just don't know if it would be right to sell it. Larry

petemi · « **Reply #10 on:** August 28, 2009, 11:34:23 AM »

I wouldn't be afraid to buy it, if I wanted one. Just post a link to this thread in your ad.

Pete

Jimbo47 · « **Reply #11 on:** August 28, 2009, 11:52:18 AM »

Quote from: trotterlg on August 28, 2009, 10:46:55 AM

Do you guys think it would be ethical to sell this if I told about the repair? I have absolutly no use for a .270, I have a 25-06 and a couple of30-30's. I just don't know if it would be right to sell it. Larry

Post it as is, make offer, and take the highest offer after a set date!

cwlongshot · « **Reply #12 on:** August 28, 2009, 12:01:16 PM »

Larry,
Your an honest man, post it up and tell/show what you did to fix it up. Yours is good solid work, don't second guess yourself. I trust your work every time I place my face on the 32-20.

CW

trotterlg · « **Reply #13 on:** August 28, 2009, 12:46:44 PM »

OK. Larry

myarmor · « **Reply #14 on:** August 28, 2009, 02:03:23 PM »

I am ashamed I didn't see this post earlier

or I would have posted for sure.
I will let you all know how the barrel performs as soon as I can, given if it locks up tight on my SB-2's and if it needs shimming or not. Looks great though larry, I believe it will do just fine... though just in case I might throw caution to the wind and strap it down to an old tire for the first safety firing

-Aaron

trotterlg · « **Reply #15 on:** August 28, 2009, 02:19:28 PM »

I've tied more than one gun to a tree for the first shot. Larry

myarmor · « **Reply #16 on:** August 28, 2009, 02:34:11 PM »

Well I didn't want to offend you.

MSP Ret · « **Reply #17 on:** August 28, 2009, 02:45:08 PM »

put me down on the side that says it's safe. Probably better than from the factory. I would shoot it and feel safe. Just disclose the work when you put it up and I am sure it would be fine....<><....

quickdtoo · « **Reply #18 on:** August 28, 2009, 02:47:11 PM »

Quote from: MSP Ret on August 28, 2009, 02:45:08 PM

Just disclose the work when you put it up and I am sure it would be fine....<><....

It's already been put up and sold!!

Tim

myarmor · « **Reply #19 on:** August 28, 2009, 02:49:37 PM »

Well I agree. Larry, you mentioned you used barrel steel, was this extra from a shotgun barrel? Just curious...

trotterlg · « **Reply #20 on:** August 28, 2009, 03:19:33 PM »

A .270 has some serious zip to it, I would be behind a big tree with a tire 10 yards out. Larry

trotterlg · « **Reply #21 on:** August 28, 2009, 03:23:48 PM »

I really didn't complete the story, first time I machined the latch I cut it too low, so I made a new shim from a lathe tool shank that holds carbide inserts, it is not as hard as tool steel, but I had to use a carbide end mill to cut it, so this one is harder than barrel steel. The barrel steel I used origionally was from a British 303 barrel. Larry

wtroger · « **Reply #22 on:** August 28, 2009, 04:23:15 PM »

The latch shelf work like a wedge and as long as the insert Larry put in stays put (and it will because it is soldered in) there won't be an issue. The underlugs on these are fairly soft and Larry has used a lot better grade of steel than the factory has ever used. Beautiful work Larry

stimpylu32 · « **Reply #23 on:** August 29, 2009, 02:05:57 AM »

Larry

Just something to think about if you ever have to do another one like that , maybe cut a slight dovetail at the bottom of the key way , that would hold it even if for some reason the solder should fail .

We used to do that for die inserts in plastic injection molding dies , just as a safety to prevent any mishaps should the insert become loose for any reason .

stimpy

PS -- The 5mm RF barrel is still shooting like a champ

trotterlg · « **Reply #24 on:** August 29, 2009, 05:45:20 AM »

I should pick up some dovetail cutters, I have had use for them in the past also. I was more concerned about a shear force, so I think the key way will take care of that. I am probably over worrying the problem, I usually do. Glad the 5mm is still working, I have had others ask for one, but they are a giant pain to make, so I think yours will remain a one of a kind. Larry

Fred M · « **Reply #25 on:** August 29, 2009, 09:53:19 AM »

Larry.
There is really no reason to be alarmed about your shelve repair.
The reason is that the uplift pressuere ore force is relativly very small compared to back thrust against the standing breech.

The uplift is the result of the hinge pin is below the center of the main thrust. If you were to clamp the action in a strong vise
with the latch fully engaged you would actually bend the barrel before anything would let go on the latch or the latch pin would shear off which is also most unlikly.

I have a math calculation that would proof this fact, since this question came up some years ago. Your repair on the latch is totally sound and well done.

When at times the rifle opens after a discharge of a cartridge as a result of practically no or very little latch support, the breech or chamber end of the barrel moves up just enough to eject the fired case. This again shows only minimal thrust.
Fred M.

trotterlg · « **Reply #26 on:** August 29, 2009, 10:05:07 AM »

We'll get a good report in a week or so. After you figure out how to get the proper angle on the shelf, the fix is amazingly easy to do. When you measure a factory shelf, it isn't parallel or at 90 degrees to any other surface on the gun, so you have to make a little tool to set it up right in the mill. Larry

myarmor · « **Reply #27 on:** August 31, 2009, 11:15:08 AM »

Well, I got the barrel in the mail just a little while ago, and it looks great. Larry did a very nice job, it looks better then a factory job I can tell you that. Also good news, is that it fit up to the first SB-2 frame I tried and locked up tight...no wiggles

i'm stoked to say the least. I do reload often for my other 270 (M70) but I will not have a chance soon to do so for this one just yet

...but not to fret, I will pick up a couple boxes of Federals and give her a go. I am short on extra scopes, so I will rob a Bushnell Trophy 3-9 and mount her up.... pics soon to come as I rummage for another digital camera

Spanky · « **Reply #28 on:** August 31, 2009, 03:50:59 PM »

Can this go into the FAQ's for future reference??

Spanky

trotterlg · « **Reply #29 on:** August 31, 2009, 03:58:09 PM »

I think we should hold off a little and see if it really works. Larry