Author Topic: Stiffening up an action (added range report) (Read 1389 times)

aulrich · « **on:** January 10, 2005, 06:41:00 AM »

A couple of the posts recently have started me a tinkering (that and some cabin fever). The threads were to do with extra barrels passing around and the fitting it took to make them fit. Specifically the one about how one guy got a used barrel to fit by shimming the hinge notch in the barrel lug. My gun has a bit of a rattle when it is locked up and I figure that that can't be good for accuracy.

as I see it there are two components that are key to action stiffness.
1. The notch to hinge pin clearance in the front.
2. The locking lug to to notch contact.

I decided to see if what I could do about #1, I used pieces of feller gauge to shim the notch to remove at least some of the play in it. I used the ever scientific method of start thin and go thicker till it gets too tight. I ended up on using a piece of .003" feeler gauge I could have tried thicker but at that thickness the rattle even with the forend off seems to have gone away.

Before I fire the gun in this configuration I though I would open it up to discussion to see if there are any negative implications to using this modification . The only one I can think of is head space, but I figure that they head space to the back of the barrel anyway so taking the extra slop out is a good thing. And if a chamber is too tight the round would not chamber correctly. So what does the group think.

With any luck here are the weather warms up some, I may get out to test this soon.

quickdtoo · « **Reply #1 on:** January 10, 2005, 07:08:03 AM »

Check the space between the standing breech and barrel when the action is locked up. I compared this space with a couple factory fitting frame/barrel combinations. A factory fitted barrel will lock up tight on a .002" feeler gauge blade with the blade layed across the standing breech above the firing pin. A .001" blade is snug but can be pulled out. When I fit them, that is what I try to acheive. Also, check the locking shelf on the barrel once you get good lock up. Smoke the shelf then install the barrel, close the action, then open it and look at the mark in the smoke, should be a good contact all the way across and as deep as the latch tip.

aulrich · « **Reply #2 on:** January 10, 2005, 07:57:31 AM »

Quick

How consistent are the factory fitted barrels. Because we maybe on to a buyers guide point. That being when you have the option between a number of handi rifles take the one with the tightest lock-up? Or if you are looking at a used one do you pass it up (or talk them down) if it is looser than "x" tho (whatever the value of x that is deemed to be too loose).

BTW What is your procedure for "tightening" up the fit?

quickdtoo · « **Reply #3 on:** January 10, 2005, 09:21:33 AM »

Shimming using Bigborefan's method. It usually doesn't take much, the last one I did was on a 22 mag barrel, used .002" steel shim stock wrapped half way round the pivot pin. A spot of J-B Weld epoxy to hold it in place on the pivot surface of the barrel, not to the pin. Did the same to my .357 maxi barrel, same thickness of shimming. My .270 barrel was too tight, removed metal from the pivot surface with an 11/32" drill bit wrapped with crocus cloth.

All of my factory fit barrels are about the same as near as I can tell just using a feeler gauge blade, tight on .002" and snug on .001", can see no light between the breech and barrel, and none are loose, open or closed.

Big Blue · « **Reply #4 on:** January 10, 2005, 09:49:26 AM »

Interesting reading guys, I'm sitting here soaking it up. I can always use this as a good reference when looking at a used Handi.
Thanks,
Don

ken s · « **Reply #5 on:** January 10, 2005, 10:36:34 AM »

YUP YUP
ken s

DON'T PAY TO MUCH FOR THE WHISTLE
B F

aulrich · « **Reply #6 on:** January 10, 2005, 11:07:38 AM »

Just had a bit of a brain wave. Plasti-guage ( the stuff used to check clearances on bearings ) should be very useful here for checking the clearance. I have to go by an automotive shop today so I'll pick some up and give it a try. I'll try to get some pictures to post too.

quickdtoo · « **Reply #7 on:** January 10, 2005, 12:07:38 PM »

I thought about using that, just never remember to pick some up!

aulrich · « **Reply #8 on:** January 10, 2005, 06:34:07 PM »

As luck would have it I needed to go put some more money down on the 204 and beside the gun shop was an autoparts store so I picked up some plasti-gauge.

Did it tell a story.

1. Without shim and forend over .006" for the whole breech face
2. Without shim and forend on .006" at the top .0055 bottom
3. .003 shim and forend on .0035" at the top .0025 bottom
4. .004 shim and forend on .003" at the top .0015 bottom
5. .005 shim and forend on .002" at the top .001 bottom

I actually settled on the .004 shim, with the .005 shim the action required some force to close. I figure I should have some gap it is a field gun after all, and I don't want dust to interfere with the lock up.

I would be real interested in some other observations. Especially if someone had a barrel that shot good on one action but not on another.

One other thing, before I glue in the shim that is made from a bit of feeler gauge should I get some brass shim stock instead? or should a dab of lithium grease do the trick against wear.

quickdtoo · « **Reply #9 on:** January 10, 2005, 07:17:01 PM »

Well, I have had a piece of brass shim stock in an old H&R single shotgun for about 30yrs and it hasn't wore out yet! It hasn't been used much but it's not been unused, either. Dad shot a tom turkey with it a few years back, it still works fine. You could probably use brass and just change it once in a while. But in a high pressure caliber it might get loose before long.

Casefiller · « **Reply #10 on:** January 11, 2005, 03:35:47 AM »

Hey, I might be one of the fellers that was talking about slop in the action. I found that I needed a .008 steel shim to tighten up the action on my 22-250 . I wrapped it on the pin, but couldn't wrap it the whole way around the pin, because it wouldn't close that way. After talking with some that post on this site, I decided that I would return it to NEF. Well, they were sweethearts ! Told me to send it back for repair. When I asked if there would be a charge, she replied that they repair or replace any gun that they manufacture. Hope to have it back by groundhog time.

Best of luck with your Handi,

CF

Hildy · « **Reply #11 on:** January 11, 2005, 08:20:43 AM »

I am starting to think I may have a problem with my gun...but you guys are going to need to help me find out if it actually is a problem :?

First, let me introduce you. The gun is a 25-06 Ultra that shoots 100y groups under 1" with both factory and reloads. It is fitted with a Swift Premier 6-18x44 and has a 9-13" bipod.

However, when I open the action the gun kind of 'falls' open without even having to touch it. My friends 223 Handi takes slight physical force to break the action open. Do think this is a problem? I am generally pretty knowledgable about guns but this one is something I have yet to learn...

Do I want to have force applied to break the action open or is it fine if it 'falls' open?

Thank You All

Mac11700 · « **Reply #12 on:** January 11, 2005, 08:36:03 AM »

Hildy:

My 25-06 just falls open...and my 30-06Ultra Comp is tight...I have to pull it down as well...both shoot good...my dear departed father always told me" Son...don't fix...what ain't broke"...ias good as yours is shooting...I would leave it alone...

Mac

aulrich · « **Reply #13 on:** January 11, 2005, 09:37:18 AM »

Hildy

I'm with mac, 1" groups with a handi should be considered good.

Mac

With your two what sort of gap do they have.

quickdtoo · « **Reply #14 on:** January 11, 2005, 10:31:43 AM »

How hard the action is to open has to do with the fit of the forend spacer. Some that I have fitted were so tight when I installed the forend on a newly fitted barrel or stock that they were hard to open forcibly. Installing a different spacer or sanding the mating surface of the spacer to the forend would solve the issue. If the barrel is loose when in the open position but locks up tight, a thicker spacer or a thin shim is necessary. Since I've swapped several stocks around, I've had to deal with this issue. It seems that if the forend just fits snug without a lot of pressure to get it in place provides the best fit. Several folks here have mentioned this, I'm just passing what I've learned here and sharing my experience since I have several rifles to work with.

Hope this helps,

Tim

Hildy · « **Reply #15 on:** January 12, 2005, 05:45:20 AM »

Thanks guys... :grin:

I kind of figured it wouldn't matter but I just wanted to make sure.

I think next in line is going to be a HB 223 Handi to partner up with the Ultra. This can't be good, Im starting to get the bug

(wait, maybe it is good?) haha

Mac11700 · « **Reply #16 on:** January 12, 2005, 06:14:20 AM »

Quote from: aulrich

Hildy

I'm with mac, 1" groups with a handi should be considered good.

Mac

With your two what sort of gap do they have.

I cannot find my good gauges...somewhere out in the garage...but on the ones I do have in the house go down to 0.002" and I can't fit that between...

The one thing I have noticed on the several Handi's I've had ...is that the forearm cut out for the barrel stud...isn't exactly placed the same on the different forends...some are dead centered...others aren't...I guess that's why they have the different spacers available

Mac

aulrich · « **Reply #17 on:** January 25, 2005, 11:37:16 AM »

Two things to report, while I did not get a proper range session I did manage to test fire the gun with the shim installed, it fired and ejected fine. The point of impact was unchanged so I went off to do some calling. One thing I had noticed was that the action would not close on some ammo. As it turned out some of the cases were too long (yet another source of inaccuracy :oops: ).

While de-buging this I discovered that the brass seem to need two strokes (better described 1.5 strokes) so that the brass would go fully into the die I guess that the big gap allowed too much case stretch. And I was not careful enough during the resizing process. So I have go about 100 rounds to pull and redo and then a major cull of my brass supply.

And not that I have a problem or anything :-D ( I could stop buying handi's when ever I wanted) but this weekend I brought home the 204. After I cleaned it up I took the plasti-gauge to it and at the chamber the gap is ~.003". At this point the action seems tight so I will run a few rounds through it before doing any mods. But I will have an O-ring and .0015 shim handi at the range the first time if I can find enough/any test ammo.

And I to can confirm that the 204 came from the factory with an acceptable trigger pull and compared to the 243 ultra the blueing seems to be deeper as well.

aulrich · « **Reply #18 on:** February 13, 2005, 03:23:19 PM »

I did manage to make it to the range finally, and things are looking way better. I was not the best day for good groups that and I had a cold almost 9 year old bugging me to shoot the 22.

The session ended with 3 shots at the center of a sheet of paper at 200 yard the ended up in a cluster of about 2 inches. I think there is more accuracy left in the gun, it still needs a trigger job. But all in all the gun has turned into a keeper.

Donaldo · « **Reply #19 on:** February 13, 2005, 04:09:59 PM »

I am going to rely on Quick to set the record straight, but if I remember right, FredM stated in one of his posts that the base of the chambered round should not be more than 0.003 inch below the barrel breach face. As to the clearance between the standing breach (frame) and the breach of the barrel, it should be as Quick has stated. In the range of 0.001 to 0.002. You should basically not be able to see daylight between the frame face and the breach of the barrel. Shim the lug on the barrel as needed, or dress it down to achieve these standards. That basically is all the factory is going to do. When they fit a barrel to your receiver, they are just going to dress the lug down until they have a certain clearance between the standing frame face and the breach face of the barrel. There is one thing that I don't think we have addressed here and that is the difference between the clearance at the top and the bottom of the face of the barrel. If your firing pin is striking the primer off center, check and see if it is side to side or up and down. Up and down might be corrected by filing on the barrel lug latch up surface. (Doing this should be done with great care). Side to side might be addressed by shiming one side or the other of the lug where it fits into the frame. If you have calipers that will reach you can check the side to side fit. Mine had about 0.015 inch clearance and I put a 0.010 brass shim, JB'ed to one side of the lug. It locks up a bit tighter now. It really doesn't matter how much wiggle waggle you have when the barrel is opened, because that depends on the fit of the fore end as Quick has stated. It is the lock up that is important. That is the thing that you want to keep an eye on. How it locks up.

quickdtoo · « **Reply #20 on:** February 13, 2005, 04:32:02 PM »

Fred mentions the .003" headspace on his web site.

http://www.angelfire.com/ma/ZERMEL/tweakultra.html

Another thing to check when fitting a barrel is the latch engagement. You can do this by removing the barrel, smoke the latch shelf with a candle or match, then install the barrel. The latch will remove the smoke in the engaged area. On factory fitted barrels, this is about 1/8" or slightly less.

One of the other things that Fred mentions is the latch and shelf should be dry, not oiled.

aulrich · « **Reply #21 on:** February 14, 2005, 05:05:41 AM »

The think the .003" thing is the general operation of the action. It needs some gap so the action can swing open. My 204 came from the factory with that sort of gap. But I think that when the chambers are cut the head space is done flush to the back of the barrel not including the gap. If I understand correctly the 3 thou is needed to take up the gap so that the brass does not get stretched as much.

I think before I do the trigger job I will do two things shim the side of the barrel lug and fully bed the forearm per Fred's instructions (the groups yesterday were with just an o-ring installed).

Donaldo
What did you use for shim stock? And did you use anything other than release agent to keep the jb weld from sticking it all together. Would it be possible to see a picture of it?

Donaldo · « **Reply #22 on:** February 14, 2005, 08:02:45 AM »

The firing pin on my 223 strikes the primer off center, quite a bit as a matter of fact. But I have had no misfires. As for the shim, I just got a piece of 0.010 brass shim stock. Cut a small piece about 3/8" wide by maybe 5/8" to 3/4" long. Put a 90 degree bend in the end, say 1/8" from the end. Like the letter L. The base of the "L" shape goes under the lug with the upright on the side of the lug. This was just so an edge would not catch and knock it loose. I tried to figure out which side it needed to be on by the offset primer strike, maybe I got it right. Anyway, the shim was placed as close to the notch where the lug latches up as possible. Put a spot of epoxy on it and pressed it down and let it set up before putting the barrel back on. I would have put 0.005 on each side but could only find 0.010 shim stock, and two was too much. I also steel bedded the barrel to the frame. Along the sides of the frame where the barrel rests or almost rests there is about 0.030 to 0.050 clearance along each side. I cleaned the frame surface of oil, waxed the barrel surface good and put steel epoxy along this surface and closed the barrel and let it set up. Be sure and get enough release agent on the barrel and not too much epoxy on the frame or you will end up with an epoxied in place barrel. I almost did that the first time, let just a dab too much run down. Had a heck of a time getting it opened up and it was just a tiny little place. But my barrel locks up real good and tight now and it seems to have helped the accuracy. Check FredM's web site, I think he did the same thing on bedding the barrel. I think however he used a bead of welding to create the extra needed width of the lug. Shim stock works as good and is easier to remove it you want to. I also filed the latch surface on the barrel lug and that seemed to help center the primer strike some, but this is very delicate work and could cause the rifle to unlatch when fired if you get the slope wrong. I used a perm. magic marker instead of smoke on the latch lug. I now have better contact between the lug and the latching lug in the frame than from the factory. I used a new fine file, two or three strokes very carefully, mark it and check the fit. File and mark and check. I probably only took off 10-20 thousands but it fits better now and the primer strike is a bit closer to center. I would not recommend using a dremel tool on this area and do not mess with the surface of the pivoting lug in the frame, AT ALL. Sorry no pics of this.