Example of bolt timing, never heard of it until now.

[craigyboy]

Just something I came across on becnhrest central, never heard of it before, something new learned everyday. May be a bt usefull to someone out there

 

Bolt timing

[Redfox]

Interesting thread Craigy

And Happy new year

Redfox

[craigyboy]

Happy new year to you also Redfox.

[Ronin]

Happy New Year to all!

 

A pity you didn't post this a few weeks ago Craigy!

 

I have a mate who snapped his bolt handle on a 300 WM (Rem 700) - dont ask how

 

Long story short, a replacement handle was obtained and silver soldered on to the bolt, (keeping the lug area cool as these are also soldered in place)

 

Had I not aquired a bolt handle jig to do the work, it would have been a devil of a job to set up the handle correctly in relation to the angle of the bolt lugs.

 

As it happens, the job went very well, after clean up and polish, the bolt now opens and closes without issue - in fact dare I say better than before.

 

Needless to say it was sent for re-proofing and passed.

 

If I ever get asked to do a similar job, I may consider Tig welding or even securing the handle to the bolt by drilling and tapping two machine head screws instead.

[Guest northernchris]

Andy

 

What ??? The bolt lugs are silver solderd in place are you sure???

 

As for mounting a bolt handle i would "Tig" it on if you are going to be loading WARM loads.

[Ronin]

Chris

 

if you look at a Rem 700 bolt, about quarter to half inch to rear of lug section (towards handle) you will see a faint ring around the circumirance of the bolt tube, this is where the join is bettween the bolt nose / lug section and the main bolt tube.

 

The lugs and bolt nose are machined from a harder steel and heat treated, then attached to the bolt body by silver soldering, which is why I said that you have to keep the lug area cool, otherwise you run the risk of weakening or even disolving this vital join.

 

I would have Tig welded in first instance, but was concerned about getting the angles correct and the replacement Rem handle is an investment cast item and of dubious quality so didn't want to end up in a situation where it, well, melted away.

 

Its aslo alot easier to undo a brazed / soldered joint than a welded one eh

 

In this pic, you can clearly see where the bolt nose / lug section joins the main body tube - this is setting up the jig with the old bolt handle still in place:

 

 

Another from "underneath"

 

 

The angle and alignment of the handle to the lugs is critcal for camming and bolt opening / closing:

 

 

Just after silver soldering completed, with home made cooling flow on lug area:

 

 

No doubt the "proper" smiths / engineers will comment on my soldered joint

[Guest northernchris]

Andy,when you said "keeping the lug area cool as these are soldered on" it sounds like you the are talking about the main bolt lugs being soldered on .Sorry my crystal ball anit fully up to speed today.

Investment cast can be welded if you know what your on with

As a "PROPER" welder i would need a closer look.

[Ronin]

Forgot to post a pic of the reason why a replacement handle was required:

 

 

Too much powder caused brass flow and stuck bolt - not my loading or doing - I was just asked to resolve the issue!

[Ronin]

Sorry about poor description and confusion!

 

Forgot to take an "after cleanup pic" for the kodak moment, but it was a nice job, silver solder in view in all mating surfaces with no "blow holes"

 

Once the flux was removed and excess solder carefully filed away I polished the camming areas with a very fine lapping medium and the bolt opens and closes as smoothly as a bank vault.

[Redfox]

Remington and others after more than 100 yrs are not completely stupid, the silver soldering of the bolt handle is entirely adequate for its purpose as it doesnt carry any of the actual firing load, it only rotates the bolt and provides a small amount of primary extraction, so no need whatsoever to tig weld it.

In fac tikkas have a dovetail in the bolt and on the handle, they pull into place and are retained by the firing pin shroud etc, they did it to overcome a stainless handle on a chrome - moly bolt and to avoid affecting the material strength ( weld affected zone + extra heat treatment). There are various methods of welding dissimilar metals or hard soldering them but they and others have chosen not to do that, the Blaser straight pull bolt is another example.

Using a jig as you have done and lapping the extractor cam is fine Andy thousands are done every year and give perfectly good service.

Redfox

[Ronin]

Hmm Tikka bolt handles.....

 

I know of a chap in Cumbria who made a similar mistake with an over pressure load.

 

As far as I am aware, the handle was knocked so hard with a hammer by the fellow trying to open the bolt, that it started to come out of the dovetail

 

Expensive mistake to make for the sake of a few extra feet per second

 

I believe the offending article has been returned to the factory, although I can guess what the Tikka engineers will say with regards to warranty.....

[Redfox]

Your right, they have seen it all many times and as you know all garauntees and consumer rights are void with home loads anyway.

Usually believe it or not an hour or two in a commercial or chest deep freezer will allow it to be moved either when cold or after warming up again may need a more than one go ( opposite of getting the heating torch on the job ) but it has worked for me, not on any of my rifles I might add.

But I still dont understand why people with little or no knowledge, assume they can ignore the advice of experts and powder makers and stick " a bit more powder in" to get as you say a few fps, which only usually gives poorer accuracy and washes out the throat faster!! beats me.

Redfox

[Guest northernchris]

Redfox

 

In agree silver/hard solder is more than up to the job,but by Tigging it on would make for a bullet proof setup.

[Redfox]

It would Chris and if happy with the bolt handle style it makes for a belt and braces job, only if you are into bolt handle jewellry would you need to change it again

I like some of the tactical handles ( nearly said knobs but that wouldnt be PC would it?) but there are plenty of goodies in front of that first

Redfox

[Vermincinerator]

Hi Ronin,

very interesting post mate just a few questions as i will be doing my own bolt handle modifications in the future.

Did you tin the inside of the bolt handle radius or did you use the conventional method?

I have thought of using a solder/flux bearing paste, whats your thoughts on that?

Did you need to do any hand fitting to the camming surfaces of the bolt handle ensure the camming/lug/recess alignment was correctly timed?

Thanks for your help buddy.

 

Ian.

[Ronin]

Ian

 

short answer is yes!

 

 

Now the detail:

 

I used a Camium free high temp Silver Solder and high temp flux - no tinning, it behaves more like braze.

 

Once I had set up the jig to the pattern of the "old bolt", I checked it with my own undamaged Rem 700 bolts to fine tune the setting. Unfortunately the jig isn't the ideal holder as it does allow some movement laterally of the bolt handle and the setting up is vital - for example the handle needs to be at more or less 90 degrees to the bolt body, but when everything is covered in flux its very difficult to see it is - you also need to set the handle as close to the end of the body tube as possible but without any overhang - again sounds easy to set, but when covered in flux it isnt.

 

Then theres the problem of cooling, I solved that by making a small hearth of firebricks on an incline and setting up a drip feed onnto the lugs - when I did the job, the portion being brazed was a dull cherry red (circa 800 degrees) but I could hold the bolt nose no problem. I had placed a "firewall" of chips from the bricks to stop heat travelling from the hearth and the heat sink helped retain the main temp in the area to be brazed.

 

Re the soldering, I cleaned all surfaces with emery so there no traces on the bolt tube of the original solder. The emery affords a good keying surface - I did the same with the new bolt handle and thoroughily degreased everything in carb cleaner before applying the flux to both the bolt tube and bolt handle. The flux I used was Tenacity 5 an acidic high temp flux specifically for silver solder, generous application of this when its mixed with water and a drop of fairy liquid makes a white paste, that goes clear and glassy at the right temp, the silver solder wire just runs into the joint by capillary action if things go right.

 

I would stay clear of self fluxing rods myself, never have liked them - (I worked in an engineering environment in a past life)

 

Re setting up after jointing:

 

After letting the job cool naturally to cold, I pickled it in a mild acid (coke in fact) to remove the excess flux - worked a treat...

 

I then used various hand files to clean up the joint to reveal a nice joint line around the entire perimeter of the joint. Then I polished the camming surfaces - thats both on the bolt and on the action to a smooth glassy finnish (like stoning a trigger) and worked the bolt several times with a lapping compoud which made the bolt open and close very smoothly.

 

Final clean up and slight application of a bit of dry moly to the primary and secondary cam area of the bolt, (the one in the end of the bolt tube) that cocks the firing pin (which I also polished by the way)

 

I had a slight problem with the tail of the bolt handle gauling by a few thou on the internal bore of the action but a few strokes of a file cured that.

 

Yes there is more to is than a simple braze and forget - like I said initially, I learned the hard wayby looking at the relationship bettween the bolt and action interfaces - fortunately my job went right first time, it would have been far easier now Ive seen the video in the BR Central link.

 

 

Hope that answered the question Ian?

[Vermincinerator]

Thanks for that Andy,

Very well answered and clearly explained mate, i have examined a jig the same as yours and have come up with a much sturdier design, just have to get round to making it, the same goes for a lathe fixture for fitting Badger bolt knobs

 

Ian

[Ronin]

Ah tactical knobs

 

Yes a fixture for the 4 jaw that hold the bolt at such an angle you can turn the original down to size utilising a live centre and then thread the stub.

 

Would be nice to make an ajustable one so that other makes of bolt could be modified as well - sure there is a market from the Tikka, Sako, Savage etc users.

 

Seem to be on the same line here mate

 

On the lathe front, sick of looking at worn out Colchesters and Harrisons - decided to buy new

[Guest northernchris]

What lathe are you after Andy???

 

I do have a good source

[Ronin]

Chris

 

I am looking at getting a GH 1330 / 1340 from Warco / Toolco or something similar on the Chester product line of the same size, I want a one meter bed and at least 1 1/2" spindle internal diameter, plus metric / imp screwcutting and fixed steady of the roller bearing variety. 4 jaw camlock chuck too.

 

 

I was looking for a Colchester Master 2500 or Student, but like I say all I have seen is worn out tat at inflated prices.

 

I have a mate who has a GH 1330 who produces work as good as anyone else - which is why I am going along those lines.

 

 

Any comments mate on these - from an engineers perspective

 

I know these are Chi Com lathes, but as the new Colchesters and Harrisons (600 group) are also made in the sunny east, I think, that I may as well step that way too.

 

 

I dont want to spent a few £ on a used and find out it needs several thousand spending to get it up to spec / accuracy, when I could get something new and away I go.

[Guest northernchris]

Whats your realistic budget?????

[Ronin]

PM on its way

[baldie]

A fixture for the bolt knob conversion isn,t difficult Ronin, have a look at the one i made next time your in.It has adjustment built in.

[Guest dasherman]

Chris

 

I am looking at getting a GH 1330 / 1340 from Warco / Toolco or something similar on the Chester product line of the same size, I want a one meter bed and at least 1 1/2" spindle internal diameter, plus metric / imp screwcutting and fixed steady of the roller bearing variety. 4 jaw camlock chuck too.

I was looking for a Colchester Master 2500 or Student, but like I say all I have seen is worn out tat at inflated prices.

 

I have a mate who has a GH 1330 who produces work as good as anyone else - which is why I am going along those lines.

Any comments mate on these - from an engineers perspective

 

I know these are Chi Com lathes, but as the new Colchesters and Harrisons (600 group) are also made in the sunny east, I think, that I may as well step that way too.

I dont want to spent a few £ on a used and find out it needs several thousand spending to get it up to spec / accuracy, when I could get something new and away I go.

 

I'd stay away from any of the far east machines. Ended up taking Warco to court some years back over the crap quality machine they had supplied and were refusing to even take my calls. [i won]

Best for the money is a Colchester Master 2500 if you can find one with an Anjest screwcutting attachment. I'm currently using a T2000 for my barrel work but have a M2500 stripped down ready to be built up to a dedecated barrel work lathe. I bought it from a company I had worked for when they went tits up so having spent a few years using it knew it was ok. Only rebuilding it because I like my machines to look good. The M2500 is about perfect for rifle work. 1 5/8" bore, short headstock so you dont have to take barrels off to screwcut them and it has a clutch so if your using it on a phase convertor it starts easily. Think I paid £1200 for mine with all the chucks/steadies/collets. I'd keep looking as there are loads of them about but like used cars be prepared to go and look at a few and walk away if its not right.They will all be dirty but you can tell straight away if its been abused.

[col48]

hi Andy

 

would this stuff do the job????

 

http://www.gunaccessories.com/Wheeler/BoltHandleTools.asp

 

ATB

Colin