Documenting a "blueprinting" job?

[eww1350]

One more opinion, then I will shut up... Locking lugs will never maintain full contact because the slop or clearance at the back bridge of the Remington action will allow the firing pin and sear to lift the bolt up therefore the top lug will loose contact in direct perportion to the amount of clearance. Depending on how tight the cartridge fits the chamber that can be corrected somewhat by the shell forcing the bolt lugs into contact.

Eddie in Texas

 

[Shrek]

One more opinion, then I will shut up... Locking lugs will never maintain full contact because the slop or clearance at the back bridge of the Remington action will allow the firing pin and sear to lift the bolt up therefore the top lug will loose contact in direct perportion to the amount of clearance. Depending on how tight the cartridge fits the chamber that can be corrected somewhat by the shell forcing the bolt lugs into contact.

Eddie in Texas

I'm thinking that the squaring of the face and lugs does matter and everything will be mated at the bolt face by the pressure of the firing pin strike and the pressure of the expanding case. By the time the bullet is released into the bore everything should be tight and the bolt body free of any interference from the sear. Am I missing something ? I don't see where bridge slop will make much difference unless it is extreme.

 

[Ggmac]

Angled sear engagement versus 90 deg sear . Bill Calfee has a good couple articles on how important it is with tests . I think it was called Just Relax .
This is one reason for Borden bumps and larger than normal bolt bodies .
It's very important .

 

[Ggmac]

Op , take all important measurements , bolt lug raceway centerline , size , bolt body size , timing , primary extraction clearance , sear height , trigger location in relation to sear ( cocks on closing ) firing pin travel , firing pin diam and if centered in bolt , new spring rate , bolt nose depth and if 90 deg bore , if centered ( firing pin strike in center of primer ) firing pin protrusion . This is just a FEW of what I do ( did ) more to follow if you want but let's use pm as this may or may not get a lot of responses and questions I don't have patience for .
Good luck Gary

 

[Ggmac]

Agreed , but the vibrations from the force applied to the top lug at firing can't be beneficial . No matter how you slice it a angled sear unloads the top lug until released OR a cartridge that has no excess ( lack of better word ) headspace , in other words pressure felt on the bolt handle while camming closed . With all the variables I'd still prefer a 90 deg sear . I'd also like to be 40 years younger !

 

[Ggmac]

just because a flawed design has worked doesn't mean we , the shooters , can never shoot a perfect zero group UNTIL all stress and every possible manufacturing tolerance is near perfect . I say near cause I've been measuring parts for years , and realize what's a perfect fit or measurement today at say 75 degrees may not be perfect at 32 or 90 degrees Fahrenheit .
The op may have a great idea . I mean if you say you tried a receiver why not give its spec sheet . I think customers will pay a few $ more , I mean we have most of the measurements anyway , how much longer would it take to fill in a spec sheet ?
Hope this makes sense , I've not had coffee yet

 

[Ggmac]

I have always learned not to go overboard when using generic terms , blueprinted is dif than trued , in my book . If I give a spec it's like any other # it has a +/- , a temp it was taken at and a type of measuring tool used and when last zeroed .
My numbers may not be the average joes , but then all should be off about the same .
We are a self regulated blue collar work force , very few remain . Even mechanics are held to state or national standards . It's up to us ( not me any longer ) to eliminate and keep hacks out of the field . If we don't , big brother will make it increasingly difficult to maintain our status . As it is liability ins , fees , and paperwork take most of our time . I would rather a small start , such as documenting work done than having it and more imposed on us .

 

[Ggmac]

If I could double like your last post I would !

 

[johnfred1965]

I am currently having an action trued and a bartlein barrel installed. It would be interesting to know how far out the action was, but I would just want to know just what the gunsmith does when "truing". I have heard "square the face and the barrel will pull down square" but I would really like the threads straight. Is there going to be a timing issue after the lugs are trued? I just want to know that the whole action was gone through, and all the critical dimensions were addressed, measurments or not.

 

[Steelnecktie]

I really enjoyed reading this post, I know the time it takes to do all the little things to get something true in a lathe. I have a 13.5x56 lathe that's around 1700lbs. When someone comes in my shop they know to not lean/rest against my lathe while working. It amazes me that even a small temp change in shop can make lathe cut a .001" taper on a 6" long piece of steel.
It still amazes me that a lot of guys use a machinist level on lathe and can't figure out why their machines cut a taper.
I also clock my barrels Alex, I'd be interested in your number/clocking method to figure out threads on starting a barrel you don't have action for. Thanks for the good read guys. Nice to see some still give a hoot about what leaves their shop.

 

[GenePoole]

I'll post a picture of the timing gage. Its just a threaded piece of aluminum with a clock face on it. What ever number lines up with the 12 oclock spot on the barrel is my timing number. I engrave it under the barrel. So a customer can call and say send a barrel for a borden brm timing number 13. Thats all I need to know. I forgot who gave me the idea, but it was a good one.

This is a great idea and so simple I'm surprised I've never heard of anything like it. I'm going to try and make one. How many graduations does your "clock" have? How do you account for the recoil lug?

 

[jelrod1]

I'll post a picture of the timing gage. Its just a threaded piece of aluminum with a clock face on it. What ever number lines up with the 12 oclock spot on the barrel is my timing number. I engrave it under the barrel. So a customer can call and say send a barrel for a borden brm timing number 13. Thats all I need to know. I forgot who gave me the idea, but it was a good one.

I think it was me when we spoke.

I have a few of these Gene. Also has a slip fit hole for a depth mic for easy gauging. There are many iterations out there. I got the idea from Terry Cross and did my take on it. Good luck

 

[ridgeway]

I made a screw on indexer, but not that fancy. My marks are hand wrote with paint marker, lol. Works good for marking BATs and Pandas...