Thread and face should be run in the same setup, if not it’s bad planning. With good tooling and reasonably stable parts a machinist should be able to get within .002 easy between setups. Tenths are really not possible with multiple setups.
Blueprinting custom actions...why?
- Thread starter Tommie
- Start date
I do a very primitive check, using a barrel stub ( that was machined in the same setup) and do a shim check. Checked that way they checked less than .002, the newer RR prefix ones ( think Remington retooled and run them on modern equipment) probably.001. Once torqued up these small differences are ok for me, sufficient torque is needed as in all threaded joints.
hogpatrol
Gold $$ Contributor
Huh? How did they stay employed? Five thousandths in the trade is carpenter's tolerance. In the shops I worked, scrap was cause for being fired.
Edit: What part of the country was this shop/plant?
Last edited:
Shrug*
It's also, as mentioned before, dependent on size. 0.005 over 10 inches is way different than it is over 1 inch. Feature complexity also plays a big role. I maintain that across setups, unclamping and reclamping the workpiece in a new orientation, that many parts would fail to hold within tenths. 0.005 is very realistic in that case without real care taken in fixture design and use.
Agreed. A small piece of barstock in a lathe being faced and threaded should hold tight tolerances between the two operations. 0.005 is most certainly a mistake! Folks throw around tenths here like that's as simple as throwing a dial indicator on it or just returning your DRO to zero, but it's way more than that!
hogpatrol
Gold $$ Contributor
Clamping and unclamping in a fixture in a CNC? They were operators, not machinists. Fixtures I made would easily hold .001. Cripes, I held less than .005 on a 60" diameter workpiece on a VBM. The level of skill in this country is in a downward spiral. If it can't be made on a CNC by some bozo with a machinist "certificate", it gets sent offshore. SMH.
Here's another "quote of the day" and it is purely my own. This will upset some folks on this thread and I could care less...here goes: there's a point in which a machinist stops being a machinist and becomes a preacher because the "work" he does is no longer machine work, it's just religion. Like many religions, it's meant to assert power and fool people.
thread lug abutments and face all in one operation agreed but what about the rest. if your getting .002 with a feeler gage at 1.375 dia. what is the back end doing your not really checking anything. just some quick math In my head gives .012 error at back end, how much clearance in bolt to raceway. I'm not condemning what your doing its just not getting you there. there are at least 8 checks starting with bore for warping and almost all are warped,taper and size. after that is straight and you know bolt will be straight you can check abutments and face and threads. funny no one mentions trigger location or or if its canted to raceway causing drag with cocking piece to trigger or its housing. and we haven't started on bolt issues....and yes tenths are capable in multiple setups its called indicating....
Tim Singleton
Gold $$ Contributor
Well, all I know is the line is full of custom actions
Not Many of them are capable of winning.
Not my opinion just look at the match reports
Not saying they need trued,blueprinted what ever you want to call it.
They do need tuned and refined
Calling them custom is a stretch
Not Many of them are capable of winning.
Not my opinion just look at the match reports
Not saying they need trued,blueprinted what ever you want to call it.
They do need tuned and refined
Calling them custom is a stretch
I almost always agree with you as I respect you and your knowledge. I have to ask this...If a claim of .0002" is made and you wish to verify and correct or improve upon it in some way, how would you do this? It's one thing to indicate something in. It's another thing when the tool touches off, and the machine needs to be capable of at least double the level of precision, just to verify in, much less remove material. Anyone can make an indicator read zero movement but if the part has .0002 and the indicator doesn't move, you're just moving the .0002 somewhere else, at best. At worst, you're doubling that error. This assumes a lathe with absolute zero runout with no tool nor bearing deflection. I agree about the bolt race way, which adds another huge variable in improving upon a .0002 claim. If the idea is for everything to be parallel and/or perpendicular to the bolt race way, and all actions warp...Well, you see where I'm going.
I spent 10 years clamping and unclamping tools on an engine block machining line, does that make me a machinist? If so, I'm going to put out a shingle and make some real money!! to hell with the Chinese
Mike I'm not sure where the .0002 number is coming from. if you run on a ground mandrel and check between centers and do all your machining then recheck and the error is gone I am not seeing tool deflection on a .002-.005 skim cut if you are something is real wrong... I have not seen any that run that good except ones I ground. I am also confused on getting a zero but part has .0002 tir sounds like indicator needs calibration or your not checking at 2 points for paralell . actions that are warped need bore straightened ie. lapped until straight and not tapered you already know your not going to just run a reamer in and make it straight. work from centerline you can not get square, checking to a bowed surface
I’m not sure how to get to
When the .012, the tenon length is about the same as the abutment surface so at the end of the tenon it’s about a 1 to 1 relationship. As long as the log surfaces run perpendicular to that and the bolt has some clearance so it can have some movement without imparting loads on the action. But again, I’m looking for reliable 1/2 moa or less not tenths. When looking at process capability it’s hard to find the capability to produce parts with tolerances less than .0005 if not ground.
As has been asked before, it would be interesting to see some data on the impact of these variations.
and as has been answered, from a true accuracy aspect benchrest is king the aggregates shrinking is the proof . of course they are always willing to have someone new prove it wrong.... 1/2 moa for how many shots or group of shots its really not that big a jump a decent bedding job and a good barrel with decent bullets should do the job. a .200 moa or under you better get to work....
Personally I base accuracy on 10 shot groups. The question is not if benchrest is king of aggregates the question is what elements of the tolerance reduction does what to groups. When applying the shotgun approach doing everything one does not know if the big improvement is from what, that is the question.
seems you have answered your own question, being that br shooters are reducing tolerances and straightening receivers and agg's are shrinking its pretty well self explained. on another note I have been back and forth with someone here that I a great amount of respect for and I am stopping any input on this thread for reasons we agree on....
Someoldguy
That's a loss for all reading this thread.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.