PDA

View Full Version : Helping others with gunsmithing questions..



Rustystud
05-11-2013, 09:26 AM
First, I want to say that Wilbur's Bench Rest Central Web site may have the largest collective group of shooting/machinist intellectuals. We all enjoy shooting and sharing our ideas for the rest of the web site community. We all may not agree on the methods but we all agree on the results.

Yesterday evening, I had a call from a shooter/gunsmith who frequents this forum. He asked me about the bolt nose cone angle of a particular manufacture. The action manufacture has been in business for a number of years and has changed their bolts a couple of times. I did not have any notes nor could I find any on the internet.

I recommended that he use a machinist protractor to set the compound on his lathe. He is an experienced gunsmith machinist and asked why not just use the indicated marks on his cross feed and compound. I explained that his indicated marks on his lathe should be verified with a protractor before using them. I told him over the years I had seen a number of lathes that were not indicated/marked accurately. He did not have functional machinist protractor and was going to get one the following day.

I explained that he could use the protractor to determine the bolt nose cone angle and to set his compound. I told him the protractor is made square a little larger than a business card. The protractor has a long arm that has a indicator mark on the short end that correlates with the protractor scale. The top and bottom sides are parallel and the sides of the arm are parallel to the indicator mark.

I explained to my friend by placing the protractor bottom on the face of the bolt and sticking the arm out at the indicated angle would give him a reference to guide the compound. By setting the flat side of tool holder on the back side compound. and adjusting the angle of the compound to run parallel to the angle of the protractor arm one can lock down the compound on the correct cutting angle. I use a small boring bar to cut the
correct cone angle in the tenon.

This explanation went off like a light bulb in my friends head. Maybe it will help someone else.
Nat Lambeth

Gene Beggs
05-11-2013, 01:39 PM
First, I want to say that Wilbur's Bench Rest Central Web site may have the largest collective group of shooting/machinist intellectuals. We all enjoy shooting and sharing our ideas for the rest of the web site community. We all may not agree on the methods but we all agree on the results.

Yesterday evening, I had a call from a shooter/gunsmith who frequents this forum. He asked me about the bolt nose cone angle of a particular manufacture. The action manufacture has been in business for a number of years and has changed their bolts a couple of times. I did not have any notes nor could I find any on the internet.

I recommended that he use a machinist protractor to set the compound on his lathe. He is an experienced gunsmith machinist and asked why not just use the indicated marks on his cross feed and compound. I explained that his indicated marks on his lathe should be verified with a protractor before using them. I told him over the years I had seen a number of lathes that were not indicated/marked accurately. He did not have functional machinist protractor and was going to get one the following day.

I explained that he could use the protractor to determine the bolt nose cone angle and to set his compound. I told him the protractor is made square a little larger than a business card. The protractor has a long arm that has a indicator mark on the short end that correlates with the protractor scale. The top and bottom sides are parallel and the sides of the arm are parallel to the indicator mark.

I explained to my friend by placing the protractor bottom on the face of the bolt and sticking the arm out at the indicated angle would give him a reference to guide the compound. By setting the flat side of tool holder on the back side compound. and adjusting the angle of the compound to run parallel to the angle of the protractor arm one can lock down the compound on the correct cutting angle. I use a small boring bar to cut the
correct cone angle in the tenon.

This explanation went off like a light bulb in my friends head. Maybe it will help someone else.
Nat Lambeth



Thank you Nat, for sharing your valuable time, experience and knowledge about gunsmithing/machining. :)

Years ago when I was learning to fit and chamber barrels, my friends and mentors, Cecil Tucker and Charles Huckeba were very patient, generous and unselfish with their time. One item of equipment they provided early on was a little stainless steel machinist's protractor like the one you described above. I still use it almost daily and consider it indespensable. I would not make an adjustment to my compound without it.

Speaking of Wilbur's 'Benchrest Central' I agree with you; this is the place to go if one wants the no-nonsense, latest, state-of-the-art information about benchrest and benchrest machining. Although I don't post as often as I used to, I still monitor the site as faithfully as ever. I have learned who to pay close attention to and who to ignore. You can never get everyone to agree about anything but in my opinion, Wilbur does an excellent job of keeping things civil and on track here on the forum.

You're right; there is a vast amount of priceless information to be had on BR Central.

Thanks again for sharing.

Gene Beggs

alinwa
05-11-2013, 06:33 PM
JUST that thread on bolt truing alone......

Yup. Wilbur has done the world a favor here :)

BTW I check in sometimes over on another forum, I've never posted but I read it when I'm bored. There are 5-8 threads right now that make me bite my tongue, nearly OFF! as it were.....

I just can't make myself post a rebuttal though.

To all you'se browsers out there, alla' you'se reading the 'net for information before you spend your hard-earned dollars, I'll speak as one who actually HAS SPENT hundreds of thousands of clams on gunstuff, the information on this site and this site only is solid gold. I'm not saying there's not some good information elsewhere but the ratio of bad info to good is HUGE. Around this forum and ONLY this forum bad info gets trounced, questioned, CORRECTED before someone gets hurt........ this specifically is why hundreds of folks will not post here :) :)

But it's worth it.

GOOD information is gold in the hand.

I know world-class gunsmiths who're personally affronted and upset by the open discourse on this forum. Altho some of those same folks, had they gotten published in 'Kinks' would be all proud.
Go figger
lol
al

Bobby Bailey
05-14-2013, 09:50 AM
Nat, Thanks for the information. I always learn something from you. And from most of the others on this site as well.
Bobby

MilGunsmith
05-14-2013, 10:42 AM
The whole point is to trade various ideas on how to accomplish a task. What might work for one may not work for you, because of different equipment or tooling availability. But by seeing many different ideas, you can make your equipment do the task. An perfect example is chambering, the steady rest vs through headstock debate will be going on for years, but if your lathe has a small spindle you can only do it one way. Hopefully we can all learn from each other and not get into some of the silly fights that go on on some of the "other forums", that may way is better than yours and if you dont agree your wrong. That has driven some good gunsmiths off those forums and we all lose there knowledge.

timbertoes
05-14-2013, 05:50 PM
Funny how the post is about a protractor...
have been eyeing them, and of course gasping at the cost.... which is the norm for anything good and useful!

but I wonder, if you have a certain make/model that you like , or it's second best choice ?

Rustystud
05-14-2013, 09:32 PM
Funny how the post is about a protractor...
have been eyeing them, and of course gasping at the cost.... which is the norm for anything good and useful!

but I wonder, if you have a certain make/model that you like , or it's second best choice ?

The protractor I used cost less than $15.00. I have seen them for as little as $6.95.

You might find one on e-bay or at a flee market for a $1.00.

Nat Lambeth

JerrySharrett
05-15-2013, 06:35 AM
The protractor I used cost less than $15.00. I have seen them for as little as $6.95.

You might find one on e-bay or at a flee market for a $1.00.

Nat Lambeth

Nat, timbertoes may be looking at something like the Starrett 359 protractor which is about $550.

http://www.starrett.com/metrology/product-detail/Precision-Measuring-Tools/Precision-Hand-Tools/Protractors-and-Angle-Measu/Vernier-Protractors/C359BZ

I think what you are referring to is a common draftsmans bevel protractor. The protractor off a combination square set would also suffice.

http://www.ebay.com/itm/24-Combination-Square-Protractor-4-Pc-Set-Ruler-New-/390595430795?pt=LH_DefaultDomain_0&hash=item5af14d498b

Jkob
05-15-2013, 08:01 AM
JUST that thread on bolt truing alone......

Yup. Wilbur has done the world a favor here :)

BTW I check in sometimes over on another forum, I've never posted but I read it when I'm bored. There are 5-8 threads right now that make me bite my tongue, nearly OFF! as it were.....

I just can't make myself post a rebuttal though.

To all you'se browsers out there, alla' you'se reading the 'net for information before you spend your hard-earned dollars, I'll speak as one who actually HAS SPENT hundreds of thousands of clams on gunstuff, the information on this site and this site only is solid gold. I'm not saying there's not some good information elsewhere but the ratio of bad info to good is HUGE. Around this forum and ONLY this forum bad info gets trounced, questioned, CORRECTED before someone gets hurt........ this specifically is why hundreds of folks will not post here :) :)

But it's worth it.

GOOD information is gold in the hand.

I know world-class gunsmiths who're personally affronted and upset by the open discourse on this forum. Altho some of those same folks, had they gotten published in 'Kinks' would be all proud.
Go figger
lol
al

AYYUP, Just offer an opinion on something and see what it rurns into. Some just seem to take it too personal.

RJM
05-15-2013, 08:17 AM
Some yrs ago, my Starrett came in a gerstner oak box loaded with quality tools. The previous owner had retired from Pratt&Whitney and had fed his family out of that box for 40 yrs. We made a deal & he was really just passing them along to someone who'd appreciate them.

It was kind of the same story with my Homer Culver measure, so keep your eyes open.

Regards,
Ron

Rustystud
05-15-2013, 01:18 PM
Here is a picture of an inexpensive Protractor. Let us cut out the personal insults go wreck your own threads. Thank You Nat Lambeth

IndianaJames
05-15-2013, 04:30 PM
...it's usually pretty easy to figure out who to believe and who's blowing smoke.

J

timbertoes
05-16-2013, 08:19 AM
Thanks for the picture, clarifies 100 % :)

sometimes....as you well know, the darn tools are to big to fit in the space to be measured. :p

timbertoes
05-16-2013, 08:23 AM
Right now..............

I'd give a left wing nut to make .22rf extractor slots that are worth a dang. driving me nuts.

Dans40X
05-17-2013, 12:04 PM
My preference is a Starrett # 493 protractor.
protractor/depth gauge.

VaniB
05-17-2013, 12:49 PM
While I am not advanced enough in this sport so that I have been machining my own parts or working with rifle bolts, I also own that same kind of tool and have used it to measure and/or produce the angle of dihedral in the wings of radio control airplane which is an important aspect of the planes flight performance. Yes, it is indeed a very helpfull and handy tool for such chores (of determining angle), and the less then $20 that I had paid for this stainless precision tool some years ago has been a good investment.

Rustystud....just need to say you're one of the good guys here that has offered me help in the past with some of my own projects and questions. This websight by far is the most invaluable source for such advice in the sport of precision shooting.