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Help! Need gunsmithing advice!
5mmgunguy
Member Posts: 3,092 ✭✭
I have a gunsmith building a rifle for me. I had Pacific Tool make me the reamer. The gunsmith called and said the reamer chattered when he tried to chamber the rifle and it was the reamer's fault. The reamer maker says it isn't my reamer'f fault, the gunsmith screwed it up. None of which any help. I don't need finger pointing I need advice how do I get it best fixed? Ask the gunsmith to redo the barrel threading and cut the chamber a little deeper? The gunsmith wants to fire cases in the new chamber and then put lapping compound on them and turn the barrel on the lathe while running the case with the lapping compound on it into the chamber. Is that an acceptable fix? Which is best? Help!
Comments
Just advice from an olde tool/modemaker
The fix you speak of is not the way to correct the problem, cutting a new chamber is the only way to fix it.
I have a lot of Dave Kiffs reamers and never had one chatter because of his workmanship.
Multitude of reasons, the last being a bad or improperly cut reamer.
1 - lack of lubrication
2 - wrong lubrication used
3 - too fast of feed rate
4 - too slow of feed rate
5 - too slow of head speed
6 - too fast of head speed
7 - incorrect setup
See where this is going? Just off the top...7 out of eight possibilities point to the person running the lathe.
I'm sorry to read about the trouble you're having with your new barrel. This should be a momentous occasion, not one fraught with problems and failures.
As much as I truly appreciate the confidence of the Captain, without being there to look at every detail, it's impossible to adequately judge the right and wrong of this situation. What I will do is play devil's advocate or the grape in 'Karate Kid' until we get some information or figure out how best to resolve this.
I am hesitant to blame either the reamer maker or the gunsmith because there can be other contributing factors to a problem with chatter. Besides, unless I can examine the reamer and the chambering set up, how can I judge? We can be suspicious of certain factors but I doubt that we can be 100% certain.
First and foremost, DO NOT let this gunsmith lap that chamber in the manner you describe or any other. If anything, the barrel should be set back significantly and a new chamber cut. That will solve your immediate problem.
I have over 150 reamers from Dave Kiff and a handful from the other makers. Of those that I purchased from Dave Kiff, I have questioned exactly two (2) of them for performance. One was an improper angle ground on the reamer which required a significant increase in tool pressure which I found unacceptable. Dave recognized the problem and fixed it, without question. The second turned out to be a problem with the barrel and not the reamer at all. Years ago, we had to get on the learning curve for the way cryogenic treated barrels needed to be cut. The first one we attempted chattered like a bandit but it just needed some changes in speeds, feeds and lubrication to correct the problem.
Gunsmiths aren't born knowing every possible variation of materials, cutter geometry, lubricants or coolants. These variants require practice, experience and staying touch with the manufacturers and custom tooling makers.
Some potential problems:
Cryo barrels need experience to cut a chamber correctly.
Lothar Walther (LW50) barrels need experience to cut a proper chamber.
Black Star barrels needed experience when they first came out.
If the hole in the barrel isn't straight, it can chatter.
If the reamer isn't sharp,
If the angles on the reamer aren't correct,
If the reamer isn't held concentric to the bore,
If the reamer bushing isn't exactly the right size,
Too much reamer pressure,
Too little reamer pressure,
Wrong coolant combination,
Wrong lubricant combination,
Hang a chip momentarily,
On and on Ad Nauseum.
Personally, I think the gunsmith should correct the problem and satisfy you the customer without question or finger pointing. You should have never heard about this in the first place. That's my feeling about customer service, it's not your fault, he cut the chamber, fix it. But...
I might have some qualms about letting him do anything because of his action in the first place. You might be better off taking the project to another gunsmith in order to get it done correctly.
Cut off the threads and cut a new chamber.
Please e-mail me if you want to discuss this further. I'll be glad to listen and respond to your questions or complaints.
Best.
I don't remember where I got the information, maybe an expert told me, but I wrapped the reamer with a couple layers of cloth or gauze and packed it well with grease and started reaming again. The packing when compressed allowed the cutting edges to cut perfectly and the compressed packing eliminated all the chatter. After a few cuts, I removed the packing and finished the chamber perfectly, just like ALL my projects.
We barnyard machinists hardly EVER goof up.
I wasn't going to explain every solution...[:D]
I ran into this with both a .50 cal. barrel and a .338 Lapua barrel, a day apart. I used Saran Wrap or some other plastic wrap to accomplish the same result. A roll now lives in my tool box by the chambering lathe. Wax paper works also but the plastic wrap seems to be a little better.
Best.