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Discussion in 'Gunsmithing' started by SwissTech64, Nov 2, 2018.
Doing a rebuild on a 6.5 Gibbs and have a few questions....
morning have u read the book written about Mr. Gibbs.
talk about cartridge modification and innovation. this
man was way before his time. he and Mr.
weatherby were very innovative. question where r u
going to get brass for the round?? justme gbot tum
Well, what are they?
Graf & sons has 'Quality' brass on hand in 6.5 Gibbs. But it is also a fireforming cartridge which is made from any of the .30-06 derivatives. This is not a cartridge for amateurs to cut their teeth on. Get help if you are not an experienced reloader/wildcatter.
Got some Qual-Cart brass from Graf & Sons
morning, many moons ago I read the book wrote by Mr. Gibbs.
I was going to build a 7mm Gibbs. my smithy talked
me out of the build. justme gbot tum
Thanks so much for the replies......
I've not had experience with this kind of thing. Have built many rifles in standard calibers from 22-250 to 338 Lapua but the 6.5 Gibbs is new to me.
A new casing (Qual-Cart) will not chamber. Have tried to resize the cartridge in the custom made RCBS die that was used to make the original rifle build but the cartridge appears largely oversized for the die. Looking for recommendations.
BWI, the smithing on this rifle was somewhat sloppy. My friend who's rifle it was passed away two years ago, a retired Lt. Colonel. A B-25 pilot is WW2.
Thanks for the reply. I'll get this book.
Good Morning from over here...
Usually when we run into a situation such as you are describing, we 'cast' the chamber. Using CerroSafe (a product from Brownells), we heat it and then pour it carefully into the chamber. It cools quickly, then tap it out. This cast allows us to measure the size of the chamber. Then measure the brass to find the discrepancy.
If this is more than what you are comfortable doing, find another shooter or gunsmith with the experience to handle it with you or for you.
Let us know how this goes, please.
Are you sure the chamber is for a 6.5 Gibbs? Is it stamped/ engraved on the barrel 6.5 Gibbs? And does the die set say the chamber on the actual die? Finally what shell holder are you using? I probably will have to make a cast of the chamber. It might be best to have a good smith look at it.
Thank you... No this is pretty simple stuff. Have had experience in designing single part molds for prototypic development. Cerrobend is the low temp material that I'd probably use for this. I'll do this and get back to you.
One major item that I noticed was reamer chatter marks on the shoulder of the chamber. Not a good sign of competency. I'll no doubt, have to rechamber this barrel or start from scratch.
Chatter marks anywhere on the shoulder of a chamber are not necessarily a low mark for the gunsmith. Personally, I would have set the barrel back a thread and re-cut the chamber for proper headspace and eliminate the chatter. Trying to polish the chatter marks out can lead to screwing up the headspace, leaving us with the set back. But if the reamer was slightly dull or the primary cutting angle was slightly off, the chatter can occur. If the speeds and feed were off slightly, chatter can occur. But the end answer should be to fix that problem before releasing the firearm to the client.
yes, yes, and yes to your questions
Yes, I have done what you have suggested several times and probably what I'll do on this project.
Chatter marking for what I do professionally in and out of rifle building is not an acceptable thing. Once chatter starts, it generally does not stop. For me the best solution is to immediately stop the ream process as you feel chatter, then bore a new receiving entry, then ream to finish.
Successful reaming as you suggest is largely due to speeds and feed, but also better tooling. My lathe is an Austrian made tool and I use a Hardinge 3J collet closure chuck with less than .0002" runout as well as other stuff, but more on that later on if interested.
I'll be making a casting as you suggested and thanks again for the reply.
I'm a bit confused. It sounds like you are either a machinist or a smith. So I'm not sure what your question was about the Gibbs or why you didn't just fireform some brass yourself.
I'm really not an apprenticed Smith but have built many rifles in my youth and a few within the past few years. Have forgotten much over the years and am getting back into shooting again with much encouragement from my sons.
I have been a toolmaker, mechanical designer, and model-maker in prototypic product development.
I am 70 and still work part time in my home shop with excellent tooling for rifle building.
I don't remember everything and have some memory issues so I don't feel totally confident as you might imagine and your advice is greatly appreciated.
Regarding fire forming brass as you suggest, the stock Qual-Cart brass will not chamber, nor will they full length size in the 6.5 Gibbs RCBS die. This is where I an stumped.