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Gunsmithing Prefit Info Needed

Airw4ves

Sergeant of the Hide
Full Member
Minuteman
Oct 10, 2014
258
138
Canada
www.youtube.com
So I have a Ruckus action on order. They guarantee tolerances, but for some reason they dont provide the information needed to get a prefit ordered from a local smith. Im wondering what information is needed to get a prefit made?
Thanks
 
Needing to measure the action completely defeats the purpose of pre-fits. They shot me down cold when I asked for a print 2 months ago. Hopefully they've changed that policy now.
That’s why you should get your smith to call.
Maybe you didn’t inspire confidence to them.
 
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That’s why you should get your smith to call.
Maybe you didn’t inspire confidence to them.
I've threaded 3-400 prefits in the last 2 yrs, granted just part time. If that's not good enough, oh well.
They told me that they hadn't released a print to any of the "big" barrel makers, but instead had chose to send out loaner actions so the individuals could take their own measurements, which they also offered to send me.
The "just have your Smith measure the action" comment makes me think that most people are just ignorant as to how far the pre-fit game has come in the last few years and the new possibilities that go along with that option.
 
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I've threaded 3-400 prefits in the last 2 yrs, granted just part time. If that's not good enough, oh well.
They told me that they hadn't released a print to any of the "big" barrel makers, but instead had chose to send out loaner actions so the individuals could take their own measurements, which they also offered to send me.
The "just have your Smith measure the action" comment makes me think that most people are just ignorant as to how far the pre-fit game has come in the last few years and the new possibilities that go along with that option.
Well without a print or an action to measure it not much of a pre fit is it.
Most here know what it is, that’s why many actions are popular.
 
Yeah, spoke to them and they wouldn't release it. Something about liability 🤷🏻‍♂️
I can have my smith measure it, but ultimately Id like to be able to call up a company and order one by providing them the specs. Unfortunately Im in Canada, so getting barrels from Proof and others is very expensive, and slow.
Truthfully I was hoping to get the specs and send them to IBI to have a prefit done up as they’re in country. Im beginning to wonder what the point of guaranteeing tolerances is if I have to send my action off to get it measured...
 
I'm no gunsmith or machinist, but one would think you would want the print with the +/- tolerance. If a guy were to measure an action that was on the high or low side of the tolerance, I would think the potential for issues with fitment would be higher. The ability to measure 100 actions would likely allow you to please the statisticians and have a relatively good handle on both ends of the dimensional tolerances.

If they are truly doing business in this regard, it does not inspire a lot of confidence as a consumer.
 
I would cancel my order for this action. I expected better from Defiance.
Terminus at least has their prints readily available online for anybody to grab.
 
Here are a few I found on the internet. I get why you want your smith to spin up the barrels, but having a smith do it ads some inconvenience. If you really want your guy to make the barrels, just send your action to him once to get measured. If not, I've never had a proof prefit let me down. I would assume there are some companies making prefits in Canada for a decent price.



 
I'm no gunsmith or machinist, but one would think you would want the print with the +/- tolerance. If a guy were to measure an action that was on the high or low side of the tolerance, I would think the potential for issues with fitment would be higher. The ability to measure 100 actions would likely allow you to please the statisticians and have a relatively good handle on both ends of the dimensional tolerances.

If they are truly doing business in this regard, it does not inspire a lot of confidence as a consumer.

Which is precisely the reason I didn't take them up on the offer of an action to measure. (Other than the inconvenience of shipping the damn thing back and forth).
If we each have a tolerance of +/- .001 and the print is .950" that would make the range .946-.950" on paper with .004" between go/no-go gauges
Without the print, the action I measure might be .949, so I subtract .0015" to hit the middle of the range, shoot for .9475", but miss it by .001 and end up at .9465. All good, still in spec, right?
Wrong. I send it out to a customer who has an action on the other end of tolerance at .951, now there is .0045" difference and it closes on a no/go. In reality, they probably hold tolerance better than .001", as do I, so the chances of that happening are slim.
Defiance is a good company that makes a nice product, it just really struck me as odd that they would advertise the new actions as "pre-fit" compatable, but then baulk at releasing the specs needed to make the prefits . Especially after I've never had even a second of hesitation in getting specs from the rest of the companies I've made the request of.
At the end of the day I've got more work than I can handle cutting barrels for other brands, so it makes no difference to me. I just think consumers need to be aware of the potential roadblock before they make a purchase.
 
Defiance Machine does not advertise actions as “pre-fit” nor do we publicly publish prints. Let me explain why. The fit between a barrel and action is the only thing protecting the shooter from the extreme pressure created in the chamber. If the fit is incorrect, people get hurt. This is the responsibility of whoever fit and chambers the barrel. They must decide what the specs are for their product. Defiance can not assume liability for something out of our control. If the print is available for “anyone to grab” and it’s very easy to buy a lathe and watch a YouTube video about how to fit up a barrel, does that mean you’re qualified? No. But, when this happens and something goes wrong, the lawyers go after the name on the receiver and the document.

There are hundreds of competent machinists/ gun builders reading this that could look at a print and produce a perfect pre-fit barrel. They all have proper measuring tools and know how to maintain and use them. They understand machine set up and proper cutting tool geometry.

The numerous barrel companies and gunsmiths that already do pre-fits for Defiance actions have created their own documentation and process. Defiance Machine is happy to work with any builders on one to one basis to advance their business. This even means sending an action to inspect and phone time to answer questions.

Glen Harrison
 
Ok, I dont pretend to be a gunsmith or a machinist. I let the professionals do their job, and I do mine.
But what does guaranteeing tolerances do for the consumer if the smith still has to get the specs off of their action in hand? Marketing? I'm not trying to be rude, I'm trying to educate myself.
If companies like Proof are able to manufacture prefits for these actions due to tightly controlled tolerances on the action, then what is stopping others like my smith? Believe me, Id love to grab a proof prefit, but unfortunately that isn't exactly the most financially feasible and with COVID halting everything at the border for months, I would love to be able to send some specs to a manufacturer, and have them spin me up a prefit. Also, shipping a $2100 (Canadian) action across the country twice with a completely inept shipping service like Canada Post is why I wanted to go the prefit route. If that's not doable, that's fine, and really isn't a slight against Defiance. They produce phenomenal actions, and I wouldn't have placed an order for one if I thought they were trying to screw me or had an inferior product. I had plenty of choices, but I chose them for a reason.
I'm just genuinely curious what the tolerance guarantee is for, if not prefits.
 
Ok, I dont pretend to be a gunsmith or a machinist. I let the professionals do their job, and I do mine.
But what does guaranteeing tolerances do for the consumer if the smith still has to get the specs off of their action in hand? Marketing? I'm not trying to be rude, I'm trying to educate myself.
If companies like Proof are able to manufacture prefits for these actions due to tightly controlled tolerances on the action, then what is stopping others like my smith? Believe me, Id love to grab a proof prefit, but unfortunately that isn't exactly the most financially feasible and with COVID halting everything at the border for months, I would love to be able to send some specs to a manufacturer, and have them spin me up a prefit. Also, shipping a $2100 (Canadian) action across the country twice with a completely inept shipping service like Canada Post is why I wanted to go the prefit route. If that's not doable, that's fine, and really isn't a slight against Defiance. They produce phenomenal actions, and I wouldn't have placed an order for one if I thought they were trying to screw me or had an inferior product. I had plenty of choices, but I chose them for a reason.
I'm just genuinely curious what the tolerance guarantee is for, if not prefits.
Screenshot_20200605-164832~2.png

Looks like I got some terminology wrong and assumed "guaranteed headspace" was the same as "Pre-fit compatible". They explain their position pretty well in the FAQ, although I don't remember seeing this last time I was on their website, so I'm guessing it's come up a lot lately.


Regardless, I stand by my opinion that guaranteeing the headspace dimension is a moot point if you won't disclose the dimension it's supposed to be guaranteed to be.