PDA

View Full Version : FN-49 - Technical Question...


Mountain Mosby
May 07, 2008, 18:39
Gathered most everything needed to WECSOG a FN-49... got a few questions for all you Gurus out there...

What's the differance between an FN-49 8mm and 7mm Reciever? (looking at pictures, it looks exactly the same...)

Would an 8mm bolt and carrier fit on a 7mm reciever? (I think that maybe the 8mm carrier would be a bit wider than a 7mm...)

For that matter, would an 8mm barrel fit in a 7mm reciever? (looks as though it will mate pretty well... timing is a little off, but looks to be easily worked out.)

Anybody got a 7mm FN-49 barrel they want to trade for an 8mm one???

Am I just wishful thinking and should just use the 7mm reciever as a pretty cool paper weight at work?

CDN_SAFN
May 07, 2008, 21:14
Well, having recently received a crash course education on the FN49 here myself, and from great sources, my best understanding is: receiver, receiver cover, sights, magazine, gas plug, bolt and springs are different between calibers. I'm sure I missed some, but I'm still on the steep part of the learning curve myself.

Even though the receiver covers are different, they can be used interchangeably, the significant differences being the stripper clip slot, and the rear sight ramp curve.

Aside from the covers, I don't THINK the other parts I listed are interchangeable, but there are others here that can tell you that for certain, or not in this forum.

One difference between the 7mm and 8mm receivers would be the bolt locking shoulder pin (or cone) that is pressed into the receiver to adjust cartridge headspace would be an issue, since headspace is not adjusted by barrel-to-receiver threading depth, or the bolt length. The shoulder pin was made in various widths to control headspace based on the designated cartridge, then pressed into the receiver. The widths adjusted the bolt lockup position forward or backward, setting the headspace.

I'll be the first to admit that these are mostly best-guesses, but I hope they help, or at least prompt others to jump in and correct any mistakes I've given.

gunplumber
May 07, 2008, 22:17
I have plenty of FN 49 locking shoulders.

bykerhd
May 07, 2008, 22:59
I don't know if an 8 mm barrel will fit.
But, Springfield Sporters(ssporters.com) had brand new old stock Belgian 8 mm barrels still in the cosmoline. Beatiful barrels. And they were DIRT cheap. I bought one a while back.
They still have them listed at $ 35.00.

Goose52 or gunplumber could probably tell you if that 7mm receiver will take the 8mm parts. Cartridges are about the same length and the bolt face would be the same. No idea whether the Belgians might have made design changes that would not make the change possible.

Goose52
May 08, 2008, 14:20
The below responses are based on an assumption that you are considering converting the 7x57 receiver to a 7.9x57 ...

Originally posted by Mountain Mosby
What's the differance between an FN-49 8mm and 7mm Reciever? (looking at pictures, it looks exactly the same...) There are a number of differences between receivers (it takes me 3 pages to describe the differences in my book), but the primary one for your purposes is that the magazine ports in the receiver are different lengths for the various chamberings. The port length on the 7x57 receiver is shorter than the port length for the 7.9x57. That means that you may have a problem with feeding the longer 7.9 ammo. The difference in port length is only .1” so it may or may not be a factor (but FN created the different port lengths for a reason …). Also, you may have issues depending on what trigger guard and magazines that you intend to use.

Originally posted by Mountain Mosby
Would an 8mm bolt and carrier fit on a 7mm reciever? (I think that maybe the 8mm carrier would be a bit wider than a 7mm...) Yes, given normal manufacturing tolerances. Of course this, along with a potential barrel change, will require checking and possibly resetting headspace (see the other posts).

Originally posted by Mountain Mosby
For that matter, would an 8mm barrel fit in a 7mm reciever? (looks as though it will mate pretty well... timing is a little off, but looks to be easily worked out.) Yes

Originally posted by Mountain Mosby
Anybody got a 7mm FN-49 barrel they want to trade for an 8mm one??? That’s not likely …

Goose

ftierson
May 08, 2008, 15:05
Originally posted by Goose52
That’s not likely …

:)

As a matter of fact, I have a couple of new 8mm barrels that I'd be happy to trade for 7mm ones too...

:)

Forrest

Mountain Mosby
May 08, 2008, 17:41
Goose, Thank you VERY much. You confirmed what I had assumed. I believe that I could make it work, but for the sake of possibly doing things to the 7mm reciever that would have the FAL Gods upset with me, I have decided to get an 8mm one for this build... I'll leave the 7mm reciever as is in the hopes of using it as a 7mm, instead of bubbaing it into an 8mm. It will make a fine curiousity as a paperwieght in my office until then...

ftierson, maybe we can get one 7mm barrel for three 8mm, I'll be happy with custody of one weekend a month and every other Tuesday...

Mark, I'll be in contact once I figure out which one I nee! How you been??? It's been a while. I still got that Izzy FALO... It's my favorite rifle!

bykerHD, good to see you! Been a while.

CDN_SAFN, thanks for the ol' collage try!

CDN_SAFN
May 08, 2008, 18:22
Glad you got the info you needed to make an informed decision on.

Double thank Goose, he (and his book) is the one who has helped me, and gave me any info I tried to pass on. I just hope I got it right...

FYI, there is a company up here that is selling new 8mm barrels called Marstar. They are not the cheapest kids on the block, but I would imagine they don't move very many, and may be a limited source when better known wells start to run dry. Unfortunately for me, that seems to be the only part, and dealer of any SAFN 49 variety here in Canada. I'll keep looking though...

Mountain Mosby
May 08, 2008, 18:57
Originally posted by CDN_SAFN
Glad you got the info you needed to make an informed decision on.
Double thank Goose, he (and his book) is the one who has helped me, and gave me any info I tried to pass on. I just hope I got it right...

Oh yeah. Goose is Da Man...

Originally posted by CDN_SAFN
FYI, there is a company up here that is selling new 8mm barrels called Marstar. They are not the cheapest kids on the block, but I would imagine they don't move very many, and may be a limited source when better known wells start to run dry. Unfortunately for me, that seems to be the only part, and dealer of any SAFN 49 variety here in Canada. I'll keep looking though...

I got all the 8mm barrels I need, want one? Now if you find a 7mm barrel for me, I'll buy you a bottle of Captain Morgan's Private Stock....

gunplumber
May 08, 2008, 19:37
I have 2 8mm barrels, new, at $65 each, and a sewerpipe at $20

Mountain Mosby
May 08, 2008, 19:48
Originally posted by gunplumber
I have 2 8mm barrels, new, at $65 each, and a sewerpipe at $20

Is the sewerpipe ceramic or cast iron? ;)

CDN_SAFN
May 08, 2008, 19:53
.... the ultra-rare smooth bore "jungle" SAFN firing high velociyt 8mm flechette rounds. I think I read about those in a book somewhere....?

(Just kidding Goose!:D )

gunplumber
May 08, 2008, 20:27
I think it was an experiment in making synthetic fur.

maximum armor
October 25, 2008, 14:11
CDN SAFN

FYI, there is a company up here that is selling new 8mm barrels called Marstar. They are not the cheapest kids on the block, but I would imagine they don't move very many, and may be a limited source when better known wells start to run dry. Unfortunately for me, that seems to be the only part, and dealer of any SAFN 49 variety here in Canada. I'll keep looking though...

I just got the last one from what i was told by Marstar lucky for me because i had put it off for a while before i ordered it. :biggrin:

hagar
October 25, 2008, 14:19
There was a 7mm barrel on GB for $130 or so.

RadioFlyer
November 04, 2008, 02:32
Have there been any conversions here in the states...

I was able to find an Argentine conversion to .308/7.62 and bought Goose's book from wet dog to go along with the now 8 mags...

Have there been any gunsmiths here that have converted say an 8mm to a .308 or even something funky like 30-06 to a .270?

Just interested to see how far this goes... I see the odd M1a in .243, and have seen the old M1 sprouting everything from .270 to .308...

Goose52
November 05, 2008, 15:29
Individual rifles have been converted by gun tinkerers but there has been no commercial program to perform cartridge conversions in the U.S.

I have heard reports of a few Egyptian contract rifles that were converted to chamber the wildcat 8mm-06 since you can perform this conversion with available parts (plus some milling on the receiver) and you don't need a new barrel. You might want to look at the "Collector's Note" on page 130 of my book for additional information on this topic.

The problem in cartridge conversions is the barrel. No one has made a run of barrels for this rifle in alternative calibers like .243 or .277. It's possible to drill out and sleeve an original barrel I guess - but that's a lot of work with little to gain.

Cartridge conversions for this rifle are popular in France where it's difficult (but not impossible I understand) to own firearms chambered for "military" cartridges. So, in France, I have heard of FN-49s rifles being converted to .270 and to .300 Savage, to name two. I don't know how the conversion is accomplished (newly made barrel or original barrel drilled and sleeved).

Goose

RadioFlyer
November 06, 2008, 03:00
Originally posted by Goose52
Individual rifles have been converted by gun tinkerers but there has been no commercial program to perform cartridge conversions in the U.S.

I have heard reports of a few Egyptian contract rifles that were converted to chamber the wildcat 8mm-06 since you can perform this conversion with available parts (plus some milling on the receiver) and you don't need a new barrel. You might want to look at the "Collector's Note" on page 130 of my book for additional information on this topic.

The problem in cartridge conversions is the barrel. No one has made a run of barrels for this rifle in alternative calibers like .243 or .277. It's possible to drill out and sleeve an original barrel I guess - but that's a lot of work with little to gain.

Cartridge conversions for this rifle are popular in France where it's difficult (but not impossible I understand) to own firearms chambered for "military" cartridges. So, in France, I have heard of FN-49s rifles being converted to .270 and to .300 Savage, to name two. I don't know how the conversion is accomplished (newly made barrel or original barrel drilled and sleeved).

Goose

Great Goose - thanks...

I did skim over several sections of the book, of course I was most interested in your info about my particular .308 rifle conversion (Argentine), I don't think you mentioned it but it does look as if the rifle I have was drilled and sleeved for the new caliber.

I would think the rare nature, and the available of other autoloaders in .243, .270 and others would prevent all but a hardcore wildcatter FN49 fan of a gunsmith to do this conversion.

Because France and other restrictive countries like Mexico MAKE reasons for conversion there would be an occasional conversion, but in the US the response would be "why bother".

Goose52
November 06, 2008, 08:47
Originally posted by RadioFlyer

I did skim over several sections of the book, of course I was most interested in your info about my particular .308 rifle conversion (Argentine), I don't think you mentioned it but it does look as if the rifle I have was drilled and sleeved for the new caliber.

Your barrel was not drilled and lined. It was a newly manufactured, chrome-lined barrel made by Halcon in Argentina. If you look at it, you will see that there are no Belgian proofs, as you would see if it was a modified original barrel.

Please look at the first sentence of page 54 of the book.

You will be amazed at what you can learn if you actually read the book ... instead of skimming over the book ...

Goose

RadioFlyer
November 06, 2008, 15:20
Thanks Goose

And yea, my bad, I have had the book now for over a month, and I have it on my office desk almost as a "coffee table book" the cover does have nice photos... but is not the most conducive to through reading, almost more of a reference book. I did enjoy the section about the history of FN and about Dieudonne Saive. The info and photos about the prototype FN 37 rifle and the EXP-1 was great.

On page 54 I do see the info about Halcon/Metalurgica Centro of Banfield and the info about matching the numbers to the receiver. That numbering procedure could lead to confusion because it at first glance would seem to be a match. Also fired about 400 rounds out of my rifle this monday and was cleaning it the other day, I noted the barrel crown was a little rough on the edges and it LOOKED like there was a secondary sleeve inside - that most likely is the chrome lined barrel with a bit of rough finish work...

Looking at page 54 and the fig. 54-1 where you show the opening of the receiver for the magazine and reviewing the other points - I would assume that to convert, say an Egyptian contract to say .243 or .308 and mod for the 20 round magazines would be a project that was within range of a gunsmith who has good machinist skills or or course a good machinist/metal worker.

My version has the original stock, and it is cracked (but arsenal repaired poorly) will any of the FN contract stocks fit this contract? Or will I have to have one pantograph duplicated? (a plan of mine is to buy a pantograph for my son who does well in HS wood shop and he could use that as a method to make a small business for himself)

I also noted that the springs in the 20 round magazines are stiff and loading completely take a bit of effort - could springs from the FNFAL magazines be used in the conversion magazines?

Goose52
November 06, 2008, 18:59
Originally posted by RadioFlyer
My version has the original stock, and it is cracked (but arsenal repaired poorly) will any of the FN contract stocks fit this contract?

I also noted that the springs in the 20 round magazines are stiff and loading completely take a bit of effort - could springs from the FNFAL magazines be used in the conversion magazines?
A Belgian contract stock will drop on. Try the usual vendors for availability:
http://www.sarcoinc.com/fn49.html
http://www.e-gunparts.com/productschem.asp?chrMasterModel=1410z1949
http://www.ssporters.com/FN49.htm

Haven't a clue as to whether FAL magazine springs would work (or any other similar springs like M14, Cetme, HK-91/G3, etc ....).

Goose