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Finished 80% cast receiver!!!!!!! by hand

21K views 48 replies 28 participants last post by  Sprat 
#1 ·
Hi

As I posted below I have completed a 70-80% receiver blank by century, I did this build by hand tools, these included a dremel, drill (cord), series of files-flat and round fine to bastard, levels, taps, cutoff wheels(stock up), grining stones, heavy vise. no milling machines no lathes or drill press. blueprints and downloaded posts by others from roderus

I will post the pictures in a few days, I have not cut the charging handle slot because I may relocate the charging handle.

this build should fire and feed fine. I am going to the range this week with a sub-caliber device 32acp in 308 adapter to fire function test. then the following week weak reloads very weak reloads

more to come

sprat
 
#2 ·
Got some pictures, also how did you heat treat.:thumbup1:

Sprat said:
Hi

As I posted below I have completed a 70-80% receiver blank by century, I did this build by hand tools, these included a dremel, drill (cord), series of files-flat and round fine to bastard, levels, taps, cutoff wheels(stock up), grining stones, heavy vise. no milling machines no lathes or drill press. blueprints and downloaded posts by others from roderus

I will post the pictures in a few days, I have not cut the charging handle slot because I may relocate the charging handle.

this build should fire and feed fine. I am going to the range this week with a sub-caliber device 32acp in 308 adapter to fire function test. then the following week weak reloads very weak reloads

more to come

sprat
 
#7 ·
Can it be done??? I did it!!!!

I test fired my century casting that I finished 70% to almost 95%

I loaded 1 weak reloads into the chamber. pulled the bolt catch and she locked up fine, with a coathanger and gun rest. I pulled trigger and low and behold no blown receiver, no cracks no deforms of any kind and I didn't loose any JB

but the primers came out and out the bottom of the mag well FLAT, case didn't eject ( gas valve not set) the neck was fire formed for a new caliber

Yes I know I am a smith excessive headspace and no I didn't headspace before hand.( bad habit building AK's) I will have to thread deeper about a half turn

To all my non friends here I was not hurt sorry to disappoint you!!!! you know who you are

when I loaded the 5 round in the mag ,she locked up tight, the pressure was high enough to blow the bottom of austrian mag out got to get that gas valve set

As of now I am the only person to have build a 70% FN FAL to fire function on all the sites I have checked

good luck with your castings

sprat
 
#9 ·
I have not heat treated the receiver as of yet, I was very concerned about this constant reference to blowing up the receiver from the beginning( I mean since 2003 when the first attempts were made to work these up over at RODERUS)
In fact some pictures for this build can be found in the FAL build section on roderus.

back to the heat treatment, after 5 shots of weak 308 there were no cracks, believe it maybe like the AK the barrel and bolt take the beaten, and yes 308 is hotter than 7.62 X 39mm
ok back to your question, bob at (a well known 80% receiver company) offered to assist me there, he nows of a facility to handle the project ( personnally I think its him)
post shooting examination revealed the jb touch up in the feeding ramp area was still in place I am wondering about the heat treatment

also two things to look out for the front of the casting is off to the left a bit. this must be compensated for.
also the feeding ramp is going to be a problem as are factory finished century receivers ( some rounds feed into the barrel base instead of the chamber. this is a common complaint on the fal files

I will answer any question on this build as long as it civil
sprat
 
#10 ·
That's pretty cool! I know these need the heat treat based on the threads I've read, and let's not forget DSArms' treatment of the issue. I think they had some blow-up pics on their site, but I don't really remember that far back.

Where do you find the castings these days? I saw one at a gun show one time, but that's the only one I've seen.
 
#11 ·
I bought one from Sprat & I've seen a couple sold here on Gunco recently. Also common on Gunbroker. WIDE range on prices. I need to learn more on operating my little mill before I tackle this one! By then I hope to have a DSA receiver to try & copy. I have three FAL kits, but no receiver stubs. So. I don't know what I'll do about a feed ramp? I've never seen a stub offered for sale. I don't even know what they look like. Maybe I can make one after getting a DSA receiver in my hands?
Good going Sprat! Let us know whay you learn about proper heat treating, as I may also have a treating oven by the time I try this project. I want to do some knife making & need an oven for that anyways.
 
#13 ·
Racerex1 said:
Here is some more information on finishing a 80% casting.
http://www.falfiles.com/forums/showthread.php?s=&threadid=60516

I thought this could give you more information and have the patience to do it.
Boy that thread isn't much help - "I think it is strong enough because it is so thick" and "I'm pretty sure you'll be OK".

I dunno - I'm not afraid of building one of these but the heat treatment would *literally* be the "make or break" part of it. It probably would be OK for the typical plinker at the range, but I tend to run mine pretty hard and would hate to have a FAL blow up on me. I think until there is a *good*, well documented process, I'm going to have to stick with a DSA. Ask me again after someone publishes a heat treat how-to document! ;)
 
#14 ·
hcpookie said:
That's pretty cool! I know these need the heat treat based on the threads I've read, and let's not forget DSArms' treatment of the issue. I think they had some blow-up pics on their site, but I don't really remember that far back.

Where do you find the castings these days? I saw one at a gun show one time, but that's the only one I've seen.

Here ya go Pook:

http://www.gunbroker.com/Auction/ViewItem.asp?Item=75889474
 
#15 ·
NO! DON'T TEMPT ME! I would do it then it would sit there forever while I searched and begged for someone to heat treat it for me! :D Sure is tempting, however. I wonder what is stamped on the side of it?
 
#16 ·
hcpookie said:
Where do you find the castings these days? I saw one at a gun show one time, but that's the only one I've seen.
I have one of these I'd like to sell. If your are interested send me a pm. I bought it and then ran into an Imbel receiver and couldn't turn it down. Couldn't wait to get the rifle shooting.
Kevin
 
#19 ·
range report

well I took the unheat treated century casing out again after setting the headspace. The first two shots were with weak 40,000psi .308 reloads again used a string to pull the trigger and guess what happened???

nothing

no blown receiver , no cracks, no movement of anykind, including the the gas system as the reloaded rounds were to weak as expected

then I loaded/shot two military 308 rounds as a proof load, only this time something happened!!!!

the gas system pushed that bolt carrier back and ejected the cartridge not once but twice. I then shot the rifle with the remaining 15 weak reloads, standing and in the gun rest. there are still a few quirks to work out. at this point a functional single shot rifle.

I need to tap the bolt carrier and form a cocking handle, because the ejector is wedged into the receiver the mag feed is/was not perfect, mag feed problems I am to understand from the threads on falfiles are common with century receivers whether 100% or 70%

that Falfile post I saw that years ago but he didn't do it by hand tools, he used a milling machine and did a fine job including heat treating with he says he used a touch
any cut or files areas are cold blued and will be parkerized and duracoated

pictures are at homegunsmithing.com

sprat
 
#21 ·
i had one of the castings and traded earlier this

year for some ak parts since i was lucky(?) enough to get a 100% century which has run 100% since i put it together. the bolt locks on the hardened locking lug which is fine but i would NEVER shoot a fal without a hardened reciever.too old and crippled to mess anything else up at this late date.i dont recall any difference in feed ramps between the unfinished and finished recivers ive had tho.
 
#24 ·
Pictures can be found on Roderus "homegunsmithing site"

and yes I shoot this rifle regularly without heat treatment, I am using 36gr of 3031 the bolt usually will not cycle. the casting is not lightened in any way except to open the chamber and to thin the rails

if you want some pictures
message me at captainjack692@aol.com and i will be glad to send what pictures I have

"the hardened locking lug which is fine but i would NEVER shoot a fal without a hardened reciever.too old and crippled to mess anything else up at this late date.i dont recall any difference in feed ramps between the unfinished and finished recivers ive had tho."
constructive comments only!!!!!!!!!!!!!!!!!!!!!!!!! since you didn't build it up how would you know if the rails were to spec or not another internet gunsmith????

sprat
 
#26 ·
sprat upload pic's to photobucket.com then post in here please
 
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