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new Polish blanks

6K views 36 replies 16 participants last post by  Coils 
#1 ·
There seems to be a little confusion regarding these blanks. There are definitely two different versions, so beware.

One version is reported to be dead soft, most likely requiring more than just the axis pin holes and ejector to be hardened. It also apparently has a sanded finish making refinishing a little more difficult. The difference is easy to spot, the Sportsman guide (and some other vendors) does not have the chicken feet.

The ones that Copes and AK builder are selling are (from what I can tell by finishing a couple) exactly the same metal as the flats that they have been selling. Making hardening and refinishing the same as we have been doing all along with the flats.

Here is a comparison of a bent blank from Copes and a flat from akbuilder that I have bent. They appear to be the same.
I took a center punch and gave them both the same whack in a spot that will be covered by the PG. The results were identical.

Top pic is from SG website
 

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#4 · (Edited)
To further muddy the issue, the Polish shell I bought from AK-Builder (not APEX as I originally posted) has the chicken feet AND has a "sanded" appearance - which I actually like and could easily smooth out as needed.

"Dead soft" is a plus IMHO, but I don't see any undue softness in the shell I bought. OTOH, if the shell can't be spot-hardened then there is a problem.

Like U.S. AKM barrels, there will always be someone who finds "fault" with the product. I like to think that the challenge of the build includes dealing with perceived shortcomings of the parts.
 
#6 · (Edited)
The one they link to in that thread (keepshooting) does not have the crows feet.
They appear to be the same ones that SG is selling. Which are the ones suspected of being soft.

They are NOT the ones that Copes is selling.
Take a look at the center punch test I did above. I gave the bent blank and the flat a good solid hit, trying to keep the hits as even as possible. the resulting divots were pretty much identical. If these were as soft as those other ones (SG, keepshooting, et al) are reported to be there would have been a noticeable difference. I could tell just by the "spring" in it when I hit, it is nowhere close to dead soft. Drilling them out also confirmed this.

On a side note; Misty called me today to get my order for the other 3, within hours I had a notice from Fed-ex saying that they were in their possession and on their way. Gotta love service like that.
 
#7 ·
I looked for this thread you are refering to on ak files cause all of my hendersons have chicken feet, maybe its the batch i got ( first offering) also I m not a metalurgist but the steel looks the same as any flat or plain steel sheet I would roll on my brake

on thing I noticed there are alot a Yahoo's on that site, and everyone is a expert

sprat

please send along that link
 
#8 ·
LOL Re: Yahoos. I know lots of them, from where I work.

Here is one link-there is more than one.

Heat treating receivers - The AK Files Forums

Seems to me whether 4130 or 1050 the only real difference is a higher annealing temp for the 1050. I tend to think 7.62x39 has this one right-they are just like what's been done all along. I'm also thinking that someone effed up spot heat treating and when the FCG holes started to come apart they blamed it on the steel...

I also think cheap wine tastes pretty good, so my opinion ain't worth much. Anyway, I'm glad I got the ak-builder blank and not one of the others.
 
#10 ·
What we need is a rockwell hardness tester. There was one were I worked years ago but that place is out of business. It was simple to use. Stick the metal in, pop it with the spring loaded puncher and read how deep it punched. I am probably over simplifeing it as I never operated it. I wonder if anyone in town has one. I have one of the Copes blanks to test. I'll look into it.
 
#11 ·
I am not going to completely let the cat outa the bag, but I just sold a Rockwell Hardness Tester to another Gunco member who is attempting to start up a side business heat treating these blanks for people. I think it's a fantastic idea, since they are not an FFL item. Gives all us homebuilders access to a higher quality standard, that only a handful of guys have had access to in the past. I know that some folks have the equipment/procedures for a full heat treat, but I bet 98% of the homebuilders that bend their own flats don't. This will be a good thing for the entire community. I wish him well, and hope that he gets his process dialed in soon, and starts an "open for business" thread.
 
#12 ·
One version is reported to be dead soft, most likely requiring more than just the axis pin holes and ejector to be hardened. It also apparently has a sanded finish making refinishing a little more difficult. The difference is easy to spot, the Sportsman guide (and some other vendors) does not have the chicken feet.
THE SANDED X39 BENT FLAT I HAVE HAS A CHICKEN FOOT.
IM NMOT SURE WERE IT CAME FROM AS IT WAS SENT TO MY BY A MEAMBER .
 
#13 ·
I am not going to completely let the cat outa the bag, but I just sold a Rockwell Hardness Tester to another Gunco member who is attempting to start up a side business heat treating these blanks for people. I think it's a fantastic idea, since they are not an FFL item. Gives all us homebuilders access to a higher quality standard, that only a handful of guys have had access to in the past. I know that some folks have the equipment/procedures for a full heat treat, but I bet 98% of the homebuilders that bend their own flats don't. This will be a good thing for the entire community. I wish him well, and hope that he gets his process dialed in soon, and starts an "open for business" thread.
THAT WOULD BE GREAT. I HAVE A FEW OTHER THINGS ID LIKE TEMPERED INCLUDING HOME MADE BENT UNDRILLED FLATS IN HEAVIER METAL..

KEEP IN MIND THEY NEED TO BE TEMPERED BEFORE ANY WORK IS DONT TO THEM OR THE ATF MIGHT GET YOU .
 
#16 ·
The one without the Y stamp for the third axis pin hole looks to be cut for a milled receiver double hook trigger and have the "drain holes" for the bending jig pins. Those just look like American-made flats that have been bent. Are the other ones already fully hardened? The imported lower bolt rails come fully hardened.
 
#17 ·
The one without the Y stamp for the third axis pin hole looks to be cut for a milled receiver double hook trigger and have the "drain holes" for the bending jig pins. Those just look like American-made flats that have been bent.
possible explanation for that. LOL. Caption from that pic

Here is a comparison of a bent blank from Copes and a flat from akbuilder that I have bent.
 
#19 ·
We are still trying to figure out exactly how many different versions of these blanks are being sold right now. There appears to be at least 3.
We know that the ones that copes and akbuilder are selling are good. They appear to be the same material as the flats we've been using.
Some of the other vendors are selling ones made of questionable material. We are trying to determine who is selling what. I'm just going to play it safe and stick with the copes/AKB versions
 
#20 ·
I corrected my original reply to this thread. According to an email confirmation I just found, my bent Polish blank is from AK-Builder and has both chicken feet and a brushed finish - not smooth like the flats he sells.
 
#21 ·
WHAT NEEDS TO HAPPEN IS SOME ONE NEEDS TO SEE HOW THE BRUSSED VERSIONS COMPARE TOT HE SMOOTH AN SEE IF THERE IS ANY DIFFERANCE. THIS IS GETTING REALLY CONFUSING ON MAYN BOARDS. SOME GUYS ARE SAYING THERE FINE OTHERS ARE SAYING THERE SOFT AN MAYNOT EVEN TAKE A TEMPER.

I DOUBT COPES IS GETTIG THERE SPECIAL FROM ANY ONE ELSE. IT WOULD BE NICE IF THEY GAVE US SOME INFO ON WERE THER COMING FORM AN HOW THERE GETTING HERE. I DONT NEED TO KNOW THE IMPORTER BUT ID LIKE TO KNOW SOME HISTORY. SOME ONE IS BUYING THESE FROM POLAND AN SHIPPING THEM HERE. SOME ONE IN POLAND IS MAKING THEM FOR SALE. THERE HAS TO BE INFO OUT THERE.
 
#29 ·
the purpose of me re-starting this thread was to jog folks memories as to who was setting up operations to heat treat these blanks??
there were several post I can't find them here or at AK forums??
I remember reading several guys were going to do it

need help here
 
#30 ·
There's a thread on the marketplace at AK-Files where a guy is offering a service to heat treat blanks.......but...

From what I've gathered:
After the spot welds are done, the blank should be stress relieved at 750
After SR the receiver gets heat treated at 1600 and quenched
After Heat treat the receiver gets annealed to 700 and slow cooled

This is how I did my last two. Used a buddy's kiln. Took most of the day for two receivers, but they did turn out great.

In the process of piecing together my own kiln, the parts are surprisingly cheap.
 
#31 ·
the purpose of me re-starting this thread was to jog folks memories as to who was setting up operations to heat treat these blanks??
I think TheDarkNight (I hope that's right) was offering it, but I don't know if he was doing it with the rails in or just the receiver as you received it as an 80%
 
#36 ·
There seems to be a little confusion regarding these blanks. There are definitely two different versions, so beware.

One version is reported to be dead soft, most likely requiring more than just the axis pin holes and ejector to be hardened. It also apparently has a sanded finish making refinishing a little more difficult.
The difference is easy to spot, the Sportsman guide (and some other vendors) does not have the chicken feet.
The ones that Copes and AK builder are selling are (from what I can tell by finishing a couple) exactly the same metal as the flats that they have been selling. Making hardening and refinishing the same as we have been doing all along with the flats.

Here is a comparison of a bent blank from Copes and a flat from akbuilder that I have bent. They appear to be the same.
I took a center punch and gave them both the same whack in a spot that will be covered by the PG. The results were identical.

Top pic is from SG website
Sorry to bring up an older thread but I and my friend just got three of these Polish blanks from Sportsmans Guide and ours are smooth finished not sanded and they have the "Chicken Feet" if that is what you all call the X and Y markings.
 
#37 ·
they have the "Chicken Feet" if that is what you all call the X and Y markings.
Yes that is what is meant by "chicken feet", but saying the X & Y stamp(ing) will still be understood.

And thanks for the heads up that you got these from SG
 
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