SSD BD-44/STG-44 question

H Wally

H Wally

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Hi all,
wondering what you guys know about the barrel assembly on the SSD BD-44? Specifically, how the barrel is attached to the receiver and the logistics of removing the original barrel and replacing it with an 18.5+ inch barrel, as I'm contemplating the viability of making a non-restricted barrel for the BD-44, as I understand that the short barrel length is the only thing limiting its status. So far I have found references to the barrel being pinned, but no direct statements and no information on whether or not it is even removable due to how the sheet metal housing is fitted.

Had an opportunity to handle an original dewatt today but wasn't able to learn much about the internals on it, so am back where I started :p
 
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I had wondered about this too... and the possibility of having the new barrel done in a more readily available caliber as well.
 
Can't say for sure, but an old European fellow once told me that the things were just a slight interference-fit achieved by heating the "receiver ring" (barrel block) and chilling the barrel, inserting the barrel into the frame, drilling and inserting a chilled pin.

Wish I could come across a few of the critters. Don't think it would take really long to figure it out.

If you really want to KNOW, get the thing X-rayed. That SHOULD tell you more than I can.

Hope this helps.
 
Looking at the parts drawings I can't find anything that really indicates how the barrel is retained. I believe that it is a combination of press fit and pin. There is a large pin directly under the chamber.
 
If they are following the standard engineering blueprints of the STG44, the barrel will be pinned in with a transitional fit, i.e. up to 0.00015" clearance or 0.00110" interference. For the machinist or engineer the fit is 23mm N7/h6. The pin has an identical N7/h6 fit, but is 8mm diameter, and thus has slightly tighter tolerances/allowances. I have full engineering blueprints for the STG44 in you need anything, or want a copy.

Or for those that like metric:

23mm N7/h6 transitional fit
Shaft= 23mm +.000/-.013 Limit values: 22.987mm to 23.000mm
Hole= 23mm -.007/-.028 Limit values: 22.972mm to 22.993mm

8mm N7/h6 transitional fit
Shaft= 8mm +.000/-.009 Limit values: 7.991mm to 8.000mm
Hole= 8mm -.004/-.019 Limit Values: 7.981mm to 7.996mm
 
Blastattack said:
If they are following the standard engineering blueprints of the STG44, the barrel will be pinned in with a transitional fit, i.e. up to 0.00015" clearance or 0.00110" interference. For the machinist or engineer the fit is 23mm N7/h6. The pin has an identical N7/h6 fit, but is 8mm diameter, and thus has slightly tighter tolerances/allowances. I have full engineering blueprints for the STG44 in you need anything, or want a copy.

Or for those that like metric:

23mm N7/h6 transitional fit
Shaft= 23mm +.000/-.013 Limit values: 22.987mm to 23.000mm
Hole= 23mm -.007/-.028 Limit values: 22.972mm to 22.993mm

8mm N7/h6 transitional fit
Shaft= 8mm +.000/-.009 Limit values: 7.991mm to 8.000mm
Hole= 8mm -.004/-.019 Limit Values: 7.981mm to 7.996mm
Click to expand...

Which drawings do you have? Are they in digital format?
 
That's good to know! Thanks for that, hadn't expected specs! I've never seen an STG taken apart past field stripping. My main concern is that somehow the stamped metal parts were fitted permanently somehow through spot welding or blind holed pins that would make disassembly to remove the barrel difficult.

This diagram is the first I've seen that shows the various parts, but still not sure how they are actually attached to each other - I don't see many screws or bolts around the stamped metal parts.... hoping they just interlock.

865322.jpg
 
"Remove the barrel by supporting the rec. and using a press, push the barrel pin out with a short hard steel pin.
To get the barrel out of the rec., I use a long piece steel round stock with a pilot lathe turned on one end to fit the back of the chamber to guide it . Support the front of the rec. between 2 steel support blocks and using the press, push on the steel round and the barrel will come right out.
Obviously, the ejector was removed to provide access for the steel rod to the back of the barrel...The barrel hole in the PTR rec. is .020 larger than a MP and the retaining pin is .070 furthur forward. Therefor a MP barrel would not work in a PTR without extensive rework." Courtesy of Pete Fleis (US licensed full auto builder).

Once the barrel is removed you would have to re-work an 8mm barrel or get SSD/Kulmbach to manufacture you an 18.5" barrel.
 
H Wally said:
Hi all,
wondering what you guys know about the barrel assembly on the SSD BD-44? Specifically, how the barrel is attached to the receiver and the logistics of removing the original barrel and replacing it with an 18.5+ inch barrel, as I'm contemplating the viability of making a non-restricted barrel for the BD-44, as I understand that the short barrel length is the only thing limiting its status. So far I have found references to the barrel being pinned, but no direct statements and no information on whether or not it is even removable due to how the sheet metal housing is fitted.

Had an opportunity to handle an original dewatt today but wasn't able to learn much about the internals on it, so am back where I started :p
Click to expand...

Just take a Dewalt Reciprocating Saw, Cut off the short barrel (SSD BD44) and install an MG34 or MG42 Barrel and Shroud for that one of a kind look!
 
You can make up a barrel from any .30-calibre blank, chamber for the .30 Kurz developed by "Dangerous" Dan Cotterman back in the early 1960s.

It is a 7.92 Model 39 case, necked slightly to handle a standard .308" bullet, otherwise no changes.

RCBS lists the dies, believe it or not.

Cotterman did this to an M-1 Carbine, had all kinds of problems. Not practical for the Carbine, but the PERFECT solution for one of these.
 
Do you have an dimensions for the .30 kurz? If it is at all base off the 7.62x39 it isn't going to work in the STG/BD44 due to a number of issues.

7.92x33Kurz isn't that hard to find, 8mm barrel blanks are not that hard to find and the barrel profile is easy to find online. I have, somewhere, a complete barrel drawing for Inventor from the STG44 blueprints.

My prints come in 5 groups I beleive, but some of the upper and lower reciever drawings are not clear enough and the dimensions are a bit confusing.
 
The .30 Kurz is the 7.92x33 (also called the 7.92 Kurz, also called the 7.92 Pistole Patrone 39) simply NECKED to a .308.

There are NO other changes. It is the GERMAN case, NOT the Soviet case: same base diameter as a .30-'06.

You can fire Boxer-primed rounds out of one StG-44 (or the modern semi-auto version), pick it up, just FL resize in the .30 Kurz die and load it up.

ONLY difference is the bullet diameter.

For the lightweight 122-grain bullets, likely you would want about a 14-inch twist.

.30-calibre barrel blanks are available commonly in 10-inch twist and 12-inch. The 10-inch twist works fine for bullets in the 150-grain to 220-grain weights, is getting marginal with 123s. The 12-inch barrels (as used on the M-14) are better suited to lighter bullets such as the NATO 145-grain BT and should serve for the 123 or 125 which likely you would want for the Sturmgewehr..... or its civvy recreation. I would think a 14-inch twist would be a custom barrel. The M-1 Carbine used 16-inch twist, but that was for the little 110-grain RN bullet; I don't think I would want it in the StG.

Numrich makes barrel blanks at fairly reasonable prices. Some of them are off-centre at one end; all you do is re-centre it on your lathe by chucking your CENTRED end into the 3-jaw and use the Live Centre on your Tailstock, trim down until you have a cut all the way around. Generally it is not much. Numrich barrel blanks are all Button-rifled on P&W machinery. I have an old Numrich catalogue here which lists a 27-inch .30-calibre blank quite reasonably.

Hope this helps.
 
Just because I'm a bit slow ( ;) :p) The reason for using the .30 kurz is the wider availability of .30 cal barrels at reasonable prices and the wider availability of bullets for reloading?

Frankly I had hoped that it would be possible to keep everything as close to original as possible, but you have definitely brought up a good point on the availability of bullets for reloading. Can't seem to find any 110 to 130gr .320 bullets out there... unless I've missed them, which is absolutely possible :p
 
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Trade-Ex had proper slugs for the Sturmgewehr last I looked.

Point three-twenty-three diameter, hundred and twenty-two grains.

When the Commies "invented" the 7.62x39 Model 43 round, all they did was copy the Sturmgewehr loading with a bullet they could make and cases from their old Jap machinery that they used making brass for the Fedorov.

Yes, availability of loading components and barrel blanks would be the reason for such a conversion.

You know, likely you could use a barrel off an FAL. There were scads and scads of FAL parts available just before The Natural Ruling Party Of Canada scrood us on using them; might be some barrels left. They are already 12-inch twist for the 145 NATO bullet would be just about perfect. Trade-Ex also has slugs for this one in 125-grain weight.

Hope this helps.
 
A cheap easy source for a .30 barrel would be a retired .308 TR barrel. These often had 1-14" twists. With the breech cut off to eliminate the chamber, cutting the .30 Kurz chamber would get a new throat. Enough meat for any desired contour.
.30 Kurz cases could be made from any number of parent cases. I suspect that if shorter ones like .250 Savage or .22-.250 were used, neck reaming would not be necessary.
For that matter 7.92 cases can be made the same way. RCBS used to supply a form set for making them; probably still do.
 
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