www.MG42.us

Crap. I just checked mine on my new TNW and it's 9.14mm. I'm thinking this isn't good. Any update anyone? Anyone had luck milling out their cone to 11mm or getting TNW to replace it?

I had my 9.5 drilled out to 11mm. It took about as long to write this, and it works much better in my TNW semi.

m2ball wrote:I had my 9.5 drilled out to 11mm. It took about as long to write this, and it works much better in my TNW semi.

Sounds like a plan. Did you use any special drill bits? Carbide? Or a lathe maybe?

sam game wrote:I fully agree with Sledge and there must be an explanation why nearly all of the booster cones mentionned in this thread are the 9.5mm supposedly rare type. I have two booster cones too and both are 9.5mm. Shouldn't original German WWII issue booster cones be stamped with the usual Waffenamt and/or manufacturer's codes? Mines show no markings at all.

FWIW, my cone looks like the pictured cone except that it is stamepd with a serial number (m/m to the gun). It is 9.5mm but is being opened up to 10.9mm today at my smith's shop

I believe a carbide bit was used.

Did you bother blending the cone taper, or just ream the existing hole and slightly radius the edges on either side?

I doubt it makes much difference personally. I'm just getting it reamed and radiused a few thou so it's easier to clean without overly sharp edges.

Got it back. The smith lathed it out to 10.7mm and it looks fine now. Range report delayed for a week though while I wait for belts to arrive

Here's an odd one. W/ all this talk about booster hole size, I decided to check mine from a matching DOT 44 parts kit, Mine measures a litttle over 10 m/m. The part is steel. matches s/n, and is also marked 10.1 (prob the dia. measurement)

I just checked 3 of mine using pin gages and they measure:

0.381" - 9.68mm
0.371" - 9.42mm
0.361" - 9.17mm

QC guys must have been on a break when mine were made -

Orin

I just checked my booster cone and it is also around 9.5mm in diameter...I got mine in 2005 from IMA (they sent me a mixture of mg42 and mg34 parts). If anyone has a spare bolt, feed tray, top cover or trigger group to sell...please let me know. Of course (as luck would have it) they have no more mg34 parts to swap out. Now, I need a booster cone too !

artie in miami

You can get an 11mm booster cone on ebay for $21 + p&p

http://cgi.ebay.co.uk/mg-34-recoil-boos ... dZViewItem

I got one just so that it had the correct size fitted. I will post pics of mine if anyone needs a better pic, as the ones on ebay are a bit fuzzy

FWIW, my smith only charged $5 to lathe the 9.25mm cone out to 10.7mm diameter and debur it. Much cheaper than ordering a replacement

I replaced the 9.5mm cone in my FA MG34 with an original 11mm cone. The MG functioned prefectly with a slightly slower rate of fire more appropriate for an MG34 than it had before. Cost of the original part - $35.

I have been shooting my 34 full auto for years, and I just checked my cone and it is 9.5mm. I also shoot 308 blanks that are weaker that the 8mm. I'm afraid if I make the hole larger that the blanks won't work.

Glad i found this thread, both my parts sets from mg34.com have 9.5 mm boosters.

I do remeber the .308 bbls from Ohio, was the 34 produced in .308? Century has the israeli bipods for $30 on their FAC site, I bought one a couple of months ago and its really neat

breda65 wrote:I have been shooting my 34 full auto for years, and I just checked my cone and it is 9.5mm. I also shoot 308 blanks that are weaker that the 8mm. I'm afraid if I make the hole larger that the blanks won't work.

I contacted Folke asking what damage would result using the 9.5 cone and this was his answer - "The unlocking cams take a beating if the bolt travels to the rear with too much force." Of course this is being said about firing live 8mm in a full auto MG34.

thanks for the heads up ordered mine today.....sure enough my booster cones were 9.5 mm

Some very astute34 owners have told me many times that a properly functioning 34 should eject case to the front of the gun, not just drop them downward. This came up when my class 3 34 started trapping cases. they noticed the ejection was almost straight downward. Turned out the bolt catch was worn and was causing the problem. Replaced it, cases then ejected to the front and has run flawlessly ever since. Has always had an 11mm booster.

Thanks for the heads up. I checked all of the cones I have, and all 3 were different! I haven't measured the holes yet but they appear to be different sizes. I have 2 styles of inside radii also; 2 of them have a straight line ramp from one end to the other. The last one has a blended area in front of the barrel and then a long hole to the end. All 3 of the outside shapes are slightly different. No markings on any of them. I'll get pics taken soon.

Craig

I have 2 booster cones one has a waa4 on it and it also has 9.5 stamped on the sid of it in the little machined area toward the nozzle end. I wonder why so many of them have the 9.5 or approximate size hole? Could it be that the Germans used a different load in their machineguns than the Norwegians? Maybe they changed them for more modern 8mm loadings? Just a thought.