How to convert between 8MM/.308 caliber.

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drooling idiot
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How to convert between 8MM/.308 caliber.

Post by drooling idiot »

This is intended to be a comprehensive guide to converting factory approved calibers in the MG42 family of firearms, both semi and full auto versions. Links to other stickies have been provided for ease of reference within this stickie, they should show on your screen in the color blue. Move your pointer over top of these colored links and click on them to open the referenced page.

For the purpose of this stickie the Yugo MG53 can be considered identical to the German MG42. Also please consider .308 and 7.62 X 51MM identical.
While I acknowledge there are differences in both examples those differences aren't important to the purpose of this stickie.

Most parts , like bolts, flashhiders,buffers & recuperators are interchangeable between calibers.

Step 1
Identify these parts of your kit or gun that are on this list & determine their caliber.
  • 1) Barrel ............. part #72 ............ 8MM or .308 only
    2) Topcover ......... part #34 or #79 ... 8MM or .308 only
    3) Feedtray ......... part #80 ............ 4 different variants
    4) recoil nozzle ..... part #84 ............ Many different variants

link to detail parts break-down.


Step 2
Determine what model you have based on barrel , topcover & feedtray combination.
Correctly identifying the feedtray should identify the model variant
  • MG 42 = pure 8MM
    MG 1 = hybrid .308/8MM
    MG 2 = pure .308 patterned after 8MM
    MG 3 = pure .308
Link to stickie on feedtrays and top covers

Step 3
Determine what model you want to achieve .

Do you want to run 8MM only?
you want an
MG 42 set-up.

Do you want to run both .308 & 8MM as cheap and with as few parts as possible?
you want an
MG 1 = A hybrid 8MM topcover & feedtray converted to .308 set up.

Do you want to run .308 on belts only?
you want an
MG 2 set-up.

Do you want to run .308 on M60 links or belts?
you want an
MG 3.

Link to brief history of the models.


Step 4
Use this guide to determine what parts you need to change to achieve your conversion goal.

------------------------------------------------------------------------------------------------------

Barrels

While it seems obvious we need to state,
A 8MM barrel should only be used with 8MM ammunition.
A 7.62 X 51MM barrel should only be used with 7.62 X 51MM or .308 winchester ammunition.


------------------------------------------------------------------------------------------------------

Top covers & feed trays

A 8MM top cover will work with


1) an original MG42 8MM feed tray
2) a MG42 8MM feed tray converted to an
MG1 .308 feed tray.
.....NOT a MG2 or MG3 .308 feed tray. [/size]


A .308 top cover will work with either

1) A MG2 feed tray using DM1 belts only.
2) A
MG3 feed tray using DM13 links or DM1 belts (if you don't mind the extra wear on your belts).
.....NOT a MG42 - 8MM feed tray or MG1 .308 feed tray that was originally manufactured as 8MM.[/size]

------------------------------------------------------------------------------------------------------

Recoil nozzles

Sadly there is no definitive answer to give on recoil nozzles , they have been proving to be a trial and error situation to achieve a balance between cycling the action reliably and excessive recoil .
Try to use the largest nozzle opening you can with the ammunition your firing and still achieve reliable cycling. 8MM guns will need and should come with a larger opening than the .308 guns .

link to recoil nozzle thread.
"good , bad, .....I'm the man with the gun."

Its amazing anything works right around here with a bunch of
over-age juvenile delinquents running the place.
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Re: How to convert between 8MM/.308 caliber.

Post by Bil »

Thank you for putting all this in one spot,on one page.I hope this goes in the stickies section.It will be a popular link. ---bil
"I dream of a world where I can buy alcohol,tobacco and firearms from the same drive-up window,and use them all on the way home from work!" Dogbert
propos

Re: How to convert between 8MM/.308 caliber.

Post by propos »

Now that is a very comprehensive explanation. Even I can understand it. Nice work, DI.
TbcSEOD

Re: How to convert between 8MM/.308 caliber.

Post by TbcSEOD »

Anyway to get the origonal links fixed or info reposted (like pictures with features to ID different feed trays/top covers?

I don't know what to look for and am leary of someone else saying "Ummm yea, its a .308........ I think"


Thanks DI,
~TbcSEOD
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DARIVS ARCHITECTVS
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Re: How to convert between 8MM/.308 caliber.

Post by DARIVS ARCHITECTVS »

Please make this a stickie, DI... It's awesome.
DARIVS ARCHITECTVS
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drooling idiot
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Re: How to convert between 8MM/.308 caliber.

Post by drooling idiot »

bumped to stickie, links repaired. the new forum software formated the links differently.
"good , bad, .....I'm the man with the gun."

Its amazing anything works right around here with a bunch of
over-age juvenile delinquents running the place.
TbcSEOD

Re: How to convert between 8MM/.308 caliber.

Post by TbcSEOD »

:cheer: :cheer: :cheer: TY DI :cheer: :cheer: :cheer:
Docwade

Re: How to convert between 8MM/.308 caliber.

Post by Docwade »

Nice, between this and the top cover feed tray comparison, I've found out I have a spare 308 top cover for my inbound m53 and a mg2 tray. Nice!
hohenstaufen

Re: How to convert between 8MM/.308 caliber.

Post by hohenstaufen »

Very good info.
42rocker
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Re: How to convert between 8MM/.308 caliber.

Post by 42rocker »

I read this a few times and the first time that I was at the range testing out everything in 8mm I was able to switch to .308 and go with it due to good work like this. Thanks again DI....

Later 42rocker
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