Mg42 SA bolt comparison

[usmc8488]

I have only one M53 SA and one MG42 SA home build under my belt. My first was in 2013 and I did the bolt modification’s myself and soon went to the BRP 2nd generation bolt.

After a catastrophic failure, out of battery detonation of a very old 8mm round, in my MG42 SA I was faced with a rebuild. The receiver was cracked the bolt rails were damaged, the rear end of the bolt cracked and the main spring broken.

After the repair to the receiver, including the replacement of the rails I started to look at the bolt.

The original bolt I build was not an option, the BRP bolt was damaged. I had limited success with the BRP bolt, hammer drag, causing feed issues and light primer strikes.

During an internet search I look for photos of the Generation 2 Wise Lite Bolt and found none.

I e-mailed Wise Lite Arms and got a few question answered. I was told I would need the buffer extension (not required) even though I was using a BRP receiver and not the 1 inch longer Wise Lite receiver. I ordered the 2nd generation complete bolt (sight un-seen) and the (not required) buffer extension.

I just wanted to share a comparison to anyone currently building or thinking of up grading their bolt in their SA weapon.

NOTE I have not test fired the Wise Lite Bolt yet.

Weight
Top MG42 FA medium Bolt 1 lbs 3.1 oz
Middle Wise Lite Gen 2 SA Bolt 1 lbs 9.6 oz
Bottom BRP Gen 2 SA Bolt 1 lbs 14.3 oz

Wise Lite bolt uses the un-modified bolt head and extractor.
The original firing pin is shortened to 30.25 mm.
The striker is drilled through to 3.3 mm, so the original shortened firing pin wont drop through.

The bolt guide is welded so it does not rotate, like original and BRP (has barring)

BRP bolt uses the un-modified bolt head and extractor.
The striker is notched out and drilled through to 3.95 mm.

The bolt guide is removable and had a barring on the top.

Original parts comparison.

[JBaum]

Is the firing pin holder what you're calling the "striker"?

[Der Alder]

Nice pics and comparison, thanks for taking the time to post that.

I would call the Wiselite rear firing pin (as some call it) a striker, the F/P guides in both that are drilled through not so much.

I run both of these on my 2 semi's. Both types have their plus's and minus's IMO. Both work fairly well when set up properly. I like the ability to tune the BRP F/P with the supplied washers (I run all 3).

The BRP is hefty compared to the WL, but I think that is by design to help strip rounds. The rotating bolt guide on the BRP is nice to reduce drag which is important on these semi builds, but IMO so long as the guide is lubed its really not an issue having a fixed guide like on the WL.

But like I said anything to help reduce drag is never a bad thing with the reduced recoil spring and hammer drag on a semi. That said I've had about equal success with both types.

[usmc8488]

Is the firing pin holder what you're calling the "striker"?

Yes striker or striker sleeve, it forces the two bolt rollers out locking the bolt head into the trunion and barrel extension.

[JBaum]

Yup, that's what the firing pin holder does alright.

On another subject, the MG42 doesn't have a trunnion. It does have a cam piece and a barrel extension, but the cam piece is only involved with unlocking the bolt rollers from the barrel extension when the locked together barrel and bolt recoil. Just sayin'.

[usmc8488]

Yup, that's what the firing pin holder does alright.

On another subject, the MG42 doesn't have a trunnion. It does have a cam piece and a barrel extension, but the cam piece is only involved with unlocking the bolt rollers from the barrel extension when the locked together barrel and bolt recoil. Just sayin'.

That's why I love this place a wealth of information.... which has brought me light years forward..