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Discussion Starter #1
Hi all,

recently my ca-94 started having fte issues. I did a full detail cleaning and still have the issue. 1 or 2 rounds per mag. It seems like it is releasing the case early, possibly the extracter spring is going. What ultimately happens is I have a spent case in the receiver and a live round being stripped from the mag causing a jam.

Would those more experienced than I recommend replacing that spring first, or is there something else to try first. Any good sources for that spring?

Thanks in advance.
-Ry
 

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Ry,
approx how many rounds? put an empty case on your bolt head . It should "snap" on. It should also stay on the head when you give it a flick with the wrist. If the empty falls off, then I would atleast spin your extractor spring out, re-bend it, then re-install. Then try the empty case again. If that fixes it, then plan on replacing the extractor spring in the NEAR future.
Dj
 

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Discussion Starter #3
Thanks for the quick reply djf. I'd say I'm approaching 750 - 1000 rounds. I'l try out your sugestion tomorrow about the empty case.
 

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Yep, any time you get a double feed like that, chances are pretty good that you've damaged the extractor spring. The live round shoves the spent casing up and out of the way, forcing the extractor to push too far on the spring.

Have you been getting FTEs from new, or did it recently develop the problem?

Also, check the actual diameter of the bolt face (part the case sits in). It should be .400, Not .410 or .420. Use calipers if you've got access to some.

Have you checked your bolt gap? Do you know how?

Good data here:

HK MP5 data inside - AR15.COM

How to: Field Strip & Replace Extractor & Ejector Lever (tons of pics) UPDATE Pg.1 - AR15.COM
 

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Discussion Starter #5
Well, It has been a while but I haven't gotten to the range since I posted this until this last weekend. My extractor would not hold a spent case, and after taking its spring out with a dental pick, it clearly had stress that looked like it would fail at any time. So I ordered some new springs, put them on and it held tight. I now can shake it with either a spent case or a live round and it does not come free of the bolt. Unfortunately shooting it caused the same issues. 3 brands of fmj ammo.

Retrodog, I mic'd the bolt face today and it certainly is not to the .400 you mentioned. I'm not great with callipers, somehow I keep getting different results, but all were above .420
Have you been getting FTEs from new, or did it recently develop the problem
It had issues when I got it, replaced the ejector with the dimpled hk one and it got better. I bought an hk extractor also but it seems the bolt wants the CA one. Any things to try before I go for a bolt face, I recall them to be expensive.

Thanks again all.

oh, thanks for the links, very nice. I did my bolt gap in the past and it was within spec. (can't lose them all :wink: )
 

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Discussion Starter #8
ok, so just the head, not a complete one? Is hkparts.net the best place to get one, or are there other good sellers? Looks like they want about 150 for one, sound right?
 

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ok, so just the head, not a complete one?
a complete head, is the head, extractor, and spring. IMO if you are getting a new one, go 100% new. Once you get something that works, you can try out your old ejector and see if its good.

Is hkparts.net the best place to get one, or are there other good sellers? Looks like they want about 150 for one, sound right?
hk parts, Gun Parts - RTG International Surplus Gun Parts and Militaria, HK Specialist - Home Page, all good vendors.
 

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Well, It has been a while but I haven't gotten to the range since I posted this until this last weekend. My extractor would not hold a spent case, and after taking its spring out with a dental pick, it clearly had stress that looked like it would fail at any time. So I ordered some new springs, put them on and it held tight. I now can shake it with either a spent case or a live round and it does not come free of the bolt. Unfortunately shooting it caused the same issues. 3 brands of fmj ammo.

Retrodog, I mic'd the bolt face today and it certainly is not to the .400 you mentioned. I'm not great with callipers, somehow I keep getting different results, but all were above .420

It had issues when I got it, replaced the ejector with the dimpled hk one and it got better. I bought an hk extractor also but it seems the bolt wants the CA one. Any things to try before I go for a bolt face, I recall them to be expensive.

Thanks again all.

oh, thanks for the links, very nice. I did my bolt gap in the past and it was within spec. (can't lose them all :wink: )
You're welcome. Nice to see you making good progress. I know it's frustrating now, but you're on the right track.

I'd agree with the others about a new bolt head. The bolt face should be as close as possible to .400 and that will help a lot.

I've had really good luck with the RCM bolt heads. Can't tell the difference (performance-wise) from real HK. I've got 2-3 of them and use them in my primary sear guns. Good stuff.

And yes, there's a chance that you might need a different ejector lever. It's always good to have an HK ejector lever laying around just in case the other one has a problem or is out of spec.
 

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Another problem that some have had is that somehow, some 40 bolt heads got mixed in with the 9mm assembly of the CA-89s. Place a 9mm case against the bolthead and see if there seems to be some slop allowing the case to move around a bit... back and forth, to and fro, like. A 9mm case shouldn't have all that much wiggle room. Two of my buds reported having this issue.
 

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Another problem that some have had is that somehow, some 40 bolt heads got mixed in with the 9mm assembly of the CA-89s. Place a 9mm case against the bolthead and see if there seems to be some slop allowing the case to move around a bit... back and forth, to and fro, like. A 9mm case shouldn't have all that much wiggle room. Two of my buds reported having this issue.
I'm pretty sure that the binding ejector lever would be a dead giveaway first, particularly since there is no slot cut in the bottom of the 40 caliber bolt heads.

What most likely happened is that someone left the 40 caliber cutting die in the milling machine when they started cutting 9mm bolt heads. That's just my guess since there shouldn't be any other way that a .420-.430 bolt face would show up on a 9mm bolt head.

.40 bolt head:



9mm bolt head:
 

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Well, actually, there was no slot such as the HK 40 cal bolthead pictured by HKPARTS. Don't know who originally made them, but they did look like 9mm bolts that were just larger. It could be how you figured. The slot was only for the bolt hold open. Early 40 conversions didn't even bother with bolt hold opens... and perhaps the current crop of 40 guns might even be better off without'em.

I may buy my buds oversized 9mm bolt. Good idea!
 

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Well, actually, there was no slot such as the HK 40 cal bolthead pictured by HKPARTS. Don't know who originally made them, but they did look like 9mm bolts that were just larger. It could be how you figured. The slot was only for the bolt hold open. Early 40 conversions didn't even bother with bolt hold opens... and perhaps the current crop of 40 guns might even be better off without'em.

I may buy my buds oversized 9mm bolt. Good idea!
But if you put a current .40 bolt head in a 9mm gun with a 9mm ejector lever, it won't even cycle by hand. Well I don't think it would anyway.
 

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Discussion Starter #15
Fortunately mine looks like the 9mm bolt head. I was able to snap in a .40 case into the bolt head, but only if I put the rim under the extractor first. Now with a spent 9mm case, I can pick the bolt up holding just the case. Not just the bolt, but the whole cast carrier piece also. If I keep the extractor on top... or anywhere but on the bottom, I can rotate the whole assembly so it is parallel to the ground.... just holding the brass case.

Looking online the bolts are Action 3, F type, regular. Which is correct? I'm sorry for asking so many questions, but I want to get this right on the first try.... well maybe the 'next' try as I did quite a bit. Also the fact that the bolt is holding the 9mm case so well really makes we want to double check first.

Also a huge Thank you to all helping. I really appreaciate your advice.
 

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I use Action 3 and F type (both). They both work correctly. The Action 3 is the latest version of the standard bolt head. The "F" version was for "French" and made to support more powerful ammo. So a lot of people use the F just to get a longer life out of it. The RCM made bolt head is based on the F design (I think). It's good to go.

If a .40 case fits in your bolt face, the bolt face is too big. I can try one tonight, but I'm pretty sure you need a different bolt head.
 

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If a .40 case fits in your bolt face, the bolt face is too big.
Correct... sounds like you have one of the bad ones. A 40 shouldn't fit no way in a 9mm bolt head.
 

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Mine (a Vector) has had the same problem with steel case rounds since I got it. (Are you using steel cased?) If so, you may be SOL on that one b/c I have replaced the entire bold head and all parts therein, the extractor lever and sent it back to Vector 2x and it still won't run the steel case. I now have it at Mike Turner's in AZ with the hope of getting it fixed.
 

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Discussion Starter #20
A million thankyou s to everyone who replied in this thread. I bought the rcm bolt, and took it out this weekend. 5 different types of ammo (all fmj), well over 300 rounds fired and absolutely zero failures. The bolt gap is a little high with the new bolt (.021) but with everything working well I do not think I'll jump to new rollers just yet. Atleast the gap was not too small, that seems to be worse for the gun.
 
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