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Priest of the P7
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If you boys are done waxing intellectual about the finer semantic points of firearms design, perhaps we can just agree that when you look down at your feet at the range and see a 9mm casing scored black with chamber flutes you think "somebody cool must have been here".
 

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I do see how you are using levels to justify calling large portions of very different guns' operating systems by the same oversimplified word. It makes sense to think of them that way.

That said, what you are calling a "subcategory" is actually a very different overall system of operation per each of the examples you listed.

Your "Straight Blowback" or open bolt "Advanced Primer Ignition" are so dramatically different technically from roller delayed that they should be called what they are.

You see this as an issue of definition. I see it as more one of context and specificity.
And what is the "context and specificity"? Extraction.

What is the same between all blowback firearms? Extraction.


It would be one thing if we were talking about some other aspect of firearm operation aside from extraction, but primary extraction is the #1 thing that makes all blowback firearms the same. So you are making a distinction without a point.

Nobody ever refers to the roller delayed blowback using only the word "blowback."
I did, because it was reasonable in context. If you don't understand that blowback extraction is all the same, you won't understand why it is reasonable to compare a Beretta 950 and an MP5.
 

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If you boys are done waxing intellectual about the finer semantic points of firearms design, perhaps we can just agree that when you look down at your feet at the range and see a 9mm casing scored black with chamber flutes you think "somebody cool must have been here".

LMAO.

Mostly I just think, ah crap I missed one the last time I was here, but a fella CAN dream....

Thanks for the discussion Handy, the last word on the topic was yours.
 

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So I guess the bolt is good to go? Or would you guys like to continue arguing about blow-back vs roller delayed blow-back? How about about a clip vs mag thread?!! Boring.......pointless.....worthless.


R
 

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So I guess the bolt is good to go? Or would you guys like to continue arguing about blow-back vs roller delayed blow-back? How about about a clip vs mag thread?!! Boring.......pointless.....worthless.


R
Get over yourself. You're not doing anything important hanging out on a gun forum.
 

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Short range report with the MAD (Moore Advanced Dynamics) Max MP5 Bolt:

IMG_1974 (1).jpg IMG_1973.jpg

- Price: $299.
- Installed in Omega OMR-9 (MP5 clone) to cure persistent failures to eject (FTEs).
- Bolt gap with this bolt remained same as original bolt.
- Genuine Heckler and Koch 10 round MP5 magazine used in testing (Calfornia compliant).
- The MAD bolt has an extractor spring under the extractor claw, with a pin holding the extractor in place. I believe this results in (1) a firmer extractor grip and (2) less overtensioning of the extractor spring. In contrast, the original bolt has the extractor spring above the extractor claw.
- Per the manufacturer, the extractor spring change interval is 15,000 rounds. They don't yet sell spare springs, but I hope they will do so in the future.

RESULTS
- 20 rounds Winchester 9mm +P NATO brass ammo: 3 FTEs (spent casings stuck in chamber, preventing chambering of next round).
- 50 rounds Blazer 9mm brass 115 grain: Perfect shooting-ejecting-cycling.
- 50 rounds Geco 9mm brass 115 grain: Perfect shooting-ejecting-cycling.
- 40 rounds Fiocci 9mm brass 115 grain: Perfect shooting-ejecting-cycling.
- 20 rounds Remington 9mm brass 124 grain: Perfect shooting-ejecting-cycling.

- Aside from the Winchester NATO 9mm +P ammo, all the other ammo functioned 100%. This bolt looks very promising from my small sample of 180 rounds.

- In contrast, with the original bolt, my OMR-9 was having several FTEs per box with all the above ammo, except the Remington 124 grain, which had a FTE rate of 1 per 300.

- With this new MAD bolt, some ammo now felt "underpowered" (i.e. I was able to perceive longer cycle times from round to round). The Geco and Fiocchi felt underpowered while the Blazer and Remington "felt right" (cycling was quicker, stronger, with more pulse). I was not able to get this perception with the original bolt. The Remmy 124 grain felt the best. Regardless of how the ammo "felt" to me, the Blazer, Remington, Geco, and Fiocchi ammo all worked well.

- I am a little leery of running steel case ammo (e.g. Wolf) because I don't know if would be safe for the bolt. I will shoot only brass rounds for now.

- For a more complete test, I will running 500 rounds of Aguila 9mm 124 grain brass ammo soon. If I can get 500 rounds of this (or any other 9mm ammo) to fire with no problems, I will officially declare the MAD Max Bolt to be a winner. Will post results of this test.

- I think we have a real game changer here. I am hoping that, with the right ammo, my Omega OMR-9 can attain Glock-like reliability.

IMG_1985 (2).jpg
 

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Were the +P FTEs in the first 20 rounds fired? I have to wonder if your new ability to feel the "underpowered" ammo is due to the new bolt head dragging a bit, which might also explain the FTEs. That could be a tiny dimensional issue, or simple new parts that haven't burnished in yet.

The new extractor design is certainly unique. It looks unlikely, but clearly it works and uses a more flexible spring design.
 

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Were the +P FTEs in the first 20 rounds fired? I have to wonder if your new ability to feel the "underpowered" ammo is due to the new bolt head dragging a bit, which might also explain the FTEs. That could be a tiny dimensional issue, or simple new parts that haven't burnished in yet.

The new extractor design is certainly unique. It looks unlikely, but clearly it works and uses a more flexible spring design.
The FTEs for the +P were in the first 20 rounds. The +P rounds were giving me problems with the original bolt, too, so I think my gun just doesn't like them.
 

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That sounds like a chamber issue, meaning the win ammo doesn't like the chamber or vice versa. Next time if you clean the gun thoroughly (chamber) and try again, start with ammo it liked, then bring in the winchester turds. If you get the same behavior, it's the ammo.

As far as the feel being different, I wonder if the new bolt weighs more. Adding mass might explain that.
 

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I cleaned the chamber with a chamber brush designed especially for HK fluted chambers, so it must be the ammo. I think I got a bad batch.
 

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SECOND RANGE REPORT - MAD MP5 BOLT

- I went back to the range today with my Omega OMR-9 rifle with the MAD (Moore Advanced Dynamics) MP5 bolt. I used Aguila 9mm 124 grain brass ammo, which was recommended to me by Wade Bailey of Top Notch Accessories, the manufacturer of the Omega line of MP5 clones.

- I had been bedeviled by failures to eject spent casings with an Omega OMR-9 with the original bolt. I was on the verge of returning the gun, as I was so unhappy with it. Then, this MAD bolt came out, so I purchased it to see if I can get this gun working.

- I am happy to say that all 500 rounds I shot performed FLAWLESSLY. Not one jam or failure to eject. Previously, I could not get past 300 rounds without a failure to eject, which then got progressively worse. Now, with his new bolt, every round, from the first to last, shot perfectly.

- If you are thinking about getting one of these to fix ejection issues on your MP5 or MP5 clone, do it. I highly recommend it. After months of trying different ammo, magazines, extractor springs, and post-two warranty repairs, I finally have a fully functioning MP5 clone.

- At $299, it's a $100-$150 dollars more than a comparable US made complete MP5 bolt, but well worth the extra money due to its reliability. It's also $200 cheaper than a genuine HK MP5 bolt, but probably more reliable.

IMG_2097.jpg IMG_2099.jpg
 

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Hmmm, since my Z5 is running flawlessly at the moment, I will file this under "tagged" for future consideration.
Since your current gun is working fine, there is no need for you to buy this bolt. I posted my findings mainly for those who have persistent ejection problems with their MP-5 clones.
 

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Issah...good to hear.

I just bought one. And I will shoot the hell out of it FA on multiple sear hosts.
I'm hopeful.

I'm sick of replacing extractor springs. I shoot a lot and replace them a lot. It's a nuisance and is the point of failure for the roller locks.
Glad to see it finally addressed.
 
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