Hop Rubbers and the 'Key'

[Ragnaraz]

I recently finished one part of my project on a TM M9/2F and have since been trying to learn a little more about other aspects and optimisations before taking the next leap.

Stumbling across many different hop types, brands and degrees. Even the same brands and degrees, but a different name, like the Maple autobot and decepticon buckings.

My google-fu may be sub par, or the info may be hard to come by. I forget the scales direction, but I know the changes in "degrees" is the softness of the rubber, changing hop efficiency and life span. What I don't get is the difference between two of the same like as previously mentioned, could anyone give me a bit of an explanation on that? Maybe a rough idea what would suit my particular pistol?

I have seen you can get different hop arms, I'd hazard a guess this is a wearable part and they're different grades of metal for lifespan?

Then, I saw "keys", I think I have seen "I", "F" and "T" keys for the M9. I read there were random types designed for older WE models and such, but it didn't actually explain what they're for/do and no shop has actually given an explanation to the parts purpose on their product listings. Reading it's for WE models While being sold for TM M9s also confused me more. Would anyone with the knowledge explain them to me and which is better and why?

If the buckings have different nubs, does that effect the compatibility with the "keys"?

I did read somewhere certain buckings were not suitable for S or R hops. They, by all account seem a lot of hassle and I am not thinking of doing that for the pistol.

All and any info/ advice is greatly appreciated.

 

[Adolf Hamster]

What I don't get is the difference between two of the same like as previously mentioned, could anyone give me a bit of an explanation on that? Maybe a rough idea what would suit my particular pistol?

if you mean the difference between say a decepticon and autobot bucking? it's the shape of the contact patch, forget which way round they are but one is more triangular and the other is more square, realistically the difference is most likely 90% marketing.

Then, I saw "keys", I think I have seen "I", "F" and "T" keys for the M9. I read there were random types designed for older WE models and such, but it didn't actually explain what they're for/do and no shop has actually given an explanation to the parts purpose on their product listings. Reading it's for WE models While being sold for TM M9s also confused me more. Would anyone with the knowledge explain them to me and which is better and why?

the key is meant to apply a more even pressure, similar to how for example the omega nub is for an aeg. the different sizes/shapes will be to fit different pistol designs, for example if a gun has a wider or narrower, longer or shorter window for the hop arm.

it's useful when combined with one of the ml buckings (or buckings of a similar style), as it means the whole patch gets pressed down rather than just the middle.

I did read somewhere certain buckings were not suitable for S or R hops. They, by all account seem a lot of hassle and I am not thinking of doing that for the pistol.

the whole idea behind the ml products is you get the same result as the s/r hop without any of the associated hassle.

by all accounts the S hop tends to have a very short lifespan, and whilst R-hops last longer these days (thanks to off the shelf products like the ml stuff) they tend to have limited use.

the only advantage an R hop has is the ability to have different compounds for the feed lip and hop patch, so a soft patch for spinning heavy ammo combined with a hard feed lip to hold a seal at higher fps.

however for the autobot/decepticon this can be solved with the metal c-clip they come with

 

[Rogerborg]

the only advantage an R hop has is the ability to have different compounds for the feed lip and hop patch, so a soft patch for spinning heavy ammo combined with a hard feed lip to hold a seal at higher fps

Veering a bit OT, but that was my thinking. I'm going with an RTV silicone S-hop under a 70 flat bucking for a ~1.8J DMR.  The RTV can be done in a couple of minutes: bit of teflon tape round a 6mm drill bit, pop it in, spooge the window, scrape off the excess with a straight edge, done.  If it's a basket case, I can just clean it out and pop a Maple Leaf rubber on there instead, so it seems worthwhile giving it a go.

 

[Ragnaraz]

@Adolf Hamster That was very informative, Thank you very much!

So what would the best Key and hop combo be for the M9? I know it's a long shot if you don't use or have experience with the gun, but never hurts to ask.

@RogerborgCould you translate that to Noob please? ??

 

[Adolf Hamster]

Veering a bit OT, but that was my thinking. I'm going with an RTV silicone S-hop under a 70 flat bucking for a ~1.8J DMR.  The RTV can be done in a couple of minutes: bit of teflon tape round a 6mm drill bit, pop it in, spooge the window, scrape off the excess with a straight edge, done.  If it's a basket case, I can just clean it out and pop a Maple Leaf rubber on there instead, so it seems worthwhile giving it a go.

Hope it works out, never tried the s-hop myself but i get the principle, if you're meaning the rtv gasket stuff surely that's gonna be too soft? I remember that stuff having the consistency of jelly.

@Adolf Hamster That was very informative, Thank you very much!

So what would the best Key and hop combo be for the M9? I know it's a long shot if you don't use or have experience with the gun, but never hurts to ask.

@RogerborgCould you translate that to Noob please? ??

Honestly for a pistol? Either rubber (i tend to go for green- nice and grippy and pistol wont get the round count to wear out too soon) and whatever key fits most appropriately. Give it a decent barrel and feed it good ammo and that's all it'll ever need.

You can get some stupid levels of accuracy/range out of pistols but there quickly comes a point where the limiting factor is more the ability to shoot well enough to make use of it.

 

[Rogerborg]

@RogerborgCould you translate that to Noob please? ??

Hah, sorry, that was getting way off topic. I wasn't suggesting it for a pistol, just mentioning it in the context of fancy hops.  "S-hopping" generally refers to filling the hop window in the barrel with silicone, then putting a flat hop bucking over it (i.e. a hop rubber with all the bumps dremelled off of it). Folk use Sugru, or just plumber's silicone. I've just done it with a tube of RTV silicone.

As Adolf says, that gives you a nice soft contact patch, but with a harder bucking with stiffer feed lips. It's more for DMRs than pistols though, and in any case Maple Leaf hop rubbers do a great job without any faffing around.