TDC modded Bolt action cant lift .48s.

[Asomodai]

Hey guys. 

Used my freshly TDCed bolt action today. Fires at 480 fps with the hop off. Using .40 ASG Precisions I can easily overhop before applying so much hop the bb wont leave the hop chamber. 

I switched to Longbow .48s and whilst it does travel reasonably far, there is no obvious "hop" at the end of the travel even on the highest setting before the range decreases because of the lever putting too much pressure on the bb. 

Does this sound right to you? I am unsure what my expectations should be. 

I am currently using a 70 degree Maple Leaf bucking, should I go down to 50 or 60 degree? Would it make a difference? 

 

[Wo1f]

I had this problem with the SRS.  You either need a bucking with a larger surface area or more grip at an equal pressure. 

Your options are either swap buckings. The flamingo bucking or the TNT TR hop are very similar. Like the maple leaf they’re long contact patch but they have more surface area because they don’t taper to a point and are basically an R hop patch. 

What nub are you running? The larger the surface area the better. If you can, use an I Key if the TDC will line up with the center shaft on it. 

Failing that you could lower the degree. A 60 will be a softer, grippier material, but I’m not sure if it will be enough. 

 

[Asomodai]

I had this problem with the SRS.  You either need a bucking with a larger surface area or more grip at an equal pressure. 

Your options are either swap buckings. The flamingo bucking or the TNT TR hop are very similar. Like the maple leaf they’re long contact patch but they have more surface area because they don’t taper to a point and are basically an R hop patch. 

What nub are you running? The larger the surface area the better. If you can, use an I Key if the TDC will line up with the center shaft on it. 

Failing that you could lower the degree. A 60 will be a softer, grippier material, but I’m not sure if it will be enough. 

I am restricted to using this hop arm, which is pressing straight down on the maple leaf bucking. (I think, I haven't opened up the rifle since the mod)

View attachment 47489

I have had to use this arm as the Well isn't quite VSR spec. I am not sure if the I key will work on this with this, (I presume you mean the nub to press down on the arm that then pressed down on the I Key. 

Would a 50 degree be too soft to use in this? I doubt I'll be using the bolty most weekends so as long as it doesn't tear apart within a couple of 1000 rounds I am golden.  

I am a complete noob when it comes to bucking other then the maple leaf so I am unsure about the ones you stated ?

 

[Yukarin]

60 degree bucking, and mod the arm so it has a concave shape pressing down on the maple leaf. So the arm isn't VSR spec at all? If it is, you have two options, Stalker Panthera Arm + Concave nub, or the Maple Leaf Arm.

 

[Asomodai]

60 degree bucking, and mod the arm so it has a concave shape pressing down on the maple leaf. So the arm isn't VSR spec at all? If it is, you have two options, Stalker Panthera Arm + Concave nub, or the Maple Leaf Arm.

I am afraid so. Mine is a tapered outer barrel, a standard VSR arm wont fit, so the Well specific airsoftpro one has a body section with less depth and nub section with more depth to compensate. 

I guess this just leaves me with getting a softer bucking? Not sure if am confident enough to dremel a concave shape at this point. 

If that doesn't work I guess I can try some .43's and .45s and stick with those. I knew that this particular type of rifle would have problems upgrading when I bought it. 

 

[Yukarin]

Like Wolf said, I don't think the 60 degree bucking will be enough, but it will definitely put you in the right direction. If you were to attempt to dremel a concave shape into the arm, it would give you more hop settings before it goes over the top and starts jamming the BB (As the shape of your current arm is probably creating 'premature jamming' and an inefficient contact shape).

 

[Asomodai]

Like Wolf said, I don't think the 60 degree bucking will be enough, but it will definitely put you in the right direction. If you were to attempt to dremel a concave shape into the arm, it would give you more hop settings before it goes over the top and starts jamming the BB (As the shape of your current arm is probably creating 'premature jamming' and an inefficient contact shape).

How much of a concave shape should I be looking at? Fairly shallow?

 

[Yukarin]

How much of a concave shape should I be looking at? Fairly shallow?

Now that I cannot answer as I haven't done anything similar, but I would assume it should roughly be the shape of the top of the bucking. (As if the shape of the arm contacts the top of the bucking perfectly).

Edit: It should have the same curve shape as the bucking.

 

[Wo1f]

Theres your problem... the 'nub' on that arm isn't very long/deep in my opinion.  You could put a tiny notch in the middle of the 'nub' section and fir an I key underneath. Not sure how a TDC would work on an arm that has a pivot point?  surely if its TDC you've got direct vertical pressure being applied to the nub and not just vertical pressure applied to a pivoting arm. The TDC mod on the mk23 for example is direct downward pressure.

if your'e going to mod that arm concave, make it very shallow. you want it to be the same or slightly less than the bucking mound curve.

 

[Asomodai]

Theres your problem... the 'nub' on that arm isn't very long/deep in my opinion.  You could put a tiny notch in the middle of the 'nub' section and fir an I key underneath. Not sure how a TDC would work on an arm that has a pivot point?  surely if its TDC you've got direct vertical pressure being applied to the nub and not just vertical pressure applied to a pivoting arm. The TDC mod on the mk23 for example is direct downward pressure.

if your'e going to mod that arm concave, make it very shallow. you want it to be the same or slightly less than the bucking mound curve.

I'll replace the bucking first, if that doesnt achieve significant results I will buy another arm and try the mod on that one. 

Thanks for the advice fellas

Maybe its just time to get the SRS Silverback I have been promising myself

 

[Asomodai]

@Wo1f

I dremelled the nub part to be flat, it was curved as in the photo so at least it gives it a better contact patch. Changed over to a 60 degree bucking and it was lifting .48's like a champ. Could likely lift even heavier if I so chose. 

Pretty happy now! Definitely pushing 90-100 metres.

 

[Rogerborg]

Nice one.  I have that hop arm in my MB-03, and wasn't impressed with it as stock. Very sloppy, needed packed out with PTFE tape wrapped around in front of the 'nub' to firm it up.

When you say that you flattened the nub, do you mean that you squared off the bottom of it?

I went the other way, I put a curve into the nub to match the curve of the rubber. The stock hop arm is similar, I assume they know what they're doing.

Yours top?  Mine is the bottom.

View attachment 48012

 

[Asomodai]

Nice one.  I have that hop arm in my MB-03, and wasn't impressed with it as stock. Very sloppy, needed packed out with PTFE tape wrapped around in front of the 'nub' to firm it up.

When you say that you flattened the nub, do you mean that you squared off the bottom of it?

I went the other way, I put a curve into the nub to match the curve of the rubber. The stock hop arm is similar, I assume they know what they're doing.

Yours top?  Mine is the bottom.

View attachment 48012

Mine was like yours when stock. But now is squared off so its not convex anymore. I could make it concave eventually, but all seems to be working ok at the moment. 

 

[Asomodai]

Mine was like yours when stock. But now is squared off so its not convex anymore. I could make it concave eventually, but all seems to be working ok at the moment. 

Nice one.  I have that hop arm in my MB-03, and wasn't impressed with it as stock. Very sloppy, needed packed out with PTFE tape wrapped around in front of the 'nub' to firm it up.

When you say that you flattened the nub, do you mean that you squared off the bottom of it?

I went the other way, I put a curve into the nub to match the curve of the rubber. The stock hop arm is similar, I assume they know what they're doing.

Yours top?  Mine is the bottom.

View attachment 48012

So I bit the bullet and bought a concave Airsoft Pro Arm despite it might not being able to fit. Reason being that although the squared off arm lifted. 48s initially it stopped doing it as soon as the temperature dropped. So it was always going to be at the limit of lifting capability. 

The new AP arm went in really easy and it's now over hopping .48s like crazy. The nub is shallower so need to adjust the TDC quite a bit tighter which is fine as it was easy to knock the setting loose before in play. 

I reckon this could lift .54+ now. 

Cant wait to use it on the field!

 

[Samurai]

As said before, long contact hop buckings need bigger nubs on the hop arms too.

And the bucking hardness is given for fps on the weight you use, not fps measured on 0.20g, and if you play in cold areas, go one lower even.

 

[Asomodai]

As said before, long contact hop buckings need bigger nubs on the hop arms too.

And the bucking hardness is given for fps on the weight you use, not fps measured on 0.20g, and if you play in cold areas, go one lower even.

The only reason why I didnt change the arm sooner was because it was intimated that Airsoft Pros Well specific hop arm was the only one that would fit my particular rifle. As it turned out I needed to dremel it in the first place anyway! 

 

[Immortal]

As others have pointed out; softer the better in this country due to the cooler climate. 50/60 buckings seem to suit our part of the planet, the people using harder buckings appear to come from warm US states (for example) etc. They're rock hard come autumn/winter over here.

Currently trying out the Maple Leaf MR 50 bucking... my other rifle has a Tan Modify 60 bucking.

 

[Asomodai]

As others have pointed out; softer the better in this country due to the cooler climate. 50/60 buckings seem to suit our part of the planet, the people using harder buckings appear to come from warm US states (for example) etc. They're rock hard come autumn/winter over here.

Currently trying out the Maple Leaf MR 50 bucking... my other rifle has a Tan Modify 60 bucking.

That is interesting. When hop is off I am firing 440 FPS. With hop on and hitting sweet spot its about 480FPS . So with .48's It will be 309 FPS. So technically a ML 50 degree should be fine? I have plenty of hop with the 60 so not sure if I need anything softer. 

 

[Immortal]

That is interesting. When hop is off I am firing 440 FPS. With hop on and hitting sweet spot its about 480FPS . So with .48's It will be 309 FPS. So technically a ML 50 degree should be fine? I have plenty of hop with the 60 so not sure if I need anything softer. 

If what you've got is working just stick with it.

Are you testing by taking the rifle out your house to fire off a few> only asking as it'll be warmer than it will be once you've run around the woods for a while... although I'd of thought a 60 will be OK. One way to truly find out. Play. If it isn't so good once it cools down then try a softer one and repeat. Not the most technical response I'm afraid.