Short question topic

[thejackal]

I just got off the phone with Mike and he confirmed that they are indeed through with UltiSpuds but that he still had items in stock that he's willing to sell. Unfortunately I can't afford to buy everything I need to complete this particular project in one order/purchase so all I can hope for is that he remains receptive to selling his in stock items for at least 3 or 4 more months.
Is anyone aware of any machinist's selling parts that are similar to those used in the BL-520 such as the offset internals and fuel metering system and pistol grip ignition system and modular ring sets?

[wyz2285]

I'm using a single M6 bolt to secure both ends of a chamber, planed to be filled up to 3000 PSI. Bolt material is unknown but it's some kind of steel (standard steel bolt with zinc to prevent rust I think). Will hydro-test it to 4500 PSI but I'd like some opinions. I'm very bad at drilling holes or making threads so I'm hoping this is a way to make PCP chambers.
From these online calculators I found a M6 screw should work for 3000 PSI, 4500 PSI would be a bit too much. The chamber is 2mm walled 304 SS seamless tube. The bolt has at least 15mm thread into the end caps.

[wyz2285]

Plus can somebody shine some light on the SSG (Stopping Spring Guide)? I have a rough idea about how it works but not crystal clear. Between it and the sling shot hammer which one is better in general? (facility of making/performance wise).

[Gippeto]

SSG essentially stops the hammer spring...the striker continues on a short distance to hit the valve stem. The valve stem is affected by the pressure within the valve during the shot cycle...creating a force that closes the valve and imparts energy back to the striker. This energy is normally transmitted back to the striker spring, which loads up....and sends the striker back into the valve stem again.

With the ssg, the striker has to travel that small gap again, and compress the already pre-loaded striker spring. The net result is that very little energy actually gets back into the spring.

SSG for a 2240. Striker as drawn/made initially was far too heavy for co2..was lightened.





Shot string from the 2240...dropped in the ssg...no actual tuning. Stock is usually around 30-40 shots. The string was done as fast as I could reload, shoot and record the result. Temp was 58 F. Waiting longer between shots or done when warmer would extend the string. Zeros are a chrony read error.



The one in my QB-ish pcp...





As far as ease of manufacture...if you read the various SSG threads on the GTA forum, it can be made REAL simple. May have to go back a several pages...

http://www.gatewaytoairguns.org/GTA/ind ... board=12.0

Original SSG thread;

http://www.gatewaytoairguns.org/GTA/ind ... c=102095.0

[wyz2285]

Got it, looks way simpler than a sling shot hammer, definitely going to try it. I knew it's for the hammer bouncing, wasn't sure how it works tho. So the hammer is free float without payload of the spring.

[Gippeto]

That is correct.

[wyz2285]

Is it annoying to hear the hammer going back and forth if you shake the gun ? Or you can barely notice?

[jackssmirkingrevenge]

Is it annoying to hear the hammer going back and forth if you shake the gun ? Or you can barely notice?

The words of a man who has tried to run stealthily with a half full hi-cap magazine

[wyz2285]

The words of a man who has tried to run stealthily with a half full hi-cap magazine

Touché, one of the reasons I switched to mid caps for a while, but running electric winding mags now because TATATATATATA

[Gippeto]

I tend not to "run with guns"...kinda like running with scissors...a bad idea all around.

Haven't carried one in the field yet, only in the shop. Don't think it'll be a problem...can hear it if you listen for it.

[mark.f]

I tend not to "run with guns"...kinda like running with scissors...a bad idea all around.

Haven't carried one in the field yet, only in the shop. Don't think it'll be a problem...can hear it if you listen for it.

I think they brought up running in regards to airsoft. At least hopefully.

[wyz2285]

[youtube][/youtube]
Someone could shine some light to this?
To my understanding, the porting simply bleed off the extra gas/air so the exiting gas/air goes out in a straight line.
@Gippeto I made a "sling shot" hammer [youtube][/youtube]

[jackssmirkingrevenge]

Someone could shine some light to this?

We get it, you vape

I don't really see the point of this for airsoft, the only reason to have asymmetric muzzle porting is to reduce muzzle climb which at airsoft power levels is virtually non-existent.

[wyz2285]

Yeah I think the smoke would come out straight even if the porting is done downwards.
The smoke does come out in a surprisingly straight line compared to the normal one.

[jackssmirkingrevenge]

The smoke does come out in a surprisingly straight line compared to the normal one.

Sure, but does it have a measurable effect on the trajectory?

What I want to see is side-by-side comparisons of group sizes over a measured range using this barrel vs an identical setup but using a normal barrel, otherwise it's literally just fancy smoke patterns.