My first Air gun - Commando (modded)

vijaycool · Post by **vijaycool** » Sat Dec 26, 2009 8:54 am

There is a small hiccup in the dimension now.. The sear is now short by 15 mm. I tried to "dry fit" the gun without the spring to check but the sear couldnot lock the trigger as the cocking arm reached its maximum limit and just shorter by 2mm. I couldnot lock the barrel in cocked state as the slot on the piston top is obstructing the cocking arm to move back by 4mm. The one way is to grind the sear larger by 1 mm and increase the leverage length by 2mm and cutting the piston slot gap by 3mm

vijaycool · Post by **vijaycool** » Sat Dec 26, 2009 10:18 pm

The short sear mod is very successful. The stainless steel material is really holding well. The sear is shorter by 11mm

which means more volume and more power. I need to make numerous adjustments to accommodate this change. The cocking lever is short by 4~5 mm which prevents cocking. The other problem as I mentioned once its cocked it cannot be locked as the top side of the piston hits the cocking slot. Also the receiver hits the barrel to cock further.
I increased the cocking length by 4mm and grind off the cocking rod in the front side to aid barrel locking. Some barrel material is removed as it touches the receiver end during cocking. Shim has been added inside the piston to have a tight fit with the spring.
Performance:: The gun improved leaps and bounds. The accuracy improved a lot. I hit hole in a hole for the first time. Earlier the sound was "phat" now the sound is quite muffled "voom". Tirtha knows this gun couldnot able to penetrate the wood now it does upto the pellet length. Leather seal is bit undersize causing the air to leak from the side causing power loss. I will attach pics tomorrow.

Cheers
Vijay

vijaycool · Post by **vijaycool** » Mon Dec 28, 2009 11:07 pm

My God the sear again gave away. The trigger blade material is very hard even the industrial grade diamond file struggle to file off excessive sharpness. The new SS welded sear sheared of within 100 shots. The only solution was to weld with much harder material. So the sear latch is welded with drilling bit (HSS) to improve hardness. I am filing the excess material with hand file. The material removal rate is pretty slow it may take 2 to 3 days. In the mean while my machinist started fabricating the spring compressor. It will be ready by tomorrow.

Big Daddy · Post by **Big Daddy** » Wed Dec 30, 2009 4:40 pm

Your first air gun is sure making you an expert gun smith.

Rahul · Post by **Rahul** » Wed Dec 30, 2009 4:52 pm

hi Vijay

I am excited to know, what happened next to the airgun bought on Nov 23, 2009.

Please dont take in wrong sense but what I understand here is the airgun was not working properly either when you bought it just a month back or after partially replaced by the shopowner.
In some cases airguns are more dangerous than fire arms. As it doesn't only require a pallet to fire, but it can fire anything whats there in the barrel. It can be just dust or small metal particals which is sufficient to make one handicap. You are simply risking yourself or others in this case.
Please spend some money and buy a good airgun than a faulty one. Or in case of a tight budget please spend your precious time in a proper channel to get closer to your dream airgun.
But if you are still keen to carry on fixing/modifying your one month old airgun then please do it in proper guidence of an expert.

Merry Xmas and happy new year..
Take Care
Rahul

tirths · Post by **tirths** » Wed Dec 30, 2009 6:28 pm

Rahul,
If I understand little bit of airgun, I can say, Vijay knows what he is doing far more than many.And he is absolutely competent to handle the risk. I would say, please keep an eye on this thread and lets lets learn from him.

BR
Tirtha

vijaycool · Post by **vijaycool** » Wed Dec 30, 2009 6:46 pm

Hi Rahul,
I am new to airguns but not in the mechanical side. Thanks for the caution. I always believe in safety and auto fire can happen with any guns. The issue is simply due to the extreme hard trigger blade matched with Mild steel piston sear. Also the shaft length is reduced to increase the stroke will cause more pressure on the contact area hence the MS will wear out faster. I have got a bad copy in all areas but it makes me to understand the gun better. The new sear is welded with drill bit material makes it equally hard and may surpass the trigger blade hardness. The edges have made little radius so it wont act as friction center. I will be assembling tomorrow so lets see after 100 shots.
The current improvement is the swept volume has been increased by atleast 15% so we can expect around 75 fps more with this mod. The poor performance is due to the undersize piston washer so once its fixed we can get 100 or more fps. I will be posting my mods for increasing stroke length for any break barrel airgun in the gun smith section, strengthening the sear will be the fore most mod.

Cheers,
Vijay

drifter · Post by **drifter** » Wed Dec 30, 2009 7:21 pm

hi vijay,

good going learning a lot from your post. keep them coming.

Prithveen.

gorakhurmi · Post by **gorakhurmi** » Wed Dec 30, 2009 9:45 pm

after so much praise of ihp.i decide to buy it.i got it in 5000.rs
i have used 400 pellets near about i am quit empress from building quality and accuracy.

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Indians For Guns

My first Air gun - Commando (modded)

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Re: My first Air gun - Commando (modded)

Re: My first Air gun - Commando (modded)

Re: My first Air gun - Commando (modded)

Re: My first Air gun - Commando (modded)

Re: My first Air gun - Commando (modded)

Re: My first Air gun - Commando (modded)

Re: My first Air gun - Commando (modded)