IHP "National" air rifles & pistols

[plinkster]

Dear Plinkster,

Thank you for the detailed instructions and pictures
I shall do a leak test using talcum powder at the earliest and consider fitting O-ring accordingly

Regards,
Vishwanath

Hey,
If yours is an untuned gun, there will be quite a bit of twang (and vibrations). Due to this, the talcum powder test might be inconclusive. Also, if the leak is from the bottom, you might not even be able to see the leak.
Its better to do a tissue paper test.

1. Cock the gun and load a pellet.
2. Take a piece of tissue paper (2 ply is better) and place it over the exit port of the cylinder.
3. Ensure that the tissue piece is big enough to cover the breech seal.
4. Holding it in place and taking care that the tissue does not tear, close the breech.
5. Fire the gun and then gently break it, and check for the tissue
6.If there is a clean hole, there is no leak. If there is a tear, the air is leaking from there.

This is also not very conclusive. If there is a slight overall leak, the tissue won't tear.

To see if you have gained any power do the following :

With original seal :

1. Shoot at an object about 15-20 m away (try shooting at a metal surface, like a dish antenna , that will make a distinct sound)
2. Try and remember the delay between the sound of the gun's thwack and the object being hit.
3. Do this a few times.


Repeat the same with the new seal (O-Ring).

You will find that the delay is reduced (more velocity = more power)

Cheers,
Plinkster

[VishyB]

Dear Plinkster,

Thanks for details of the tissue paper test.
I tried it out today morning - at least the tissue did not tear.
I am trying to get familiar with the gun first & then will change to O-ring

Cheers
Vishwanath

[VishyB]

Hi Friends,

The two screws holding the stock (front) on my new IHP 35 are working loose by 1/4 to 1/2 turn after 20~30 shots.
I am afraid of overtightening tham so I am just tightening them snug after every shooting session.
Is it set in the wood or just the screws working loose in the threads?
If not set in the stock, I can try some non permanent Loctite I suppose.
If the wood in the stock is setting, is it a temporary phenomena and will it settle down after a while?
Appreciate feedback from experienced members.

Regards,
Vishwanath

[plinkster]

The two screws holding the stock (front) on my new IHP 35 are working loose by 1/4 to 1/2 turn after 20~30 shots.

The loosening of the screw is because of both factors. The vibrations result in the loosening of the screws, as well as compression of the wood. The washers that have been put in place don't do a good job, and instead end up eating the wood. When you tighten each time, you will see the screws going in marginally each time.

Loctite is the best solution if done early. Due to the vibrations, the threads on the 5 mm screws are going to get worn out. After that, they will just stop gripping - all this if you are lucky. If the receiver threads get worn out instead, you will have to tap the same to 6mm and replace the screws with 6mm (allen bolts are good).

The best option is to get screw caps made and put them in the holes of the stock to prevent the screw and washer from eating into the wood, and then loctite the screws in place (blue loctite - 242 or 243 - costs 500 for a bottle)

[VishyB]

Dear Plinkster,

Screw caps & Loctite 242 ..... worth a try I suppose
I see that there is a star washer under the screw directly in contact with the (soft) wood.
Therefore the star washer is not getting compressed enough to perform its locking function.
I shall try a plain steel washer between the wood and the star washer & then use Loctite to tighten.

Thanks & Regards,
Vishwanath

[bennedose]

I prefer leather seals because I can make them to any size in 15 minutes and they are "self-trimming". If it is sticking out a bit too much it simply gets crushed and amputated. Here is an image of a leather seal made out of an old shoe on my SDB 50 and the result of the tissue paper test. I have fired about 4000 to 5000 shots since I made that seal. Still going strong.
https://docs.google.com/file/d/0B3JNY4I ... sp=sharing

[bennedose]

With original seal :

1. Shoot at an object about 15-20 m away (try shooting at a metal surface, like a dish antenna , that will make a distinct sound)
2. Try and remember the delay between the sound of the gun's thwack and the object being hit.
3. Do this a few times.


Repeat the same with the new seal (O-Ring).

You will find that the delay is reduced (more velocity = more power)

Another option would be to simply record the sound on a phone and then compare the sound wavefrom on a sound editing software such as audacity.

I am tempted to try the Loctite trick but I worry that it may be impossible to unscrew when I really need to do that. I have been tighteing screws every now and then.

[VishyB]

Dear Bennedose,

Thanks for the tips

Breech seal self adjustment - "crushed and amputated ..." well put because that is exactly what I see in in my new gun at the present - the seal material is getting crushed & smearing over the groove faces
Stock Screws - I am OK with tightening required now & then but I am worried about requiring it every session
I shall try plain washer between the wood & star washer first & see if the loosening frequency reduces.
If it still loosens frequently - Loctite it is.
Liked the idea about recording sound & analyzing - I have seen threads on the topic & shall read them.
I guess a non permanent grade like 242 or 243 should be OK

Cheers,
Vishwanath

[VishyB]

Dear Bennedose,

I shall try plain washer between the wood & star washer first & see if the loosening frequency reduces.

Hi Friends,

This is regarding issue of my new IHP 35 loosening the front stock mounting screws with each shooting session
I want to share a solution that seems to have worked for me
I have shot over 40 pellets in two sessions with plain washer added between the wood stock & star washer below the screws.
There is definite improvement with one screw not loosened at all & other screw only fractionally loose (less than 1/16th turn)

Now need to settle down to improve my skills - Reducing hold sensitivity, Steadiness of sight picture & follow through.
Here is an example of my accuracy as of now, shot at 10m standing
The target is from Aimco which I had ordered along with pellets.
Largest diameter is 95 mm and black circle is 45 mm.

http://vishyb.zenfolio.com/p612838644/e25d14e22

Pellets are "Microshot Pointed"
Have just received Mastershot export quality , round as well as pointed from Aimco and will try them out today.

Happy Diwali to All

Cheers,
Vishwanath

[VishyB]

Have just received Mastershot export quality , round as well as pointed from Aimco and will try them out today

Hi Friends,

Want to share comparison between Microshot Pointed and Mastershot Export Quality Round Head pellets

http://vishyb.zenfolio.com/p612838644/e95f57c9

Both seem to work well with my IHP 35
Mastershot Round Head working well is a big relief as it is a standard brand & the 1000 pellets ordered thru Aimco can be put to good use
The Microshot fit snug and the Mastershot fit loose in the breech.
Thankfully that does not seem to be much of a factor affecting accuracy

Regarding shooting technique - standing exact 90 deg to the target (perfectly side-on), stock rested on open palm of left hand and trigger hand grip using thumb & middle finger only (ring & little fingers loose) seems to work for me.
Still working on the follow through

Cheers,
Vishwanath

[bennedose]

Both seem to work well with my IHP 35

Air rifles take time to settle. My SDB, tuned by me, settled only after 2000 shots or so and is now a real pleasure 4000 shots down the line. I think my IHP is just beginning to settle.

[bennedose]

Just a note about shoddy quality in my IHP 35.

It is about 9 months and possibly 1500 shots old. The the threads on the holding screw on one side have worn out.

There are two brackets that engage the screws that hold the receiver to the stock. One bracket is just forward of the trigger and the other is mid receiver to take the side screws. Both brackets have come loose as the spot welds that held them have come off.

I am doing my own repairs on this and will post. But I find it remarkable that my SDB showed no such failures in 20 years and my Weihrauch had none in 25 years.

[najad]

[/attachment]

Just a note about shoddy quality in my IHP 35.

It is about 9 months and possibly 1500 shots old. The the threads on the holding screw on one side have worn out.

There are two brackets that engage the screws that hold the receiver to the stock. One bracket is just forward of the trigger and the other is mid receiver to take the side screws. Both brackets have come loose as the spot welds that held them have come off.

I am doing my own repairs on this and will post. But I find it remarkable that my SDB showed no such failures in 20 years and my Weihrauch had none in 25 years.

this one is a good solution and same is done in my ihp, http://www.network54.com/Forum/79537/th ... +and------
[attachment=0]Picture043.jpg

[bennedose]

this one is a good solution and same is done in my ihp, http://www.network54.com/Forum/79537/th ... +and------
[attachment=0]Picture043.jpg

LOL Thanks! In fact this is exactly what I have done - but I decided to use Araldite instead of a weld because it does not involve stripping down the rifle and taking it to the local workshop for a weld. Let me see how it works. Will post pics when it's done and will post if it succeeds or fails

[sathya.sniper]

this one is a good solution and same is done in my ihp, http://www.network54.com/Forum/79537/th ... +and------
[attachment=0]Picture043.jpg

LOL Thanks! In fact this is exactly what I have done - but I decided to use Araldite instead of a weld because it does not involve stripping down the rifle and taking it to the local workshop for a weld. Let me see how it works. Will post pics when it's done and will post if it succeeds or fails

And one more small info..... regarding this kind of work i too have done it. And Araldite din't long last. Better to weld it.
If you plan to weld a Nut to the receiver.... make sure that you screw the bolt inside and then move on to welding process. (This is a tricky stuff... Contact any experienced GAS welder for this job)
If you don't follow this while heating the Thread in the nut will collapse due to Heating.

Regards.