Walther LP300 - cylinder question

[Walnut92]

Anyone here who could help me with a LP300 I have just acquired second-hand?

The cylinder was at 200 bar when I borrowed it - lovely gun, so agreed to buy.

I ran it down to around 100 bar and it unscrewed easily. I pressurised it up to 230-ish bar and tried to screw it back on - very hard!

Let it down to 100 - screwed on fine, and then raised to 150 bar - tighter but fine.

Before I persevere up to 200+ again, can anyone advise me as to any issue here? I have cleaned threads carefully etc. and applied a small smear of silicone grease.

By the look of the valve design (in the cylinder) it would seem that it will get harder the higher the pressure in the cyl, but I'd value advice from those who know the gun well.

Thanks

[Rutty]

I’ve had an LP300 for 10 years. It should not be difficult or hard to screw on and there should be no need to use any grease of any kind on the threads.

Rutty

[Walnut92]

Thanks. It has probably hardly been used in probably that sort of time - might that contribute to this?

I can only assume it is the valve that is 'hard to open' - the actual action of threading has no resistance until you start engaging the valve.

[mikec4]

I used to own a Walther LP 300 - the cylinder is steel and rated to 300 bar. I filled to 250 bar and had no problem fitting or removing the cylinder.

have it checked out; as you say, it could be a tight valve.

[RobinC]

Regardless of pressure right up to 300 the cylinder should be an easy fit right up until the last little twist, which is where it opens the valve into the regulator, which is where the first time it has pressure in the action. On yours it is clearly acting against the pressure most of the way in, hence its stiffer with more pressure, so this is an issue/problem/fault either with the valve in the cylinder or the action actuator.

If you have any one you know with another cylinder LP300 or 400, just try theirs and see if it goes in easily, if it does its a cylinder issue on yours, if its the same as yours, its the pistol action. Either way its easy to resolve, but best by some one who is familiar with them, I'd suggest contacting Wonky Donky on here, he'll sort out either the cylinder or regulator.

Have Fun
Robin

[Walnut92]

Thanks Robin, it is actually getting a lot easier with use.

Due to tightness I initially charged to only 150 bar, at which point it was not an issue. Yes, it's only as the valve engages, not the general thread.

Am now charging it to 200bar and it is also going on fine. Irrespective have ordered a new cylinder as it is well out of date and as it's an oldish model would not now want to find it obsolete.

I suspect it hasn't been used for possibly up to ten years!

It's bloody brilliant. Even as a complete novice of 3 weeks to match pistol shooting, I can keep it in a 20mm group freehand at 6m. Now need to get the longer 10m range sorted...

[RobF]

It could still be the thread on because that part of the thread is not engaged until under pressure. We saw it with reg testing in the early days before we built a system that avoided thread loading.

You could try tiny smear of lube designed for air components on the reg thread and see if this helps.

It depends which thread is affected as to if it will occur with another bottle. It could be recut again if it’s the reg thread.

Although the regs and steel cylinders can take 300 the ally ones are designed for 200 and 200 gives an easier time on the reg and threads.