Outer barrel inner diameter

[Conker]

Hi,

I'm looking for the standard inner diameter of an outer barrel (or outer diameter of an inner barrel).

Unforturnately I don't have any accurate tools on hand to get it myself

Why? I'm thinking of trying to zero my red dot as well as to adjust correctly my hopup using a boresight, and I must know what is the closest diameter for this. It may be overkill, but a decent boresight isn't that expensive and could most likely help achive this goal.

Thanks for your help!
Conker

[ILLusion]

You shouldn't be looking for the inner diameter of the outer barrel, NOR should you be looking for the outer diameter of the inner barrel.

If you want it to be accurate, you should be sighting to the bore of the actual firing barrel - in the case of airsoft, this would be the inner barrel.

What you should be looking for is the bore of the inner barrel. That shouldn't be hard to figure out without measuring. Just figure out what brand the barrel is, and it's easy to find out what the inner diameter is. ie, KM = 6.04mm, Systema = 6.04mm, Prometheus/9Ball = 6.03mm, Marui = 6.08mm, PDI = 6.01mm or 6.05mm, etc etc.

I use a laser bore sighter with a .22cal adapter. It's slightly adjustable and can expand outwards to fit anywhere from 5.98mm up to 6.10mm airsoft bores. You'll need to check with the one you're using to see if it can adjust as well.

[G26]

OEM OD of inner barrels usually around 8.XXmm, outer barrel's ID might be up to 9mm. From what I know, different manufacturer (or even same manufacturer with different models/revision) has slightly different diameters.

Unless you get the help from a person who has the exect same manufacturer/model/revision as yours, the reading might be off.

But then again, are boresighting useful for AS? With the instability and flight path of a BB, it might just give you a very rough guess of where the BB will impact, IMHO.

Also, how do you plan to set the hopup with boresighting?

[m102404]

6mm = .243 cal if the bore sight that you're looking at only lists imperial stuff. Most adaptors/inserts have a wide adjustable capacity...so most kits will work.

Boresights are usefull to get your sights on/close if you can't get the chance to sight in by actually shooting.

With the POA dead on, if you set the POI between 0.5-1" high on a 360-400fps gun in about 25-30ft of space, you'll be pretty close when you get out to the field and tune in the hopup. For a lot of setups...it'll be close enough to shoot the game.

It's handy and lots of guys have done it. I've seen Illusion come out to a pistol match, bore sight his pistol's doctor sight (which are fiddly things to get zero'd) and shoot a match.

[Conker]

All my barrels are 6.03. I was thinking of putting it in the outer barrel to ensure I don't scratch the hopup sleeve or the inner barrel, but... I understand it's pointless.

Originally Posted by G26

Also, how do you plan to set the hopup with boresighting?

Usually, you have two variables: the sights and the hopup (and the wind, but that would be done inside).
If I can boresight to adjust correctly my irons or optics, then it will be easier and more accurate to adjust correctly the hopup.

So I guess I'll try to find an adjustable .22 boresighter then. Thanks for the tips, it should be very helpful!

EDIT: I'll soon be getting a TK Twist Barrel for my MEU. What's really the diameter? I've seen retailers saying 6.04, while a Google search gave me forum posts where people where saying it's more 6.08...

[ILLusion]

The bore sighters generally won't go deep enough in to the gun to end up scratching your hop up sleeve (unless you're sighting in a derringer or another similar short barreled gun.)

And besides, the adapters are generally plastic that's softer than BBs. If a BB can't scratch your inner barrel, the adapter shouldn't, either.

No idea what the inner diameter of the Twist barrels are, but I use my bore sighter with my Twist barrels all the time. Again, .22 adapter.

[Conker]

Do you think that this: Amazon.com: Bushnell Laser Boresighter: Sports & Outdoors should do the job?

If not, is there one you would recommend?

Note that I've put here probably the cheapest I could find (almost; actually this was), but if something cheap does it, then it's all good! Of course, if it's shitty I'm ready to invest more, as long as it's not the price of the gun^^

[ILLusion]

That's exactly the one I have. So yes, I think that should do the job.