RAW Barrel Swap .25 to .25 Polygon?

I don't think there hard to do from what I saw when I had my RAW but can't say for sure. But I definitely would love to see a Maple stocked RAW so I support you 100% on that

Dirte i have a RAW hm1000x lrt in 30 cal , and was thinking about asking Martin ,if i bought the right barrel and probe can i switch calibers say like you to a 25 cal poly, good luck on your project hope it works for u pat

Hi guys, a barrel swap for a RAW is a 10 minute job, even less when sticking to the same caliber.
I machined a BSA barrel blank in .25 for my (ex) .30 HM1000x and sleeved it with a CF tube. Made a custom LDC as well and it shot very well in stock .30 settings with king heavies. So Dirte, I'd leave the regulator out, and only swap the barrel

The intention of a switch barrel gun, is that you can swap out barrels very easily, when you also have to swap the reg and other things, most part of this advantage is gone.

In your case, you only have to remove the regular barrel and install the poly barrel.
If you wish, you can also swap out the LDC, so you only have to order a CF sleeved barrel. (However, I think Martin needs to know some measurements of your current barrel to copy the sleeve dimensions)

But..... going from a conventional to a poly barrel in the same caliber..... Dunno really.
I think I'd leave it as is, because the cost will probably not cover the possible improvements.
A regular .25 LW barrel performs very well too (I tried this first hand of course ) but after trying out about every LW barrel, I stuck with the LW chokeless poly barrels about 1.5 years ago.
This barrel type tends to foul the least of any barrel.
B.T.W, I have understood RAW recently switched over to chokeless poly barrels as wel for their .25 cal's. Nuff said

What is the difference between the normal .25 barrel and polygon barrel?

This is the best i could find:
http://www.airgunnation.com/topic/polygonal-barrell-vrs-reg-lothar-barrel/

but then everyone just starts talking about tuning the gun to the pellet. Im more interested in which is better and how one is better than the other? 

Dirte,

My receiver from my RAW .30 is with Martin right now being setup so I can shoot both .30 as well as .25. I am getting the .25 poly barrel/probe/new moderator/magazine and the price was like $450 I think for everything.

"FukoChan"What is the difference between the normal .25 barrel and polygon barrel?

This is the best i could find:
http://www.airgunnation.com/topic/polygonal-barrell-vrs-reg-lothar-barrel/

but then everyone just starts talking about tuning the gun to the pellet. Im more interested in which is better and how one is better than the other?

Click to expand...

The main difference is the form of the rifling. Conventional barrels have lands and grooves, polygonal barrels have sort of "flat edges" (facets) with a defined twist to it.

@sharoff, I'm very curious why Martin would need your receiver to setup to make it shoot both calibers.
It is just a matter of taking out the barrel, loosen the probe, install probe for new caliber, install barrel with new caliber, adjust probe and shoot Not really much to set up IMO
Only thing I can think of is drilling the .25 barrel's transfer port to a certain diameter to make it shoot the pellet of choice with the desired speed running the .30 reg and H.S.T. settings.
But that would be a rather crude adjustment. Fine tuning is always needed to perform the best IMO.

Weatherby,

I sent him the receiver to look at as the .30's fps dropped under 800 again with the hammer spring adjuster fully cranked. Martin had ideas about what could be causing it and explained what to check, but I didn't want to get that far into taking the receiver apart.

Getting it setup for .25 poly barrel and the new moderator design while it was there was just a bonus. I'll be doing my own barrel / probe swaps once I get it back. Then one turret tape for .25 and one turret tape for .30 and I've got a solid platform in one gun for both calibers.

"sharroff"Weatherby,

I sent him the receiver to look at as the .30's fps dropped under 800 again with the hammer spring adjuster fully cranked. Martin had ideas about what could be causing it and explained what to check, but I didn't want to get that far into taking the receiver apart.

Getting it setup for .25 poly barrel and the new moderator design while it was there was just a bonus. I'll be doing my own barrel / probe swaps once I get it back. Then one turret tape for .25 and one turret tape for .30 and I've got a solid platform in one gun for both calibers.

Click to expand...

Makes sense, thanks for the clarification
And indeed, 1+1=2 when you already have your gun over there anyway, why not make the most of it, and get some nice new accessories (b.t.w. 450$ is totally justified IMO for barrel, probe and LDC)
You won't regret it, I have shot most AG calibers, but the .25 is by far my favorite

cheers, Gijs


Hi Guys, I will share what Matin told me. Their research found that the new polygon barrel shoots the king heavy best at 900fps. The RAW 1000X .25 with LW barrel which was set up to shoot kings around 920 fps does not push enough air to shoot a king heavy at 900 fps. They need to enlarge the transfer port to achieve this. I can not remember if he said the regulator needed to be adjusted but it would not surprise me.
I have regular LW barrel and found that it shoots king heavies really good at 830-840 fps. Some of you that have the same barrel might want to try that first before you choose a new barrel. You might have to get a stronger hammer spring (or ad some washers) to get the fps from around 800 fps to 840 fps.
Drippinlead

"DrippinLead"Hi Guys, I will share what Matin told me and that is the regular LW .25 barrel that was set up to shoot kings around 920 fps does not push enough air to shoot a king heavy at 900 fps which is what they say performs best in the polygon barrel. They need to enlarge the transfer port to achieve this. I can not remember if he said the regulator needed to be adjusted but it would not surprise me.
I have regular LW barrel and found that it shoots king heavies really good at 830-840 fps. Some of you that have the same barrel might want to try that first before you choose a new barrel. You might have to get a stronger hammer spring (or ad some washers) to get the fps from around 800 fps to 840 fps.
Drippinlead

Click to expand...

This seems not barrel related, but indeed pressure/transfer port related.
I reached 900 fps easily with both conventional and polygonal barrels, all other things equal. (That saying, tried this in my converted Boss, but the RAW 30 cal easily went over 900 fps as well with BSA .25 barrel installed)
The reg. pressure indeed needs to be increased to about 160bar to reach the desired speed. Also found out that my 30 cal had a single hammer spring, while my friend's .25 cal has got 2. (Never liked the idea of using 2 hammer springs anyway, a single one will do just fine )
To be exact, if one decides to use 2 hammer springs, one should be wound clockwise, while the other one should be wound anti-clockwise to prevent binding.


"Dirte"

"weatherby"Hi guys, a barrel swap for a RAW is a 10 minute job, even less when sticking to the same caliber.
I machined a BSA barrel blank in .25 for my (ex) .30 HM1000x and sleeved it with a CF tube. Made a custom LDC as well and it shot very well in stock .30 settings with king heavies. So Dirte, I'd leave the regulator out, and only swap the barrel

The intention of a switch barrel gun, is that you can swap out barrels very easily, when you also have to swap the reg and other things, most part of this advantage is gone.

In your case, you only have to remove the regular barrel and install the poly barrel.
If you wish, you can also swap out the LDC, so you only have to order a CF sleeved barrel. (However, I think Martin needs to know some measurements of your current barrel to copy the sleeve dimensions)

But..... going from a conventional to a poly barrel in the same caliber..... Dunno really.
I think I'd leave it as is, because the cost will probably not cover the possible improvements.
A regular .25 LW barrel performs very well too (I tried this first hand of course ) but after trying out about every LW barrel, I stuck with the LW chokeless poly barrels about 1.5 years ago.
This barrel type tends to foul the least of any barrel.
B.T.W, I have understood RAW recently switched over to chokeless poly barrels as wel for their .25 cal's. Nuff said

Click to expand...

I believe the Raw is the simplest gun I have been in to. I would like to swap once in a while depending on what I prefer. So a couple screws to change out barrels would be nice. Adjusting the regulator would take more time. I've seen Theoben regulator adjuster tool on some European sites. I don't know if they would be the same. Also for $160 I could drop a setup spare in.

Click to expand...

When you don't swap caliber, it is not needed to swap the regulator at all IMO.
If you need adjustments, they will be small which is easily adjusted by changing your hammer spring tension.
B.t.w. the reg. piston retainer of a RAW regulator is not locked in place like it is the case with FX regulators. So when you handle it outside the rifle, it is easy to turn the knurled brass retainer unintended, which will change your reg. setting.
In your case, you only have to loosen the 3 set screws on top of you receiver, and swap the barrel.
Then the probe needs to be adjusted and you are good to go. I wouldn't bother to mess with the reg. if it were my gun.
At the time, I made a reg. tester for the RAW, and it is just as easy to readjust the reg pressure, than it is to swap it completely. Instead of buying a 160$ reg. I'd rather buy a reg. tester as it is way more usefull than a spare reg.
In that case you can set it at any pressure you want, and play around with different settings. 


"weatherby"

"FukoChan"What is the difference between the normal .25 barrel and polygon barrel?

This is the best i could find:
http://www.airgunnation.com/topic/polygonal-barrell-vrs-reg-lothar-barrel/

but then everyone just starts talking about tuning the gun to the pellet. Im more interested in which is better and how one is better than the other?

Click to expand...

The main difference is the form of the rifling. Conventional barrels have lands and grooves, polygonal barrels have sort of "flat edges" (facets) with a defined twist to it.

@sharoff, I'm very curious why Martin would need your receiver to setup to make it shoot both calibers.
It is just a matter of taking out the barrel, loosen the probe, install probe for new caliber, install barrel with new caliber, adjust probe and shoot Not really much to set up IMO
Only thing I can think of is drilling the .25 barrel's transfer port to a certain diameter to make it shoot the pellet of choice with the desired speed running the .30 reg and H.S.T. settings.
But that would be a rather crude adjustment. Fine tuning is always needed to perform the best IMO.

Click to expand...

Thank you for the information. Does this difference in rifling in turn translate to better accuracy? 

@Fuko Most barrels I have tested performed very well, that's why I can't really say which one is actually "the best" barrel.
The reason I like chokeless polygonal barrels so much is that they barely foul, and give a very good seal with the pellet because there are no lands and grooves.

That doesn't mean conventional barrels are any worse, but I just have very good results with poly barrels.
Another advantage is that one can polish the sh@t out of it, you can't ruin the lands because there aren't any That's the advantage of having smooth transitions of the flats inside the barrel.

Eventually, it all comes down to the quality of the pellets, and the match with a certain barrel. In my opinion the quality (consistency) of pellets is just as, if not, more important than the barrel (speaking of airgun barrels here of course, not PB's)

I've seen several Hatsan .25 barrels which I wouldn't give a dime for after I slugged the bore, but they shot less than half inch groups at 50m all day long......

@Dirte when you turn the brass part (b.t.w. a good way to adjust reg. pressure the easy way ) you will change the piston stroke slightly. Because of this, the belleville washers need to be compressed less or more, hence the changing regulator pressure.
Actually, the FX regulator is a miniature version of the RAW/Theoben regulator, exept that FX puts some threadlocker on the brass part, so reg. pressure has got to be changed by turning the nyloc nut on the reg. piston.
The operation of both regulators is exactly the same

Excellent explanation.