Model 1 300 Fireball thread pitch

[TCCrewchief76]

Just got off the phone with a lady from M1, and she specified that the thread pitch on their Fireball barrels is 1/2-36. The option to have it changed is $50. I don't understand why they don't use 5/8-24.

Kevin

[Fudmottin]

I think it's because they don't really want to do 300-221 barrels. Look up tp555 and get a real barrel. You can have your 5/8-24. It's no more difficult to machine that from a Douglas barrel blank then any other thread. Also you get the port in the pistol position.

[TCCrewchief76]

tp555? Is this a username here? Company? The blank is a Douglas? What are the benefits of having the port in the pistol position? I would assume this would allow the use of pistol powders to cycle the action, yes? Higher port pressure closer to the action as opposed to the placement down the barrel.

I love this place,

Kevin

[HotLead]

tp555 makes barrels for ARs. His business is Paladin Machine service:

The pistol gas position should allow for more flexibility with subsonic loads. Other users have barrels with the gas port in the pistol position and have had fairly good results, I am sure they will chime in with input.

Paladin Machine Service
3832 gates ford rd.
Kershaw,Sc 29067
(803) 475-7542

(He is just now finishing my barrel in .30/221) :grin:

[TCCrewchief76]

Do you mind me asking how much you paid for your barrel at Paladin?

[HotLead]

Do you mind me asking how much you paid for your barrel at Paladin?

Sent you a private message

[mooster1223]

I think it's because they don't really want to do 300-221 barrels. Look up tp555 and get a real barrel. You can have your 5/8-24. It's no more difficult to machine that from a Douglas barrel blank then any other thread. Also you get the port in the pistol position.

M1S WILL thread 5/8 24 AND port in the pistol position. All you have to do is ask. The reason they charge extra for the 5/8 24 threading is that they order the barrels from an outside source and assemble your upper from a "box of parts". If you want 5/8 24, they order a non threaded barrel and then thread it in their shop. Just costs extra to "have it your way". If money is no object then a fully custom barrel is the way to go.

[Fudmottin]

Thanks for the correction.

As far as money goes... Barrel blanks are not all that expensive. Although you certainly won't be getting a $500 upper going the custom route unless you already have spare parts lying around that you don't count into the cost. But you can "have it your way" for a reasonable price.

In my area, ARs and everything related to them are super expensive. I did not pay more building my own than going with an off the shelf rifle. I didn't save money either of course.

[AfricanJerry]

I bought a M1S 300 fireball upper this month and 5/8 24 is now the standard thread pitch on them. They are also sending them out with a .123 gas port hole size standard.

[sharky47]

I do manufacture an adapter to go from 1/2 X 36 to 5/8 X 24 for those that have a M1 Sales barrel with that thread.

PM for details, it costs less than the $50 that they want to charge......


When I ordered my M1S barrel, I asked them to leave the threads and the gas port off completely and I would take care of that stuff. They did leave the gas port undrilled, but still sent me a 1/2 X 36 barrel. Wasn't worth trying to mess with an exchange so I setup of the CNC lathes and made a pile of adapters.

[mstarling]

I think the original reason they used the 1/2"x36 thread is that they did not want anyone to put a .223 flash hider on one of the larger bore barrels ... and the 9mm standard already was 1/2"x36.

I don't think there is any question that tp555 is not as cheap as M1S ... but then he doesn't use E.R. Shaw barrel stock either and he will provide barrels in stainless steel. His work is superb.

He does thread muzzles in 5/8" x 24 if asked. He will also do a chambering gauge for you too for a very reasonable price. His turn-around times are terrific.

Sometimes quality costs a little. It's almost always worth the little extra!

[sharky47]

Yeah, I know why they did it - but they should have put a little more thought into it and gone with 5/8 from the start.

Oh well, there are plenty of barrels to choose from - and I have a low price option for the guys with 1/2 x 36, so everyone is covered......

[TCCrewchief76]

I bought a M1S 300 fireball upper this month and 5/8 24 is now the standard thread pitch on them. They are also sending them out with a .123 gas port hole size standard.

How's that barrel shooting for you? I'm interested, and ready to buy a barrel. I'm going to be using subsonic ammo only.

Regards,

Kevin

[tdale4]

I don't think there is any question that tp555 is not as cheap as M1S ... but then he doesn't use E.R. Shaw barrel stock either and he will provide barrels in stainless steel. His work is superb.

He does thread muzzles in 5/8" x 24 if asked. He will also do a chambering gauge for you too for a very reasonable price. His turn-around times are terrific.

Sometimes quality costs a little. It's almost always worth the little extra!

A huge +1 on tp555

I cant give a higher recommendation then a tp555 barrel

I bought a .300 whisper barrel, 3 position gas block, and flash hider from him. he does excellent work. Much better quality then a M1S and his prices are very reasonable plus you can have it exactly the way YOU want it.

his work is simply outstanding and well worth the the small price increase over a M1S

[tp555]

The biggest cost for a barrel is the blank.Carbon goes $200 and stainless $280.
Douglass or Pac nor prices are about the same.The model 1 barrels cut a bit different than chrome moly barrels.I have recut the model 1 barrels to pistol gas location and rethreaded them.If you can score a blank in 8 twist cheap.The rest is easy.

[sharky47]

"The model 1 barrels cut a bit different than chrome moly barrels.I have recut the model 1 barrels to pistol gas location and rethreaded them."

I have done two M1S barrels so far. The one I bought for me, I ordered with no threads and no gas port. They sent me one with no gas ports, but it WAS threaded 1/2X 36 - which is why I initially set a CNC live-tool lathe to make the adapters I now sell. I moved the gas block shoulder back and drilled a port in the pistol position, gun runs GREAT.

The second one was for a customer, ordered with no threads and no port and they actually got it right this time. Cut it to 10", relocated the gas port to pistol length, and threaded/crowned the barrel 5/8 X 24. This gun also runs flawlessly.


But yeah, if anyone is stuck with the 1/2 X 36 threads, I have a bunch of adapters to 5/8 X 24 for a VERY reasonable price.......