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View Full Version : Reaming 300 Fireball to 300 Blackout?


MechEng
06-27-2012, 8:13 AM
Good Morning Calgunners,

I recently bought (second hand) a 16" barrel in 300 Fireball from another member of CG. Transaction was great, and the barrel arrived in the mail!

After doing some research, looks like there is enough of a difference in the 300 FB chamber and 300 BLK chamber as to consider them incompatible.

Since 300 BLK casings, loading info, etc. are much more prevalent, I'd like to rechamber the barrel to 300 BLK.

Does anyone know of a 'Smith that has the reamer to rechamber the barrel, and roughly what they charge?

Thanks!

kendog4570
06-27-2012, 8:29 AM
Good Morning Calgunners,

I recently bought (second hand) a 16" barrel in 300 Fireball from another member of CG. Transaction was great, and the barrel arrived in the mail!

After doing some research, looks like there is enough of a difference in the 300 FB chamber and 300 BLK chamber as to consider them incompatible.

Since 300 BLK casings, loading info, etc. are much more prevalent, I'd like to rechamber the barrel to 300 BLK.

Does anyone know of a 'Smith that has the reamer to rechamber the barrel, and roughly what they charge?

Thanks!

Do you have chamber or reamer drawings for the two calibers? These are needed to determine if there is enough meat to cut away for the new caliber, and to see if it can be simply plunged, or must be step-bored for reamer pilot contact at the start of the cutting operation. With a gas gun you don't have the option of cutting off the rear of the barrel so the new chamber will clean up the original one.
The cost will vary with the amount of work required to do the conversion. For instance, cutting a .222 to .223 is pretty straight forward. Cutting a 30-06 to 300 Win Mag requires very accurate boring of the '06 chamber to get the 300 reamer to start properly. Converting a .222 to .221 Fireball requires a barrel setback, then reaming for new caliber. The last two mentioned require significantly more work. It can be done, but it is the same or more labor and setup (sometimes more) than cutting a new blank.

MechEng
06-27-2012, 8:52 AM
Unfortunately, I do not have the the chamber drawings for either. I was relying on the expertise of the Forum Members :)

The barrel is a heavy profile, as well.

russ69
06-27-2012, 10:26 AM
The two cartriges are very close to each other. If you know who made the chamber, you might give them a call.

http://en.wikipedia.org/wiki/.300_Whisper

MechEng
06-27-2012, 10:35 AM
It's a Model-1 barrel, assumed to be made by ER Shaw. I spoke to Model 1 Sales, and they said:
"The .300 Fireball has a shorter chamber that the .300 Blackout. The gas port is also larger in a .300 Fireball as it operates on a lower port pressure. You can not safely shoot .300 Blachout ammuniton in a .300 Fireball."

I found the dimensions of both cases, and indeed they are VERY close. Since the 300 BLK has a longer chamber, I'm assuming that the 300 FB can be reamed to its dimensions, as there is material to be taken out to make the chamber longer to match 300 BLK.

I'm a newbie at gunsmithing particulars, especially chambering specifics, so please pardon me... :)

MechEng
06-27-2012, 10:36 AM
Regarding port pressure, I can modify the gas block port to resize to the proper size for 300 BLK.

MechEng
06-27-2012, 6:04 PM
If there is a gunsmith on here, or one that someone knows, that can do it but doesnt have the die, I'll spilt the cost of the die and they can keep it.

kendog4570
06-27-2012, 8:06 PM
If there is a gunsmith on here, or one that someone knows, that can do it but doesnt have the die, I'll spilt the cost of the die and they can keep it.


I can do it for you. I'm not real crazy about owning that reamer, but maybe we can work something out.

kendog4570
06-27-2012, 9:56 PM
I can get the 300 AAC Blackout reamer print from my regular reamer supplier. Where can the fireball drawing be had?

superhondaz50
06-27-2012, 10:14 PM
Easier solution for that barrel, just trim 300AAC brass to Whisper length, whalah, all the benefits of 300AAC without reaming. BTW I have had good success 300AAC load data in that barrel, I prefer a 150gr FMJ running a hair under 2000fps...

MechEng
06-27-2012, 10:52 PM
Thanks Guys,

Superhonda, I think that's what Im going to go with and just trim to whisper length. Cheaper, esp since I'm gonna reload my own brass.

So you're running a Fireball/Whisper chamber? For supersonic, do you run an adjustable gas block?

Kendog4570, thanks for the offer, though.

MechEng
06-27-2012, 10:54 PM
Kendog....I was able to get the case dimensions from ammoguide.com for both the whisper and blackout

superhondaz50
06-30-2012, 8:53 AM
No, standard gas block and carbine tube, no problems at all, it gets plenty of gas to operate the bolt, it's super reliable...

MechEng
07-01-2012, 9:58 PM
Awesome, good to hear. I've seen some posts where people swear that an adjustable GB is needed, others not...

Do you shoot mostly super or subsonic rounds?