New .30 cal Barrels for JSB Pellets

[rsterne]

I'm just going to let the cat out of the bag a bit here.... SeanP and I have decided that since JSB are making pellets for the FX and Daystate .30 cals that are smaller than will properly fit in a "standard" .308" barrel (LW, TJ's or PB).... we are ordering a mandrel from Mike at TJ's to have airgun barrels produced to properly fit the new 46-50 gr. JSB pellets, which have a 0.300" head diameter.... Once the mandrel is made, we will be getting some barrels done in 0.50" OD which would fit an MRod, and I will be doing a prototype riser breech to adapt that size barrel to a 22XX/Disco using a modified MRod .25 cal clip (Lloyd's) that will allow 7 shots in .30 cal.... This breech will also accept a .25 cal MRod barrel, or a .25 Auto TJ's barrel blank as well.... We already know that the .25 MRod clip will accept the 53 gr. cast Lyman bullets and the 50 gr. Mr. Hollowpoint bullets, so if all works out as planned, both the MRod and 22XX/Disco platforms will move up to shooting 46-53 gr. pellets/bullets in both .25 and .30 cal....

SeanP is hoping to produce the breeches & bolts, along with providing machined .30 cal barrels, and valves opened up to provide the additional airflow required.... I'll be doing the prototype work, and at the moment FPE numbers are just a guess, as we want to make everything as much of a "drop-in"/"bolt-on" as we can.... However, my goal is 850+ fps with the 46 gr. JSBs which would be 74+ FPE and hopefully more depending on the pressure and barrel length used.... There is no reason that shorter .25/.30 cal barrels could not be fitted to the 2240/50 pistols as well, using the new repeater breech.... Down the road, SeanP may get some 0.59" OD (15mm) blanks made and machine them up for a single-shot conversion for the QB 78/79 rifles as well.... along with matching bolts....

Please don't bug us, as it will be a while before any of this gets prototyped, let alone into possible production.... The above information is all I can supply at the present time.... My prototype will be a new project, which is a .30 cal Disco Double (from Lloyd at AirGunLab) in a Blaster stock with an MRod trigger (from Norm at DiscosRUs).... When I have anything concrete to report, it will be in a thread I will start on that project....

Bob

[strever]

sounds exciting and fun

[Bruce]

Sounds like lots of fun! Good luck on your quest!

[Nomadic Pirate]

that will be a hot seller

[rsterne]

Update on these barrels.... The mandrel is made, and the barrels will be produced to the following specs:

.30 cal Airgun barrel intended for the new JSB 46 & 50 gr. pellets
Made from CrMoly steel, hammer forged
Groove 0.300"
Land 0.294"
Twist 1 turn in 26"
6 Lands
OD 0.500" (0.590" also available)
Standard length 25" (12.5" for pistols)

What they are NOT: They are not intended to use 0.308" cast bullets, nor are they intended to use any bullet over 0.48" in length, as those will not fit into a modified .25 cal MRod magazine, and may not stabilize in the 26" twist....

Sean will be placing an initial order as soon as we can collect pre-orders and determine a price.... For THIS ORDER ONLY, and only for BARREL BLANKS with no machining, we will accept orders for lengths other than the above, but be advised there may be a small surcharge from the manufacturer for barrels over 29" long....

I will be contacting those who have expressed an interest in pre-ordering barrel blanks.... Anyone else who wants to get in on this initial order, either for blanks or for machined barrels.... please contact me ASAP.... Sean will be finalizing the list within a week, getting prices, and then contacting you to arrange payment.... Sean will be offering all machining services (chambering, porting, and crowning, and can even add a choke) at extra cost if you desire, please ask him for details directly....

Bob

[MultimediaMan]

What is the difference (aside from Barrel Length) between this barrel and the LW barrels. I'm asking because I don't know.

[rsterne]

The LW barrels are 0.300" land and 0.308" groove, and IIRC, 17.7" twist, and intended to work with .308" cast lead PB bullets, and their standard length is 28" with an OD of 0.67".... Incidently, the first batch of our barrels are on the way....

Bob

[MultimediaMan]

How much are these barrels of which you spaeak?

[rsterne]

A 25" blank was $177 including postage....

Bob

[rsterne]

First results of a target, shot with JSB pellets at 921 fps average (filled for each group to 2650 psi) from the new barrels.... Not my work, a chap from Alberta, using a 29" barrel on a modded Condor at 12X....



The grid and the orange circles are 1", targets shot every 5 m from 50 m to 90 m (which is 100 yards).... I think you can safely say we did our homework on bore size and twist rate....

Bob

[Bill G]

Oh so Nice!  That's like 86-87fpe that would be yote lethal at 100yrds.  Now look what you did, gotta start another project fund and I don't have any of the others done.

[nonsheep]

Hi Bob!
I know this thread is a little old, but I would like to know if it is possibly to get one of your .30 super barrels?
I want to attempt an Mrod conversion.

Thankx,
TJ

[rsterne]

The barrels are available through Sean (PM to SeanP).... If you can't reach him, I can give you his email in a PM.... Sean can even supply the barrel machined for an MRod and a bolt if required (I know he has already done that)....

Bob

[nonsheep]

Thankx for the reply Bob!
I tried to search SeanP but he seems to be unlisted on GTA, can you please help me more?

[rsterne]

PM sent....

Bob

[nonsheep]

Thank you sir!

[PakProtector]

just to head off confusion, it is SeanMP that he goes by... may have to get another Marauder to run one of these on.

The changes I had done to a 2263 valve body should be sufficient for this barrel. 20-degree angled port at around 5mm exhaust and a throat betwen .250 and .280 should do. De-sleeved of course.
cheers,
Douglas

[rsterne]

Thanks for that correction on Sean's handle, SeanMP is correct, me bad!.... One of our original considerations for this barrel was that it be compatible with a .25 cal MRod breech (ie 1/2" OD) to allow Marauder owners the ability to try a .30 cal conversion should they desire.... Sean can provide .30 cal barrels machined to slide into an MRod, and complete with a new bolt.... PM him for further information about price and availability.... From the experimenting I have done on my .30 Disco Double, I would think that a 3/16" exhaust port.... which can be achieved without installing a new seat and angled port in an MRod valve.... should produce a quite capable .30 cal MRod.... I got over 900 fps (83 FPE) with the 46 gr. JSBs using a 20" barrel and 3/16" porting at about 2500 psi during initial testing on my Disco, and in reality the only difference between the valve I was using and what you can do in an MRod was the angled exhaust port....

Bob

[tkerrigan]

Have you tried the 50gr pellets in you 20" barrel? I'm thinking with a longer barrel (Mrod 24 or 28") 50gr would help keep the speed at a reasonable level?  Does he do a .30 magazine or single shot?  Regards, Tom

[rsterne]

I now have a 25" barrel, and I didn't have the 50 gr. pellets when I had the shorter one (which was actually .308 cal, shooting upsized (swaged) JSB 46 gr).... My gun currently shoots the 50 gr. at over 950 fps (103 FPE), but I don't think you could achieve that velocity without extensively modding the MRod valve like PakProtector has done.... The Disco valve actually has more potential than the MRod valve because there is room to angle the exhaust port and make it bigger than the MRod valve will tolerate without moving the seat forward (not easy to do).... Lloyd at AirGunLab makes .30 cal magazines for the MRod, converted from the .25 cal.... they hold 7 shots and fit right into an MRod breech....

Bob