Why diameter difference from JSB?

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Tnx.
So what are the part numbers for the British .303 compatible NOE molds? I would like a 2 or 4 pellet diabolo. ALL the NOE drawings I examinied show .308 for the skirt dimension

I hear exactly what works in your gun and I know round balls are not the same but .308 ball or slug will not go in mine.  Anything solid  over .303 jams. Seems like the .308 skirt will be highly compressed into the rifling. JSBs .30 works great.

I just measured the skirts on a handful of new JSB Exact .30 diabolos, 44.75 gr using micrometers and they are between 7.62/.301  and 7.78/.3065  None were as big as .7.82/.308    What gives?

Tnx,
Enginator

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[rsterneParticipant]

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I designed the NOE Pellet Moulds, and the skirt diameter was taken as the average of the three pellets that JSB make, the 44.8 gr. the 50.2 gr. and the Predator Polymag…. I just rechecked several tins of pellets I have of all three types, and got these average skirt diameters (the heads all averaged 0.300″)….

JSB 44.8 gr…. 0.306″
JSB 50.2 gr…. 0.307″
Predator Polymag…. 0.309″

I have both NOE moulds, and checked them as well….

Hunter 45.7-49.6 gr…. 0.307″
Hunter Magnum 59.2-65.7 gr…. 0.308″

As I am sure you are aware, the skirt diameter on pellets is significantly larger than the head diameter, to insure proper sealing…. The skirt of a pellet is very thin walled, and designed to collapse on loading, to allow pellets to fit a wide range of barrel and chamber diameters….There are lots of the NOE moulds out there, and I have never heard of anyone having a chambering issue…. The head diameter on the NOE pellets measures, on average, 0.300″….

You are correct, .308 caliber slugs or ball will not chamber easily (if at all) in any .30 cal airgun barrel…. as the bearing surfaces are solid, and not designed to collapse…. If you wish to shoot slugs in an airgun barrel, you normally have to increase the length of the chamber, and add a tapered leade, as they are intended to be used with pellets where the head diameter barely engraves the rifling and the skirt collapses to comply…. In addition, slugs must be sized to the groove dimeter of your barrel, and the manufacturers designation of the Daystate as a .303 (to take advantage of the popularity/recognition of that caliber in the Enfield rifles) may or may not have anything to do with the actual diameter…. The Lothar Walther .30 cal airgun barrel, for example, is 0.298″ land and 0.306″ groove diameter…. If you try and chamber a .308″ slug in that barrel, you will also find it too tight…. My NOE Bob’s Boattail slugs intended for .30 cal airguns have a nose diameter of 0.300″ and a driving band of 0.302″ so that they can be chambered properly, and even then, if the chamber is too short they will require some force to engage into the rifling…. Pellets, however, are not an issue, and chamber and function properly in any airgun barrel they have been tried in….

Bob

[enginator]

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Thank you Bob for the concise response. If the NOE diabolo designated as .30 are what I need then I need the part number to order a double or quadruple mold! Do you happen to know Those numbers and where I order? I think a LOT of the discussion could be simplified by standardizing the British .30 (.303) for airguns so there needs to be less searching to be sure of the right pellet:-)) 30 cal is a misnomer. Also the discussion of lands and grooves should always be clarified in relation to naming of the caliber. But almost no one does it.  Part numbers and source??

[rsterneParticipant]

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The .30 cal pellets are at the top of this page in the NOE Store….

http://noebulletmolds.com/NV/index.php?cPath=30&osCsid=ruv5v6dkfks96kkkqd68fc0ao2

http://noebulletmolds.com/NV/index.php?cPath=30_585 is the Hunter, 45.7 – 49.6 g. plus a bonus flat base pin that is  57 gr….

http://noebulletmolds.com/NV/index.php?cPath=30_532 is the Magnum Hunter, 59.2 – 65.7 gr. and 73.3 flat base….

Both are available as the RG2 (2 cavity) or RG4  (4 cavity)…. and come with complete sets of all 4 pins, three HB plus the FB…. I notice that the only moulds left for the .30 cal Hunter pellet is the RG4 Brass (only 2 left)….

Just as with other calibers of airguns, the .30 cal has no standard diameter…. There are barrels available at 0.294″ land with a 0.300″ groove, the LW at 0.298″ land and 0.306″ groove, plus whatever the Daystate actually measures, then the FX barrels, plus all the other manufacturers of .30 cal…. The same problem exists in .177 cal, .22 cal and .25 cal, the actual measurements are all over the place…. as are the twist rates…. It would be nice if there was a standard, like there is for Powderburners (eg. .300″ land / .308″ groove)…. but sadly that is not the case….

Bob

[enginator]

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Thank you for the links. for a newcomer to pellet casting you can understand my caution. I will not spend the money for the Brass so I hope NOE is about to produce more .30 cal diabolo molds. I really do not want to order from South Africa! Anyone at NOE reading this??

[larrynuferParticipant]

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If people realized how accurate the cast pellets are that come from the NOE molds that I have they’d start casting their own too. 

[Author]

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