- This topic is empty.
-
Topic
-
SwedeNelson
-
Replies
-
rsterne
michaellovett
I’m in on this one as well Al!
The 100 grain spitzer fp was very successful decked to throw at 81 grains, and shoots as well as the 80 gr. RDFP. I sent the 80 gr RD to Eric for his magic and I don’t know how anyone could ask for better performance. If the BBT can match it, and exceed it with better BC, It will be a game changer!
KnifeMaker
laurenwright
Being new to casting bullets I have a question. I read that using pure lead for air guns the bullets would be heavier. Sure enough I got a lyman .257 65 gr mold that puts out 71-72 gr bullets. With these air gun molds are you taking that weight difference into account? Will bullets from this mold with pure lead be 78 +- 1 gr?
I’m betting your Lyman mould is a 257420…. I don’t know of anyone that ever managed to cast them at under 70 gr., I suspect the weight was calculated wrong…. Mine drop at 73.4 gr. using 2% tin and 98% pure lead…. That is typical for that mould….
The weights on this bullet were calculated with pure lead, so if you use that, it should be very close to 78 gr…. +- 1 gr. would be my guess…. I just got an NOE mould for my 51 gr. BBT, and they dropped at 50.8 gr. in 2% tin…. virtually right on target weight….
Bob
This design has now progressed to Group Buy Status…. http://noebulletmolds.com/smf/index.php/topic,1628.0.html
Bob
Borrowing an idea from the Group Buy on the 65 gr. bullet, I have had a look at the possibility of making a second, shorter, lighter version of this bullet available…. I have yet to discuss this with Al, but I see no reason it could not be easily done without another set of tooling…. In addition to making the 78 gr. version as drawn, by simply not plunging the tooling as far into the mould block, it should be possible to make a version with a shorter boattail having a larger base diameter…. ie the exact same shape but missing the back 1/16″ of the bullet….
Not only would the bullet be lighter, about 72 gr. instead of 78 gr…. placing it half way between the 65 gr. and 78 gr. BBTs…. but the shorter, larger diameter boattail would mean the bullet would be easier to stabilize…. There is no reason that the shorter version should not stabilize in a 14″ twist, which is the standard for the commonly used 25-20 barrels…. I would definitely be interested in both versions, but some with interest in an airgun bullet in this weight range may have been shying away from this design because of the 11″ twist recommended…. If you are interested in getting a shorter boattail version, please post below and I will have a chat to Al and see what we can do….
Bob
davidgoldstein
According to my calculations, shortening the bullet 1/16″ at the back…. reducing the length of the boattail and increasing the base diameter…. should make it work in a 14″ twist…. I have made the proposal to Al, just waiting to hear back about the possibility of offering two versions…. the original at 78 gr. and the shorter version at 72 gr….
Bob
rsterne
michaellovett
teemu
thurmondmoore
laurenwright
davidgoldstein
tnt76
markbooth1- You must be logged in to reply to this topic.