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rsterne · Moderator

I've been waiting for my .257 bullet molds to arrive, and they came in the other day and I had a chance over the last couple of days to try them out.... I ordered three molds and had them shipped directly to Erik Ohlen at Hollow Point Bullet Mold Service in Oregon to have him modify one cavity on each mold to a hollowpoint.... Here is a link to his website....

http://www.hollowpointmold.com/

Erik is a joy to deal with, and has a good knowledge of airguns and their requirements.... Emails were answered promptly and completely, and full of suggestions so that I received the best posssible product for the job I wanted to do.... He makes several other types of HP conversions, and has a stock of some Lee molds already converted so that both cavities drop hollowpoints.... I purchased his "Standard" conversion with two extra pins for each mold to allow me to play with the hollowpoint size and cavity shape.... Here are the results....

I hope this will be the primary bullet for my Hayabusa in .257 cal.... This is a 65 gr. Lyman #257420.... The bullets drop at 0.258"-0.260" in pure lead (1% tin) and the solids weigh 73 gr. and the HPs weigh 66 gr.... Eric's use of a 5/32" pin resulted in setting the meplat slightly further back but he suggests a 5/32" pin for airgun use because the larger cavity will expand easier at our velocities....

I wanted a heavier bullet to experiment with as well.... This is an RCBS 85 gr. "Cowboy" mold, #82301.... The bullets also drop at 0.258"-0.260", with the solids weighing 87 gr. and the HPs coming in at 77 gr.... You can see an example of the different pin shapes for the HP cavity.... Although the OD of the pin is 5/32", the front of the cavity measures 0.120" - 0.135" depending on design, to leave a flat lip around the edge of the meplat....

This last mold is only 0.250", a 50 gr. RCBS mold intended for the .25 ACP pistol, # 57902.... The bullets drop at 0.251"-0.253", and the solids weigh 53 gr., the HPs 46 gr.... These are intended to shoot from a .25 cal airgun barrel, not the 14" twist .257 diameter 25-20 barrel I'm using on the Hayabusa....

I went through one 4-5 lb. run of lead for each mold, casting both cavities, so in theory I would end up with half solids and half hollowpoints.... I did the bullets in the above order, and although I have cast bullets before, these smaller molds with the narrow lip around the hollowpoint took some getting used to.... I also purchased a lead thermometer, and I don't know how I ever got along without it before.... If you are even thinking of casting bullets buy one at the very start, they are INVALUABLE.... On the 65 gr. bullets, I didn't have the lead hot enough, ~800*F, and a lot of the HPs weren't properly formed at the tip.... I cast ~450 bullets, but only ended up with 196 usuable solids and 88 HPs, the rest were remelted for the next run.... By the time I started the 85 gr. run, I pretty much had a handle on it, and by keeping the lead at ~850*F I had virtually no wrinkled (too cold) or frosted (too hot) bullets, and the nose of the HPs were fine.... I cast ~340 bullets, and ended up with 162 solids and 152 HPs.... The last run was for the little 50 grainers, and I started running them at ~850*F, but the HPs were not all perfect, so I increased the temperature to ~880*F, and that solved the problems.... In 2 hours of actual casting time I made just over 510 bullets, and 235 solids and 247 HPs were keepers.... It took another 1/2 hour to inspect every bullet and throw out the 31 culls, so I mananged about 200 per hour, plus the setup time, melting the lead, fluxing it, cleaning the molds and installing the handles, and then cleaning up and putting everything away.... I only sized 100 of each type of solid, to .250" and .257" as applicable, through some reground Lee .243 cal dies that I reworked with my Dremel Tool Post Grinder on my Lathe.... That was another VERY lengthy process, enlarging those dies, but the result was worth it.... Lee, unfortunately, doesn't make a quarterbore sizing die....

Now that I've cast bullets in .25, .30, and .35 cal, I can see why people don't like casting the smaller ones, they are finicky until you find the right temperature and rhythm.... I can imagine that .22 cal would be worse, and .22 cal HPs much worse.... but like anything else, practice makes perfect.... Now that I have my .257 cal bullets to measure, I can get on with making my chambering reamer for the .257 Hayabusa barrel and finish the chamber, leade, and porting.... Then it will be on to the first tests....

Bob

whm1974 · Veteran Member

Neat, I use to cast bullets for my stepfather when I was a kid. Kind of miss it.

rrdstarr · Member

Bob what kind of results did you get with these bullets?
So you are saying most .25 calibre air rifle barrels ar .25 and not .257?

Thanks, Rick

rsterne · Moderator

No long range testing is possible until the weather warms up.... Yes, the standard size for .25 cal air rifles is a .250" groove diameter, with the lands being 0.243-0.245".... This is the same as a .25 Auto handgun, and bullets drop at about 0.251".... PB rifle barrels are typically 0.257" bore and 0.250" lands, and the bullets usually drop about 0.258" when cast.... They are NOT interchangeable, although it may be possible to resize (in 2-3 steps?) from 0.258" down to 0.250"....

Airgun twist rates are too slow for 60 gr. bullets and over....

Bob