Adjustable .520 RCBS Smith/Maynard

[Jerry Ward]

Anybody have experience with this one yet?

Looks like the hollow base is useless for carbine work since the bullet will be oversized for the bore......

What is a good starting point for the flat base bullet's third ring? I assume I will need a third ring for bearing surface since the first one looks like more of an alignment ring. Mic the second (first full ring) and duplicate that? Any weights or lengths to aim for in a Hoyt/Navy Arms Smith?

Am I way off?

Thanks guys

[Lee Hoffecker]

Gerry,
Glad you asked about the RCBS .520 hollow base bullet in a Navy Arms Smith.
I started out shooting the Rapine 515 solid base bullet unsized in my Smith carbine and got mixed results. I had the barrel relined by Bobby Hoyt which made a big improvement especially at 100 yds. while still shooting the Rapine bullet.
I then bought one of the RCBS .520 mold and cast bullets with the hollow base plug, sized them to .515. I had been using 25 gr. FFFG, other skirmishers said they were using 33 gr. and 38 gr. so I loaded up 25 rds each of 25 gr., 33 gr., and 38 gr. using the RCBS and Rapine bullets. Also I used 10 gr. of cream of wheat filler in each 25 gr. round. No filler was used in the 33 gr. and 38 gr. loads. The best results were with the RCBS hollow base bullet at 50 yds. At 100 yds. the best results were with 33 gr. FFFG and again the RCBS bullet. There was no significant change using 38 gr. of powder.
The most important thing that I learned that affected accuracy was that if the bullet was seated too deep in the plastic tube and jumped forward into the rifling then there was a significant decline in accuracy. Using filler on top of the powder solves this problem.
Lee

[Walt Magee]

I had excellent results with the 515139 Lyman mould. You can get one now from Midsouth of under $40. Other Lyman moulds have been hard to find since Ray Tech now runs Lyman and has discontinued many of the older moulds. But then there is always Ed Beale in NH who has just about every mould Lyman ever made. I could dig up his # but he is in the book in Barrington NH

[MR. GADGET]

I then bought one of the RCBS .520 mold and cast bullets with the hollow base plug, sized them to .515. Lee

Lee, What was the weight of the bullet you were using or how long was the bullet.
Jon

[Lee Hoffecker]

Jon
The information you requested is as follows:

Wt. 263.39 grs.
Overall length 0.7550 inch
Bearing surface length 0.4055
Dia. at base after resizing 0.514-0.517
Upper and lower grove dia. 0.428
Hollow base wall thickness 0.083
Thickness of top ring 0.064
Thickness of middle ring 0.095
Thickness of bottom ring 0.099
These bullets were sized using Lodgewood 515 dia sizer made for Lyman 45 and 450 sizers. However, the were sized nose down and instead of using a nose punch I used a hollow base plug from Northeaster trader.
Lee

Measured with a Micrometer, Marked with chalk, and Cut with an axe.

[MR. GADGET]

Lee, thanks for the info now I got something to take a second look at.
I think mine were in the 325gr or more gr and that may have been the reason for it not shooting as good I will drop it back to the 260-270 and try that.
got the northeast 517 and 515 sizer and the hollow base plug too, I was steping them 517 then the 515.
Very good info to know.......

Thanks
Jon

[Lee Hoffecker]

Jon,
I have seen two versions of the Rapine Smith bullet. I am sure they are cut with the same cherry, one is just a little longer than the other and has an additional lube grove. If I remember correctly one was 325 gr and the other 365 gr.
Lee





Measured with a Micrometer, Marked with Chalk, and cut with an axe.

[MR. GADGET]

Jon,
I have seen two versions of the Rapine Smith bullet. I am sure they are cut with the same cherry, one is just a little longer than the other and has an additional lube grove. If I remember correctly one was 325 gr and the other 365 gr.
Lee





Measured with a Micrometer, Marked with Chalk, and cut with an axe.

Just need to look and see what one it was that I got from you last year,.,. I cast some and it was doing ok never did put it on the bench yet and just felt the need to see if I could make the Rcbs mold that I have work to and then bench them both this fall and really put time in to it.

[Lee Hoffecker]

Jon,
It was a Rapine mold and probably a 515365. I checked to see which I have and it is a 515365. I don't recall ever selling one of the smaller size molds.
Lee

[Gary B]

Lee,
Were you using hard lead or soft lead with the hollow base rounds ?
I too had mixed results with the solid base, so I will try the hollow base as you did.
Thanks for sharing the information.
Gary B.