- This topic is empty.
-
Topic
-
howardfoster
Hi all,
I have a two grove 03A3 Springfield for which I’m seeking a good bore rider design. Col. E. H. Harrison in the classic NRA publication “Cast Bullets” recommends the Lyman #311334 for two grove barrels. But nobody makes this mold anymore and an ebay one (these don’t come up very often) unfortunately throws undersized noses at .297-.298. Double beagling this mold produces .3005 to .3015 which is still a tad undersized and there’s a lot of diameter variation which requires each bullet to be miked and culled—a pain. N.O.E. doesn’t make a 311334 but their 311331 mold is close, with a blunter nose, so I bought one of these. The problem here is that this mold produces bullets that half the time are too big and the bolt won’t close with the bullet jammed into the barrel lands. I seem to be on a steep learning curve to fix this, with the following potential problems and possible fixes–comments/help?
Note: bullets are cast w linotype and wheel weights; linotype ones are .0005 to .001” larger. All bullets are w. gas checks.
1. I’ve determined bullet seating depth by placing a bullet into a fired (unsized) case and closing the action. This places the bullet so that the scraper grove is 1/32” above the case mouth – looking good! But, in a sized case the bullet is firmly held and any misalignment (i.e., the cartridge lying on the bottom of the chamber) causes a tight bullet to jam and the bolt won’t close.
2. I’ve determined my bore size to be .3020-.3025 at the chamber end. Bullets (wheel weight source) come out of my N.O.E #311331 at somewhere between .302-.304” (nose portion). But, after coming out of the sizing machine a .3023 bullet becomes a .3030” bullet which is at the limit of chambering. This means half of my bullets, after being sized and lubed, won’t chamber. One idea is that my .310 sizing die (in a Lyman 4050 sizer) is too small and the bullets are being bumped expanded (i.e., compressed into a football shape) to a larger size. This is especially true w. 311331 with its very long, straight sided nose maybe making this bullet vulnerable to bump-expanding. Fixable with a looser .311 die?
3. Maybe the design of 311331 itself is problematic. As alluded to above, the nose is a long cylinder terminating in a blunt, rounded nose. 311334 has a longer-ogive nose which moves the point of contact with the lands rearward. This by itself might reduce feeding problems with larger bullets
4. Are there nose sizing dies? This would at least offer an additional avenue to experiment with.
5. I’m on a learning curve here with many new factors to consider in bullet casting. I’m also in the middle of testing for group sizes with problems with fliers which might be attributable to shooting technique. The doubled beagled 311334s show promise with 22 grs of AA5744 but I’ve only shot two 5-shot groups of 311331 w. 19 grs of 5744 but both groups are a mediocre very evenly scattered 2” and 2 3/8” (100 yards) groups. But many of the issues raised might turn out fixable or not a problem. However, right now, the best solution would be if NOE would make a .301-.302” (nose portion) 311334.
Any comments would be appreciated.
(usual obsequies)
-Howard
howardfoster
-
Replies
-
lwatson
lwatson
Mike B.- You must be logged in to reply to this topic.