Trailing edge failure - I'm stumped

[popper]

Read the sticky about trailing edge problems and gas cutting. I cut a 1/4" wide groove through the base band of 5 .401, 180 TC, single lube groove, ~ 20 BHN, max load of HP-38. Lubed and shot. 3 holes touching , 2 in same hole and 1 is 1/2" further out, at ~ 20 ft. I expected flyers and didn't get any. Is the CB hard enough to avoid gas cutting or is a single band all that is needed? Muzzle pressure at exit not enough to make it a flyer? Any ideas?

[Larry Gibson]

An honest question; how far do we really expect a "flyer" to "fly out" at 20 feet?

Larry Gibson

[popper]

Wondered about that myself, but I'm such a lousy shot I don't know if I could tell a flyer or my bad at 50'. Curious as to what would be expected. Any experience?

[geargnasher]

An honest question; how far do we really expect a "flyer" to "fly out" at 20 feet?

Larry Gibson

Indeed, I've had tight groups with boolits hitting sideways at that distance.

Popper, try 25 yards MINIMUM for handguns, 50 yards better, and if yoreally want to know how it shoots, find your elevation at 100 and shoot some groups. Shooting from a bench with handguns at longer distances is very educational.

Gear

[Larry Gibson]

With handguns shooting cast bullets a solid rest at minimum 25 yards is generally needed for me to discern a flyer from just a poor shot. I learned real quick with .38 SPLs in my PPC revolver many years ago that a square base was needed to eliminate flyers and maintain the best accuracy. I also relearned that lesson with soft .32 cast being push sized through Lee sizers nose first. If the base was rolled over the bottom edge at all the accuracy was not going to be good, maybe not bad but not good either. When I started push sizing them base first the bases stayed square and accuracy was better and more consistent.

Larry Gibson

[375RUGER]

Try shooting at 25+ yds from a sand bag rest then see if you have "flyers".

[40Super]

Or a ransom rest/shooting vice. Just don't clamp everything down tight ,its best to allow the gun to move a bit when fired.

[Longwood]

If the base of a bullet has damage or is ever so slightly uneven, you can expect it to go just about anywhere it pleases.

And,,,,
It will.

[popper]

Now I gotta go PRACTICE (that's a shame) @ 25. Lucky me!

[tmc-okc]

Larry ststed "If the base was rolled over the bottom edge at all the accuracy was not going to be good, maybe not bad but not good either. When I started push sizing them base first the bases stayed square and accuracy was better and more consistent."

Larry, I am new to the Cast Boolit game so please help educate me. If you push boolits thru nose first then the nose of the next boolit is pushing against the base of the boolit ahead of it, If you push boolits thru base first then the base of the boolit is pushing against the nose of the boolit ahead of it. It sounds as if you reversed every other boolit then everyother boolit would be pushing base to base and everother boolit would be pushing nose to nose. That would help insure bases staying flat but then the nose to nose set would have more deformed noses.. What am I missing here ???

TMC

[geargnasher]

When using a nose-first sizer, like a Star or a Lee, the majority of the effort is done by the pushrod on the boolit being sized. The next one in line merely nudges the previous one through the die, very little pressure on it because the die ID gets larger after that.

The problem with base-first sizing is almost all of the equipment set up to do it (RCBS, Lyman, Saeco) has a lot of wobble in the ram, which can and does bend boolits and get the noses out of square with the bases, particularly on long, skinny rifle boolits.

Gear

[Larry Gibson]

With the Lee push through sizer if you have the die adjusted correctly the ram pushes the bullet all the way through the sizing portion. The next bullet doesn't push on anything until it is coming out of the sizing portion. It then is only lifting the weight of the bullets above it and doesn't get deformed by that.

If the alloy is soft enough the nose, when pushed through base first, can get slightly flattend by the ram depending on the amount of sizing being done. Numerous test have conclusively demonstrated that slight deformation of bullet tips many times gives not accuracy problems. However, it is well known that a deformed or un square bullet base will cause accuracy problems.

If the noses are deforming to much then you are sizing too much in one step or not lubing the bullets before sizing.

Larry Gibson

[felix]

As Gear says, stress and strain on boolits is not good because of consistency sake. However, if the boolits are HARD (tough does not matter in this instance) as NAILS, then it should make no difference between nose-first/base-first because resistance is equalized anyway you push it. However, this can be a moot point when load is not appropriate for the boolit hardness. ... felix

[popper]

I've pushed rifle and pistol CB base first ( to 'clean up' the base) and had nose expansion so great they don't chamber anymore. WD and sat 2 weeks before sizing.

[Larry Gibson]

I've pushed rifle and pistol CB base first ( to 'clean up' the base) and had nose expansion so great they don't chamber anymore. WD and sat 2 weeks before sizing.

Yes, and that can easily happen in a standard lubrasizer also. The lubrasizer is pretty much self lubricaing so unlubed bulllets can be sized. However with push through sizers the bullets should be lubed first. I use a light coat of Dillon spray case lube on the bullets before sizing. I also, with TL bullets to be lubed with LLA, will TL them before sizing. Also as I previously mentioned nose deformation also will occur if sizing too much in one step for the hardness of the alloy used. If the sizing pressure on the hardened bullet is greater than yield strength of the nose then the nose is going to get squished or flattened.

Solution is to lube the bullets before sizing and don't size too much in a single sizing step. How much is "too much" sizing depends on the alloy, the hardness, amount of bearing surface to be sized and the bullet design. Long skinny bullets with narrow noses will squish and bend easier than short fat ones with large noses.

Larry Gibson

[Bob Krack]

With handguns shooting cast bullets a solid rest at minimum 25 yards is generally needed for me to discern a flyer from just a poor shot. I learned real quick with .38 SPLs in my PPC revolver many years ago that a square base was needed to eliminate flyers and maintain the best accuracy. I also relearned that lesson with soft .32 cast being push sized through Lee sizers nose first. If the base was rolled over the bottom edge at all the accuracy was not going to be good, maybe not bad but not good either. When I started push sizing them base first the bases stayed square and accuracy was better and more consistent.

Larry Gibson
Larry,

Are you referring to lead being rolled over onto and/or over the gascheck or are you saying the gascheck itself was being damaged? Or?

Bob

[Larry Gibson]

Larry,

Are you referring to lead being rolled over onto and/or over the gascheck or are you saying the gascheck itself was being damaged? Or?

Bob

Talking about plain based bullets only here as far as the trailing edge goes. The nose of a soft cast bullet or a long skinney one for that matter can get bent or squished with the Lee push throughs if seating and crimping a GC. The bullets can also get bent and squished in lubrasizers if the sizing is too much in one step.

Larry Gibson

[canyon-ghost]

I'm with ya, on this one, popper. I went from 15 yards up to 50 yards with the Blackhawks. It's not easy to tell what is going on until you get your offhand technique settled down. I wound up with a tendency to drop my point of aim, until I went out to 50 yards and used a smaller target (steel rounds, as opposed to paper, 8x11).

And, really, doesn't anybody want the chance to shoot 100 shots or more? How about 50+ in one range session? Everyone would love doing that!