Help with Nonlisted loading data for 700x and Truncated Cone

[KyleKidd]

I recently just purchased a lee 356 120 TC mold for casting my own 9mm bullets. I'm pushing them with 700x at the moment and plan on moving on to titegroup after this pound of 700x is done with.

The bullets are truncated cone which have an actual weight of 127 grains after casting.
I'm trying to find loading data for the 700x powder and was hoping you guys could help.

I started at 2.9 grains, which fired but failed work the action.
I went up to 3.4 grains which worked the action but resulted in constant stove piping.

I'm afraid to go up any further without consulting you guys first. What is your recommendation for powder grain to use and the COL?

 

[anachronism]

Try looking at the loading data for jacketed bullets, which shows a slightly higher top load than the lead data does. Still, you're at book max as it is, and you may have another issue somewhere. I'd try a slower powder myself.

 

[ra]

I use a lot of 700X, it is my favorite target load powder. 3.4 is max, I don't know why you have stove pipes, but I don't think the powder is the cause.
I also don't have a set OAL, I set them to where they look right and work in the mags.

Roger

 

[Cheesewhiz]

Most books list lead 124gr to 130gr at max being 3.7gr. RCBS lists it a bit higher (.4gr more) for their 124gr lead bullet. For FMJ Speer lists up to 4.7gr for 124gr to 130gr. I would think that 3.3gr would push enough with most pistols. I would check your length, truncated cones have a small feed window. The other thing to check for is a balky extractor.

 

[KyleKidd]

I'm leaning more towards the OAL.

Anyone know an optimal OAL for TC bullets in an SR9C?

I believe I was at 1.15

Perhaps I should try 1.1

Failed to mention I also had a few Nose up jams on the ramp.
After some reading, that could be indicative of too long an OAL. A long OAL would also reduce the power of the blast correct?

Maybe a shorter OAL with solve all my problems.

 

[Cheesewhiz]

You need to find the proper loaded length for that bullet. I do that with every bullet that I may use in my semiautos, it is extremely important for truncated cone and JHP bullets. Those normally end up with a much shorter OAL because of the position of the ogive, the first point of contact with the rifling.

Pull the barrel out of the gun being tested. I put the bullet I'm testing just barely into a spent casing and insert that dummy into the chamber. I let the rifling push the bullet further into the case. I then measure the OAL of that now pushed in dummy round. I subtract .015" from this found length and make that my target OAL for that bullet in that gun. I do this several times to make sure I'm getting good numbers with my "push test".

Loading a bullet long can cause bullet to rifling case pressure issues and possible feeding problems , too short will cause feed issues and depending on powder load, case pressure issues.

 

[DGW1949]

You need to find the proper loaded length for that bullet. I do that with every bullet that I may use in my semiautos, it is extremely important for truncated cone and JHP bullets. Those normally end up with a much shorter OAL because of the position of the ogive, the first point of contact with the rifling.

Pull the barrel out of the gun being tested. I put the bullet I'm testing just barely into a spent casing and insert that dummy into the chamber. I let the rifling push the bullet further into the case. I then measure the OAL of that now pushed in dummy round. I subtract .015" from this found length and make that my target OAL for that bullet in that gun. I do this several times to make sure I'm getting good numbers with my "push test".

Loading a bullet long can cause bullet to rifling case pressure issues and possible feeding problems , too short will cause feed issues and depending on powder load, case pressure issues.

I'll second what he said.

It could also turn out that your gun just aint going to like the particular bullet shape that you are trying to feed it.
Personaly, I've not had much luck with TC bullets in the semi-autos that I've owned because the orgive position on most of them is wrong for a ramp (and throat) that's designed around a RN-FMJ bullet.

DGW