Brazos Bullets 9mm OAL problems

[jyc]

I'm having problems plunk testing the 125gr grooveless bullet sold by Brazos bullets. Test pistols are a Springfield 1911 9mm and a CZ SP-01.

Last range session, I had a few rounds that didn't feed in both guns because the bullets seemed to be stuck in the lands - OAL was 1.085". I haven't had malfunctions for about 800 rounds at 1.075" and below.

However, none of my rounds pass the plunk test (meaning they fall free from the chamber) until they're loaded down to 1.043". What am I missing?

Lyman Cast Manual 4th edition states the 124gr bullet can be loaded to 1.050", the 120gr bullet at 1.065", and a 125gr HP bullet at 1.010". What gives? I know CZ chambers are notorious short, but I believe that the bullet ogive is the issue. Is it safe to load to 1.043" using w231 powder?

All advice welcomed!

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[Sandspider500]

Looks like a copy of a Lee 125 2r with no lube groove, short stubby little thing. That's pretty short oal. The Lyman 356242 is .625 long. I would start a couple tenths below the starting loads for the Lyman, use a chrono. Another bullet that's short and stubby like that is a Hornady 124gr RN, which has a knurled bearing surface and a short little nose and seats deep to an oal of 1.040 with a max load of 3.5gr of bullseye powder for 32,900psi and 1008fps. As a comparison the Lyman starts at 3.4gr of bullseye at 23,600 cup and 939fps, notice the difference. Seems like maybe you should either throat your barrel or start getting a truncated cone design instead of the round nose.

[alland]

I load that Brazos bullet at 1.115 with no problems in my CZ 75 or most other guns, but my Springfield Range Officer must have had a very short throat and would not chamber. I just used a throating reamer to deepen the throat. The Brazos bullet was not the only coated lead bullet that was a problem for me. Blue bullets also had problems in that Springfield.

[bumpo628]

I had the same ogive problem with Missouri Bullets smallball bullets. I just load them on the bottom end of the W231 powder charge chart and push the bullets in until they fit. They work fine at 1.070, but they have to be pushed into place. At about 1.045 they will drop in. So, it sounds just like your bullets.

I'm just going to use these up and then switch to something that has a better profile.

[mindwreck]

pretty much mirrors my problems. i had to lower my COALs to 1.115 for brazos and blues bullets for my CZ TS and m&p and various guns to chamber correctly.


theres nothing wrong with seating deeper. just lower your charge a few tenths and work back up. or stop using that bullet.

I load that Brazos bullet at 1.115 with no problems in my CZ 75 or most other guns, but my Springfield Range Officer must have had a very short throat and would not chamber. I just used a throating reamer to deepen the throat. The Brazos bullet was not the only coated lead bullet that was a problem for me. Blue bullets also had problems in that Springfield.

[jyc]

Glad to know I'm not the only one with this problem using Brazos 9mm Bullets. I heard ACME had a similar problem when they changed their bullet profile, and they ended having to switch back to their old profile after enough people made a stink about it.

It sucks with Brazos though, they really are the best bang per buck out there, but I'm not going to continue using their 9mm bullets if I have to seat that deep. Maybe I should give them a call.

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[bumpo628]

Know anyone with a chrono? You could check to see what effect the deeper seating has before switching. Otherwise they start around $100.

I'm not seeing any signs of overpressure, so I'm not concerned about it. I bought a bullet mold that tested well, so I'm going to replace mine with my own cast bullets.

[jyc]

Know anyone with a chrono? You could check to see what effect the deeper seating has before switching. Otherwise they start around $100.



I'm not seeing any signs of overpressure, so I'm not concerned about it. I bought a bullet mold that tested well, so I'm going to replace mine with my own cast bullets.

I thought pressures could spike despite a normal velocity due to a short OAL? I'm not sure. I just purchased two sample packs of the 125gr grooved bullet and 147gr truncated cone bullet. Hopefully these work better.

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[Sandspider500]

Hmm, if the Lyman 356242 is .625 long and it's loaded to 1.065 it has .314 inside the case, if yours is .561 long and loaded to 1.043 then you have .269 inside the case, which means your fine using the data for the 356242 I believe.

[Sandspider500]

Did some more digging and the Hornady lead round nose is .59 long so if it's seated at 1.040 that's .030+ more than yours

[jyc]

Did some more digging and the Hornady lead round nose is .59 long so if it's seated at 1.040 that's .030+ more than yours

So it seems like I should be fine using these bullets seated to 1.040". I guess the only option left is to load a few rounds starting at 3.7gr and 3.9gr with w231.

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[jyc]

Update:


I just received a sample pack of Brazos' 125gr grooved beveled bullet. May I just say this is the bullet profile you want if you to load at normal OAL.

I made 3 dummy rounds and 1.180" plunks, spins and falls free in my CZ SP-01. Fantastic! A huge difference from the 1.045" needed from the 125gr no grooved bullet. My Springfield 1911 wasnt able to plunk at 1.100", so I'll need to make a few dummy rounds to see what fits in that chamber.

Pictures for those who'd like to see the difference. The grooved profile has a smaller ogive which makes all the difference. I may need to take my Springfield to the gunsmith to ream chamber. Feel free to give input!

125gr NGR = 0.568"
125gr GR = 0.608"

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[hambam105]

Datum Line.

Bullet datum line. Maybe someone else can better explain it.

It is not cartridge over all length.

[jyc]

Datum Line.



Bullet datum line. Maybe someone else can better explain it.



It is not cartridge over all length.

"Headspace for rimless rifle cartridges, such as the .30-06, is measured from the boltface to a point on the shoulder called the datum line. The datum line on the .30-06 case is the point on the shoulder that measures exactly .375 diameter."

So let's say for .45ACP, the datum line would be the diameter of where the mouth of the case headspaces?

Is that gunsmith talk for I need to ream the chamber/extend the point at which the case contacts the datum line?

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[sef]

Don't know if this is helpful but this is what I load and have no problems in my CZ-SP01, CZ-P07, Sig 228, Colt 1911 9mm.
Bullet - Brazos 125 GR. With Lube Grove
Powder - WWW-231 - 4.0gr.
OAL - 1.110
LabRadar -1050 fps.

I know it is not the same bullet but performance should be close.

-sef