Extrapolating 9mm load data?

[ddpenn]

I am new reloader and was fortunate to get 1000 Zero 124 gr FMJ and 500 lead round nose (betterbullets.com) for pretty cheap. I would like to use titegroup powder with mixed remington and wwb brass I have. And my gun is a CZ Shadow.

I cannot find load data in the books I have for the Zero fmj or brand of cast bullets I have. So my question is how do I safely extrapolate load data for OAL and charge weight from one type of bullet to the ones I have? is it safe to substitute OAL for one brand of 124 gr FMJ to another or could there be a difference in bullet lengths that would cause unsafe pressure.

Thanks in advance

Edited July 27, 2010 by ddpenn

[G-ManBart]

Generally speaking, any normal 124gr FMJ will be pretty close to that Zero in length/shape etc, so you can use published data (OAL, charge etc) with reasonable assurance you'll be fine. With any combination you want to work up to max loads carefully, but if you start at the low to middle range, it's not going to be a problem. R,

[Hi-Power Jack]

I am new reloader and was fortunate to get 1000 Zero 124 gr FMJ and 500 lead round nose (betterbullets.com) for pretty cheap. I would like to use titegroup powder with mixed remington and wwb brass I have. And my gun is a CZ Shadow.

I cannot find load data in the books I have for the Zero fmj or brand of cast bullets I have. So my question is how do I safely extrapolate load data for OAL and charge weight from one type of bullet to the ones I have? is it safe to substitute OAL for one brand of 124 gr FMJ to another or could there be a difference in bullet lengths that would cause unsafe pressure.

Thanks in advance

Be careful - I believe you'll need less powder for the lead bullets

to achieve the same velocity as the fmj bullets.

Jack

[kevin c]

If you head over to the reloading forum and search in the 9mm subforum, I'm sure you'll get more than a few TG recipes, including OAL's, for the Zero's, as they are a popular bullet. To be safe, start 3% to 5% below and work up, watching for velocity and pressure sign.

Generally, given the same powder charge and internal case volume, a cast bullet will be faster (read, higher pressure in the case) than a jacketed bullet of the same weight, so being down a couple to three or four tenths of a grain on the charge and still getting the same velocities as jacketed is what a lot of folks find.

When the published data is still not enough, consider starting at 10% below the published charge for the velocity you want, and load your bullet of the same weight to maximum SAAMI COAL. This should be a safe load, but likely under what you want velocity wise. Work up by one or two tenths at a time from there. If you need to shorten the OAL, you'll need to drop the charge again and work up, or you can start with the shorter OAL and a minimal published charge and work up.

If the load you want to use is extra long, be extra cautious; the loads are long not just for the sake of improved feeding in some style guns, but also because the extra length gets you more internal case volume and reduces what otherwise might be excessive pressure, and shortening the round to the SAAMI standard could be hazardous (ask me how I learned this).

And remember, of course, that anytime you go outside published data from the big companies who can test with pressure barrels and the like, you take on all risk to life, limb and gun.

Good luck!

Edited July 27, 2010 by kevin c

[CZinSC]

In addition to what Bart said, make sure you weigh the Zero bullets. I recently got two shipments from Shooters Connection for Zero 124 FMJ, and they actually weight 125gn. So you may want to weigh the ones you have, and if they are in fact 125, make sure you work up the loads based on that info.

Edited July 27, 2010 by CZinSC

[noylj]

Whose gun can differentiate between a 124 and a 125 gn bullet, unless the construction is wildly different. You're picking nits...

COL is determined by your barrel and magazine. Load a dummy round or two. First remove your barrel from your gun and take the barrel to your reloading bench. You now have the most perfect gauge to determine dimensions.

Resize a couple of cases and verify that they drop in the barrel with a nice "clunk." Now expand and bell the mouths of the cases. Seat a bullet and set the COL to about 1.170. Remove the bell but do not crimp the bullet yet. Does the dummy fit in you magazine or is it too long? If too long, it needs to be seated deeper.

Keep removing the bell until the dummy slides into the barrel. If it slides in the barrel but is too long to chamber completely, then go back and seat the bullet deeper. Try a COL of 1.150. I know the typical COL for the Zero 124 gn JHP is 1.145, so you FMJ should be slightly longer. When you get a COL that fits the magazine, feeds properly (good reason to have two dummies), and chambers properly, then you crimp the dummies, mark them for bullet used, and use them to set up your dies any time you load that bullet.

Remember, COL is entirely based on your gun and, in general, I advocate the longest cartridge that fits your magazine, feeds reliably, and chambers in your gun.

[Sarge]

Don't CZ's have short chambers? Or am I thinking of another brand? I think you should look up loads for the CZ specifically. I think 1.14 are going to be too long?

[CZinSC]

Don't CZ's have short chambers? Or am I thinking of another brand? I think you should look up loads for the CZ specifically. I think 1.14 are going to be too long?

They do, but I'm reloading Zero 124FMJ ( which I've mentioned above are actually 125 ) and I'm loading to 1.150. They feed reliably and I have had no problems at all. I went all the way up to 1.160 and had no issues. Based on my own accuracy, I chose to load to 1.150. I'm using an SP01, 4.2gn of Titegrouop.

[sigsauerfan]

all the poeple i know shooting a shadow at the match (IPSICK) use an oal of 1.100 for feeding reliability.my self i use to load same oal as factory rounds, but found myself with FTF troubles and i'm trying to get a 1.100 repiece with VV340 vihtavuori, wich enter in the ''unplubished data'' grey zone lolol.

[G-ManBart]

i'm trying to get a 1.100 repiece with VV340 vihtavuori, wich enter in the ''unplubished data'' grey zone lolol.

Why a grey zone? VV publishes 9mm data with N340 and bullets all the way from 90gr up to 150gr.

Edited August 3, 2010 by G-ManBart

[sigsauerfan]

i'm trying to get a 1.100 repiece with VV340 vihtavuori, wich enter in the ''unplubished data'' grey zone lolol.

Why a grey zone? VV publishes 9mm data with N340 and bullets all the way from 90gr up to 150gr.

for sure...as example, i load a 147 grs at 9.5 grams, it's suggested i should use a 1.142 oal...

then,if i go with an OAL 5% shorter than the suggested OAL(wich give 1.095) , i'm falling into the unknown.

Edited August 3, 2010 by sigsauerfan