Reloading Newb Needs Your Help

[EMR]

So I've been reloading 9mm for 1500 rounds and I think I've found a recipe that makes all my 9mm pistols shoot great.

Here's my usual recipe:
124gr Xtreme plated RN
1.142 COL
4 grains VV N320
Mixed Range Brass
Federal Primers

I head out to my LGS today and pick up a box of Xtreme 9mm 124gr bullets. I got home and after I opened it, realized I bought flat points instead. I thought no biggie, I'll just see what VV says how to load.

I made three dummy rounds to test. According to their website ( http://www.lapua.com/en/products/rel.../relodata/6/34), it says to keep the COL at 1.142.

They all fit in my case gauge and they pass the plunk test in my P226. However, in CZ75b they fail to go into battery and fail the plunk test. In my XD they go into battery but look sketchy on the punk test.

Can anyone advise? Am I missing something or are these rounds at this min COL with N320 just a no-go with my pistols?

Thanks for the advice!

[bsumoba]

measure the length of the flat point bullets and one of your standard 124gr RN bullets and see what the difference is. I bet the flat nose is shorter and you will be able to seat them deeper while maintaining the same pressures.

The P226 probably has a longer throat so the bullet ogive doesnt engage the rifling but in the CZ, the rifling is closer and that is why it is failing the plunk test.

I have some Xtreme FN and RN, but the FN is almost 0.030" shorter than the RN.

[EMR]

Ah, good point. So the RN measures 0.588 and the FP measures 0.526. I'm assuming that it would be safe to say that I can subtract the 0.062 difference from the COL and maintain the same pressures? So instead of 1.142, 1.08 would be the COL with the same case pressures?

[bsumoba]

Ah, good point. So the RN measures 0.588 and the FP measures 0.526. I'm assuming that it would be safe to say that I can subtract the 0.062 difference from the COL and maintain the same pressures? So instead of 1.142, 1.08 would be the COL with the same case pressures?

Not necessarily...but in your case, it is probably okay. If the CBTO (cartridge base to ogive) is the same, then chances are you will get similar pressures. You measure this with a comparator. I dont know too many people that measure this way for pistol. Typically, this is only done in precision rifle shooting, or maybe in precision handgun like bullseye competition shooting. Most guys I know just measure OAL (overall length of the loaded round from base to tip).

My FN bullets are around 1.10" OAL for a 124gr bullet. My RN is around 1.12" OAL. This feeds reliably in my XDs, CZs, VP9s, PPQs, Glocks, etc.

[EMR]

Not necessarily...but in your case, it is probably okay. If the CBTO (cartridge base to ogive) is the same, then chances are you will get similar pressures. You measure this with a comparator. I dont know too many people that measure this way for pistol. Typically, this is only done in precision rifle shooting, or maybe in precision handgun like bullseye competition shooting. Most guys I know just measure OAL (overall length of the loaded round from base to tip).

My FN bullets are around 1.10" OAL for a 124gr bullet. My RN is around 1.12" OAL. This feeds reliably in my XDs, CZs, VP9s, PPQs, Glocks, etc.

I'll try making another two dummy rounds with 1.10 OAL and see if it works. Thanks for the help!

[Grunt81]

Remember, longer is safer when working up a load. This increases the volume in the case in which combustion can occur. Combustion in a larger volume decreases pressure. This concept, however, is a different beast when talking about rifles, as pressures can increase as the jump to the lands is shortened.

I too have done the same thing you have and accidentally bought 124 gr FP when I thought I was buying 124 gr RN.

I loaded my 124 gr round nose to around 1.155" and found I could used the same charge with good accuracy, when loading the flat point to around 1.122".

I agree, to a point, with the method stated above in subtracting the difference between the two bullets. This will give you a quick and dirty estimation as to the ball park in which your new OAL should be. But you should measure 20-30 bullets of each type. Use the length of the shortest RN and subtract the length of the longest FP. Doing it this way, will make your OAL estimation the safest.

Another factor in bullet profile that increases pressure is the lenthg of bearing surface (the length of the bullet that is the true diameter of the caliber and is actually engraved by the rifling). A longer bearing surface increases pressure as well and should be taken into account. What is safe for one bullet, can lead to high pressure using a different bullet with a longer bearing surface. To get an estimate of the bullet's bearing surface without having a comparator, using a resized 9mm case, place the bullet upside down inside the case, as level as possible. Then make a pen mark (ink from a ball point pen does write on copper) all around the bullet and carefully measure with your calipers.

As a side note, I've discovered I prefer FP bullets to RN. Accuracy is about the same at reasonable distances (RN will fly a little better due to being more aerodynamic but I haven't noticed a difference up to 100 yards on a 12' target). FP bullets will penetrate a few inches less in ballistics gel and dump more energy in target. The larger meplat pushes tissue outward at a 90 degree angle which leads to a larger temporary and permanent wound cavtity. If SHTF, I'd choose FP over round nose any day. Plus, they're about the same price for practice and plinking. If you like a 124 grain bullet and FP feeds reliably in all your pistols, I'd say just stick to them. I personally prefer the Xtreme 135 gr RNFP and have developed an accurate and reliable load for that bullet. I think it's the all around best of all worlds (velocity, mass, energy, accuracy, feeding, damage) for 9mm non JHP pistol rounds. In talking SD JHPs, it does give up very little to the 147 gr in penetration and deflection resistance, but makes up for it by a little more, almost negligible, expansion and energy dump. I don't plan on starting over for a while. I've got enough on my plate with rifle reloading!

Hope this helps.

[Grunt81]

By the way, Federal small pistol primers are my favorite, despite the bulky packaging. I've had FTFires with Winchester and Reminton 1.5s more than once. Federals go bang every time.

[EMR]

Hey Grunt, thanks for the insight. I'll go ahead and measure several of them to get a good average. Except for I'm all out of the RNs which is why I went to the LGS to pick up some more. I would pull some loaded cartridges but I'm a casual target shooter and I don't stock thousands of rounds at a time.

And I'll also have to try measuring for the bearing surface. I must admit that I thought this was more of an issue for rifle cartridges. I'll have to go over my Lyman manual again and brush up on this.

[Grunt81]

Your welcome. But remember, pressure spikes can happen way more easily in straight-walled pistol cartridges because of smaller volume. When you over charge by 0.5 grains in 9mm, that's 12 X more significant than 0.5 grains over charge in a .308. On the same note, 0.01" deeper seating in a 9mm is also way more significant for pressure and velocity.

I would suggest to find an OAL that feeds the flat point reliably. What I would do is start at 1.125" . Make 10 rounds at 3.8 grains, and 10 rounds at 4.0 grains. Then, make 10 rounds each of 3.8 grains and 4.0 grains, loaded to 1.120". Then, make 10 rounds each of 3.8 grains and 4.0 grains loaded to an OAL of 1.115". That's 60 rounds, do 5 each instead of 10 if you prefer, but I like to test a whole magazine when testing for function. I would rest my wrists on a sandbag (or Caldwell bags stacked up) and shoot at paper, around 15-25 yards away (indoor range is fine). Try not to limpwrist but take relaxed, well-aimed shots. You'll find the combination you want to mass load this way, and all loads should still be safe. If you notice sharper recoil, it might be a sign the pressure is getting high. I put the cases back in the box upside down, in the same spot they came from, so I can inspect the primers. You should notice a larger dent when the pressure is getting higher. I pay $0.25 for each NRA target with a 1.5" red bullseye. It's easier to see in the low light of indoor ranges. I shoot a ten round magazine at the same target. Each ten rounds get their own target. I save all the target and write down the load on them. Shooting at a different target of the same type, in the exact same place each time, keeps your point of aim the same for each load. This eliminates another variable. Whichever load is most accurate, no over pressure signs, and fed 100% reliably, consider this your load for Xtreme 124 FP and VV N320. Once it's done, it's done and you can load and shoot to your heart's content without worrying about over pressure or jams. If you have multiple 9mm pistols, make ammo for each pistol and test under the same conditions, that way your ammo works well for all the nines. I wouldn't dare waste my time making separate ammo for my G17 and Beretta 92F.

This is just the way I do it. Nothing is set in stone except to start low and work up.

Buenos Suerte

[Grunt81]

Oh, and be prepared to pull bullets at the first sign of a pierced primer. These loads I'm recommending you test, should be on the mild to medium side, however, because VV N320 data was done with a copper plated Rainier loaded to 1.142".

[Eljay]

I was curious so I measured a flat point 147gr Federal 9mm round and it had an OAL of 1.065.

[Grunt81]

I've found similar results with factory ammo - a long bullet seated at a short OAL. I think there may be an obvious explanation for this:

1) Factory ammo is designed to feed and function in all 9mm pistols. That includes ones with shorter chambers such as CZ pistols.

2) It's cheaper to obtain velocity by seating the bullet deeper, rather than adding more powder. Since Federal probably makes over a million rounds a day, it's a huge cost savings for them to do this.

Just my guess.