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Shortening 9mm OAL - is this a bad idea?


BigJerm
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Hi guys, I am one of the legion of COVID-19 newbie reloaders, so bear with me:

 

I loaded my first 100 last week and went to the range over the weekend to test them out. The results were ... they wouldn't run in my CZ SP-01 Shadow (they ran OK in my Sig and M&P), which is weird because I got the load data from a guy who says he uses the load in his Shadow 2. Anyway ... I've since done the "plunk" test on my CZ and found that with The Blue Bullets 147gr RN the OAL length basically needs to be 1.075 to pass. I also made 5 dummy rounds of that length and cycled through magazines. They all chambered. Any longer and the rounds would not chamber in the CZ.

 

The current load is: 3.0gr Titegroup / BB 147gr RN / Federal Primers loaded to 1.125. (I loaded some of that original 100 to 1.10 with no problems)

 

I'm a new reloader and nervous to shorten OAL willy-nilly like that. Is this something safe to try? Or is there possibly a different solution to this problem?

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2 minutes ago, 4n2t0 said:

Completely safe. You can always shorten a published load so it chambers.

Really? (genuine question) I was always under the impression that shortening the overall length could ultimately lead to unwanted pressure spikes and potentially be dangerous?

Edited by BigJerm
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You will never blow up a gun shortening a round so it chambers. Again, PUBLISHED LOAD!

 

Don't worry, many have similar fears. Watch, soon someone will tell you to ream the chamber (fear) which is completely unnecessary in your circumstance. With that said...the choice is always yours.

Edited by 4n2t0
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Just now, BigJerm said:

Really? (genuine question) I was always under the impression that shortening the overall length could ultimately lead to unwanted pressure spikes?


In the CZ 1.08 is a typical OAL with that bullet. Your biggest problem will be bulging brass because it’s seated so deep. 
 

Search the forum and you’ll find loads similar to yours.

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If it were me, with any other powder, I'd just crank in that extra 50 thou seating depth and call it good... I'm not a fan of titegroup(I do use it though) it just burns so fast and is so dense, it's easy to double charge and not even notice. Combine that with it's relatively safe loading window, and it's just an accident waiting to happen. But again, I do use it, and I've got 9 loaded up with it right now. I just prefer more bulky powders that fill the case more. I like to hit 100% case fill, maybe a tad compressed. Makes it really hard to even load over pressured rounds that aren't particularly dangerous (i.e, not even "proof" load pressure). Anyway that was just explaining why I don't like titegroup, because I'm sure that would be asked, but I'm in no way trying to start any discussions on that, because that's not important in this case.

If it were me personally, with those I'd just look at a book and see where you fall in the window. I'd want to be below the halfway point (for example, if the book says start at 2.8 and max is 4.0, as long as I was below 3.4) before I cranked them down. And then it would only be 15 or so, to test fire and check cases and primers for pressure signs. If I was over that half way point, I'd just start over with everything.

Is it "completely" safe to just crank them down more? Probably. I'd rather not risk it. But not so far as to say you have to disassemble them and start over.

Sent from my SM-G975U using Tapatalk

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I’ve throated more than a few SP-01 barrels for guys with exactly this issue who didn’t want to have to load stubby ammo just for one gun. So yes, it’s common.

 

I’ve loaded Titegroup and Prima V specifically to both 1.150 and 1.090ish with everything else being the same, just to see what the difference was.

 

It might have been one powerfactor, if that. It was small enough that I would have needed an average of more than ten shots to say for certain that it was even there.

 

Shorten them up without fear, when loading to minor you’re at the lower end of the acceptable range with something like Titegroup.

 

When you’re loading something hot that’s at the upper end of book max, or using a lot of a slow-burn powder where you might wind up compressing it? Then you REALLY need to be cautious.

 

Not so much for 130-133 powerfactor with most of the powders we usually use.

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8 minutes ago, MemphisMechanic said:

I’ve throated more than a few SP-01 barrels for guys with exactly this issue who didn’t want to have to load stubby ammo just for one gun. So yes, it’s common.

 

I’ve loaded Titegroup and Prima V specifically to both 1.150 and 1.090ish with everything else being the same, just to see what the difference was.

 

It might have been one powerfactor, if that. It was small enough that I would have needed an average of more than ten shots to say for certain that it was even there.

 

Shorten them up without fear, when loading to minor you’re at the lower end of the acceptable range with something like Titegroup.

 

When you’re loading something hot that’s at the upper end of book max, or using a lot of a slow-burn powder where you might wind up compressing it? Then you REALLY need to be cautious.

 

Not so much for 130-133 powerfactor with most of the powders we usually use.

Very helpful, thanks a ton!

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If you use well-worn brass with thicker walls, you may notice an increase in case gauge failures: the further back you stuff that loooong 147gr bullet, the greater the chances that one side of the case will develop a bulge from the force / expansion required.

 

Just something to be aware of, if you see an increase in failures to feed. This is why I like my ammo longer. 👍

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21 minutes ago, MemphisMechanic said:

If you use well-worn brass with thicker walls, you may notice an increase in case gauge failures: the further back you stuff that loooong 147gr bullet, the greater the chances that one side of the case will develop a bulge from the force / expansion required.

 

Just something to be aware of, if you see an increase in failures to feed. This is why I like my ammo longer. 👍

 

Makes sense. If I run into that issue a lot, I may just end up going with a 124 gr next time. Thanks

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8 minutes ago, lll Otto lll said:

Why does every newbie choose Titegroup as their first powder to load with? 

 

My newbie answer:

 

Honestly, it's the one I'd heard people talk about the most, and I had no idea what makes a powder "good". I also figured that since it was so well known, I'd have plenty of people to answer my questions specifically once I thought of them, lol.

 

So... It seems like the Glock of powders ... that's why 😂

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I shoot a CZ Shadow Target and load with several different powders. My normal OAL is 1.06. I have never had any problems with over pressure. I admit they look to short but they function as they should. 

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Here's some numbers. . . 

 

I ran some calculations through QuickLoad. 

 

First, I ran Hodgdon's numbers for a 145 grain ACME RN bullet at 2.9 gr of Titegroup at 1.150" OAL.   Hodgdon says that runs at 26,700 psi.   QL returns a pressure of 24,177 psi. So QL is a slight underestimate of Hodgdon's data.    (for simplicity, I used the same bullet length of 0.665" as noted below for a 147 BB RN)

 

Now the calculations with BigJerm's numbers. . . 

 

147 grain lead bullet, 0.665" long (based on my BB 147 RN bullets), 3.0 gr Titegroup.

 

OAL = 1.125"  = 30,056 psi.   The shorter OAL, 2.0 gr more bullet weight, and 0.1 gr more powder has bumped up the pressure 5,879 psi.

 

OAL = 1.075" = 43,007 psi. That's an (estimated) increase of 12,951 psi due simply to a change in OAL.

 

For reference:

standard pressure limit of 9mm = 35,000 psi

9mm +P pressure limit = 38,500 psi

 

Here's charge weights for the 1.075" OAL and QL's estimated pressure output.  velocity estimates for 5" barrel.

 

2.9 gr. = 39,678 psi, 917 fps

2.8 gr. = 36,548 psi, 897 fps

2.7 gr. = 33,604 psi, 876 fps

2.6 gr. = 30,838 psi, 855 fps

2.5 gr. = 28,238 psi, 833 fps

2.4 gr. = 25,797 psi, 811 fps

 

Hodgdon's data is from their website. http://www.hodgdonreloading.com/data/pistol

 

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2 hours ago, hump said:

I shoot a CZ Shadow Target and load with several different powders. My normal OAL is 1.06. I have never had any problems with over pressure. I admit they look to short but they function as they should. 

It’s okay to have short OAL as long as you decrease or use less powder accordingly.

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Speaking in general here.

 

Think for a sec what you're doing: you're asking complete strangers on the internet whether it's safe to do something. Yes, this is sort of an extended shooting family, and the advice here is usually very good, but I seriously doubt anybody here or on any web forum is going to take responsibility if advice given goes seriously sideways. Even advice given by people who you know for a fact are very accomplished and have gained your respect can go wrong. For instance, a IPSC world champion personally recommended a load to me that promptly blew up my gun because he assumed I knew to load it 65 thousandths over SAAMI spec, but as a novice reloader I didn't know to ask. 

 

Short version: you're probably going to be OK, but it's your gun, your ammo, your body and ultimately your responsibility. If you're not sure (and the fact you're asking says that's so), but want to proceed, then work up to it, watching for pressure signs.

 

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8 hours ago, George16 said:

It’s okay to have short OAL as long as you decrease or use less powder accordingly.

 

No, it's ok period.

 

These threads come up all the time and they always end up the same way. People for some reason want to believe that shortening a load so it chambers is a life altering decision. $hit, even after telling everyone I SAFELY load 3.6gr of Titegroup @ 1.08ish with a 147gr thick plate bullet (max load for an FMJ) people are still cautioning the OP to beware of the impending doom that awaits him should he decide to shorten his load.

 

I guess at some point all you can do is sit back and laugh....

Edited by 4n2t0
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41 minutes ago, 4n2t0 said:

 

No, it's ok period.

 

These threads come up all the time and they always end up the same way. People for some reason want to believe that shortening a load so it chambers is a life altering decision. $hit, even after telling everyone I SAFELY load 3.6gr of Titegroup @ 1.08ish with a 147gr thick plate bullet (max load for an FMJ) people are still cautioning the OP to beware of the impending doom that awaits him should he decide to shorten his load.

 

I guess at some point all you can do is sit back and laugh....

If your only choice is to decrease the OAL to make sure it chamber, likeI said you have to decrease the powder accordingly too if you want to stay at the same PF. Don’t just decrease the OAL without decreasing the amount of powder accordingly.

 

If you don’t want to have your barrel reamed, change to a different bullet and/or powder so they’ll plunk at a longer OAL, then decreasing the OAL and reducing the powder load accordingly is the only way.
 

Decrease the OAL, decrease the powder load and stay at the same PF.

Edited by George16
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Titegroup is a small volume powder and it's not usually recommended for new loaders due to the potential to easily double charge the case.  With that being said, I have used titegroup exclusively in all my handgun and PCC loads over the last 5 years.  I would certainly look for over pressure signs on the cases and ensure the cases are inspected.  If it were me, and I needed a load that short, I would probably drop the charge and work up until I found the load that made PF, Cycled all my guns and didn't show any over pressure signs.

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12 hours ago, kevin c said:

Speaking in general here.

 

Think for a sec what you're doing: you're asking complete strangers on the internet whether it's safe to do something. Yes, this is sort of an extended shooting family, and the advice here is usually very good, but I seriously doubt anybody here or on any web forum is going to take responsibility if advice given goes seriously sideways. Even advice given by people who you know for a fact are very accomplished and have gained your respect can go wrong. For instance, a IPSC world champion personally recommended a load to me that promptly blew up my gun because he assumed I knew to load it 65 thousandths over SAAMI spec, but as a novice reloader I didn't know to ask. 

 

Short version: you're probably going to be OK, but it's your gun, your ammo, your body and ultimately your responsibility. If you're not sure (and the fact you're asking says that's so), but want to proceed, then work up to it, watching for pressure signs.

 

 

You're right ... I'm just not sure who else to ask these questions to. Since I don't have anyone teaching me to reload. I'm essentially trying to make a load at an OAL that doesn't exist anywhere in the reloading data I've looked at (Hodgdon or Lyman manual) ... what would you do in this situation?

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