9mm Max seating depth?

[ColoradoNick]

Got into a conversation on another forum that has left me a little confused. Getting into reloading 9mm for my Shadow 2. As everyone knows the chamber is very small and in order to plunk test 9mm blue bullet 147 RN's I need an OAL of around 1.08-1.09. The bullets are measuring .717. This is giving me a seating depth of around .387 which was brought to my attention on this other forum as being too deep. I'm waiting on a cartridge gauge to show up but they don't seem bulged. They're measuring .376 at the crimp, .382 mid case, and .387 at the base. This is assorted range brass. I see a lot of people here are loading blues to 1.08 or 1.09 in their Shadow 2's and also using Titegroup. At the same time I have also found older posts that makes it sound like the length of 147gr RN Blues has lengthened over the years. What's the deal? 

Edited March 16, 2023 by ColoradoNick

[Nathanb]

5 minutes ago, ColoradoNick said:

Got into a conversation on another forum that has left me a little confused. Getting into reloading 9mm for my Shadow 2. As everyone knows the chamber is very small and in order to plunk test 9mm blue bullet 147 RN's I need an OAL of around 1.08-1.09. The bullets are measuring .717. This is giving me a seating depth of around .387 which was brought to my attention on this other forum as being too deep. I see a lot of people here are loading blues to 1.08 or 1.09 in their Shadow 2's. I have also found older posts that makes it sound like the length of 147gr RN Blues has lengthened over the years. What's the deal? 

I reamed my barrels in order to load to normal length. The blue profile does not help as they are pretty pudgy too. I found that when I tried to load them shorter I ended up with an abnormal amount that failed to gauge and I got tired of it. 

[Dirty_J]

SAAMI spec for 9mm is 1.00” - 1.169”

 

If you’re within that, your firearm functions/feeds and having no pressure signs, there’s nothing else to be concerned with. Send it. 

[Dirty_J]

1 minute ago, Nathanb said:

I reamed my barrels in order to load to normal length. The blue profile does not help as they are pretty pudgy too. I found that when I tried to load them shorter I ended up with an abnormal amount that failed to gauge and I got tired of it. 

That’s a brass issue, exasperated by the seating depth. (Tapered wall thickness, stepped brass, brass with cannelure, etc). An issue with heavier/longer bullets only. Rarely seen with 115/124 at any seating depth. 

[ColoradoNick]

7 minutes ago, Dirty_J said:

That’s a brass issue, exasperated by the seating depth. (Tapered wall thickness, stepped brass, brass with cannelure, etc). An issue with heavier/longer bullets only. Rarely seen with 115/124 at any seating depth. 

 

Thanks, that makes sense to me. Before I break them down I'll run them through a gauge. In the mean time I'm waiting on an order of 135gr TC's. 

[Boomstick303]

47 minutes ago, ColoradoNick said:

This is assorted range brass. I see a lot of people here are loading blues to 1.08 or 1.09 in their Shadow 2's and also using Titegroup. At the same time I have also found older posts that makes it sound like the length of 147gr RN Blues has lengthened over the years. What's the deal? 

 

I would load out to 1.10 at a minimum if your barrel allows.  My CZ Shadow 2 will shoot 1.15 if my memory serves me correctly.  I don't shoot it much and I do remember I loaded some ammo for my SIg P320 that I thought was not going to work, but ended up working in the CZ at 1.15.  

 

[ColoradoNick]

44 minutes ago, Boomstick303 said:

 

I would load out to 1.10 at a minimum if your barrel allows.  My CZ Shadow 2 will shoot 1.15 if my memory serves me correctly.  I don't shoot it much and I do remember I loaded some ammo for my SIg P320 that I thought was not going to work, but ended up working in the CZ at 1.15.  

 

 1.1095 is what I measured when I did a push test with these bullets. Backing off the rifling a bit I think I need to be at least 1.09

[ColoradoNick]

Blue 135 TC's just showed up. Max COAL in one of my shadows was 1.10 and the other was 1.09. This is with subtracting 0.015. Headed to a match this evening and I'm going to talk to a gun smith about reaming the throat. If anyone has a recommendation for a smith that has done this with CZ's that's located in the Denver area please let me know! I have some Acme 135 RN's showing up later today I will also test and I might try some Berry's from the shop later but at this point I'm not very hopeful. Really weird because both shadows feed factory ammo and reloads I've been purchasing just fine and they're measuring 1.14

[m700]

I have a handful of 9mm's now and everything likes and shoots well with 1 load , aside from my shadow 2. I have to batch out the short stuff for it. Who offers a throat job for them? Its either that or sell it for me

[VeilAndrew]

@M700

Patriot defense offers a reaming service for CZs.

 

Personally, I load 147gr BB RNs to 1.135 without issue in my Shadow 2 in an unreamed barrel. It's going to be totally dependent on the bullet profile of the projectiles you're using. 

Edited March 16, 2023 by VeilAndrew

[Dirty_J]

1 hour ago, ColoradoNick said:

Blue 135 TC's just showed up. Max COAL in one of my shadows was 1.10 and the other was 1.09. This is with subtracting 0.015. Headed to a match this evening and I'm going to talk to a gun smith about reaming the throat. If anyone has a recommendation for a smith that has done this with CZ's that's located in the Denver area please let me know! I have some Acme 135 RN's showing up later today I will also test and I might try some Berry's from the shop later but at this point I'm not very hopeful. Really weird because both shadows feed factory ammo and reloads I've been purchasing just fine and they're measuring 1.14

It’s not weird at all. The ogive of coated lead and FMJ/plated projectiles is quite different. 

[Miranda]

coloradonick,

well, to attempt to answer the question as asked...

 

I believe the case is .750 inches.

a seating depth of .387 has the bullet that far into the case

 

what is important here is the volume left in the case.

cases vary a lot inside so I can't calculate into small tolerances.

the volume has to be big enough to allow the amount of powder you need

and as you get to smaller volumes, the need to be more  exact in powder weights

as the amount of powder goes up.  Adjust powder upward in small increments.

Buuuuut that means attention to a good guess for starting powder...

find a known and listed bullet and calculate the seating depth.

that depth is telling you the volume you need for that combo to be safe.

 

If you can't calculate a bullet to your depth... knock your closest guess

off by about half (stay away from clays) and try that.  go up from that point.

 

frankly I would not try to shoot those bullets in that pistol.

well. it is easier to use 125-ish bullets for this weapon.

 

 

 

Edited March 17, 2023 by Miranda
removed an extra calculation I did not need

[shred]

In my business (the one where I make and sell case gauges), its rare to see 9mm rounds with cases bulged oversize by deep-seating.  What you will see is higher pressures with the reduced powder volume, so pay close attention to that.

 

[Dirty_J]

56 minutes ago, Miranda said:

frankly I would not try to shoot those bullets in that pistol.

well. it is easier to use 125-ish bullets for this weapon.

 

The S2 and 147gr Blue bullets are probably the most commonly used combo in all of USPSA… but okay.  

 

And the vast majority of those folks don’t have their barrels reamed… and they’re loading them to 1.08”-1.09”

 

It’s certainly easier to load 125’s and not have to worry about the potential for gauging issues with the longer 147 projectile in certain headstamps.  

 

I’ll reiterate… 

 

If they pass the case gauge, feed well in the gun AND you’re not getting any pressure signs on brass…. SEND IT. 

Edited March 17, 2023 by Dirty_J

[ColoradoNick]

23 minutes ago, Dirty_J said:

The S2 and 147gr Blue bullets are probably the most commonly used combo in all of USPSA… but okay.  

 

And the vast majority of those folks don’t have their barrels reamed… and they’re loading them to 1.08”-1.09”

 

It’s certainly easier to load 125’s and not have to worry about the potential for gauging issues with the longer 147 projectile in certain headstamps.  

 

I’ll reiterate… 

 

If they pass the case gauge, feed well in the gun AND you’re not getting any pressure signs on brass…. SEND IT. 

 I should have some Chrono numbers Sunday 

[Miranda]

31 minutes ago, Dirty_J said:

The S2 and 147gr Blue bullets are probably the most commonly used combo in all of USPSA… but okay.  

 

And the vast majority of those folks don’t have their barrels reamed… and they’re loading them to 1.08”-1.09”

 

It’s certainly easier to load 125’s and not have to worry about the potential for gauging issues with the longer 147 projectile in certain headstamps.  

 

I’ll reiterate… 

 

If they pass the case gauge, feed well in the gun AND you’re not getting any pressure signs on brass…. SEND IT. 

 

siiiigh.  yup. you have your conclusion.

I am pleased you and many others like that combination.

 

If I ever find I am at a USPSA event with an S2...

I am sure I will have tried that combo.

right now, I have no known problem with any 147 bullet.

the OAL I used was a bit longer in my testing.

 

hard to imagine a 147 Gr lead bullet causing bulges in a brass case.

the rounds are gunna plunk.

any issues with lead in the rifling?

 

I agree that at some point you need to stop worrying

and shoot what you made.

 

miranda

 

 

 

 

[ColoradoNick]

Acme's were a little bit better. I was able to load the 135 RN's to 1.130 and they plunk fine. 

[Dirty_J]

10 hours ago, Miranda said:

 

 

hard to imagine a 147 Gr lead bullet causing bulges in a brass case.

the rounds are gunna plunk.

any issues with lead in the rifling?

 

 

If you’re loading all the same headstamp… you’re right, it is hard to imagine. 
 

But for folks loading mixed headstamp… there’s all sorts of wonky **** that various brand do to their brass. 
 

The most common problem I’ve seen is case wall thickness that tapers. So with those… setting deeper will absolutely cause what is being described by the OP. 

[HesedTech]

21 hours ago, ColoradoNick said:

If anyone has a recommendation for a smith that has done this with CZ's that's located in the Denver area please let me know!

If you have a new Shadow 2 the barrels are hardened and will chew up a standard reamer. You need to find someone who has a carbide reamer. 

 

Honestly I run two CZ Shadow 2s with stock barrels, 147 FN coated (the Blues work great as do Brass Monkey) at 1.12+ perfectly. The RN 147 Blues work, but you will be around 1.08 - 1.10. The 124s have less issues with brass bulging and with the heavy Shadow 2 you won't really notice much difference. 

Edited March 17, 2023 by HesedTech

[ColoradoNick]

2 hours ago, HesedTech said:

If you have a new Shadow 2 the barrels are hardened and will chew up a standard reamer. You need to find someone who has a carbide reamer. 

 

Honestly I run two CZ Shadow 2s with stock barrels, 147 FN coated (the Blues work great as do Brass Monkey) at 1.12+ perfectly. The RN 147 Blues work, but you will be around 1.08 - 1.10. The 124s have less issues with brass bulging and with the heavy Shadow 2 you won't really notice much difference. 

I shot the 147gr blues today with 3.0gr of titegroup at 1.07 OAL and they felt like soft farts...

 

The 135gr acmes with 3.3gr of TG at 1.13 OAL felt similar but were definitely a little snappier. I prefer the 147's. Didn't go up from there as I didn't have a chrono today. I did find a place that will ream CZ barrels for $60 with a 48 hour turn around, thanks for the Patriot Defense recommendation. Hoping to have them both back by next friday for another weekend match. 

Edited March 17, 2023 by ColoradoNick

[4n2t0]

I've been loading a particular 147gr bullet to 1.08 for my Shadows without any worries whatsoever for years. I do gauge all my rounds in a hundo. I'm not sure why it would be necessary to ream the barrel. Convenient, yes, necessary, no, at least not in my opinion, but I guess it depends on the components one chooses to load.

Edited March 19, 2023 by 4n2t0

[ColoradoNick]

3 minutes ago, 4n2t0 said:

I've been loading a particular 147gr bullet to 1.08 for my Shadows without any worries whatsoever for years. I do gauge all my rounds in a hundo. I'm not sure why it would be necessary to ream the barrel. Convenient, yes, necessary, no, at least not in my opinion, but I guess it depends on the components one chooses to load.

yea mostly done for convenience I guess. I'm planning on loading 147gr flat points from Acme. I'll post up here when I get the barrels back. Headed to the range Friday and have a match Saturday. 

[goneracin]

1 hour ago, ColoradoNick said:

yea mostly done for convenience I guess. I'm planning on loading 147gr flat points from Acme. I'll post up here when I get the barrels back. Headed to the range Friday and have a match Saturday. 

I had my Canik barrel throated as well.  I didnt want to have different loads for different guns.  All my other stuff i load out to 1.130, and didnt want to have to be 1.090 for 1 gun. 

BTW, where are you shooting matches around denver?  What type?  IDPA, or?

Im thinking about getting back into shooting matches maybe.

[ColoradoNick]

56 minutes ago, goneracin said:

I had my Canik barrel throated as well.  I didnt want to have different loads for different guns.  All my other stuff i load out to 1.130, and didnt want to have to be 1.090 for 1 gun. 

BTW, where are you shooting matches around denver?  What type?  IDPA, or?

Im thinking about getting back into shooting matches maybe.

USPSA and some bowling pin matches. Join ECOUSPSA if you haven't, they have match calendars posted and there's a Google group with email alerts. Saturday is Colorado Springs. Sunday is Aurora Gun Club in the morning and Centennial indoor in the evening. Boulder gun club is also doing a steel match  Sunday morning. I shoot pins at Bristlecone on Mondays and The Gallery on Thursday's. Bristlecone has some more rules- basically production class guns only. The gallery is run what you brung. 

[usmc1974]

On 3/16/2023 at 3:54 PM, Dirty_J said:

It’s not weird at all. The ogive of coated lead and FMJ/plated projectiles is quite different. 

What kind of found is to be true. In about all of my 9 mm's if I'm running the coated bullet I like it to be .355 this is just me, But then I don't run 147's