The Original CZ Forum
GENERAL => Ammunition, questions, and handloading techniques => Topic started by: Fuzzy Sights on May 05, 2019, 10:50:03 PM
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Working on developing some 9mm 147 gr loads for bowling pin and ran into a problem. On two of my CZ 9mm the chambers are tighter than on the one I used to measure the loads (a TS). The VV website gives a 1.142 OAL and I am meeting that on the nose, but will not chamber in a 75B or P-01 (plus a Tanfolio). There are clear marks that the bullet is engaging the rifling. Any suggestions or do I need to have the chambers reamed?
JW
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Personally in 9mm I load to the shortest of my guns and then shoot them in all. If I was loading for super accuracy competition I would load specifically for the gun I was going to use.
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Personally, in 9mm I load to the shortest of my guns and then shoot them in all. If I was loading for super accuracy competition I would load specifically for the gun I was going to use.
I'm sure Wobbly will be along and get ya on the right track but with that said you NEED to shorten up the OAL! I loaded some 148s tonight myself and they run @ 1.125+or- some. Just because they run in one gun does not mean they will run in them all! I always use my 07 cuz that's the shortest/tightest chamber of all my CZs. Do the work/measurements and you should be good, you say it yourself, there are clear marks on the bullets, move em back, LOL! ;)
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+1 on Larry's suggestion.
Shorten the OAL so it will fit in the shortest chamber, and reduce the powder charge accordingly.
When you give us more details on how much you need to shorten the OAL, we can help with reducing the charge.
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Working on developing some 9mm 147 gr loads for bowling pin and ran into a problem. On two of my CZ 9mm the chambers are tighter than on the one I used to measure the loads (a TS). The VV website gives a 1.142 OAL and I am meeting that on the nose, but will not chamber in a 75B or P-01 (plus a Tanfolio). There are clear marks that the bullet is engaging the rifling. Any suggestions or do I need to have the chambers reamed?
JW -
Have you read This Article Right Here (https://czfirearms.us/index.php?topic=103620.0) ? Especially the second post at the bottom of the page concerning 147gr bullets ?
There are a lot of files in our "Stickies" that will be very helpful to you. You should spend some time there reading.
Regards
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From the suggested reading...
For 9mm, if your particular 147gr bullet still leaves you in the dilemma of being caught between staying out of the rifling versus staying out of the case wall, then we can suggest the plated 147gr RN from Berry Mfg. On standard CZ pistols this bullet can usually be loaded out to 1.150" OAL.
;)
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The problem in this case is that reducing the OAL is not possible due to the amount of powder it takes to get the velocity needed to move a bowling pin off a table reliably. For a 147gr bullet that is about 1150 fps. There are not that many loads that reach that velocity without exceeding safe pressures or greater than SAMMI spec OAL. For the moment I am working with VV 3N38 whose starting load will get 1171 fps and the OAL for the 147gr XTP is 1.142 in. This load will not chamber in my TS 9mm (Tanfolio, or a CZ 75B) even though it is within SAMMI secifications. Loads from the Hornady manual all list 1.169 as their OAL for 147gr XTP loads, which is max OAL.
Was able to contact CZ Custom Gunsmith shop and they confirmed my fear that to use this or similar loads the barrel would need to be reamed. Sadly they are currently over tasked and declined the work. Cajun Gun Works has agreed to do the work for about $30.00 a barrel and has kindly already sent the paperwork. Will ship three barrels on Monday after this months match.
Will take a couple of weeks for the barrels to get back, but will happily post pictures; if my wife ever gives me back my camera...
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The problem in this case is that reducing the OAL is not possible due to the amount of powder it takes to get the velocity needed to move a bowling pin off a table reliably. For a 147gr bullet that is about 1150 fps. There are not that many loads that reach that velocity without exceeding safe pressures or greater than SAMMI spec OAL. For the moment I am working with VV 3N38 whose starting load will get 1171 fps and the OAL for the 147gr XTP is 1.142 in. This load will not chamber in my TS 9mm (Tanfolio, or a CZ 75B) even though it is within SAMMI secifications. Loads from the Hornady manual all list 1.169 as their OAL for 147gr XTP loads, which is max OAL.
Was able to contact CZ Custom Gunsmith shop and they confirmed my fear that to use this or similar loads the barrel would need to be reamed. Sadly they are currently over tasked and declined the work. Cajun Gun Works has agreed to do the work for about $30.00 a barrel and has kindly already sent the paperwork. Will ship three barrels on Monday after this months match.
Will take a couple of weeks for the barrels to get back, but will happily post pictures; if my wife ever gives me back my camera...
Respectfully... you can modify any load to fit a barrel provided the OAL is over 1 inch, and the seating depth, for long bullets like the 147 grain doesn't end up swaging the bullet base, or cause chambering issues.. The listed OAL in the data is simply a report, not gospel.
If you reduce OAL, chamber pressure will increase, but if you proprtionalize the load, and reduce the charge, pressure will drop and velocity will remain in the range you require.
Usually, no need to ream barrels if you're willing to experiment.
Have you performed a push teat to determine the max OAL with your chosen bullet?
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Painter your suggestion is interesting. Have not done a push test ever in a pistol (several times with rifles). Rough guess is that my max oal in this barrel for the 147gr XTP is 1.120 or so. That is 22 thousandths shorter than the VV manual. How much powder do I need to remove off the 6.3gr starting load of VV 3N38 powder for a start load. Positive you can not decrease the OAL to 1.120 and have 6.3gr of this powder, bullet would never seat as this is more than a compressed load. Have a chronograph to do the velocity measurements, but finding that start load that does not detonate my gun is an issue. Even the start load on this one or any that are in this category are not light loads. VV does not list the pressure on this load, but does show that from min-max is only six tenths of a grain, which is a pretty small window.
Would dropping a grain of powder and work up from there. Initial load would probably not run the TS or Tanfolio as they are both pretty heavy slides and springs. Curious what you think.
JW
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I know everyone has there "favorites" but the bottom line is to change your powder! I have some 148s that a buddy casts and then we powder coat them. I ran a couple thousand of them running Power Pistol and they ran great were super accurate and they were not even close to MAX. I just started using the same 148s but am using Universal this time around. My OAL is 1.125+or- a few but pretty close! I started with a 3.5 and everything looked good no signs of pressure or flat primers but darn, out of my 07 they were pretty stout! I'm @ 3.2 right now with some test loads and will get out Thursday or Friday and test, then Chrono them and we should call it good if I make power factor and everything else is GTG!
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Painter your suggestion is interesting. Have not done a push test ever in a pistol (several times with rifles). Rough guess is that my max oal in this barrel for the 147gr XTP is 1.120 or so. That is 22 thousandths shorter than the VV manual. How much powder do I need to remove off the 6.3gr starting load of VV 3N38 powder for a start load. Positive you can not decrease the OAL to 1.120 and have 6.3gr of this powder, bullet would never seat as this is more than a compressed load. Have a chronograph to do the velocity measurements, but finding that start load that does not detonate my gun is an issue. Even the start load on this one or any that are in this category are not light loads. VV does not list the pressure on this load, but does show that from min-max is only six tenths of a grain, which is a pretty small window.
Would dropping a grain of powder and work up from there. Initial load would probably not run the TS or Tanfolio as they are both pretty heavy slides and springs. Curious what you think.
JW
I'd really rather you did the push test and come up with a real number, rather than a guess due to the seating depth issues with long bullets, as I already mentioned. The 1.12 OAL sounds long for that bullet in a CZ. I'm pretty sure the HAP won't run that long in my 85. I'm not sure of your experience, but there's a ton of great info in the stickied threads at the top of the page. Some of it explains the differences in reloading for CZ's short throat, covers the push test, and is well worthwhile regardless of your level of experience.
Your final load will not make less pressure, or velocity, than the load you're using. It should run all your pistols, as it does now. If starting load does't run your pistol, then this reduced one won't either. The danger of reducing OAL with the 147 gr bullet is running into a seating depth issue due to the internal shape of 9mm brass. Generally seating depth must be kept to .250 with an absolute max of .30, depending on your brass.
There are many threads about this very subject here on this forum.
You also might search this forum for 147 gr XTP to see the range of OAL people are finding necessary for that bullet.
The best method is the push test in your barrel.
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Fuzzy: I am in the ?Ream the barrel? camp. I have 4 9mm 1911s and 4 9mm CZs, including a TSO like you. I have every CZ Barrel chamber reamed to take the same rounds that I load for the 1911s, so I know any round I load will run in any 9mm I own. CGW does great work, they built 3 of my CZs.
As for your question, I shoot 147gr bullets in all mine and use either VV N320 or Alliant Sport Pistol. No problem with overfilled cases.
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As for your question, I shoot 147gr bullets in all mine and use either VV N320 or Alliant Sport Pistol. No problem with overfilled cases.
The problem with N-320 is it won't push a 147 gr bullet to 1150 FPS with out exceeding VV max load (as the OP wants).
147 HP/XTP Hornady 1.142 N320 Min load. 3.1 784-fps Max. 3.9 978-FPS (from VV 2017 load data)
Fuzzy another choice is a bullet like the ZERO 147 JHP, very similar to the Hornady, EXCEPT it can be loaded MUCH longer. 1.142 is no problem in my CZ's YMMV
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JW -
Have you read This Article Right Here (https://czfirearms.us/index.php?topic=103620.0) ? Especially the second post at the bottom of the page concerning 147gr bullets ?
There are a lot of files in our "Stickies" that will be very helpful to you. You should spend some time there reading.
Painter your suggestion is interesting. Have not done a push test ever in a pistol (several times with rifles). Rough guess is that my max oal in this barrel for the 147gr XTP is 1.120 or so.
So let me get this straight...
? This is a common issue to all CZ reloaders
? We take the time to detail a process (containing 2 solutions) that will get you to a speedy resolution
? You solicit help from the members of this forum
? We take the time to point to the location of this process within your own thread
? You apparently ignore this advice
? You complain *a lot* when your thread gets locked
It's like you already have an answer, and you're only looking for confirmation.
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" Positive you can not decrease the OAL to 1.120 and have 6.3gr of this powder, bullet would never seat as this is more than a compressed load."
JW
Well, I can tell you for a fact you can load 6.3gr and it will compress. In my Czechmate I load a 125gr Blue bullet with 8.5gr 3N38 @ 1.145" and it is compressed about 0.070". 8.5gr fills the case all but about 0.70" and 9.0gr fills the case all but about 0.050". 3N38 is a relatively slow burning powder and burns cleaner when it is compressed. I would start out at 5.7gr and work your way up to no more then 6.5gr with your (1.120")OAL. YMMV
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Well just got back from a test run. I shot both my 07 & 01. Average for 10shots out of 07 was 897, with PF being 132. Out of my 01 average for 10 shots was 884 with PF being 130. 148 powder coated bullets are loaded in mixed brass with Tula primers and 3.2 grains of Universal & OAL is 1.125. Ran perfect with no issues at this time. Will load up a couple hundred and reconfirm everything and then have at it,LOL For sure out of my Shadow 2 and SP-01 Tac the average will go up and so will the PF,I could drop another .5 or so and see but would rather have reliability than a soft load that might not run in an awkward position.
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Wobbly - Have not made a decision yet. My last post was asking Painter for an opinion.
Painter the real number is 1.122 in. To back this off a another 5 thousandths or so for safety would be 1.117. Dillion usually gives +- .02 for seating. Will look a the stickies shortly. Thanks!
Will also email VV and see what they have to say. They seem to be a pretty cautious group and will probably be unhappy that I am using Speer and not Lapua Brass. (Even when stationed in Germany I never saw 9mm Lapua Brass.) Never know they may have a ratio they use in making such adjustments. Worst case is they will tell me to ream the barrel.
Leaning towards a split decision. Send my TS barrel to Cajun Gun Works and retain the Tanfolio and experiment with dropping powder charges and shortening OAL. My main concern with the dropping of powder and shortening is that it takes a certain amount of powder to push the bullet at the required speed. Guess I need to read the stickies as Painter suggested.
Just tried BB RN 147s the best I got was 971 fps and the primers were pretty flat. Surprised at how soft the load felt. Backed off 2 tenths grain and that is what I will use for match on Sat. Really accurate, extreme spread only 6 fps at 950 fps. Only second bowling pin match so I will suck anyway. These are still better loads than I shot the first match with and I ran third.
Thanks to all for suggestions! Lots to think about.
JW
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Painter, thanks for the direction to look at the stickies. Huge amount of information. Lots of good posts from Wobbly with diagrams and graphs. Great explanation for use of VV powders in 9mm (wish I had some VV N330 & N340). So Mission Analysis is done time to select my course of action. Will go both directions at once after the match. Send the TS Barrel and have it reamed, then develop loads just for that firearm for this type of match. While the barrel is out for a couple of weeks I will try some small experiments with my Tanfolio which has a slightly longer throat than the TS and see if reducing the charge and OAL can get me to Nirvana, (147 gr XTP OR Berry's HP to 1150 fps). Cost is only $30 plus shipping and it greatly enhances the possibility of reaching my goal. Also having a throat tailored for a load is great way to obtain greater accuracy. They do it in precision rifle all the time. Granted I only need to hit a 1 inch target at 10 yds which frankly is not that hard for pistols as well made as any of my CZs in this case I just have to hit it really hard.
Will post results when accomplished. Sadly I am on the road for work for the next couple of weeks, so it may take a bit to see another post from me.
Thanks one and all. JW
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Just finished bowling pin match for the month. Used the TS 9mm with the 147gr Berry's Plated RN and 6.5gr of VV 3N38 at 950 fps. Only had two shots where I was positive of a good hit and the pin did not leave the table. Rest of them were clearly my screw-up. Result - Tied for second place. Not bad for a second match. Still feel the need for a little more power to eliminate those spinning pins on the second, third and forth shots that take up so much time.
JW
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Just finished bowling pin match for the month. Used the TS 9mm with the 147gr Berry's Plated RN and 6.5gr of VV N320 at 950 fps.
JW
WOW that's a HOT load. I show VV says 147 RN Heavy Plate, X-Treme Bullets with N-320 has a max load of 3.7 grs.
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SoCal. Thanks for the catch the powder was 3N38 not N320. Edited original. JW