Benefits of different Center-fire gun (vs 45)

As a long time shooter but new to bullseye, I'm curious about the usefulness of a separate Center-fire gun for 2700 matches.  1911's are very comfortable in my hand, and I've shot more than a few clean (or nearly) timed & rapid targets with a 45.

Would a separate center-fire gun offer benefits? I'm considering a custom 1911 in 9mm:
My initial thoughts are:

• Pros: lighter trigger pull, slightly more accurate (~1/2" long line), less (different) recoil impulse, slightly cheaper to reload,
  
• Cons: Different trigger pull, smaller diameter bullet, sharper recoil impulse, another caliber to load, can be more finicky than 45 to develop accurate long line
  

Some of these considerations may be wrong and many missing.  Please provide some guidance.

What do the top shooters use?

If you want to build a CF gun that may get you more points (though it sounds like you're more than comfortable with a 45), I would look towards a 1911 in 38 super or 38 special. The recoil for accurate loads for those calibers will be significantly lower, due to lower velocities. 

If your concern is to score more points, I'd focus on the 45. If you want an excuse to build a gun, have at it. You don't need a really good reason!

Obviously, my opinion won't buy you much. I'm just a newbie too. By the way, I believe most top shooters shoot a 45 for CF.

Dave

At this moment, I have a Dan Wesson PM-9 that shoots smaller groups than my 45.  I found a couple loads that shoot well.  First is a 115 HAP ahead if 4 grains Titegroup which gives me 1025 Fps.  I have shot hand held groups just over an inch at 25 yards.  My fifty yard load is fill power 115 FMJ 6,0 Unique for 1200 fps.  I have shot 5 shot groups under one inch at 25 yards.   Since its around zero degrees here, I have not tried it at 50 yards much.  

I am NOT a top shooter, buty like to use my PM-9 for the center fire part.  Its still a 1911.  Has a 10 lb recoil spring and great trigger just like my Valor in 45.    

Its what ever you can score best with.

Right now my wife shoots the PM-9 in our weekly matches.  I shoot the 45.  Its 50 feet so accuracy is not as important.

David

Dcforman I would look towards a 1911 in 38 super or 38 special. The recoil for accurate loads for those calibers will be significantly lower, due to lower velocities.\" wrote:
Snip

Dave

Is 38 super different twist than 9mm?  I don't know much about it.  I understand the 38 special low velocity.

David

Anyone on this board named Dave or David is a good guy

I am not a top shooter myself but personally know a few national record holders.  (The vast majority of) these individuals shoot the .45 for both the CF and .45 matches.  And they also keep the trigger pull weight the same for all three guns. 
 
There is also a high master who contributes on this forum regularly that told me and others that if you want to learn how to shoot the .45, then shoot the .45.

Typical twist for a super is 1-16. Some folks are working with 1-10. The super can be loaded to velocities close to the 38 and still maintain excellent accuracy. I have shot a.super for CF but today i stay with the 45. I actually shot the super better score wise, but my 45 scores suffered so i have concentrated on the 45. The two supers my nephew and i shoot will hold under 2" at 50 with lead loads. Better with jacketed.

This year i probably will shoot a 38 special i built for fun a few times. For fun

David R wrote:

Dcforman I would look towards a 1911 in 38 super or 38 special. The recoil for accurate loads for those calibers will be significantly lower, due to lower velocities.\" wrote:
Snip

Dave

Is 38 super different twist than 9mm?  I don't know much about it.  I understand the 38 special low velocity.

David

Anyone on this board named Dave or David is a good guy

+1 on the Dave/David thing! Most of what I heard on here states 38 super will run accurate at velocities around 800 fps (with lead) vs. the 1100 or so for 9mm. I still haven't seen anyone state why. Some people were experimenting with faster twist for 9mm, but I haven't heard about the results of any testing. I am currently building a 1:10 twist 38 special 1911. Should be fun!

Dcforman wrote:If you want to build a CF gun that may get you more points (though it sounds like you're more than comfortable with a 45), I would look towards a 1911 in 38 super or 38 special. The recoil for accurate loads for those calibers will be significantly lower, due to lower velocities. .....

I had KC build a 1911 in 9MM with a 1-32 twist KKM barrel because at the time the AMU were using a 1-32 KKM barrel in their Berettas.  It is a sub 1.25" gun @50yds but you need to push a 115gr HAP or XTP @ 1100fps to achieve this and because I recently had carpal tunnel surgery my wrist didn't like the sharp recoil.  Because of the work Jerry Keefer was doing with fast twist barrels and on KC's suggestion I had KC convert the 9MM to a .38 Super with a fast twist 1-10 KKM barrel.  With the .38 I can shoot loads that feel just as soft as my M52-2 and they are accurate - ransom rested @ 50yds it groups @ 1.5".

I shoot the .38 during the winter indoor leagues for fun and to give my wrist and trigger finger (arthritis) a rest.  Even though the 38 Super is my favorite gun to shoot I still shoot the 45 (another KC gun) in the summer.  I actually score about the same with them.
- Dave 
yep another one

Dave. Your wrist will feel better in a.couple of months. I had that surgery back in late 18.. wrist was weak for awhile but fine now and my fingers far better.. nothing like shooting BE with numb fingers

Dcforman wrote:If you want to build a CF gun that may get you more points (though it sounds like you're more than comfortable with a 45), I would look towards a 1911 in 38 super or 38 special. The recoil for accurate loads for those calibers will be significantly lower, due to lower velocities. 

The question is why not 9mm? Okay, the bullet weights are higher. But why do you have to go to 38?
If you're reloading, why not use the desired weight and profile 375/38 bullets in a 9mm case?

Dcforman wrote:Most of what I heard on here states 38 super will run accurate at velocities around 800 fps (with lead) vs. the 1100 or so for 9mm. I still haven't seen anyone state why. Some people were experimenting with faster twist for 9mm, but I haven't heard about the results of any testing. I am currently building a 1:10 twist 38 special 1911. Should be fun!

The problem I see in asking the questions around these issues is that there are a lot of people who have a lot of hands on knowledge and experience with what exists and how to make it work best, but very little ballistics experience to say WHY and what makes things work best or what needs to be changed to improve performance if one variable is changed. Then there's the difficulty of getting possibly non-standard parts.

With no experience and no bias, I look at the people successfully loading 357/38 bullets into 9mm cases.

Look to SAAMI for standards and testing (https://saami.org/wp-content/uploads/2019/01/SAAMI-Z299.3-Centerfire-Pistol-Revolver-Approved-12-14-2015.pdf) and you find that the test barrels and projectiles are:

9mm
     Barrel Bore: .346 (8.79), Groove: .355 (9.02)
     Bullet dia: .3555 -.0030 (9.030-0.076)
     Bullet weight: 88 - 147 gr.
     Velocity: 1100 - 1375 fps (15in. barrel)

38 special
     Barrel Bore: .346 (8.79), Groove: .355 (9.02)
     Bullet dia: .3590 -.0030 (9.119 -0.076) (lead), .3580 -.0030 (9.093 -0.076)
     Bullet weight: 100 - 200 gr.
     Velocity: 775 - 1050 fps (15in. barrel)

357 Magnum: 
     Barrel Bore: .346 (8.79), Groove: .355 (9.02)
     Bullet dia:  .3590 -.0030 (9.119 -0.076) (lead), .3580 -.0030 (9.093 -0.076) (jacketed)
     Bullet weight: 101 - 180 gr. 
     Velocity: 1400 - 1715 fps (15in. barrel)

Differences, where they exist, are minute. The only place where where they are not identical is that the smallest 9mm (.3525) would be .0025 smaller than the smallest allowed jacketed 38/357 (.3550)

So, elementary physics should dictate that if you can fire a 38 special cartridge with a bullet of a given profile, weight, and velocity and achieve good accuracy, why the heck can't you match the accuracy with a 9 mm cartridge firing the SAME bullet profile, weight, and velocity?

The only possible differences, looking at it without further info, are barrel twist, and powder properties. Ease of reloading?

If I had the time, money, and knowledge, it seems to me an interesting garage experiment would be to take a 38/357 barrel blank, cut equal lengths, give one a 1911 9mm chamber, the other a 1911 38sp chamber.

Then shoot the same bullets. Either prove there's a casing constraint that makes attaining the same performance impossible, or put the idea that one is better than the other to rest by showing they're the same or identifying which variable makes the difference.

Basic guessing is that ideal barrel twist is a function of weight and size. As the range of weights and sizes are different, the common one-size fits all twists are different.

And while the ranges overlap, the best weight/velocity for one falls outside the twist rate for the best weight/velocity for the other.

After the above, I took a break, did some searching, and read this:
http://blog.westernpowders.com/wp-content/uploads/2015/04/Webfile_Barrel-Twist-Rate.pdf

A 24 inch twist for 38 Super, 9x19, 40S&W, and 45ACP AET barrels, often sub-one inch accuracy at 50 yards.

The niggly question remaining? What do they mean by "often"?

And this is why they need to revoke my internet access at work.

Get too caught up diving down interesting rabbit holes.

Straying from why another calibre over .45, but interesting discussion of weights, powders, and accuracies for 38 super. And throwing 38 super comp into the mix of things I now know about.

https://www.shootingtimes.com/editorial/2019-new-ammo-roundup/331304

Case length. Load a 148 hbwc to .38 special length in a 9mm case to get comparable performance.

james r chapman wrote:Case length. Load a 148 hbwc to .38 special length in a 9mm case to get comparable performance.

Be very careful doing this with a HBWC too heavy a load and you leave the base behind and you bulge your barrel with the next round.  This even happened way too often with both the P240 and the M52
- Dave

james r chapman wrote:Case length. Load a 148 hbwc to .38 special length in a 9mm case to get comparable performance.

WC? Yeah, if you want a wadgun that certainly points to any of the .38 flavours.
But how about a SWC?

KKM makes a 1:10 twist .355 barrel, going to try one for a 1911 9mm just because sometimes I don't want to pick up brass.  Knowing that 9mm is finicky to load for I will see how it does with 124gr Nato FMJ for accuracy.  I have a NM Beretta being rebarreled by David Sam's with a 1:18 twist 9mm barrel, the originally 1:32 twist was made specifically for the 115gr bullets.

In the end I might just end up back with the .45acp 1911...  As it works and larger bullets matter.

Sc0 wrote:KKM makes a 1:10 twist .355 barrel, going to try one for a 1911 9mm just because sometimes I don't want to pick up brass.  Knowing that 9mm is finicky to load for I will see how it does with 124gr Nato FMJ for accuracy.  I have a NM Beretta being rebarreled by David Sam's with a 1:18 twist 9mm barrel, the originally 1:32 twist was made specifically for the 115gr bullets.

In the end I might just end up back with the .45acp 1911...  As it works and larger bullets matter.

With the 1-10 try a 147gr JHP, my 9MM XDM loves them, there were several people shooting that load with the XDM that made the Presidents 100.
- Dave

james r chapman wrote:Case length. Load a 148 hbwc to .38 special length in a 9mm case to get comparable performance.

This is a horribly bad idea.  If you want to shoot 148 HBWC's, get a .38 Special.

Just to add in the conversation, I have a Clark Heavy Slide in .38 Special that I had built back when I was shooting a lot of international matches.  I find it fun to shoot in the CF match, since I can consistently shoot in the 830 to 840 range, even though it just has the Bo-Mar rib and no dot.  However, it is a different animal and takes a lot of concentration, due to the different trigger pull and recoil profile.

When I was looking for Leg points, I put it away and shot my Leg gun for the CF match, which in turn, made me a better .45 shooter.

Just some thoughts on a Friday.

It was said in humor. Obviously can’t be done.

Said in response to how can we duplicate a 700 FPS .38 spl load in 9mm

I knew you were joking James. But now you went and done it. Obviously "can't be done" are challenge words. Now, about SWC. I have tested a lot of different 9mm loads. This was the most accurate with 158gr L-SWC in the RO. The 952 didn't like them at all. I increased the load slowly from this and the RO started throwing them off the paper. If I can get 158gr to work then 148gr could be done. Feeding might be problematical.

Finding the right load for your pistol. Priceless. Take a look at these two 9mm. The difference between these two pistols is very small. 1:16 and 1:18.75. The 952 is also a "match" pistol and the RO is stock (when testing was done) The only difference in this pair of targets is a different powder. I guess that is why we test. I should mention that I was doing this testing to find a soft recoil sustained fire load. I have a good LL load for both pistols. This testing was done at 25yds. I was looking for the alternative to the .45 also.

james r chapman wrote:It was said in humor. Obviously can’t be done.
Said in response to how can we duplicate a 700 FPS .38 spl load in 9mm

Sorry I missed the humor.  Guess I take reloading advice to seriously.

I appreciate all the feedback.

LenV wrote:The difference between these two pistols is very small. 1:16 and 1:18.75.

In my mind, what would be really interesting would be the logic/physics/design choice between those differences. How much of the testing everyone does individually is really just confirming whether the designers knew what they were doing (but failing to communicate)?

I did some testing and found a 115 HAP load at 1025 fps in my Dan Wesson PM-9.  Its not the guns best load, bue will do just over an inch @ 25 yards.

I tried a few powder coated lead bullets and just found the missouri bullets 125 SWC made for 9mm will give me a 1.5" 10 shot group at 25 yards.

I am holding the gun on sand bags doing this test.   I just ordered a 
HySkore Pivoting Pistol Shooting ResT  to help improve my bench skills.   A ransom rest out for now. 

I can get one inch at 25 with the same gun with 115 FMJ @ 1225 fps. 

25 yard range is indoors.  too cold out to shoot at 50 yards right now.


David