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New to Open guns, 38 Super Comp testing load advice needed


DukeSoprano
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I have a CK Arms limited gun in 40 and love it, I stumbled on a great deal for a 38 Super Comp CK arms open gun (3 holes)  and been working up loads. I have a C-More 4 moa

So far I have tried: (all loads chrono'd with a lab radar) and a HAP 125 grain @  1.23 oal

 

HS-6---8 grains = 169 PF

N105----9.6 grains = 169 PF

N105----9.9 grains = 173 PF

AutoComp---- 7.5 grains = 171 PF

HS-6----8.6 grains = 174 PF

 

Accuracy is perfect with all the above loads and I have tried both 8lb and 9lb springs.

 

So my question is, what exactly am I looking for next?

 The DOT returning asap? Flat shooting?

 

Thank you,

Jeffrey

Edited by DukeSoprano
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You have a great start there, with a great gun, super caliber (pun intended)

good bullets and some good powders) 

 

BUT,

 

I don't see anything about a timer.

 

What your should look for is any speed savings with the different loads.

 

Pick a COF (El Presidente, or anything else).  Which load is faster, for

YOU, in Your gun.  If the five loads result in 5.9, 5.8, 5.7, 5.6 and 5.5

seconds, I'd take the 5.5 second load.

 

BTW, if you're going to put up with the inconvenience of shooting .38 Super

(the brass issue), I'd use the advantage of the caliber and use 3n38 or

one of the other slower powders than WAC or even HS6.

 

But, the issue, is that your best load is the one that you can shoot the

fastest with,  IMHO.  So, you need a timer.    :) 

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2 hours ago, DukeSoprano said:

Any others powders to suggest?

 

38SC is a large case.  You N105 load looks good.  That is slower than 3N38.  Here is the deal.  You have three holes and a comp, all of which I'll assume you want to work to the fullest.  So start with your N105 173 PF load.  Go to the range and fire into a white no shoot target from 2 or 3 inches away.  If you get a very light splattering, all of the gas is being put to work by the poppels and the comp ports.  If you get a lot of black splatter, you are making too much gas for your setup to handle.  Gas jetting out the front of the comp increases the hit to your hand.  If that happens, try the N105 169 PF load and see what happens.

 

If you still get a lot of crap coming out the front, you'll need a faster powder like 3N38.  The object is to get every baffle in your comp working to reduce felt recoil with nothing (or very, very little) coming out the front.  When you achieve this, your load is perfectly balanced for your gun.

 

Now for the bad news.  You may not like it.  Say you are getting more dot/muzzle rise than you like.  If you cannot tune that out with changes to your recoil spring, mainspring and firing pin stop, you'll have to add more powder and accept the harder hit to your hand.

 

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3 hours ago, DukeSoprano said:

Any others powders to suggest?
 

Accurate #7 (9.8 gr to start) or  Silhouette  (8.0 gr to start).   Shooter's World Major Pistol is also poplar with some guys in my club in SuperComp, but I haven't tried it.  

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On 2/29/2020 at 7:08 PM, zzt said:

 

38SC is a large case.  You N105 load looks good.  That is slower than 3N38.  Here is the deal.  You have three holes and a comp, all of which I'll assume you want to work to the fullest.  So start with your N105 173 PF load.  Go to the range and fire into a white no shoot target from 2 or 3 inches away.  If you get a very light splattering, all of the gas is being put to work by the poppels and the comp ports.  If you get a lot of black splatter, you are making too much gas for your setup to handle.  Gas jetting out the front of the comp increases the hit to your hand.  If that happens, try the N105 169 PF load and see what happens.

 

If you still get a lot of crap coming out the front, you'll need a faster powder like 3N38.  The object is to get every baffle in your comp working to reduce felt recoil with nothing (or very, very little) coming out the front.  When you achieve this, your load is perfectly balanced for your gun.

 

Now for the bad news.  You may not like it.  Say you are getting more dot/muzzle rise than you like.  If you cannot tune that out with changes to your recoil spring, mainspring and firing pin stop, you'll have to add more powder and accept the harder hit to your hand.

 

 

What an interesting concept...  Seems totally logical, but I've never heard of it before...

 

Great post!

 

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On 2/29/2020 at 7:08 PM, zzt said:

 

  If you cannot tune that out with changes to your recoil spring, mainspring and firing pin stop, you'll have to add more powder and accept the harder hit to your hand.

 

 

Well thought out post    :) 

 

One other option :  Steel Grip.   Big difference.

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I have noticed that you have not tried VV 3N38 yet, which will be telling. Yes, it is currently hard to find now, but I recently (like yesterday) was able to test load the VV N105 and compare it directly with the VV 3N38 and the 3N38 was softer. I am running a 124 grain Montana gold bullet through a 5.4 inch barrel with 3 popple holes, so we have similar guns. At 9.8 I was at 171 power factor. 

 

I would recommend you get your hands on some 3N38 and then figure out which one shoots better. At 9.2 grains of 3N38, this load is shooting my Limcat VERY flat. We were able to compare right next to a Limcat running 9mm Major with VV N340 open and all 4 of us agreed that the 38 Super Comp running 3N38 was softer. Now a friend of mine was running 10.2 grains of 3N38 out of his 9mm major, but I did not have the opportunity to try that out in his gun yet. 

 

One more thing, get a steel grip. HUGE game changer. Oh, and maybe a heavy barrel (tungsten sleeved). 

 

Good luck sir!!

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N's 3N38 load may well have been softer than the N105 load.  If so it wasn't about the powder, it is all about the amount of gas generated.

 

It took me a long time to wrap my head around the fact that the jet of gas exiting a regular barrel (or the front of a comp) is still accelerating the bullet after it has left the muzzle.  It also increases the velocity of the slide's rearward movement.  You can easily prove this to yourself. 

 

I shot 40 Open for two seasons when my eyes told me I had to give up Limited.  My Limiter major load (180 over 3.7gr e3) made 172 PF out of my Limited gun.  It didn't in my Open gun.  Okay, the two 3/16" popples drained gas while the bullet was still in the barrel.  That made sense.  What didn't make sense was the brass was ejected 6' out of the Limited gun with a 14 lb. recoil spring, but barely dribbled out of the Open gun with a 9 lb. spring. ???  e3 is fast, and that little bit of powder could not possibly have generated enough gas to get past the poppels with enough left to work the comp baffles.  So there had to be another reason.  The reason is the gas the comp directs upwards is no longer available to push on the back of the bullet, even though it had left the barrel.  So slide speed is slower.

 

My 172 PF Open load of 155gr over 7.3gr Silhouette ran fine in the Open gun, but was so violent in the Limited gun I feared for its longevity.  These and other experiments led me to the conclusions above.  I plan to retest this when it gets warmer.  I built a dedicated 1911 9mm Open gun for Steel Challenge.  It shoots my 168 PF major loads perfectly, and my 144 PF steel loads as long as I use a 7 lb. spring.  I recently fitted a new Barsto barrel to that gun, because my home range does not allow Open guns, comps, etc. in their matches.  So I will be able to repeat these experiments with the same gun.  The only differences will be the two barrels and the recoil spring weights.  I'll start with the minor load and see if the velocity differences are the same as for major.  I don't know if I'll test the major load, because I already know that shooting a 115 @ 1470 fps out of an uncompensated gun hurts.

 

Back to 40 Open.  I used WAC, Silhouette and HS-6 because that was what everybody was using.  I decided to see how flat I could get the gun to run.  It had two 3/16" poppels in the barrel and a 4-chamber, 5-port comp.  I used HS-6 for these experiments.  I found that after a certain point the load stops shooting softer and starts hitting your hand harder.  I went all the way up to 188 PF to get that gun to shoot dead flat.  It was really loud, violent and it hurt.  The reason was more and more gas was jetting out the front of the comp and increasing felt recoil and slide speed.

 

By this time I had also built a 2011 9mm Open gun and was shooting it along with the 40 Open.  I was using Major Pistol powder under a 115 in the 9mm.  I was still shooting the 7.2gr Silhouette under a 155 in 40.  The two guns felt pretty much the same.  On a lark I decided to try MP in the 40.  10.1gr under a 155 made major and was so much softer and flatter shooting than the Silhouette load it was shocking.  The extra gas worked the poppels better (flatter) with enough left over to work the comp baffles (softer).

 

I had already figured all of this out before reading an article by Bob L at Brazos Custom.  It was he that recommended shooting on white paper to check your Open load.

 

 

Edited by zzt
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On 3/2/2020 at 10:17 AM, zzt said:

N's 3N38 load may well have been softer than the N105 load.  If so it wasn't about the powder, it is all about the amount of gas generated.

 

It took me a long time to wrap my head around the fact that the jet of gas exiting a regular barrel (or the front of a comp) is still accelerating the bullet after it has left the muzzle.  It also increases the velocity of the slide's rearward movement.  You can easily prove this to yourself. 

 

I shot 40 Open for two seasons when my eyes told me I had to give up Limited.  My Limiter major load (180 over 3.7gr e3) made 172 PF out of my Limited gun.  It didn't in my Open gun.  Okay, the two 3/16" popples drained gas while the bullet was still in the barrel.  That made sense.  What didn't make sense was the brass was ejected 6' out of the Limited gun with a 14 lb. recoil spring, but barely dribbled out of the Open gun with a 9 lb. spring. ???  e3 is fast, and that little bit of powder could not possibly have generated enough gas to get past the poppels with enough left to work the comp baffles.  So there had to be another reason.  The reason is the gas the comp directs upwards is no longer available to push on the back of the bullet, even though it had left the barrel.  So slide speed is slower.

 

My 172 PF Open load of 155gr over 7.3gr Silhouette ran fine in the Open gun, but was so violent in the Limited gun I feared for its longevity.  These and other experiments led me to the conclusions above.  I plan to retest this when it gets warmer.  I built a dedicated 1911 9mm Open gun for Steel Challenge.  It shoots my 168 PF major loads perfectly, and my 144 PF steel loads as long as I use a 7 lb. spring.  I recently fitted a new Barsto barrel to that gun, because my home range does not allow Open guns, comps, etc. in their matches.  So I will be able to repeat these experiments with the same gun.  The only differences will be the two barrels and the recoil spring weights.  I'll start with the minor load and see if the velocity differences are the same as for major.  I don't know if I'll test the major load, because I already know that shooting a 115 @ 1470 fps out of an uncompensated gun hurts.

 

Back to 40 Open.  I used WAC, Silhouette and HS-6 because that was what everybody was using.  I decided to see how flat I could get the gun to run.  It had two 3/16" poppels in the barrel and a 4-chamber, 5-port comp.  I used HS-6 for these experiments.  I found that after a certain point the load stops shooting softer and starts hitting your hand harder.  I went all the way up to 188 PF to get that gun to shoot dead flat.  It was really loud, violent and it hurt.  The reason was more and more gas was jetting out the front of the comp and increasing felt recoil and slide speed.

 

By this time I had also built a 2011 9mm Open gun and was shooting it along with the 40 Open.  I was using Major Pistol powder under a 115 in the 9mm.  I was still shooting the 7.2gr Silhouette under a 155 in 40.  The two guns felt pretty much the same.  On a lark I decided to try MP in the 40.  10.1gr under a 155 made major and was so much softer and flatter shooting than the Silhouette load it was shocking.  The extra gas worked the poppels better (flatter) with enough left over to work the comp baffles (softer).

 

I had already figured all of this out before reading an article by Bob L at Brazos Custom.  It was he that recommended shooting on white paper to check your Open load.

 

 

Walk me through the whole.shooting on white paper thing again? I have an open gun I want to test

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16 hours ago, AverageJoeShooting said:

Walk me through the whole.shooting on white paper thing again? I have an open gun I want to test

 

I spelled it out in my first post.  Read the Brazos article and reread my first post.  You will have to try different powders.  You already have N105.  Major Pistol powder and AA7 are around the same burn rate.  Both are considerably less expensive than any of the VV powders.  I'm partial to MP.  Somewhat faster powders are in the 3N38 burn range.  The fastest I would try are powders in the 3N37 range.  I cannot imagine needing anything faster than that with three holes and an efficient comp.  In fact, I'd be really surprised if you needed anything faster than 3N38.

 

You choice of bullet weights will also be a factor.  You started with a 125gr bullet.  Le't suppose you test your 173 PF load and find that little gas is exiting the front of the comp.  The first thing I would do is up the powder charge and go to a 115gr bullet.  If that tests well, the only way to generate more gas is to go with an even slower powder and up the charge.  You can do the same if you want to stick to 125s.

 

Your three poppels are going to flatten out the gun a bunch.  So the object is to replace some or all of the gasses exiting the poppels so the comp baffles get 'worked'.  I like the paper test, especially for your first slow powder, because it gives you a baseline.

 

Unlike a lot of shooters, I always start with the slower powders.  I always start with 115s.  I have two 3/16" poppels and a custom, very efficient three port comp.  I know from previous experience I need a lot of gas to flatten and soften the gun.  Unlike you, I am limited by the small case capacity of 9mm.  It is difficult to fit enough powder in the case and still seat a bullet to a manageable OAL and get the gun to shoot flat and soft at the same time.  I'm case capacity limited.  You are not.

 

I load 10.2gr Major Pistol powder under a 115 at 1.161" OAL.  That makes 169 PF.  You would have to use considerably more, because your case is larger and you are seating longer.  You can make more gas and at lower pressure.  Having a flatter shooting gun makes your second shot faster.  Having a softer shooting gun makes the gun more controllable and more comfortable to shoot, especially if you didn't get a perfect grip on the gun when you drew it.  Those spit seconds really add up over the course of the match.  You have the case capacity to make your gun shoot flat AND soft at the same time.  I'd take advantage of that.

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1 hour ago, DukeSoprano said:

That was 4 different loads

I019 is 7.5 AutoComp

I020 is 8.6 HS-6

I015 is 9.7 N105

I014 is 8  HS-6

 

 I019 feels the best so far

 

Interesting.  Describe your comp, and post a picture of it.  When it was align reamed, what was the diameter of the reamer?

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  • 2 weeks later...
32 minutes ago, AverageJoeShooting said:

@zzt bless me with your anaylsis

 

Not bad.  I'd like to see a little less splatter, but that might just be the contrast.  My splatter is lighter and more gray.  Describe your gun (poppels and comp) and what the PF of that load is and I'll opine further.  Also, how far away from the target was the front of your comp?

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