KKM barrel quality over stock

[chauncey]

I shoot a G29 in IDPA and at times have shot a G20 in 3gun. I have a significant amount of factory and reloaded rounds through two G29's.

 

I shoot a G30 in GSSF and (now) only occasionally in IDPA. I previously shot a G30 almost exclusively, in IDPA. I shoot a G41 in 3gun. I have a significant amount of factory and reloaded rounds through two G30's.

 

All my 10mm and 45acp Glocks are Gen 4 guns.

 

My daughter shoots a Gen5 G17 in IDPA, 3gun and GSSF.

 

I have several Glocks and bought KKM barrels for some of my 10mm and 45acp Glocks. 

 

I have experienced problems with factory loaded, plated bullets tumbling and keyholing out of my 10mm Glocks. I have not experienced these problems in any caliber other than 10mm, or using KKM barrels, or using jacketed bullets.

 

I also experienced problems with factory  10mm brass splitting, with a much higher frequency using OEM barrels but on a limited basis with the KKM barrels. I believe this was a brass problem.

 

I use only KKM barrels with factory or reloaded jacketed bullets in my 10mm Glocks.

 

In my other Glocks I use OEM barrels and jacketed or plated ammunition, with no problems.

 

This is relevant especially because the OP is asking about 40S&W in a G35. 40 and 10 use the same bullets and probably the same barrel ID.

 

YMMV

Edited October 6, 2019 by chauncey

[Merldizzle]

On 9/1/2019 at 7:47 AM, Silverscooby27 said:

They are more accurate.

Agree 100%

[firerain]

if you fit nicely, it will make some difference in accuracy

[GARD72977]

I use KKM barrels becasue I am a lead bullet shooter. I have seen a lot of different twist rates quoted by people using KKM barrels. Best I can tell mine is  1 in 16.

 

First off there is no lead to soft for pistol velocities in the 125 PF.

 

This twist is not going to shoot 147gr bullets with the best accurracy. 

 

It preforms best in the 130 and lighter bullets. Lead is less forgiving than jacketed with twist rate.

 

I use a throating reamer and shoot .357 diameter bullets. 

 

Just some of my reasons for using a KKM barrel. If I were shooting Jacketed I would not spend the money.

 

 

 

[bigtimelarry]

1 hour ago, GARD72977 said:

I use KKM barrels becasue I am a lead bullet shooter. I have seen a lot of different twist rates quoted by people using KKM barrels. Best I can tell mine is  1 in 16.

 

First off there is no lead to soft for pistol velocities in the 125 PF.

 

This twist is not going to shoot 147gr bullets with the best accurracy. 

 

It preforms best in the 130 and lighter bullets. Lead is less forgiving than jacketed with twist rate.

 

I use a throating reamer and shoot .357 diameter bullets. 

 

Just some of my reasons for using a KKM barrel. If I were shooting Jacketed I would not spend the money.

 

 

 

 

Yep..

[Yondering]

On 11/8/2019 at 12:03 PM, GARD72977 said:

I use KKM barrels becasue I am a lead bullet shooter. I have seen a lot of different twist rates quoted by people using KKM barrels. Best I can tell mine is  1 in 16.

 

First off there is no lead to soft for pistol velocities in the 125 PF.

 

This twist is not going to shoot 147gr bullets with the best accurracy. 

 

It preforms best in the 130 and lighter bullets. Lead is less forgiving than jacketed with twist rate.

 

I use a throating reamer and shoot .357 diameter bullets. 

 

Just some of my reasons for using a KKM barrel. If I were shooting Jacketed I would not spend the money.

 

There's a lot of misleading info in that post. I hate to see someone misled by stuff like this.

 

- you do NOT need to buy an aftermarket barrel to shoot lead in a Glock. Choose bullets that fit the bore, and avoid soft swaged bullets, and the Glock barrels are just as good as any aftermarket barrel and better than most. 

 

- There is definitely such thing as "too soft" with lead bullets for 125 PF, both in Glock and aftermarket barrels. 10-12 BHN is fine but softer than that gives up accuracy in 9mm even in very light loads. Commercial swaged lead bullets are typically 5-6 Bhn, being made from nearly pure lead, avoid that stuff. Most commercial cast bullets are in the 18+ Bhn range for reference, while a lot of us bullet casters go with 10-12 or so. 

 

- 1:16 twist is plenty for 147gr bullets, and MUCH heavier than that. I even use it with 180gr bullets in 9mm subsonic loads. If anything it's actually a bit fast for the lighter 9mm bullet weights. 

[GARD72977]

On 11/9/2019 at 10:57 PM, Yondering said:

 

There's a lot of misleading info in that post. I hate to see someone misled by stuff like this.

 

- you do NOT need to buy an aftermarket barrel to shoot lead in a Glock. Choose bullets that fit the bore, and avoid soft swaged bullets, and the Glock barrels are just as good as any aftermarket barrel and better than most. 

 

- There is definitely such thing as "too soft" with lead bullets for 125 PF, both in Glock and aftermarket barrels. 10-12 BHN is fine but softer than that gives up accuracy in 9mm even in very light loads. Commercial swaged lead bullets are typically 5-6 Bhn, being made from nearly pure lead, avoid that stuff. Most commercial cast bullets are in the 18+ Bhn range for reference, while a lot of us bullet casters go with 10-12 or so. 

 

- 1:16 twist is plenty for 147gr bullets, and MUCH heavier than that. I even use it with 180gr bullets in 9mm subsonic loads. If anything it's actually a bit fast for the lighter 9mm bullet weights. 

 

I stand by my post.

 

You are confusing a problem with poor lube carrying ability of swaged bullets with lead hardness. I have cast plenty of bullets from stick on wheel weights. Leading is not a problem and accurracy is no different than harder bullets. Traditional lube works fine and powder coated will take these soft bullets even higher in velocity. The lack of sufficient lube is the problem with swaged.

 

As far as twist goes 1 in 16 is to slow for best accurracy with most 147gr bullets.

I have a custom set of molds for my Ballisticast. They are very short 147gr bullets. These shoot great in 1 in 16. Most people will have access to the Magma 147gr style that is much longer. This style starts to suffer at 25yds.

 

My 147 great requires the barrel to be throated to get proper OAL.

 

http://imgur.com/a/39PZxWP

 

 

 

 

 

 

 

[RangerTrace]

On 8/31/2019 at 7:34 PM, rovpilot337 said:

I will be shooting a Glock 35 in USPSA limited. I was wondering if anyone knows if the KKM barrels are any more accurate than the stock barrels. Just a side note I do not reload and shoot all factory ammo.

Yes.  I didn't read all the posts, but I did this same testing with ZEV, KKM and stock Glock with a G34.  The KKM grouped better than all the others.  Not by much, but it was better.  It locked up tighter on the slide than the other two.

[Yondering]

18 hours ago, GARD72977 said:

 

I stand by my post.

 

You are confusing a problem with poor lube carrying ability of swaged bullets with lead hardness. I have cast plenty of bullets from stick on wheel weights. Leading is not a problem and accurracy is no different than harder bullets. Traditional lube works fine and powder coated will take these soft bullets even higher in velocity. The lack of sufficient lube is the problem with swaged.

 

As far as twist goes 1 in 16 is to slow for best accurracy with most 147gr bullets.

I have a custom set of molds for my Ballisticast. They are very short 147gr bullets. These shoot great in 1 in 16. Most people will have access to the Magma 147gr style that is much longer. This style starts to suffer at 25yds.

 

My 147 great requires the barrel to be throated to get proper OAL.

 

http://imgur.com/a/39PZxWP

 

 

I'm not confusing anything. In fact, your claims about soft bullets and about twist rate are directly related, and neither have anything to do with lube. 

 

Look at the bullet on the left in this picture; this is the problem with bullets that are too soft - the soft alloy doesn't resist the rifling twist forces well enough. This is a mild example that still shot reasonably well and didn't lead, but worse examples can strip the rifling entirely (especially in polygonal bores) and lose accuracy or even tumble. Coated or lubed doesn't matter; it's not a lube problem it's an alloy strength problem. Heavy bullets with shorter engagement surfaces suffer from this more than light bullets. That is the problem with softer bullets, whether cast or swaged. 

 

 

If you use a hard enough alloy (10-12 Bhn is adequate most of the time) 1:16 twist is plenty fast enough for 147 grain bullets and much heavier than that. I use a couple different 1:16 twist rifles to shoot 250gr jacketed and up to 280gr cast bullets at 1,000 fps with better accuracy than you'll ever see from a pistol; the twist rate is not a problem for little 147 gr bullets as long as the bullets actually follow the rifling.

 

I'd like to know where you got the idea that 1:16 twist is too slow for 147gr bullets; it certainly isn't from any of the twist rate formulas or tables, like Greenhill. I think I can guess though - you're using a lead alloy that is too soft for that bullet, and the bullet isn't following the rifling completely so accuracy suffers. Your Ballisticast mold has more engagement surface, which is partly why it works better with your soft alloy. 

 

Use a more normal (harder) alloy, and you'll be able to shoot whatever weight bullet you want from Glock barrels or any other aftermarket barrel you choose. Your use of very soft alloys is the cause of the other things you're saying don't work. 

[GARD72977]

You are getting gas cutting because  bullet undersize. The rifling mark looks good. Where did it slip in the rifling?

 

I gave no advice for Glock factory barrel.

 

You may have an issue trying to push bullets to 124PF with a 1in10. I have none with 1 in 16.

[Yondering]

The gas cutting in the other bullet pictured has nothing to do with the discussion here; that pic was taken for a different discussion of why undersized bullets are bad.

 

I can show many other pictures of soft bullets that slip in the rifling; if you're not recovering and examining bullets maybe you don't realize how badly it happens with your soft bullets. The slip marks are plainly visible and documented in the picture, not sure how else to explain it to you if you can't see that. It's visible on the dark green bullet on the right too. 

 

I said nothing about 1:10 twist or 124 PF. You definitely have rifling slip if your 147gr soft bullets don't stabilize fully in a 1:16 twist; you claim the twist rate is at fault, but it's the soft alloy not holding up to the twist rate. Those of us using harder alloys don't have the same problem. Try it. 

 

Even slower twist rate (1:20 for example) is commonly used in 357 and 38 Special for much heavier bullets, in both rifles and revolvers. You can find many other examples besides the ones I've provided that show a 1:16 twist is more than adequate for 147gr bullets. Your claim about that just doesn't hold water. 

 

And about the Glock barrels - you said you bought an aftermarket barrel because you're a lead bullet shooter. Whether you intended it or not, that's misleading to anyone who believes your implication that you needed an aftermarket barrel to shoot lead. You don't. 

Edited November 16, 2019 by Yondering

[GARD72977]

You posted the picture implying it was relivant to our discussion.

 

357 rifle twist has nothing to do with shooting a pistol bullet subsonic.

 

In done replying to this. I posted what works for me with many years of experience casting bullets for rifle and pistol. If you don't like my advice don't use it.

[Yondering]

36 minutes ago, GARD72977 said:

357 rifle twist has nothing to do with shooting a pistol bullet subsonic.

 

It sure does when we're comparing subsonic loads. A twist rate that handles 280gr bullets at 1000 fps accurately can handle 147gr at whatever speed you want. Or if you're talking about the 1:20 357 & 38 Special - if it works for a 158gr lead SWC at 700 fps, it works for a 147gr. 

 

You are not the only one here with many years of casting bullets. I replied because you gave bad information that is misleading to anyone who might believe you. Use hard enough bullets, and everything else you said or implied was a problem just works fine - the twist rate, Glock barrels, etc. 

 

It sounds to me that your determination to use really soft alloys has led you to flawed conclusions about other things, hence this discussion. 

Edited November 16, 2019 by Yondering

[jessesmith121]

I probably didn't need to buy a new barrel.  I bought an old LE trade in blaster.  I just wanted to make sure that everything was new.  The cost of the gun was so low that I wasn't bothered by the piece of mind with having a new barrel.  

 

That being said, I have tried both and my KKM is more accurate but is also brand new VS 15 years old beat up LE gun.  Not in my opinion by an amount that would make a huge difference in the USPSA game.  Like I said it was just for a piece of mind part for me.   

 

If building a budget blaster and your bullets are not keyholing just send it... 

[Bfrisk72]

OEM barrels perform well in USPSA, and in my opinion the newer Gen5 barrels being some of the most accurate from the glocks I've shot/owned.  I do have a few aftermarket barrels (KKM, Double Diamond, Lonewolf) however their increase in accuracy results more from the fitting process to my slide than simply a drop in replacement for an OEM.

 

If were to recommend a barrel change, I would suggest a Bar-Sto or similar barrel that is intentionally oversized specifically for fitting.

[rooster]

I have gone through 2s3f, 3 Barsto, and 2 KKM‘s. For me they were all no better than oem. I decided to try one more time after reading how barrels were made. I read where button rifling was the preferred method of rifling match grade rifle barrels. Of all the barrel making companies only KKM and a new kid on the block rifled barrels using this method. KKM does 1in16 twist, Faxon a maker of AR barrels does the traditional 1in10. Their barrels are also salt bath nitrided. I bought one and I can tell you straight out that it is more accurate than stock. Another plus is it’s as reliable as stock. I have over 3k through it and not one failure. The only negative that I have come across is the chamber is real short. The longest bullet so far has been the Blue Bullet TC. I can load that out to 1.115, everything else is around 1.085, to 1.070. I say for most shooters stay with stock until you are sure that you should move on to a aftermarket barrel. Inside of 15 yards the stock barrel will be fine. From 15 on out is where the aftermarket market will start to out do stock.

[Reinholt]

Great topic and lively discussion here.  Little late to the party but I am also looking for a barrel for my G34 (gen 3).  I acquired G34 slide comp'd and ready to go.  Plan to dress it back to production.  Have to buy a barrel.  My CO G34 (gen 4) loves 115gr FMJ  but hates 125gr lead .355 dia.  Want something that will shoot all the ammo I have.  Just getting back into the game with both kids in out of state college so price is a factor but I want some accuracy.  Plenty of trigger time here, I'm a high master in NRA Action Pistol.  Glock gets me in the game for now, 2011 once the kids are out of college.