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Bullet tip impact on barrel feed ramp vs feeding quality


CHA-LEE
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Over the years I have gotten a lot of questions from shooters struggling to improving the feeding reliability of their semi-auto pistols. My experience on this topic is primarily based on the 1911/2011 platform but the same basic strategy applies to every other type of pistol I have owned. I also want to point out that every gun I have owned, even within the same platform, has required tuning of the ammo, mags, or feed ramp depth/angle to produce the proper impact point on the feed ramp. Simply put, there isn’t a magical one solution works for every gun setup. YES, you have to put in the tuning effort to optimize the feeding on EVERY gun you own.

 

Before you start making changes to your ammo or barrel feed ramp the first thing that you need to standardize are the magazines. I have lost count of how many times a shooter has random feeding problems and they have an inconsistent mixture of magazines brands, springs, followers or whatever. You need to pick ONE brand and vintage of magazines and ONLY use that set of magazines. Every magazine manufacture makes them slightly different than the next manufacture and each type of magazine usually requires a unique ammo setup to function reliably. Even when you have the same brand and vintage of magazines but they have all been “Tuned” by different people/companies can cause issues. Purchase an identical set of magazines that are all “Tuned” exactly the same. Magazine springs and followers don’t last forever. Proactively replace the springs and followers at least a couple times a year to ensure reliable functionality. Lastly you need to maintain the magazines regularly by chemically cleaning the tubes and followers to ensure friction free function. Most importantly, you need to religiously verify and maintain a consistent feed lip width. In my experience the optimal 40 caliber feed lip width is 0.385” and 9mm is 0.345”. This feed lip width produces a very even case wall engagement from front to back between the feed lips and the sidewall of the case. You want the feed lips engaging the sidewall of the case fully from front to back with no gaps. A general rule of thumb that I like to use is that the pointing angle of the case should match the angle of the feed lips. The front to back feed lip width will determine the “Pointing” angle of the case. Optimally the feed lip width should be the same from front to back. To generate this even feed lip to case engagement also means that the case wall needs to be fairly straight. If your brass is bulged or excessively undersized then it will produce an uneven feed lip engagement on the sidewall of the case and it will dramatically change the tipping angle of the bullet as it is stripped out of the magazine during feeding.

 

After every match, practice, or range session I will fully disassemble every magazine used to clean, inspect, tune, or replace whatever is needed then reassemble the magazine. This is done to ensure they are good to go the next time I use them. I have successfully resolved many shooters inconsistent feeding issues simply by mandating that they standardize on one brand of magazine and proactively maintain them on a much more frequent basis. The magazines are the foundation of reliable feeding. If your mags are all screwed up then it’s a waste of time to try to change other things to solve the issue. Also accept the fact that magazines don’t last forever and eventually you will need to replace them. YES, magazines don’t last forever and you need to throw them away when they stop functioning reliably.

 

The best “tool” to use in order to gauge the quality of feeding in your pistol is observing where on the barrel feed ramp the tip of the bullet impacts. This can easily be done by looking at the swipe mark on the feed ramp after you shoot a few hundred rounds. The picture shown below is from my Atlas Titan Limited gun in 40 caliber after a 400 round practice session while using four different magazines. You can see that the swipe mark is about three quarters the way up from the bottom of the feed ramp and in a fairly small circular pattern. This is what it should look like when the ammo Overall Length, magazine feed lip width, and brass cases are all setup properly.

 

146433039_AtlasBarrelFeedRamp.thumb.jpg.574450e20c6602554cafe633fa49a84e.jpg

 

You can achieve the same swipe mark evidence by shooting only 10 – 20 rounds if you clean off the barrel feed ramp then use a black sharpie marker to black out the feed ramp. The tip of the bullets will scrape off the black marker wherever it hits. This is actually the best method to start off with when you are trying to figure out what the optimal ammo overall length should be.

 

The up/down/left/right impact point or the average size of the circle on the feed ramp tells you which aspect of the gun, mag, ammo configuration is having issues. It’s easiest to explain this one axis of impact at a time.

 

A consistent vertical displacement of the impact point is directly related to the depth of the barrel feed ramp, ammo overall length and magazine feed lip width. As mentioned at the start of this topic, we want all the magazine feed lips setup identical to one another with the case wall even with the angle of the feed lips. So changing the feed lip width shouldn’t be the primary tuning item. The primary tuning item to change the vertical impact point is the Overall Length of the ammo. Lengthening the ammo will raise the impact point and shortening the ammo will lower the impact point. Also keep in mind that the bullet tip profile also has a major effect on the impact point. For example, if you setup the OAL initially with round nose bullets then switch to flat point or hollow point bullets, then the impact point is going to be lower with the flat/hollow point bullets. Just as we need to stick to the same brand and vintage of magazines, you also need to stick to the same brand and type of bullets. The final factor to consider here is that since every gun is slightly different you will likely need to do additional tuning on a different pistol when using the same ammo. A good example of this is having a primary and backup gun. You want the same ammo to produce the same vertical impact point across both guns. The best plan of attack in this scenario is to setup the ammo OAL on whichever gun has the deepest feed ramp. Then modify the feed ramp on the other gun to match the first. Its easy to take away material from a feed ramp. It’s much more work to weld and recut a feed ramp to add more material. Modifying the depth of the barrel feed ramp may be beyond the skill set of most shooters. If you don’t feel comfortable with doing it get it to a qualified gunsmith to do it for you. Keep in mind that the optimal ammo OAL for feeding may also produce a length of ammo that is too long compared to the throating depth of the rifling. The top priority for OAL in a semi auto pistol is to produce reliable feeding by impacting the feed ramp in the correct location. Rifling Throat Depth should be changed to whatever is needed to work with the optimal feeding OAL. I have seen it happen quite often when a barrel has a really shallow rifling throat and the shooter uses that as the OAL limit then battles endless feeding issues because the ammo is too short to feed reliably. If the barrel throating needs to be increased to function with a longer OAL then increase it by getting the barrel reamed.

 

A consistent horizontal displacement of the impact point is directly related to how the magazine is retained within the grip or the overall left/right pointing angle of the feed lips. I have seen feed lips setup to the correct width, but they are biased to the left or right causing a horizontally displaced impact point on the feed ramp. You need to readjust the left/right pointing angle of the feed lips while also maintaining the correct width. The width of the magazine where the mag catch engages may also be inconsistent causing the whole magazine to be biased to one side causing the consistent horizontal displacement of the bullet impact.

 

An inconsistent bullet impact circle spot on the feed ramp while using the same magazine is usually a feed lip width issue, or a brass case straightness issue. This could also be caused by worn out magazine springs or follower. Once again, the assumption here is that the magazines are being maintained properly to start off with. If you have a consistent bullet impact circle size but the circle is displaced on the feed ramp from one magazine to the next, then you have a magazine feed lip width or pointing direction issue. In an optimal setup all of the magazines should produce the same size and location of the bullet impact circle on the feed ramp.

 

Lastly, I also want to point out that the extractor engagement depth and tension also have a major impact on reliable feeding. Your Extractor MUST be setup properly to ensure proper feeding and extraction. There are already a bunch of threads on this forum that cover the proper extractor tuning to promote reliably feeding and extraction for a wide range of different guns or brands of extractors. The search function on this forum is your friend when looking for that information. The reason why I put this extractor tuning requirement last is that even though tuning the extractor properly is a requirement, that effort needs to happen AFTER the proper OAL, mag feed lip, and ammo case straightness tuning has been done. Basically put, if the ammo can’t get stripped out of the magazine and climb the feed ramp effectively, then it really doesn’t matter how the extractor is tuned because it’s going to cause jams anyway before the rim of the case even has the opportunity to get under the extractor hook. Too many shooters focus on tuning the extractor in an attempt to improve feeding when the root cause of the issue is due to the wrong OAL, or poor magazine maintenance issues.

 

Hopefully this information helps in resolving peoples ammo feeding issues. Let me know if you have any questions.

Edited by CHA-LEE
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4 minutes ago, Silent said:

Wow! I’d never even considered half the stuff you mentioned. Thanks for taking the time to write it up. 
 

What do you mean by “chemically” cleaning the magazine? 

 

Spraying the tube and follower with a chemical cleaner that breaks down and removes the burnt powder and whatever else gets inside of the tube. I like to use CRC QD Electronic Cleaner because it works great on breaking down burnt powder residue while also being plastic safe. You can find this CRC QD Electronic Cleaner at most Walmart's and auto parts stores. Or order it online as referenced below. I have no affiliation with the Amazon link or seller listed below. I am only listing it as an example reference of the cleaner I use. I usually just buy this cleaner at a local Walmart as its convenient to do so.

 

https://www.amazon.com/CRC-05103-Electronic-Cleaner-11/dp/B000BXOGNI/ref=sr_1_2?crid=1B3P6TZLTON00&dchild=1&keywords=crc+electronic+cleaner&qid=1583258952&sprefix=CRC%2Caps%2C175&sr=8-2

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15 minutes ago, CHA-LEE said:

 

Spraying the tube and follower with a chemical cleaner that breaks down and removes the burnt powder and whatever else gets inside of the tube. I like to use CRC QD Electronic Cleaner because it works great on breaking down burnt powder residue while also being plastic safe. You can find this CRC QD Electronic Cleaner at most Walmart's and auto parts stores. Or order it online as referenced below. I have no affiliation with the Amazon link or seller listed below. I am only listing it as an example reference of the cleaner I use. I usually just buy this cleaner at a local Walmart as its convenient to do so.

 

https://www.amazon.com/CRC-05103-Electronic-Cleaner-11/dp/B000BXOGNI/ref=sr_1_2?crid=1B3P6TZLTON00&dchild=1&keywords=crc+electronic+cleaner&qid=1583258952&sprefix=CRC%2Caps%2C175&sr=8-2

Got it thank you. I will pick some of that up and give it a try

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1 hour ago, yigal said:

Thanks so much for the article. The angle of your atlas ramp is correct 31 deg. What to do when the manufacturer uses a 21 deg. angle. Only good polish on feed ramp  remains and mags tuning?

 

If the feed ramp angle is too steep, but its still biased forward, I will grind it to a less steep angle. As mentioned before, you can weld material onto the feed ramp then recut it to whatever angle you need. This will retain the fully supported case within the chamber while having an improved feed ramp angle. But the cost, tools needed and time invested in doing the Weld/Recut is likely the same or more than just swapping the barrel with another brand that already has the feed ramp at the correct angle and depth. The age old advice of "A turd is still a turd even if you polish it" applies. Using the correct parts up front makes your life a lot easier vs trying to force the wrong parts to work. I prefer KKM barrels because they come with the feed ramp at an optimized angle and they are also far back enough to adjust the depth of the ramp if you need to. That and KKM supports the shooting sports by sponsoring many matches all across the nation. I choose to patron the vendors that support the shooting sports.  

Edited by CHA-LEE
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  • 2 months later...
On 3/3/2020 at 2:59 PM, CHA-LEE said:

 I prefer KKM barrels because they come with the feed ramp at an optimized angle and they are also far back enough to adjust the depth of the ramp if you need to.

An outstanding post CHA-LEE!

 

A couple of months ago I ran across an old, nasty Springfield 9mm ramped barrel in my parts drawer and being a little bored decided to fit it to a 9x23 pistol so I could have a "swap-barrel" pistol.  During the process I changed the angle of the barrel's ramp which got me to wondering what angle various barrel makers used for their 9mm ramped barrels.

 

So I contacted several and this is what I was told:

  • KKM - 25 degrees
  • Kart - 26 degrees
  • Nighthawk - 30 degrees

I believe I'll be trying a Nighthawk barrel for future projects.

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  • 9 months later...
On 3/3/2020 at 10:54 AM, CHA-LEE said:

Over the years I have gotten a lot of questions from shooters struggling to improving the feeding reliability of their semi-auto pistols. My experience on this topic is primarily based on the 1911/2011 platform but the same basic strategy applies to every other type of pistol I have owned. I also want to point out that every gun I have owned, even within the same platform, has required tuning of the ammo, mags, or feed ramp depth/angle to produce the proper impact point on the feed ramp. Simply put, there isn’t a magical one solution works for every gun setup. YES, you have to put in the tuning effort to optimize the feeding on EVERY gun you own.

 

Before you start making changes to your ammo or barrel feed ramp the first thing that you need to standardize are the magazines. I have lost count of how many times a shooter has random feeding problems and they have an inconsistent mixture of magazines brands, springs, followers or whatever. You need to pick ONE brand and vintage of magazines and ONLY use that set of magazines. Every magazine manufacture makes them slightly different than the next manufacture and each type of magazine usually requires a unique ammo setup to function reliably. Even when you have the same brand and vintage of magazines but they have all been “Tuned” by different people/companies can cause issues. Purchase an identical set of magazines that are all “Tuned” exactly the same. Magazine springs and followers don’t last forever. Proactively replace the springs and followers at least a couple times a year to ensure reliable functionality. Lastly you need to maintain the magazines regularly by chemically cleaning the tubes and followers to ensure friction free function. Most importantly, you need to religiously verify and maintain a consistent feed lip width. In my experience the optimal 40 caliber feed lip width is 0.385” and 9mm is 0.345”. This feed lip width produces a very even case wall engagement from front to back between the feed lips and the sidewall of the case. You want the feed lips engaging the sidewall of the case fully from front to back with no gaps. A general rule of thumb that I like to use is that the pointing angle of the case should match the angle of the feed lips. The front to back feed lip width will determine the “Pointing” angle of the case. Optimally the feed lip width should be the same from front to back. To generate this even feed lip to case engagement also means that the case wall needs to be fairly straight. If your brass is bulged or excessively undersized then it will produce an uneven feed lip engagement on the sidewall of the case and it will dramatically change the tipping angle of the bullet as it is stripped out of the magazine during feeding.

 

After every match, practice, or range session I will fully disassemble every magazine used to clean, inspect, tune, or replace whatever is needed then reassemble the magazine. This is done to ensure they are good to go the next time I use them. I have successfully resolved many shooters inconsistent feeding issues simply by mandating that they standardize on one brand of magazine and proactively maintain them on a much more frequent basis. The magazines are the foundation of reliable feeding. If your mags are all screwed up then it’s a waste of time to try to change other things to solve the issue. Also accept the fact that magazines don’t last forever and eventually you will need to replace them. YES, magazines don’t last forever and you need to throw them away when they stop functioning reliably.

 

The best “tool” to use in order to gauge the quality of feeding in your pistol is observing where on the barrel feed ramp the tip of the bullet impacts. This can easily be done by looking at the swipe mark on the feed ramp after you shoot a few hundred rounds. The picture shown below is from my Atlas Titan Limited gun in 40 caliber after a 400 round practice session while using four different magazines. You can see that the swipe mark is about three quarters the way up from the bottom of the feed ramp and in a fairly small circular pattern. This is what it should look like when the ammo Overall Length, magazine feed lip width, and brass cases are all setup properly.

 

146433039_AtlasBarrelFeedRamp.thumb.jpg.574450e20c6602554cafe633fa49a84e.jpg

 

You can achieve the same swipe mark evidence by shooting only 10 – 20 rounds if you clean off the barrel feed ramp then use a black sharpie marker to black out the feed ramp. The tip of the bullets will scrape off the black marker wherever it hits. This is actually the best method to start off with when you are trying to figure out what the optimal ammo overall length should be.

 

The up/down/left/right impact point or the average size of the circle on the feed ramp tells you which aspect of the gun, mag, ammo configuration is having issues. It’s easiest to explain this one axis of impact at a time.

 

A consistent vertical displacement of the impact point is directly related to the depth of the barrel feed ramp, ammo overall length and magazine feed lip width. As mentioned at the start of this topic, we want all the magazine feed lips setup identical to one another with the case wall even with the angle of the feed lips. So changing the feed lip width shouldn’t be the primary tuning item. The primary tuning item to change the vertical impact point is the Overall Length of the ammo. Lengthening the ammo will raise the impact point and shortening the ammo will lower the impact point. Also keep in mind that the bullet tip profile also has a major effect on the impact point. For example, if you setup the OAL initially with round nose bullets then switch to flat point or hollow point bullets, then the impact point is going to be lower with the flat/hollow point bullets. Just as we need to stick to the same brand and vintage of magazines, you also need to stick to the same brand and type of bullets. The final factor to consider here is that since every gun is slightly different you will likely need to do additional tuning on a different pistol when using the same ammo. A good example of this is having a primary and backup gun. You want the same ammo to produce the same vertical impact point across both guns. The best plan of attack in this scenario is to setup the ammo OAL on whichever gun has the deepest feed ramp. Then modify the feed ramp on the other gun to match the first. Its easy to take away material from a feed ramp. It’s much more work to weld and recut a feed ramp to add more material. Modifying the depth of the barrel feed ramp may be beyond the skill set of most shooters. If you don’t feel comfortable with doing it get it to a qualified gunsmith to do it for you. Keep in mind that the optimal ammo OAL for feeding may also produce a length of ammo that is too long compared to the throating depth of the rifling. The top priority for OAL in a semi auto pistol is to produce reliable feeding by impacting the feed ramp in the correct location. Rifling Throat Depth should be changed to whatever is needed to work with the optimal feeding OAL. I have seen it happen quite often when a barrel has a really shallow rifling throat and the shooter uses that as the OAL limit then battles endless feeding issues because the ammo is too short to feed reliably. If the barrel throating needs to be increased to function with a longer OAL then increase it by getting the barrel reamed.

 

A consistent horizontal displacement of the impact point is directly related to how the magazine is retained within the grip or the overall left/right pointing angle of the feed lips. I have seen feed lips setup to the correct width, but they are biased to the left or right causing a horizontally displaced impact point on the feed ramp. You need to readjust the left/right pointing angle of the feed lips while also maintaining the correct width. The width of the magazine where the mag catch engages may also be inconsistent causing the whole magazine to be biased to one side causing the consistent horizontal displacement of the bullet impact.

 

An inconsistent bullet impact circle spot on the feed ramp while using the same magazine is usually a feed lip width issue, or a brass case straightness issue. This could also be caused by worn out magazine springs or follower. Once again, the assumption here is that the magazines are being maintained properly to start off with. If you have a consistent bullet impact circle size but the circle is displaced on the feed ramp from one magazine to the next, then you have a magazine feed lip width or pointing direction issue. In an optimal setup all of the magazines should produce the same size and location of the bullet impact circle on the feed ramp.

 

Lastly, I also want to point out that the extractor engagement depth and tension also have a major impact on reliable feeding. Your Extractor MUST be setup properly to ensure proper feeding and extraction. There are already a bunch of threads on this forum that cover the proper extractor tuning to promote reliably feeding and extraction for a wide range of different guns or brands of extractors. The search function on this forum is your friend when looking for that information. The reason why I put this extractor tuning requirement last is that even though tuning the extractor properly is a requirement, that effort needs to happen AFTER the proper OAL, mag feed lip, and ammo case straightness tuning has been done. Basically put, if the ammo can’t get stripped out of the magazine and climb the feed ramp effectively, then it really doesn’t matter how the extractor is tuned because it’s going to cause jams anyway before the rim of the case even has the opportunity to get under the extractor hook. Too many shooters focus on tuning the extractor in an attempt to improve feeding when the root cause of the issue is due to the wrong OAL, or poor magazine maintenance issues.

 

Hopefully this information helps in resolving peoples ammo feeding issues. Let me know if you have any questions.

 

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On 3/4/2020 at 11:00 AM, MisterCoffee said:

Outstanding write-up, CHA-LEE. Very carefully thought-out. Thanks. 

Absolutely. Great write up. As one that has has feeding issues in the past, this was refreshing.

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  • 4 months later...

There is a lot of great info here, but, I must say it sort of makes me glad I’m shooting a Glock. It may be a bit more forgiving. But, I’ll also say that as I get ready to load a new bullet I haven’t used before, I will reread this info and learn from your experience. I only use OEM Glock mags, and I know there is variance there too. But there is a lot of other great info I should have been doing right along. 
 

Thanks. 

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One more thing is you can also get different-height mag catches for some guns that hold the mags slightly higher or lower than stock which will change how rounds feed as well.

 

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So after reading this and tuning the heck out of 8 STI mags I just couldn't get them to feed reliable in my new 2011 with the LSI grip. Tried my one 40 cal MBX and it was perfect! I am not much more confused then I was before. Not mad though i just ordered 5 more MBX mags. But I dont get how 8 sti mags didnt work and MBX ran 100%.

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Apply pressure to the base pad, then cycle slide.  If it works, it's the mag release or the position in the frame.

 

edit: if the mag is too low in the frame, the bullet transition will be held back by the mag lips.

Edited by 38super
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Charlie, sounds like you're not using a mill to recut the feed ramp.. If you would, elaborate on the methods, tooling and other equipment that you use.. I understand this is not for the faint of heart and one risks sacrificing a  barrel if done incorrectly. Would really like to know what you have settled on to do this..  Thanks so much for your time!

 

Great article, very informative.

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On 8/2/2021 at 7:57 AM, Pat B. said:

Charlie, sounds like you're not using a mill to recut the feed ramp.. If you would, elaborate on the methods, tooling and other equipment that you use.. I understand this is not for the faint of heart and one risks sacrificing a  barrel if done incorrectly. Would really like to know what you have settled on to do this..  Thanks so much for your time!

 

Great article, very informative.

I free hand the barrel feed ramp angle/depth change using a dremel with stone and polishing bits. If you wanted a super precise angle/depth change then yes, doing it in a Mill would be your best resource. Like I said in my initial post, if you are not comfortable or confident in making a barrel feed ramp change yourself then have a qualified gunsmith do it. The good thing is that the vast majority of the time you DON'T need to change the barrel feed ramp angle/depth to solve feeding issues. That should only be done when you have exhausted all of the other suggestions I provided in Ammo/Mag tuning.

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