20 practical AR shoots poor from magazine

[Logbuilder35]

I just built a new 20 practical on an AR platform and it shoots phenomenal loading one round at a time in the chamber but goes south when feeding from magazine any ideas are appreciated,thanks

 

[Mark M.]

Not enough neck tension on your bullets

 

[garandman]

Does feed ramp angle make nose of bullets "slam" into chamber wall ?

 

[Logbuilder35]

Does feed ramp angle make nose of bullets "slam" into chamber wall ?

Not sure but I was thinking it was something like that

 

[garandman]

Not sure but I was thinking it was something like that

One of the accuracy secrets to the Vudoo 22rf rifle is the mag system - the bolt literally "plucks" the top round off the the AICS style mag and direct / straight feeds it into the chamber... without touching the chamber wall.

That and finding the right ammo velocity (via lot testing... ideally they put the velocity on the box / label) makes for a very accurate gun.


Have you tested slow operation of the bolt handle vs. fast, to minimize contact with the chamber wall?

 

[jepp2]

any ideas are appreciated

Measure the COAL/CBTO of a loaded round. Chamber a round, put the measured round as the top round in the magazine and put it in the rifle. Fire the chambered round. Eject the new round in the chamber and compare measurement. Bullet might be moving backwards or forwards during chambering.

 

[Logbuilder35]

Thanks for all the info keep it coming

 

[RussellJ]

I just built a new 20 practical on an AR platform and it shoots phenomenal loading one round at a time in the chamber but goes south when feeding from magazine any ideas are appreciated,thanks

Who is the barrel manufacture? I have a Black Hole Weaponry 20 Practical barrel and when it was blackened at the factory. The process made the chamber tight to the point that the bolt would only practically close(lock up). I ended up lapping the chamber with a 20 Practical case that I drilled and tapped for a long 1/4-20 bolt to use as a handle.

 

[Logbuilder35]

Who is the barrel manufacture? I have a Black Hole Weaponry 20 Practical barrel and when it was blackened at the factory. The process made the chamber tight to the point that the bolt would only practically close(lock up). I ended up lapping the chamber with a 20 Practical case that I drilled and tapped for a long 1/4-20 bolt to use as a handle.

Mueller is the brand of the barrel,I cut the threads and done chamber work,it was my second AR build,I have built several bolt guns with no hitch but this Thing is causing me some head scratching lol

 

[Coyotefurharvester]

I have a BHW 20p barrel on order,raw ss hopefully I will not have to mess with the chamber. I used a diamond file on the barrel extension ramp edge(they were very sharp and marked bullet) on my Shilen 17 rem barrel and adjusted the magazine lips, dropped one mag once would not feed at all.

 

[RussellJ]

I have a BHW 20p barrel on order,raw ss hopefully I will not have to mess with the chamber. I used a diamond file on the barrel extension ramp edge(they were very sharp and marked bullet) on my Shilen 17 rem barrel and adjusted the magazine lips, dropped one mag once would not feed at all.

I should add that I'm extremely happy with the BHW 20 Practical barrel shooting a 40grn V-Max. I also have a buddy that has a BHW 20 Practical and he is also extremely happy as well, he is shooting a 32grn Sierra BiltzKing bullet at 3850fps.

 

[Logbuilder35]

I should add that I'm extremely happy with the BHW 20 Practical barrel shooting a 40grn V-Max. I also have a buddy that has a BHW 20 Practical and he is also extremely happy as well, he is shooting a 32grn Sierra BiltzKing bullet at 3800fps +/-.

What kind of accuracy are you guys getting

 

[RussellJ]

What kind of accuracy are you guys getting

My buddy is at 3850fps with the 32grn Sierra BK bullets 3/4"moa with 24.5grn H4198(he was happy with this load & didn't do much load developing).
I'm getting 1/2"moa with new brass with the 40grn V-Max 3338fps 25.0grn H335 powder CCi-450 primers. Both guns have 20 inch barrels and no over pressure signs.

 

[1lessdog]

I have a 20 inch BHW barrel and it shoots great. I was having a problem with it feeding the first 2 or 3 shells in a 10 rd mag. I started only loading 6 or 7 rds in and no problem after that, It likes the 32 gr V Max bullets. I shoot H335 AND IT SHOOTS GREAT.

 

[Rdlningcltchdmpr]

I just built a new 20 practical on an AR platform and it shoots phenomenal loading one round at a time in the chamber but goes south when feeding from magazine any ideas are appreciated,thanks

Same problem , bullet's are concentric then they get slammed into feed ramp at high speed causing runout and tip damage both.

 

[Logbuilder35]

Same problem , bullet's are concentric then they get slammed into feed ramp at high speed causing runout and tip
Were able to correct the problem

 

[Logbuilder35]

Were you able to correct the problem

 

[simo hayha]

Polish everything that the bullet tip slides on. Will help cut down on damage

Load tight neck and crimp

 

[GrocMax]

The only difference for me is a collet crimp on the AR load vs the bolt rifle load.

 

[Logbuilder35]

The only difference for me is a collet crimp on the AR load vs the bolt rifle load.

Who makes a collet crimp die for 20 practical,thanks for the info