Can someone with a Hahn block tell me the height from the top of the block to the top of the feed ramp on the front of the ramp?

I have a dedicated 9mm lower from Black Creek Precision that is .300" while my Hahn block is only .225" which seems to be causing me problems with HP ammo as it doesn't make it into the barrel without deforming the HP.

I have a Hahn dedicated magwell in an Anderson lower. I’m just confused on where you need it measured?

I will be able to post measurements tomorrow once I figure out where you need them from.

Between the two lines please.

The top of the body of the block (the top of the lower) to the center of the ramp.

Attached File

Getting JHP ammo to feed in a Colt system is problematic.... a barrel chamber face mod by Macon Armory is about your only attempt at getting satisfactory feeding results.

I have a stock 6450 and a Colt 10.5” upper with Hahn block and Neither feeds jhp reliably

H

Got it, will post measurements tomorrow

Good to know.


My QC10 barrel on the same lower with the Hahn block doesn't so much as nick the XTP in my testing so it can be done it appears.

I did cave and ordered 8.5" and 10.5" barrels from Macon Armory today so we'll see how they work.

If nothing else I guess I'll switch lowers around.

Thanks!

My measurements are 0.225in

The same as yours, on a personal note I have never tried HP ammo through the gun.

Okay.  Thanks for the confirmation!

Hopefully the Macon Armory barrel will work as well as my QC10 barrel does with JHP.

I did go out and shoot my 9mm AR pistol today with Federal made Expanding FMJ loads and experienced one failure to feed, the EFMJ is kinda like a 9mm wad cutter. So ya no hollow points for me

Good to know....thanks for checking!

Maybe I'm just expecting too much and was just spoiled that the QC10 barrel eats anything.

No problem, and my barrel is a Faxon 10.5ish inch barrel I think. I’m starting to think that this is an issue with the platform

Yeah it could be a platform issue as a whole.

The QC10 barrel was my first exposure with HP's so I guess I just ASSumed that they should work.

I'm still going to sell the BA barrel though as they said they only guarantee it to feed FMJ  (which isn't stated anywhere on the product page) and won't take it back since I installed it into an upper (it has to be in new and unused condition).  Overall, they were kind of jerks about it...oh well.  I just know not to buy anything from them again.

That’s shitty, I have had good luck with them. Damn that really dampens my view of them. Sorry about that

I have the BA 8.3" 9mm barrel and it eats anything, but I am using Endomags and a standard lower.

The Macon Armory "guaranteed to feed" feed cone should fix you right up.  Both my AR9 ( 1 Colt/KAK adapter, 1 Glock ) have the modification and feed all ammo including 147 HST without issues.  Worth every penny.

That's my hope.  They'll be here on Monday.

Went shooting yesterday with my Macon modified barrel on a CMMG mark 9 lower............gobbles up everything!

I've got a couple Colt style mag. lowers.

One is using a Spikes dedicated 9MM lower and PSA upper.  No issues with hollow points.  Not 115 grain anyway.  My reloads (same load I carry/shoot in my CZ pistols.)  115 grain Precision Delta or Everglades (different profiles) feed perfectly, so far.

The second is an Anderson lower with a 9MM mag. adaptor in the mag. well.  Again, no issues with the 115 grain hollow points.

The Spikes lower and one other PSA lower I know of (also a dedicated 9MM lower) had to have the bullet guide/ramp up front modified in order to get the upper/lower to close with the bolt installed.  I modified the feed ramps on both to get the receivers to close/clear the bolts and both worked fine afterwards (no idea about hollow points in PSA upper/lower pistol).

On the two I modified I also polished the metal mirror smooth/shiny.

Can't tell you how much they were lowered.  The picture isn't so good as I think the polished area was throwing off the focus/distance it was so bright/reflective compared to the rest.  Gives you an idea for how wide it was vs. the receiver.



This was the Spikes lower, not the standard AR15 lower with the mag. block in it.

Maybe I've just been lucky with mine feeding, but I've not tried 124 grain or 147 grain hollow points.