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Discussion Starter #1
Looking for some advice. I've got a NH frame with an Ed Brown RMR slide that I'm working on. Last weekend I got the slide on to the frame, it came out pretty well, within .0025" difference. Noticeably more tighter than my Remsport slide on the PSA frame. Moving on to the barrel fitting, also an EB, I noticed that the barrel bed on the frame seems too long, long enough that there is a pretty good gap between the barrel ramp and the frame feed ramp.

Here is a comparison of the barrel beds on a PSA frame (left) and the NH frame (on the right)

Barrel Bed 3.jpg


When I lay the barrel in the bed of the NH frame the space is much bigger than .030"
Barrel Bed 1.jpg


Compared to the PSA frame, which appears to be about .30" , tested and feeds fine
Barrel Bed 2.jpg


I took various measurements in comparison to the tech drawings I have. They appear correct. Such as the SS to VIS = .431".

The VIS on the NH frame is .304" long and on the PSA frame .271" long.

Is this a nothing burger, or will I have an issue with feeding with this NH frame? I looked over the JK books and he did mention cutting down the back of the lower lugs but I'm not too keen on that idea, unless that is the answer.

TIA
 

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In my experience the gap can be greater than 0.30" with no ill effects but it cannot be less.

The absolute minimum length of the barrel bed is 0.246". The ideal frame ramp angle is 31.5 degrees and the ideal ramp depth from the top of the rails is 0.400" but could be less to allow for the correct ramp angle and sufficient barrel bed length.
 

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Just a disclaimer I am no gunsmith but have been in your shoes. And was curious with the pin in how does the barrel interact With the vis and bed? My psa frame was the same as yours. And had the same issue with a foster frame.
 

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Discussion Starter #4
Cool, Thanks Steve! I knew the gap shouldn't be smaller, but I was concerned with the max gap, and everything I looked at was a little vague.

I'm going slow on this build, it's a little more challenging then the PSA frame. I appreciate your feedback!
 

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Discussion Starter #5
Just a disclaimer I am no gunsmith but have been in your shoes. And was curious with the pin in how does the barrel interact With the vis and bed? My psa frame was the same as yours. And had the same issue with a foster frame.
I'm a little confused, are you saying that you saw a larger gap on your Foster frame between the barrel and the frame's feed lamp, like on my Nighthawk frame shown above? And that your psa frame had the minimum gap like on my psa photo shown above?

On my PSA frame build, if I placed the barrel on the bed the minimum gap to the frame's feed ramp was .030". On my NH frame this gap was wider, so it was about .060".

On my psa frame, with the complete slide installed on the frame, with the slide back (out of battery) the barrel lines up very nicely with the .030" gap to the feed ramp. I used a sharpie to mark up the ss pin, lower lug area where the ss pin "should" contact it, and the vis. After I test fired I tore it down and saw that I had contact on the vis from the area where the lower lug "meets" the barrel, and contact on the lower lug area where the ss pin "sits" on the lug. And there were two even spaced marks at the 2 o'clock position on the top of the ss pin. So, on my psa build I'd say the pin, barrel, both upper and lower lugs are all interacting like they're supposed to.

I've only got the slide to the frame fit complete on the NH build. Next is getting the upper lug engagement, which is close, and then the lower lugs/ss pin, etc.
 

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Dremel jockey
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Let's see a pic of the frames feed ramp.
If your barrel bed length is .300" the feedramp is either VERY shallow or cut on a far too steep angle.
Yes, it might feed ball ammo from 7rd mags, but not hollow points from an 8rd mag.
 

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HS Custom LLC
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Looking for some advice. I've got a NH frame with an Ed Brown RMR slide that I'm working on. Last weekend I got the slide on to the frame, it came out pretty well, within .0025" difference. Noticeably more tighter than my Remsport slide on the PSA frame. Moving on to the barrel fitting, also an EB, I noticed that the barrel bed on the frame seems too long, long enough that there is a pretty good gap between the barrel ramp and the frame feed ramp.

Here is a comparison of the barrel beds on a PSA frame (left) and the NH frame (on the right)

View attachment 395851

When I lay the barrel in the bed of the NH frame the space is much bigger than .030"
View attachment 395861

Compared to the PSA frame, which appears to be about .30" , tested and feeds fine
View attachment 395863

I took various measurements in comparison to the tech drawings I have. They appear correct. Such as the SS to VIS = .431".

The VIS on the NH frame is .304" long and on the PSA frame .271" long.

Is this a nothing burger, or will I have an issue with feeding with this NH frame? I looked over the JK books and he did mention cutting down the back of the lower lugs but I'm not too keen on that idea, unless that is the answer.

TIA
If I recall NHC leaves their bed lengths that long so if the gun is ramped it's where they want it. If it's a non ramped barrel then it needs set up in the mill and moved forward also allowing you to set frame ramp angle and depth to your liking.

Sent from my SM-N950U using Tapatalk
 

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Discussion Starter #9
Let's see a pic of the frames feed ramp.
If your barrel bed length is .300" the feedramp is either VERY shallow or cut on a far too steep angle.
Yes, it might feed ball ammo from 7rd mags, but not hollow points from an 8rd mag.
^^^^
This is assuming it is a 45acp.
Yes, it is 45acp. The NH ramp is shown on my initial post up top. Its the frame o the right, the frame on the left is my psa frame for comparison. Here's another view
20200119_162626.jpg
20200119_162553.jpg
20200119_162450.jpg
20200119_162553.jpg
20200119_162626.jpg
 

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Discussion Starter #11
If I recall NHC leaves their bed lengths that long so if the gun is ramped it's where they want it. If it's a non ramped barrel then it needs set up in the mill and moved forward also allowing you to set frame ramp angle and depth to your liking.

Sent from my SM-N950U using Tapatalk
It’s because Nighthawk cuts there frame ramps at 27 degrees not 31.5 and they feed just fine. Shocking!!!
I'm really new to this, and I understand that each manufacturer produces a different spec with regards to their frames. But I was really looking for someone that either has seen this or built a NH frame.

I'm also really new to this forum, and I have no idea who's who, for lack of a better term. But I figured this would be the place outside of contacting NH to check.

Of course I did send NH an email, so I guess I'll eventually find out what's going on.

Anybody have pics of the frame bed on a NH govt frame 45 with a big ass gap between the barrel and feed ramp?
 

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MP Custom
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Built many guns on nighthawk frames. Nighthawk uses the spec that Bob Marvel shared with them and the Kart barrels fit perfect. I’ve never fit a nighthawk barrel but I bet the bottom rear barrel lug to rear barrel ramp is the same as a Kart barrel. Measure from the back of the bottom lug to the beginning of the feed ramp and see what you have.
 

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MP Custom
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Just pulled a new Kart barrel from the shelf and measured it. Rear of bottom lug to feed ramp is .260”
 

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Discussion Starter #14
Built many guns on nighthawk frames. Nighthawk uses the spec that Bob Marvel shared with them and the Kart barrels fit perfect. I’ve never fit a nighthawk barrel but I bet the bottom rear barrel lug to rear barrel ramp is the same as a Kart barrel. Measure from the back of the bottom lug to the beginning of the feed ramp and see what you have.
Just pulled a new Kart barrel from the shelf and measured it. Rear of bottom lug to feed ramp is .260”
I'm using and Ed.Brown drop in, it measures .249. I have another new EB, it measures .247.

Looks like 10 thou smaller than your kart
 

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Dremel jockey
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I pulled a very recent NH frame from the safe.
Bed length is .300".
Feed ramp depth: .358".
Feed ramp angle: 26 1/2 degrees.

Kart barrel measures .260".

 
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Dremel jockey
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To be honest, I don't know.
I have never tried.
I believe NH knows how to build a gun.
 

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Discussion Starter #18
Thanks pistolwrench! I really appreciate you doing that.

I looked at my first post and realized I made a typo, I stated the VIS was .304, and what I meant to write was the barrel bed was .304" long. It's probably closer to your measurement at .300, I couldn't figure out how to measure it any better.

Well, I'm sure you're right, NH knows what they're doing, just like you. I just happened to notice it and was curious of the implications.

Seriously, thanks again for pulling those dimensions. I'm curious to what NH has to say, I'll update this post when I find out.
 

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I pulled a very recent NH frame from the safe.
Bed length is .300".
Feed ramp depth: .358".
Feed ramp angle: 26 1/2 degrees.

Kart barrel measures .260".

Interesting that NightHawk would not stick to the 31.5 degree angle. I wonder about their reasoning?

Also what’s the likely hood of rounds contacting the frame below the feed ramp?
 

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HS Custom LLC
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It's not that they don't stick to the 31.5. What they've done is left it back so if the build will be ramped it keeps the bottom back portion of the ramped barrel evenish with the frame. Kind of like how you have to dress that portion of the barrel back usually?

Second if the build will be traditional the smith has full control of ramp placement, angle, depth etc. I'd much rather see more to work with instead of salvaging what's there from standard manufacturing on other name brand frames. Of course a guy can always weld and machine but that's not as much fun as it sounds.

Sent from my SM-N950U using Tapatalk
 
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