View Full Version : cutting a frame for a wilson/nowlin ramped barrel
October 19, 2006, 07:55 PM
I have a springfield that I am putting a sti trubor barrel on to build a race gun and need specs on cutting the frame. Any help or pics would be appreciated. thanks Rick
October 19, 2006, 08:31 PM
You're wanting to go from a non ramped configuration to ramped barrel, right?
October 20, 2006, 07:16 AM
That is correct. The only info I have is that you take a .375 cutter and cut between the frame rails at a depth of .315 through into the mag well. There has to be more to it. I have a local gunsmith that is a friend of mine but he has never done this before and is depending on me to find the info. Looking through the brownells catalog I saw a bride cutter that you stand the frame vertically, but they have dropped it from their inventory. Thanks Rick
October 20, 2006, 09:35 AM
I assume your local smith does have a mill, this is the only way it can be done accurately.
Also you should ask your local smith if he fully understands barrel timing as this is very crictical especially with the extra weight of the compensator added to the end of the barrel.
Even after the initial two cuts for the ramped barrel are made in most cases the frame will have to go back to the mill to correct the barrel timing.
If your local smith wishes he can call me at the shop next week and I'll be glad to explain the cut and how to do it.
Shop hours are 10:00am to 6:00pm Central time Monday thru Friday.
October 20, 2006, 10:58 AM
Which is why my FLG hates fooling with the blamed things. Fiddle, fiddle, fiddle to get it in right.
October 20, 2006, 12:00 PM
Home gunsmith frame cutting...
October 20, 2006, 03:30 PM
Oh Yes, We have the equipment , He has a bridgeport mill and I have a small grizzly milling machine and a lodge and shipley lathe for home projects. He has fit many comp barrels for me but this our first cutting a frame. I have fit my own barrels and slides for years but never anything like this. I have worked as a machinist for the last 13 years.
October 20, 2006, 05:43 PM
Are you doing this on a 1911 single stack? If so, don't - we've had feeding problems in 45 ACP with ramping 45 frames - now 9MM or the Supers work great.
I do not have my diagragms here in the basement but I'll get them and give you the exact measurements for the nowlin (square bottom) ramped bbl.
You will need also to make your own verticle cutter with the dust cover guide to mill accurately - DO NOT USE THE BROWNELLS JIG! It will chatter!
October 20, 2006, 08:53 PM
"DO NOT USE THE BROWNELLS JIG! It will chatter!"
I have not had that problem. I purchased it for a one off job initially, otherwise I would have made one.
There does seem to be a signifiact variation in the inside if the dust covers nd some pretty rough machinining on some.
I have made a number of extra guides as needed.
October 20, 2006, 10:59 PM
With the bridgeport and your experience as a machinest the ramp barrel cut should be a walk through the park.
Again pay close attention to barrel timing, it's very critical when using a ramp barrel with a compensator.
Also if you have not already bought the barrel I would consider a barrel with a Para style ramp, the Para cut is a stronger cut.
October 21, 2006, 12:17 PM
I agree, Bob - I'll get those measurements this afternoon hopefully.
October 21, 2006, 07:53 PM
Sorry I've not been to the shop yet but tomorrow I'll get your measurements.
The "pilot" that holds the Brownells cutter in the dust cover is short - mine is long enough that there is no vibration at all.
These diemnsions I'll give you are standard for all Nowlin cuts - they were taken from a factory pistol and are factory cut dimensions.
Will get it tomorrow.
PS. I made my won cutters and extensions - you could do this cut with a mill simply.
October 22, 2006, 10:02 AM
I sincerely apologize! I cannot find my info!:mad: You must have this information to cut that frame! Yes, the .315 down is just to clear the first part of the bbl. flat. I've lost the rest of the measurements! I'm very sorry.
You could call Nolin and they could give you that info.
So0 Sorry Harry B.
October 22, 2006, 11:42 AM
As Harry said your first cut is with the frame rails horizontal you cut 0.315 deep with a 11/32 flat bottom end mill. Be sure and center this cut between the rails.
The second cut of the Wilson, Nowlin ramp will be with frame rails vertical using a 29/64 flat bottom end mill or the cutter that Nowlin offers. Insert a slide stop pin and measure from the rear of the slide stop pin to the face of the standing lug slot. Subtract this distance from 0.500 and it will give you the depth you will need to cut the rear impact surface. Typically it should be around 0.160 deep. This cut is very important to the barrel timing, as I said earlier the frame may have to go back to the mill to change this lower impact surface by a several thousands. If the barrel is not timed right you will ruin the barrel and the slide. Do not remove material from the standing lug on the barrel, the changes must be done to the frame cut for the timing to be correct.
At the junction of the standing lug slot and the rear impact cut you need to make a 45 degree chamfer cut, the chamfer cut should be about 0.050 wide.
Again all cuts must be centered between the rails.
October 23, 2006, 08:59 AM
Thanks Guys for all the replies. First off, I am using a double stack frame 1911 or 2011 if you prefer, It's a springfield 45 frame but changing it to a .38 super and I have already purchased the STI trubor barrel. I have wanted a gun like this for years and saved up enough to buy all the parts I needed to built. I wish I could have bought one completed but just couldn't afford it right now with a new baby boy on the way. Me and my gunsmith have found someone local that has built alot of raceguns for himself and he has agreed to show us how to make the cuts needed. I just want to say that I have been doing research on this subject for a month now and you guys and this forum is the only place that I have found the answer I needed. Everyone else either wouldn't or couldn't answer because they didn't want to give away their secrets. I will keep posting as my project progresses, I will try to take pics and post them. Thanks to all. Rick
October 23, 2006, 08:24 PM
Kg4mon, good luck with your project gun. Here's a picture of a 38 super racegun I built for a customer,the gun started life as a P14 Para.
October 23, 2006, 08:31 PM
Really looks aok 1, Bob. Beautiful Bob!
October 24, 2006, 12:09 PM
Holy @#it, Now that's what I'm talking about!!!! Awesome!!!! If my project don't turn out to suit me can I give you a call?
October 25, 2006, 07:19 AM
Yes you can.
Thanks for the compliment on the gun.
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