User Panel
User Panel
User Panel
|
Posted: 9/9/2005 8:45:33 PM EDT
[#1]
I'm using two sets of KNS anti-rotation pins in my carbines.
A large dia. pin set for my Colt 6721 Tactical Carbine and a small pin set for my LMT M4gery carbine. Both of them are solid, no movement at all. Maybe you could measure both of your pins with a mic or calipers and see if there are a difference in length. I also have a spare small dia. set and I could measure them for comparison if you wish. Let me know. |
|
|
|
Posted: 9/9/2005 8:48:22 PM EDT
[#2]
i have noticed that there is slight variation in the length of the pins.
but it could possibly be out of spec lowers as well. |
|
|
|
Posted: 9/10/2005 6:02:56 AM EDT
[#3]
I have the same pb on a Colt - no idea why or what to do about it.
|
|
|
|
Posted: 9/10/2005 6:04:17 AM EDT
[#4]
i dont see it as a problem since its actually "anit-rotational" pins
|
|
|
|
Posted: 9/10/2005 6:19:33 AM EDT
[#5]
That's what I thought as well, though I am surprized by the tolerances on the receivers.
|
|
|
|
Posted: 9/10/2005 7:16:51 AM EDT
[#6]
Yeah, receiver forging tolerances are not exactly high precision.
I have not measured a large number of raw forgings, but I would suspect any given 10 to vary by +-.003 at least in thickness in a given spot around the midsection. I have +100 in a box in the garage. I'll try to measure some of them in this area and post results when I get home in a couple weeks. When I put one of those forgings on the mill and run a dial indicator around it, the needle bobs and dips like an Arizona oiled road. Pardon the blasphemy, but these come from a company that supplies Colt. |
|
|
|
Posted: 9/10/2005 7:26:13 AM EDT
[#7]
Which company supplies Colt?
|
|
|
|
Posted: 9/10/2005 8:02:54 AM EDT
[#8]
www.cerrofabricated.com/products_firearm.htm , l think. The logo is that little triangle over a blue A, in any case. They had some cool stuff on their website before, and you can see a 1911 forging now. I asked about buying a substantial batch of 1911 recievers, but they said the dies were property of colt and they could not sell forgings made by Colt dies. I imagine Colt buys forgings from anyone who can supply a given quality and quantity at a given price - I am not into all that collector nonsense like subcontractor markings, but that is the way the real world works. I bought a case of M16 lower forgings for an EDM venture, and got a good price break since my non-military requirements did not need that intensive QA paper trail. |
|
|
|
|
Posted: 9/10/2005 8:35:47 AM EDT
[#9]
Cerro's logo looks like a key hole. The triangle over an A is Anchor Harvey Aluminum.
Forgings outer mold line surfaces doesn't have to be too precise if it does not have to mate with anything. As long as the measured dimensions are per engineering drawing it's acceptable to quality inspection and good enough to sell. The manufacturer with good quality will hold a tighter tolerance and less variation. Ref. ANSI Y 14.5 and ISO 9000. Receiver Logos and Markings Thread link |
|
|
|
Posted: 9/10/2005 8:39:45 AM EDT
[#10]
Duh, yah, I bought those from Anchor Harvey. I could not find their website in my favorites.
The whole EDM adventure turned out to be a bad dream so far. |
|
|
|
Posted: 9/10/2005 9:19:01 AM EDT
[#11]
That's cool, at least you could mark them anyway you want after the machining is completed. Why not just machine the areas with loose tolerances and just EDM the final stage of the critical areas. EDM equipment must be expensive. I know I can't afford it. EDM technology was great for the 1911 combat shooters like the Nowlin barrels/ other parts and there should be a some good use for it in the AR fabrication. |
|
|
|
|
Posted: 9/10/2005 11:57:04 AM EDT
[#12]
I found Anchor Harvey: http://www.forgings.com/
|
|
|
|
Posted: 9/10/2005 12:17:42 PM EDT
[#13]
i have seen broken A's and keyholes on just about everything i own
bushmaster (both) rra(A) cmt(A) |
|
|
|
Posted: 9/10/2005 8:18:26 PM EDT
[#14]
I installed a set of pins in a RRA receiver , and found them to be to long as well. I just filled down the pins , to fit flush .
|
|
|
|
Posted: 9/10/2005 8:58:03 PM EDT
[#15]
it didn't mess up the threads at all to file them?
-sigadvantage- |
|
|
|
Posted: 9/11/2005 7:22:14 AM EDT
[#16]
i would just leave it as is.
there are some lowers i have that fit perfectly |
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
