It's been a very good discussion.
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It's been a very good discussion.
Larry Gibson
“Deficient observation is merely a form of ignorance and responsible for the many morbid notions and foolish ideas prevailing.”
― Nikola Tesla
Okay Mr Larry Gibson, this is kind of the test you and I have been waiting for. I got the Colt unit today, was suppose to be here yesterday, but we had some really horrible thunderstorms that resulted in trees down and a power outage of 10 hours for me. So here is what I did. I tested at 25 yards just to see what I'm going to be working with. I won't lie the results at that distance weren't very gratifying. So then I started swaging the 22's. I had the unit out and it's has a generous chamber and accepted my swaged ammo A Okay. Let me remark at this point the Colt unit appears to be very much a copy of the military M261 except for one thing, the magazine. Colt supplied a decaded magazine. Back to the test. The swaged bullets reduced the groups by 50% or so. Still not what I was looking at. I checked out some things on the unit and saw what I thought all along might be the accuracy problem. I'm not going to mention here (sorry guys) because it is a permanent modification to the unit and requires tools that most people won't have. So I done that and went out again at 25 yards with the swaged bullet. VIOLA!! The group improved by almost a 100%. It shot a raggy butt hole at 25 yards, say in the order of smaller then 1/2 inch easy. Very very encouraging so now to test at a further distance and not with one brand of ammo, but various 22 ammo I have. BTW that initial test ammo was PMC. I hope the old 7 twist HBAR holds up to some useable accaracy at further distance.
I have been out of town. In my earlier comment I should have said brace, but still on an AR15 pistol that still has a buffer tube, I still would not put a fixed focus scope. Especially if it is 7.125 length tube that is the carbine length buffer. ATF says that the 7.125 inch length is ok for a legal pistol, but it is still possible for some people to shoulder such a bare buffer tube. The ATF says 6.5 inches is a pistol buffer length, but their discussion on cost impacts of their ruling said that the 7.125 tube was ok and did not need to be changed.Originally Posted by M-Tecs
I have no idea what they would say if there was a fixed focus scope on the carbine length buffer tube on such a pistol since that means someone is planning to use the buffer tube for shouldering in their minds.
But it really looks like ATF is going be defeated on the ruling on administrative causes if nothing else.
So maybe I am making much ado about what will be nothing.
Most of my handgun scopes are fixed focus scopes even if they are extended eye relief. Being a fixed focus scope is not the issue. Focus length and eye relief are not the same.
Eye relief can become an issue if the short eye relief does not allow the pistol from being fired unless the brace is likely to be touching the shoulder per the ATF. Cheek rests extensions are still considered legal. That is where the “intent” gets to be an issue. If you can’t see thru the scope without the brace likely touching your shoulder intent is established per the ATF. If you can’t use the brace as designed as a wrist support due not being able to sight thru the scope due to short eye relief how are you intending to use it?
I don’t agree with the ATF but they have the legal authority for prosecute you if you go against their regulations.
An AR15 pistol with a brace using an extended eye relief scope is fine in the areas where braces are currently legal. Just don’t get caught shouldering it. At one time the ATF stated if was legal to shoulder the Sig brace. That has been rescinded.
The issue is ability to shoulder it when the barrel is less than 16". Contenders, Encores and AR pistols with braces become short barrel rifles when shouldered with a barrel of less than 16" per the ATF's definition.
A normal handgun is basically impossible to fire from the shoulder. Contenders, Encore and various other handguns are commonly and legally scoped with "rifle" scopes and shot from rests or bipods. Since they can't be shouldered it's not a legal issue nor is there any possibility for using it as a short barreled rife when the pistol grip is installed.
There is nothing in the legal definition of SBR that specifically involves your intent or how you actually use it. The legal definition is just a physical description of the firearm itself.
2.1.3 Rifle. A rifle is a firearm designed to be fired from the shoulder and designed to use the energy of an explosive in a fixed cartridge to fire only a single projectile through a rifled barrel for each single pull of the trigger.11 A rifle subject to the NFA has a barrel or barrels of less than 16 inches in length.
NFA Handbook - Appendix A (atf.gov)
The law 26 U.S.C. 5845(c):
(c) Rifle. The term 'rifle' means a weapon designed or redesigned, made or remade, and intended to be fired from the shoulder and designed or redesigned and made or remade to use the energy of the explosive in a fixed cartridge to fire only a single projectile through a rifled bore for each single pull of the trigger, and shall include any such weapon which may be readily restored to fire a fixed cartridge.
https://www.atf.gov/file/58141/download
The ATF's NFA Handbook:
2.1.3 Rifle. A rifle is a firearm designed to be fired from the shoulder and designed to use the energy of an explosive in a fixed cartridge to fire only a single projectile through a rifled barrel for each single pull of the trigger. A rifle subject to the NFA has a barrel or barrels of less than 16 inches in length. The ATF procedure for measuring barrel length is to measure from the closed bolt (or breech-face) to the furthermost end of the barrel or permanently attached muzzle device. Permanent methods of attachment include full-fusion gas or electric steel-seam welding, high-temperature (1100°F) silver soldering, or blind pinning with the pin head welded over. Barrels are measured by inserting a dowel rod into the barrel until the rod stops against the bolt or breech-face. The rod is then marked at the furthermost end of the barrel or permanently attached muzzle device, withdrawn from the barrel, and measured.
https://www.atf.gov/firearms/docs/at...ter-2/download
Gun Control Act Definitions
Pistol
18 U.S.C., § 921(A)(29) and 27 CFR § 478.11
The term “Pistol” means a weapon originally designed, made, and intended to fire a projectile (bullet) from one or more barrels when held in one hand, and having:
• a chamber(s) as an integral part(s) of, or permanently aligned with, the bore(s);
• and a short stock designed to be gripped by one hand at an angle to and extending below the line of the bore(s).
Firearms - Guides - Importation & Verification of Firearms - Gun Control Act Definition - Pistol | Bureau of Alcohol, Tobacco, Firearms and Explosives (atf.gov)
2nd Amendment of the U.S. Constitution. - "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
"Before you argue with someone, ask yourself, is that person even mentally mature enough to grasp the concept of different perspectives? Because if not, there’s absolutely no point."
– Amber Veal
"The Highest form of ignorance is when your reject something you don't know anything about".
- Wayne Dyer
You did not consider what I posted and this is dealing with no brace on an AR15 pistol with a buffer tube long enough that according to ATF can be shouldered via the buffer tube. A bare buffer tube can be shouldered. You put a short eye relief optic on the gun this could show intent on the part of the ATF that you will be shouldering the AR pistol and get you in hot water.
Be very careful about saying something is legal. Me while I am saying something could be illegal, if I am wrong no one goes to jail; telling someone that the ATF will not go after them can have horrendous consequences if you are wrong.
Big boy rules here.
On pistols with no buffer tubes put what ever you want on them relative to sights. Without a brace/stock or buffer tube, there is no way that they can be considered an SBR. For this we are talking about rifled barrels here and shotguns are more complicated.
As of now any brace pistol unless it and everything on the gun passes ATF approval may be an SBR. One might still have a chance in court to challenge the ATF assigned SBR status. When I say everything on it, that means the sights and optical sights also. They want to see the entire package and any change could make the gun an SBR in their opinion.
I have no intention in possibly getting caught up in something like that. I have my retirement set and do not want it to take a change of venue like a federal court room and that will take every penny that I have and could end up in a federal prison.
Likely next year the whole brace ruling gets thrown out anyway.
You know Larry Gibson asked me to take this 22LR conversion unit thread and start a new thread when I took the thread we both were in off topic. If you two fellows want to talk about the SBR's, ATF, etc, would you please start a new thread? Please?
If you don't want thread drift don't post garage and expect pushing garage to go unnoted. At one time the conversation units were the only game in town. We have more options today. Pointing out the real limitations of the conversion units is helpful for all. Making claims like The ATF forbids iron sights or fixed focus scopes on AR pistols. and then you are stating that's it's a good post not so much particularly when it's factually wrong.
It's good that you are pointing out that to get even mediocre accuracy you need to swage the bullets. Same for me pointing out that if you are going to purchase new better options are available for not much more money. I've had to qualify too many times with them and used them too much to not know there are better options. After I moved to dedicated uppers my three M261's have been fired very little. My dedicated uppers get used a lot. If you don't want other people's comments you can always PM or email.
2nd Amendment of the U.S. Constitution. - "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
"Before you argue with someone, ask yourself, is that person even mentally mature enough to grasp the concept of different perspectives? Because if not, there’s absolutely no point."
– Amber Veal
"The Highest form of ignorance is when your reject something you don't know anything about".
- Wayne Dyer
The thread was to determine why there is inaccuracy when the unit is used in the 7 twist rifle, not that there are better options, which most of us are all aware of. Apparently you missed that and that's why Larry Gibson wanted this thread. I particularly asked Larry what where reasons for this inaccuracy and pointed out the three main question of what it indeed the twist, or was it the 22LR bullet being undersized, was it the unit is a separate part inserted into the barrel.
My comment to barnetmill was he had a good reason for the conversion unit.
Again the thread isn't about a better option.
Last edited by TD1886; 08-09-2023 at 01:01 AM.
Well my last post was correct and I am not getting into a whizzing contest here, we should be better than that here. I have learned a lot here from the thread.
If my post was read correctly it wasn't only swaging the bullets that increased accuracy it was the mechanical alteration that was the thing that greatly enhanced it.It's good that you are pointing out that to get even mediocre accuracy you need to swage the bullets.
Some of us do have the capability to modify the units. Probably more than you think. Sharing would be helpful and appreciated for all even for those that don't have the capability to do the mods.
As I stated I have three of the AF 261's. I also have one USGI 601 14 twist upper and two USGI 604 uppers with 12 twists. Getting them to shoot well with the conversion units would be nice. I would also be interested in knowing how the modified unit shoots without swaging the bullets.
Last edited by M-Tecs; 08-09-2023 at 01:40 AM.
2nd Amendment of the U.S. Constitution. - "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
"Before you argue with someone, ask yourself, is that person even mentally mature enough to grasp the concept of different perspectives? Because if not, there’s absolutely no point."
– Amber Veal
"The Highest form of ignorance is when your reject something you don't know anything about".
- Wayne Dyer
I plan to buy that unit that was mentioned. I just got back into town and am a little behind.
Even if my task does not demand it, I want the most accuracy that I can get. Says will work with CMMG that I have. Better alignment might make the gun run better and reduce leading also.https://borebuddy.com/product/borebu...amber-adapter/
$52.50 – $61.50
Swap the collar on your bolt for this chamber adapter to shoot 22lr through any standard 223/556 AR. The chamber adapter is compatible with BoreBuddy/CMMG/RTB/Palmetto 22lr bolt groups.
barnetmill there are many things wrong with that CMMG unit. I can give you a link to where an original M261 conversion unit is for sale, a bid site, but he has buy it now too which I believe that price may be cheaper then the CMMG unit. As you noticed on that site that sells that buffer tube adaptor that they sell other things like the gas blow back block you put in the charging handle. What I'm getting at if you have to do all that to the CMMG unit to make it work better, it's better to start out with a device that is better from the start. On the Colt and military M261 they have a flat spring sticking up on the read of the device at 12 o'clock and that presses against the buffer to keep the device forward. It doesn't need that bore buddy. Also the Colt and M261 doesn't blow gas back at you. If you wish to have the link I'll pm it to you, just let me know.
As I said I just initially started testing my Colt unit. It was preliminary to see what I was dealing with. You brought a good question as to how it shoots with regular non swaged 22LR's with the modification. I will find out, but suspect it won't be as good and that's an assumption.
When Larry chimes in I'll ask him if he thinks it's a good idea to post the permanent modification.
Thanks for the detailed advice. The gas blow back is not a big deal for me since i have set the gun up for cheek shooting that entails a very high mounted sight and my eyes are well above it. I have not had any real complaints yet with system other than certain brands of remington ammo for example bend while the cmmg unit is trying to them into the gun. Their brass case is weak and bends for their cheaper plinking ammo and unfortunately i have a lot of it. I have three mags and unit and it all works reasonable well. For another $60 or so, if the collar will work, that is about as far I would want to go. Thanks for the offer of the link, but for now I will pass on it.
But I will do some reading on the cmmg and see what it failings are. What I see so far is that it is a one size fits all and so is loose. I typically fire about 200-350 rounds in a session. Lately it has been too hot here in florida and I may wait till September.
If you don't want to publicly post them you can PM or email me if you want. It would be appreciated. Here's a free download for the TM 9-6920-363-12&P. Operator's & Organizational Maintenance Manual Including Repair Parts & Special Tools List. Conversion Kit (Caliber .22 Rim fire Adapter) M 261 for Rifle M16 & 16A1.
https://www.liberatedmanuals.com/TM-...3-12-and-P.pdf
2nd Amendment of the U.S. Constitution. - "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
"Before you argue with someone, ask yourself, is that person even mentally mature enough to grasp the concept of different perspectives? Because if not, there’s absolutely no point."
– Amber Veal
"The Highest form of ignorance is when your reject something you don't know anything about".
- Wayne Dyer
As you mentioned the CMMG fits loose, it sends gas down the charging handle groove, and it's the only one out of the two being the Colt and M261 that has the full 5.56/223 piece that inserts inside the chamber and by full I mean it even has the case neck. Whether that is good or bad I don't know. I do know that it's mighty thin for the 22 bullet having to pass throught it. CMMG at one time had some sort of failure around that part that is shaped like the cartridge. Usually CMMG makes quality parts and firearms in my opinion. Their radial delayed blow back system is genius they have on their pistol caliber rifles and carbines.
I've never inspected the standard M261. Is the chamber insert rifled same as the AF version?
2nd Amendment of the U.S. Constitution. - "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
"Before you argue with someone, ask yourself, is that person even mentally mature enough to grasp the concept of different perspectives? Because if not, there’s absolutely no point."
– Amber Veal
"The Highest form of ignorance is when your reject something you don't know anything about".
- Wayne Dyer
I've never examined the M261, but the Colt, which is almost identical, is not. Wouldn't that be kind of odd? The chamber insert would give the bullet some speed as the 22LR is pretty efficient in a short barrel, so what twist would it be if it was rifled? Wouldn't that make matters worse if it was and then the bullet hits the rifling of the AR's barrel? Larry mentioned one of the things that might hurt accuracy with the 7 twist is the bullet hitting that steep angle of the rifling and damaging the bullet.
Not that anyone is doubting you, but are you positive the AF one is rifled? Can you take a picture of that and post it? This is most interesting.
No need Tecs, I found it. This is what I found:
There was also a .22 rimfire conversion designed by U.S. Air Force Master Sergeant Julius V. Jurek. The “Air Force” conversion had a rifled chamber insert, and was gas-operated.
Question arises as to why?
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