Questions on ARs?

[HoLeChit]

Is JP the only company selling thermo fit / undersized uppers?

Zev uppers are thermofit. Zev makes uppers for Mega, Zev, Sons of Liberty Gunworks, and the Primary Arms House brand, I forget their name.

My understanding is San Tan and BCM also have a few uppers (maybe all?) that are thermofit.

There’s others for sure. I recently bought a blem Sons Of Liberty Upper/lower set for a build and it was def thermal fit. It’s a nice solid feel thermal fitting parts together. My BCM MCMR hand guard was also thermal fit, but that ended up being a nightmare.

There’s one or two companies as well that make oversized barrel extensions too. I forget who though.

 

[conditionzero]

Zev uppers are thermofit. Zev makes uppers for Mega, Zev, Sons of Liberty Gunworks, and the Primary Arms House brand, I forget their name.

My understanding is San Tan and BCM also have a few uppers (maybe all?) that are thermofit.

There’s others for sure. I recently bought a blem Sons Of Liberty Upper/lower set for a build and it was def thermal fit. It’s a nice solid feel thermal fitting parts together. My BCM MCMR hand guard was also thermal fit, but that ended up being a nightmare.

Heck yeah thanks!

 

[HoLeChit]

Heck yeah thanks!

You bet. If I can get ahead with my coursework tomorrow I’ll hit the range for the first time with that rifle, and will try to do some sort of a decent review over it. It’s my first personally owned decent quality AR. But it is a homebuild.

 

[danc46]

JP doesn't use epoxy. As far as I know.

Who was the builder and what were the rifles for?

Your depth of misunderstanding unitizing is impressive! Adjustable gas caps for M1s are not allowed in High Power, although they do exist to allow hotter to be ran to not bend the op rod. It has NOTHING to do with "tuning" the gas system.If you read the rules for High Power you will see they are not allowed!

I am rated a high expert in High Power, and I shot on several of the teams back in the day when we used M-14s. I spent lots of time with our armorers, and you are absolutely wrong about why the M-14 is unitized the way it is. The gas spindle on an M-14 is either on or off and there is no "positioning" them to "tune" the gas system.

Next, throat erosion has nothing to do with "sizing". Free lesson for you, case headspace is measured off the shoulder of the case to the base of the case and has absolutely nothing to do with the throat of the chamber for bottle neck cases! Your understanding of these things is at best vague!

J.P does not, nor has ever used epoxy on extensions. Thermo fit, absolutely, but no epoxy! Which makes me wonder where a builder would use epoxy on a pistol barrel

I have the AMTU and USMC manuals for building both the M1 and M14 and have built both.
The past armorer from OKARNG, Dan S. Now long gone, helped me several times when I had questions. I have enough spare parts to build an M14 NM (including a unitized gas cylinder I built and didn’t buy) except for receiver and barrel.
i know exactly why gas systems are unitized and why they aren’t on service grade rifles. I can also tell you how much difference each and every part makes as you add them to your rifle.
The biggest difference in an M1A I ever got by adding a part was a pencil type recoil guide instead of the flat one. And a nitride coated trigger pin.
Why use a round recoil guide in n NM instead of a flat one? The answer should be obvious - more consistent bolt lock up.
Have you ever built an NM Garand or M14?
Those adjustable gas valves on the Garands don’t show. I’ve never seen ann inspection go past the trigger weights. And show me a Garand NM shooter that will let anyone touch the gas cylinder on his rifle! Especially at a match.
As far as shooting the throat out, the headspace is going to increase just from shooting. Are you saying that isn’t going to happen? I’m not going to explain to you why some barrels are pulled, shortened a small bit then rechambered. Or why people seat their bullet further out to compensate for throat wear.
And you say headsacing has nothing to do with accuracy? OK, keep believing that.
I’ll let you figure all that out for yourself.
So you are playing with a rifle built by JP whoever?
Why didn’t you build it yourself?
So you’re trying to improve a good shooting rifle by putting in parts from your rifle builder?
And they can’t tell you why things went to shit when you changed those parts?

Doesnt look like I can help you either.

 

[danc46]

JP doesn't use epoxy. As far as I know.

Who was the builder and what were the rifles for?

The rifles were built in Arkansas and I suspect put together by $10 an hour farm hands.

 

[danc46]

Not buying that. If the bolt heats up, it would be a constant no matter the carrier, and 5 rounds is hardly enough to Heat a bolt to the point it would undergo thermal expansion. If in fact heat causes ARs to change group size all ARs would exhibit the same tendency, but they don't.

If heat doesn’t build up and affect accuracy even in a couple of shots, why is such emphasis placed on the first cold shot from a sniper’s rifle in training them? Bolt lock up can change from one shot to another and heat, even a few defrees, can make a difference in a rifle with very tight tolerances.

 

[KurtM]

You have already told me everything I need to know about you, but feel free to keep typing.

 

[danc46]

This thread was intended to help others that have an AR and little experience.
It is intended. to help them save money and do things themselves if possible if they want to change or modify it. Hopefully I can help them do that and point them in the right direction. Or others can help.
I never presented myself as the ultimate authority, only a serious hobbyist.

If you want to shit in this thread, I suggest you stick your head up your ass and jump.

 

[danc46]

You have already told me everything I need to know about you, but feel free to keep typing.

I noticed you haven’t offered to help others,
you certainly did your best to shit in this thread for whatever reason.
i told you exactly what you can do in my previous post.

 

[KurtM]

And now proctology advice! Your depth and breadth of knowledge is truly breath taking! It must be crowded in that head of yours with all that greatness and all.

 

[danc46]

And now proctology advice! Your depth and breadth of knowledge is truly breath taking! It must be crowded in that head of yours with all that greatness and all.

It is easy to do when you have to deal with an asshole.
I’m glad you’re impressed. It is amazing you can see to shoot through that porthole you have in your belly button.

 

[JEVapa]

What does that mean?

 

[KurtM]

I'm pretty sure all it means is he felt free to keep typing.

 

[danc46]

I'm pretty sure all it means is he felt free to keep typing.

It seems you do too.
ETA Do me and yourself a kindness. If you can’t contribute to helping someone else in this thread, stay out of it.

 

[KurtM]

Well, since you asked, I will try to answer a few of your questions.
Yes I have "built" around 15 match grade M-14s, or at least was a part in that process. I did a 6 month T.A.D at the 22nd AMU support at camp Lejeune, you know the place that made the M-14 match rifles for the Marine Corp.... Note, not an M1A, a real M-14.
I have only built 1 match type M1
As to the M1 cylinder cap, it is not legal in Service rifle matches. Do you really think all they do is put a trigger pull weight on it and call it good? I can guarantee at the all service matches the
tech inspection is very thorough! Do you really think that the Marine Corp wouldn't love to catch the Army cheating?

yes I don't believe headspace increases as you shoot. At 7000 rounds my M1A still won't close on a no-go gauge. The throat was eroded out, but the headspace was just fine, just like the other two barrels I put on, and chambered all by myself.

The AR 10 in question was built by DPMS, and re-assembled with the parts I wanted by me.... Not by "J. P. whoever". That was made clear in my first post.

as to why we stress "cold bore" zero, has nothing to do with heat, and group shift when hot, although about 75% of precision rifles do not exhibit any shift what so ever. The reason it is stressed is because that first shot HAS to hit and if that first shot is out side of your rifles main group that is the one shot you zero the rifle to. No real mystery there

I was trying to make a good shooting rifle lighter, not better, just lighter, with a part that historically has been a drop in part with no impact on grouping, or accuracy.

sorry, I got a little out of order... We set back barrels to recut the eroded throat, not because the headspace has increased and, spoiler alert, you have to cut them back by at least 1 full turn to freshen the throat.

if you had been reading a long, I have told people how to tune their gas tubes to carrier key, told folks how to Thermal Fit a barrel that is not on an undersized upper, isn't that helpful?

Take heart, however, I do agree with you that people will load bullets longer in the case to make up for throat erosion, but on the magazine fed rifles we are talking about we run out of room to do so due to magazine length.
carry on now!

 

[danc46]

Well, since you asked, I will try to answer a few of your questions.
Yes I have "built" around 15 match grade M-14s, or at least was a part in that process. I did a 6 month T.A.D at the 22nd AMU support at camp Lejeune, you know the place that made the M-14 match rifles for the Marine Corp.... Note, not an M1A, a real M-14.
I have only built 1 match type M1
As to the M1 cylinder cap, it is not legal in Service rifle matches. Do you really think all they do is put a trigger pull weight on it and call it good? I can guarantee at the all service matches the
tech inspection is very thorough! Do you really think that the Marine Corp wouldn't love to catch the Army cheating?

yes I don't believe headspace increases as you shoot. At 7000 rounds my M1A still won't close on a no-go gauge. The throat was eroded out, but the headspace was just fine, just like the other two barrels I put on, and chambered all by myself.

The AR 10 in question was built by DPMS, and pre-assembled with the parts I wanted by me.... Not by "J. P. whoever". That was made clear in my first post.

as to why we stress "cold bore" zero, has nothing to do with heat, and group shift when hot, although about 75% of precision rifles do not exhibit any shift what do ever. The reason it is stressed is because that first shot HAS to hit and if that first shot is out side of your rifles main group that is the one shot you zero the rifle to. No real mystery there

I was trying to make a good shooting rifle lighter, not better, just lighter, with a part that historically has been a drop in part with no impact on grouping, or accuracy.

sorry, I got a little out of order... We set back barrels the recut the eroded throat, not because the headspace has increased and, spoiler alert, you have to cut them back by at least 1 full turn to freshen the throat.

if you had been reading a long, I have told people how to tune their gas tubes to carrier key, told folks how to Thermal Fit a barrel that is not on an undersized upper, isn't that helpful?

Take heart, however, I do agree with you that people will load bullets longer in the case to make up for throat erosion, but on the magazine fed rifles we are talking about we run out of room to do so due to magazine length.
carry on now!

I know one thing about you mentioning the M14 gas cylinder. Some are indeed screwed but the USMC welds the stock ferrule to the cylinder. I chose that method when I unified my gas cylinders. I also turned the jigs to use to set the tension on the barrel when glass bedding.
And the best M14s I shot had the actions closing much slower than standard rifles. I was told with great emphasis by Dan S. “ don’t ever touch the gas valve“ and he explained why, more consistent bolt lock up.
I rewired his lathe at his house to put a reverse on it. It was literally a barn find at an auction.
I learned a lot from him .
As far as the gas valves not being checked on Garands, I wasn’t talking Camp Perry or intersrrvice matches, just from what I’ve seen at the OKC HiPower and the Red River Arsenal matches. I know several of them had the valves on them.
My demands of a rifle are different than yours. The NM standards are determined by 10 shot groups with specific ammo shot in a short period. Trying to make those tighter groups is not worth the great expense some people will go to on gas operated guns.
But they are free to do what they want.
I’ve run the AR line at TriCity on Women on Target for several years but not this last year due to radiation treatments. I take 6-7 ARs, ones I built and maintain for that purpose. I’ve never had a problem with any of those rifles at WOT with thousands of rounds shot through them.
You did not answer any questions others asked. The purpose of this thread was to try to help others. You pretty much came in this thread and tried to prove you were the top dog for whatever reasons you have.
This thread had one purpose. If someone has a problem, needs help, advice on doing something to their AR, they could come here and get help.
Dan S. helped me a great deal and I think only right to help others if I can with their shooting projects. They should look at it from every direction possible, research it, and pick their path. They’ll learn by doing and maybe find someone that has tools they can use without buying them.
i rather do that than argue with somebody trying to be the big dog!

 

[KurtM]

My "demands" of a rifle is 2MOA or better (I like a lot better but 2MOA will do), no matter how hot I get it, but it must be absolutely reliable. It isn't uncommon for the matches I shoot to be in the 40-60 rounds in around a minute to a minute and a half, from 5 meters to 500 meters all in the same stage.

I wasn't trying to be "the big dog" but I usually speak up when questionable info is given.

I do wish you the best with your radiation treatments and recovery, that is a very tough row to hoe!

 

[danc46]

My "demands" of a rifle is 2MOA or better (I like a lot better but 2MOA will do), no matter how hot I get it, but it must be absolutely reliable. It isn't uncommon for the matches I shoot to be in the 40-60 rounds in around a minute to a minute and a half, from 5 meters to 500 meters all in the same stage.

I wasn't trying to be "the big dog" but I usually speak up when questionable info is given.

I do wish you the best with your radiation treatments and recovery, that is a very tough row to hoe!

IMO you shit all over the thread -one intended to help others. You asked for an opinion of the possible problem you are having, then threw shit n everything I said. Consistent bolt lock on a gas operated weapon is essential to accuracy. I repeated that in one instance after another which you say is incorrect. Well, fuck me if that isn’t what I’ve seen and been told from iver 50 years of dealing with all types of rifles. That would includes helping over 20 guys build AKs in my garage (some are here and good friends), helping numerious people change out barrels and hand guards on their ARs, trouble shooting ARs for friends and their friends, etc teaching Scouts for their rifle badges, doing YHEC for years, teaching ARs at WOT for years, and never made a dime out of it.
Back to you and your question, you change to a lighter bolt carrier and you accuracy goes sideways. What does the bolt carrier do? It carries the bolt carrier into lock and with the lighter bolt carrier your accuracy goes sideways.
And you still say it isn’t bolt lock up.
Just stay the fuck out of ny threads and I’ll do the same for you.

 

[HoLeChit]

 

[JEVapa]