Not really a Frankengun

Mohave-Tec · June 16, 2013, 07:43 PM

Not only have I never owned an AR-15 but I've only ever handled one before. Now I'm almost finished building one.
This is an odd rifle. I spent money where it seems I needed to and I went cheap where it seemed I could. I've got a BCM BCG in a slick sided DPMS. (yep)
I've built many other rifles before (not ARs) and I hugely surprised about the lowly DelTon 2 staged advanced trigger group I picked up for $125 'cause it is what I could get. That thing shows evidence of 2 stage right before the break and it breaks at 4 pounds right before the end of trigger travel. Who'd-a-thunk.
QUESTION: I've got a $50 DPMS receiver extension/buffer/spring kit I paid $50 for. Question is why would I hold out for a Vltor? The real question is...Is there any logic to going high end in some parts and saving a buck on others contingent that part's function and place in the hierarchy of importance of AR assembly? What say yea?
Just to let you know ahead of time. The rifle will be finished with a flashy Stoner fluted stainless barrel and a JT hand guard and adjustable gas block.

BTW, I've built several very expensive bolt rifles for long range shooting.

Quentin2 · June 17, 2013, 01:26 AM

It's really not unusual for a first timer to build their AR. I did mine and it turned out fine, so did my second and third. If you know what you want and put enough thought into it it's not hard to build a better rifle than the boring Bushmasters and DPMSes off the rack at your LGS.

I like good parts and would sell the commercial diameter DPMS receiver extension kit and aim a little higher. You can get a milspec diameter RE kit from PSA for $50 if you keep your eyes open. I have two of them and two BCM RE kits and though the BCMs are noticeably higher quality, all four have worked out well for me. (Yes, I'm starting my fourth build!)

Yeah, you want to be proud of your build, and have it work well so buy quality parts!

BTW you were wise in your choice of BCG. I have two BCM BCGs and you really can't do better which is smart since it's such a crucial part. I put one in my PSA upper and my BCM upper. My Daniel Defense upper has a DD BCG.

ETA: is your SS barrel 18" midlength gas?

Mohave-Tec · June 17, 2013, 08:06 AM

Greetings.
I did use a milspec diameter DPMS receiver extension kit. What I was wondering is what makes one receiver extension kit better than another. It seems the springs are the same and if the weight weighs X in both kits and the tube is solid and holds the stock rigid then what could be the difference?
To answer your question, yes, my 18 inch SS barrel is mid length gas. May I ask why you ask?
I'm having so much fun. I bought an armorers kit because I feal like I make build more in the future.

Mobuck · June 17, 2013, 09:14 AM

."..Is there any logic to going high end in some parts and saving a buck on others contingent that part's function and place in the hierarchy of importance of AR "
Only for those who suffer "logo ego" and can only be satisfied with the most expensive rather than "what does the job".
I've assembled about 20 AR type rifles over that last 4-5 years using both higher end parts and budget priced parts. In some cases the bargain priced assemblages were more accurate than the more expensive stuff and in no case did I find that specific parts were what some refer to as "junk". I'll admit that some parts fit together smoother than others but not necessarily as a result of what the parts cost.

Quentin2 · June 17, 2013, 03:01 PM

Quote:

Greetings.
I did use a milspec diameter DPMS receiver extension kit. What I was wondering is what makes one receiver extension kit better than another. It seems the springs are the same and if the weight weighs X in both kits and the tube is solid and holds the stock rigid then what could be the difference?
To answer your question, yes, my 18 inch SS barrel is mid length gas. May I ask why you ask?
I'm having so much fun. I bought an armorers kit because I feal like I make build more in the future.

I've never seen a milspec DPMS RE, only comspec. I'd try to borrow a known milspec stock and see if it actually fits the DPMS RE. The main difference is a quality milspec RE is made of 7075T6 alloy and every comspec RE I've seen is 6061 alloy. It might never matter unless you have to mortar the rifle but then the cost is so close, why not get the better component?

As far as the SS barrel, you didn't give the length or gas length in the first post so I was curious. 18" and midlength gas is a good choice. Also, back to the RE kit, with the better vendors you often can upgrade the standard carbine buffer to the H buffer for an extra $10-15. Should be a good fit with the 18" middy. I use H buffers exclusively in my 16" middys and yours has an extra 2" to add even more to the gas impulse. Not a huge deal starting out but someday try an H buffer, I bet you like it.

Mohave-Tec · June 17, 2013, 09:19 PM

Brownells
231-000-338WB
DPMS Buttstock Mounting Kit, Mil-Spec Carbine
Mfr Part: CS09DODA
Scroll to the bottom item.

I bought the Magpul CTR Buttstock and it is snug as a bug on the DPMS. I'm certainly not trying to sell DPMS but it was what I could put my hands on and it was listed as Mil Spec. I make a good living so if I ever get a chance to put good and bad side by side I will make the change.
I was aiming for 4oz or a little more for buffer weight by my calculations but didn't know what this one would come with. As it turns out it weighs in at 2.9 oz. I will certainly go a bit heavier but I will hold off until I see what the adjustable gas block will do. I absolutely intend to tune the rifle between the two.
I am fully of the differences in quality components but I also want to get this rifle started. A sturdy receiver extension didn't seem like it would make as much difference as the quality of my BCM BCG would and I was bent on an 18 inch wylde mid gas barrel. I'm ahead of special projects in a mechanical engineering department. I don't know diddly about ARs but I'm gonna!

Quentin2 · June 17, 2013, 09:40 PM

Interesting that DPMS now offers a milspec diameter RE. Brownells does list it as a new item.

This indicates that all the discussion over the years about lesser/better parts is moving the industry toward better offerings. Today's parts are better than 10-15 years ago.

Mohave-Tec · June 17, 2013, 11:29 PM

It was on Brownell's for about 15 seconds. LOL.

tgstoken · June 18, 2013, 12:13 AM

AR must have list: Good BCG, good barrel, good FCG. Cheap out on stock, stripped upper, handguard and stripped lower (forged, not plastic). Then get good optics, mid grade ammo.

Mohave-Tec · June 18, 2013, 07:28 AM

I'm building a very nice rifle.

June 16, 2013, 07:43 PM	#1
Mohave-Tec Senior Member Join Date: May 28, 2013 Location: Las Vegas Posts: 118	Not really a Frankengun Not only have I never owned an AR-15 but I've only ever handled one before. Now I'm almost finished building one. This is an odd rifle. I spent money where it seems I needed to and I went cheap where it seemed I could. I've got a BCM BCG in a slick sided DPMS. (yep) I've built many other rifles before (not ARs) and I hugely surprised about the lowly DelTon 2 staged advanced trigger group I picked up for $125 'cause it is what I could get. That thing shows evidence of 2 stage right before the break and it breaks at 4 pounds right before the end of trigger travel. Who'd-a-thunk. QUESTION: I've got a $50 DPMS receiver extension/buffer/spring kit I paid $50 for. Question is why would I hold out for a Vltor? The real question is...Is there any logic to going high end in some parts and saving a buck on others contingent that part's function and place in the hierarchy of importance of AR assembly? What say yea? Just to let you know ahead of time. The rifle will be finished with a flashy Stoner fluted stainless barrel and a JT hand guard and adjustable gas block. BTW, I've built several very expensive bolt rifles for long range shooting.

June 17, 2013, 01:26 AM	#2
Quentin2 Senior Member Join Date: June 18, 2009 Location: NorthWest USA Posts: 1,996	It's really not unusual for a first timer to build their AR. I did mine and it turned out fine, so did my second and third. If you know what you want and put enough thought into it it's not hard to build a better rifle than the boring Bushmasters and DPMSes off the rack at your LGS. I like good parts and would sell the commercial diameter DPMS receiver extension kit and aim a little higher. You can get a milspec diameter RE kit from PSA for $50 if you keep your eyes open. I have two of them and two BCM RE kits and though the BCMs are noticeably higher quality, all four have worked out well for me. (Yes, I'm starting my fourth build!) Yeah, you want to be proud of your build, and have it work well so buy quality parts! BTW you were wise in your choice of BCG. I have two BCM BCGs and you really can't do better which is smart since it's such a crucial part. I put one in my PSA upper and my BCM upper. My Daniel Defense upper has a DD BCG. ETA: is your SS barrel 18" midlength gas? Last edited by Quentin2; June 17, 2013 at 01:38 AM.

June 17, 2013, 08:06 AM	#3
Mohave-Tec Senior Member Join Date: May 28, 2013 Location: Las Vegas Posts: 118	Greetings. I did use a milspec diameter DPMS receiver extension kit. What I was wondering is what makes one receiver extension kit better than another. It seems the springs are the same and if the weight weighs X in both kits and the tube is solid and holds the stock rigid then what could be the difference? To answer your question, yes, my 18 inch SS barrel is mid length gas. May I ask why you ask? I'm having so much fun. I bought an armorers kit because I feal like I make build more in the future.

June 17, 2013, 09:14 AM	#4
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	."..Is there any logic to going high end in some parts and saving a buck on others contingent that part's function and place in the hierarchy of importance of AR " Only for those who suffer "logo ego" and can only be satisfied with the most expensive rather than "what does the job". I've assembled about 20 AR type rifles over that last 4-5 years using both higher end parts and budget priced parts. In some cases the bargain priced assemblages were more accurate than the more expensive stuff and in no case did I find that specific parts were what some refer to as "junk". I'll admit that some parts fit together smoother than others but not necessarily as a result of what the parts cost.

June 17, 2013, 09:19 PM	#6
Mohave-Tec Senior Member Join Date: May 28, 2013 Location: Las Vegas Posts: 118	Brownells 231-000-338WB DPMS Buttstock Mounting Kit, Mil-Spec Carbine Mfr Part: CS09DODA Scroll to the bottom item. I bought the Magpul CTR Buttstock and it is snug as a bug on the DPMS. I'm certainly not trying to sell DPMS but it was what I could put my hands on and it was listed as Mil Spec. I make a good living so if I ever get a chance to put good and bad side by side I will make the change. I was aiming for 4oz or a little more for buffer weight by my calculations but didn't know what this one would come with. As it turns out it weighs in at 2.9 oz. I will certainly go a bit heavier but I will hold off until I see what the adjustable gas block will do. I absolutely intend to tune the rifle between the two. I am fully of the differences in quality components but I also want to get this rifle started. A sturdy receiver extension didn't seem like it would make as much difference as the quality of my BCM BCG would and I was bent on an 18 inch wylde mid gas barrel. I'm ahead of special projects in a mechanical engineering department. I don't know diddly about ARs but I'm gonna!

June 17, 2013, 09:40 PM	#7
Quentin2 Senior Member Join Date: June 18, 2009 Location: NorthWest USA Posts: 1,996	Interesting that DPMS now offers a milspec diameter RE. Brownells does list it as a new item. This indicates that all the discussion over the years about lesser/better parts is moving the industry toward better offerings. Today's parts are better than 10-15 years ago.

June 17, 2013, 11:29 PM	#8
Mohave-Tec Senior Member Join Date: May 28, 2013 Location: Las Vegas Posts: 118	It was on Brownell's for about 15 seconds. LOL.

June 18, 2013, 12:13 AM	#9
tgstoken Member Join Date: December 17, 2006 Posts: 35	AR must have list: Good BCG, good barrel, good FCG. Cheap out on stock, stripped upper, handguard and stripped lower (forged, not plastic). Then get good optics, mid grade ammo.

June 18, 2013, 07:28 AM	#10
Mohave-Tec Senior Member Join Date: May 28, 2013 Location: Las Vegas Posts: 118	I'm building a very nice rifle.