[fez]

I noticed my barrel was a 1:7 twist. Under the barrel is stamped: wm 556 1-0-7 p. Which I imagine is a 1:7 twist. This surprised me because I only thought the vtac models came with 1:7. So I emailed SW. They only sold the lower. So this is a build? I did not know SW sold components. The bolt is marked dt hpt/mpi. I can't identify the carrier. The only mark on the upper behind the deflector is a triangle over an H. The top of the H is tapered in. Can you guys identify anything? Is it decent? SW reply:
We would like to thank you for your e-mail and contacting Smith & Wesson / Thompson Center.



Your firearm was produced on: 10/2/2008. It was sold as a lower only so I cannot tell you about the upper. It may not even be our upper. Sorry.

Smith&Wesson values its customers and we are happy to have served you today. Please do not hesitate to contact us should you require further assistance.

Regards, Steve

 

[fez]

Here are some pics:

 

[haertig]

This looks to be your bolt:

http://www.del-ton.com/AR_15_Bolt_Assembly_p/bc1008.htm

"DT" sounds like "Del-Ton", and their bolt is description includes the text "HPT/MPI". Sounds like a potential match to me.

I searched Google for some "AR manufacturer logo pictures" but didn't see yours ilustrated.

Obviously, you have a build, not a factory S&W product. I would ask the guy who sold it to you what its history is. A build is not necessarily bad. Many of them are better than factory-made. It would depend on the skill of the builder and the manufacturer/components they chose to use.

If your AR works, is reliable, and is accurate, it's a winner no matter what it's history is.

 

[fez]

This looks to be your bolt:

http://www.del-ton.com/AR_15_Bolt_Assembly_p/bc1008.htm

"DT" sounds like "Del-Ton", and their bolt is description includes the text "HPT/MPI". Sounds like a potential match to me.

I searched Google for some "AR manufacturer logo pictures" but didn't see yours ilustrated.

Obviously, you have a build, not a factory S&W product. I would ask the guy who sold it to you what its history is. A build is not necessarily bad. Many of them are better than factory-made. It would depend on the skill of the builder and the manufacturer/components they chose to use.

If your AR works, is reliable, and is accurate, it's a winner no matter what it's history is.

Delton seems to get overall good reviews. From what I read 1:7 is desirable because it can handle more weights from 55gr up. That seems ok. Now I wonder who manufactured the barrel and upper.

 

[Pwndy]

That's an 'Anchor Harvey' forging mark. No clue who did the machining though because they provide to several manufacturers. In just a short time of research I've found PSA, Olympic Arms, Bushmaster, Doublestar, LMT, BCM, Sig Sauer, and Colt uppers that are marked with that marking.

Honestly don't worry about who made it. Just shoot it.

 

[Steve912]

Delton seems to get overall good reviews. From what I read 1:7 is desirable because it can handle more weights from 55gr up. That seems ok. Now I wonder who manufactured the barrel and upper.

Now it sounds like Bubba lost the gas tube roll pin...in the kitchen.

 

[fez]

Now it sounds like Bubba lost the gas tube roll pin...in the kitchen.

See, that's what I'm concerned with. The build quality. I've tried to educate myself on these builds and what I found out is that who ever staked the key and receiver nut did the right job. The key seems to be moacks style stake job. Promising signs so far. The jerk o did misrepresent it though as a "Smith Wesson MP15".

 

[Steve912]

who ever staked the key and receiver nut did the right job. The key seems to be moacks style stake job. Promising signs so far. The jerk o did misrepresent it though as a "Smith Wesson MP15".

Yeah, well normally the bolt and bolt carrier are added as complete assemblies,
so that staking was done at the factory, not the kitchen table.

I can't recall seeing any keys or key-less carriers for sale, even in Shotgun News. Barrel extensions (the part with the locking lugs) are also typically installed on barrels, and not sold separately, so you shouldn't have any problems there, either.

A typical home build might be installing a barrel and gas tube onto an upper, with the builder putting the gas tube retaining pin into the gas block. Some barrels are sold with gas block and barrel nut installed, but bare barrels (with extensions) are available too.

Things to look for might be a gas tube that's not-quite aligned (gas tube hits one side of carrier key as it enters), loose barrel nut, broken index pin (on barrel extention--might not be visible without undoing barrel nut, and not necessarily a problem, but an indication of goofy assembly technique), twisted/tweaked/marred upper receiver (poor technique when torquing barrel nut), canted gas block/front sight base assy.

Was the seller the 'original' owner? If he bought it second hand, he might just be repeating what he was told, as being an S&W...

 

[fez]

Yeah, well normally the bolt and bolt carrier are added as complete assemblies,
so that staking was done at the factory, not the kitchen table.

I can't recall seeing any keys or key-less carriers for sale, even in Shotgun News. Barrel extensions (the part with the locking lugs) are also typically installed on barrels, and not sold separately, so you shouldn't have any problems there, either.

A typical home build might be installing a barrel and gas tube onto an upper, with the builder putting the gas tube retaining pin into the gas block. Some barrels are sold with gas block and barrel nut installed, but bare barrels (with extensions) are available too.

Things to look for might be a gas tube that's not-quite aligned (gas tube hits one side of carrier key as it enters), loose barrel nut, broken index pin (on barrel extention--might not be visible without undoing barrel nut, and not necessarily a problem, but an indication of goofy assembly technique), twisted/tweaked/marred upper receiver (poor technique when torquing barrel nut), canted gas block/front sight base assy.

Was the seller the 'original' owner? If he bought it second hand, he might just be repeating what he was told, as being an S&W...

Most of what you say gets passing marks. Also upper to lower fit is flush. No gap or wobble to speak of. The rifle seems to have a lot going for it so I'm gonna keep her. Shoots ok now so I have to get into sighting it in now and hopefully the stock stays put. I'm not going to get in touch with the guy as who knows if what he says is true anyway.

 

[fez]

By the way I got some more info from SW. The lower was sold as a complete assy.

 

[Steve912]

By the way I got some more info from SW. The lower was sold as a complete assy.

That's good.

As long as it feeds and cycles ok, the barrel & gas block are probably good to go, installation-wise.

I'm curious about the barrel. "MW" doesn't ring a bell and Del-Ton seems to mark their barrels.

http://www.gunsandammo.com/wp-content/blogs.dir/2/files/del-ton-dti-15/del-ton6.jpg

Edit: make that "WM", barrel marking.

 

[fez]

That's good.

As long as it feeds and cycles ok, the barrel & gas block are probably good to go, installation-wise.

I'm curious about the barrel. "MW" doesn't ring a bell and Del-Ton seems to mark their barrels.

http://www.gunsandammo.com/wp-content/blogs.dir/2/files/del-ton-dti-15/del-ton6.jpg

Edit: make that "WM", barrel marking.

Yeah, I'm curious also but can't come up with anything. You seem to know your way around the ar so I have a question for you: I have the m4 style ramps. The barrel extension is slightly higher where it meets the lower receiver creating a lip. Could a round get caught on this lip on the way into the chamber? Should I knock that lip down?

 

[Steve912]

I have the m4 style ramps. The barrel extension is slightly higher where it meets the lower receiver creating a lip. Could a round get caught on this lip on the way into the chamber? Should I knock that lip down?

Which pic looks like yours?

http://i.imgur.com/657njJ8.jpg

 

[fez]

Which pic looks like yours?

http://i.imgur.com/657njJ8.jpg

The best I can tell upper right m4 extension-m4 receiver. What's wrong with the "bad" one. To me the rifle ext looks the same as the m4 ext.

 

[Steve912]

The M4 ramps are wider and a shallower angle, and (by design) carry from
the barrel extension *into* the upper receiver.

The (older style) 'rifle' ramps are narrower, at a steeper angle, and exist only
in the barrel extension. There's actually a narrow 'lip' at bottom edge of each
ramp--the rifle ramps are not machined to full diameter of the barrel
extension (and that's where most of the problem comes, with this particular
mismatch).

A 'rifle' upper receiver has no ramps milled into it.

The lower left (ramped M4 receiver, 'rifle' barrel extension) is considered undesireable
as certain bullet weights/styles can tend to enter the receiver ramp and stall against
the edge of barrel extension.

I'm glad you don't have *that* combination.

 

[fez]

I see now but what about that slight "step" where the ext ramp meets receiver ramp? When I push a wood dowel up the receiver ramp I can feel a slight catch as it goes into the ext ramp on the lip where the two meet.

 

[fez]

Here's the best pic I could get

 

[Steve912]

Ugh....

I'm not 100% certain, but it looks like an M4 extension.

The receiver ramping doesn't look right...from that pic
it looks like there are burrs left at lower edges of the
ramps.

Look at the M4 receiver work in those pics again. The
receiver cuts should be symmetric, smooth and free of
burrs/wire edges from grinding.

It might just be the pic, but I get the impression somebody
("Bubba") cut/ground the receiver ramps.

 

[Steve912]

Can you get a pic thru the ejection port, like this?

http://i56.tinypic.com/28cetk1.jpg


Edit: Sent ya a PM.

 

[fez]

The pics are distorting things somewhat. The rifle shoots fine but I'm just trying to avoid trouble but want opinions first before I do anything. Best I colud do thru the port. Did you get my reply to your pm? I'm bad with that stuff.