AR project

[Mike]

I'm ordering a Shilen barrel for my new .204 AR project, but am torn on the twist rate. I want this gun to shoot 40 grain pills and have the option of 9, 10 or 12 twist. My Cooper is a 12 and does well with the 39 and 40 grain bullets, but part of me is afraid that the 12 twist will favor smaller 32 grain pills. I talked with someone at Shilen about this, but got nowhere.

Anyone else shooting a Shilen barrel in an AR that can offer some feedback?

[BabaOriley]

My AR has a Shilen Select Match 1:10 cut to 23". I haven't found many loads it won't shoot sub MOA with bullets from 32 to 50 grains. Groups do come easier with 39-40gr+ bullets, although I am still looking for velocities nearer 4000fps than 3600fps with an accurate load.

I'd recommend talking to Mike at Dtech and ask him about where to locate the gas port, and what diameter to make it.

I did some testing recently with Reloader 10x looking for some higher velocity, but it wouldn't cycle my AR semi-auto. My starting load cratered the primer yet would not cycle the action. I'm waiting for some Tubbs parts (flat wire buffer spring and others) that may help alleviate the problem, but until I can try them, I have come to terms with the fact that my AR may not be able to use the faster burning powders.

Here's an e-mail response from Mike at Dtech about the issue:
"I just finished and shipped a .20 Tactical (necked down and improved .223 case) to one of my customers in Long Island, New York. This is his 5th of my rifles, and he is a very skilled shooter and hand-loader. He had the exact same findings with 10X. The only difference being, his gas-port is just a little larger than yours.

As the article that you attached says, the gas-port is the key to feed and function. The port that you have is the same sized port that I have used for two years. Just very recently I had two different 20 cal rifles have feed and function that was right on the edge, so I increased the gas-port size to the next size up, and that took care of the issue. One of them was being shot in high altitude, so I theorized that was the problem. When the next issue popped up in Louisiana, I decided to make the next size gas-port standard on .20 cal rifles. The rifle I shipped to New York had the larger port and still experienced pierced primers and high-pressure signs, but yet it did not reliably feed and function. After visiting with him on the phone and giving him all of his options, he went with a different powder and everything was fine. What I told him was that if he was set on using that powder, I could adjust the gas-port to where it would work reliably with 10X, but then if he wanted to use some slower burning powders at a later time, he may end up with problems on the other end of the spectrum.

The article you send summed it up pretty well. ArmaLite also found the limitations to port-size in there AR-10 rifles. They sent information with the rifle that outright stated that it probably would not function with the lighter bullets. (they kept the statement simple as not to confuse the masses) Basically what they did was port their barrels for what "most" customers were going to use their rifles for, the heavier bullets. By doing that, they had a port that worked well with the heavy bullets, and slow-burning powders but would not feed and function reliably with the faster burning powders and the light bullets that went hand-in-hand.

Bottom line: I would be glad to open your port up to the new standard, or even beyond if you wish. From my new experience, the new port-size will still not allow you to use the 10X. If you are set on that powder, we would have to increase the port-size even further. I will open it to whatever you wish, but it is a "one way street" Once you open it up, that is what you have, unless you go with an adjustable gas-block or something like that.

There are other factors that can complicate feed and function issues besides the gas-port. Some after-market hammers drag excessively on the carrier and will cause problems with marginal gas situations. After-market operating springs that are designed to delay un-lock can exaggerate a gas problem. Dirty or galled buffer/tube can inject enough drag to give problems with feed/function.

Hope all of this helps. Let me know if there is anything you would like me to do for you.

Mike"

Dtech Contact Info:
(218) 444-7419 (Apparently he's only answering the phone on Monday and Thursday mornings due to a recent move of his whole operation, and a huge backlog of work.)
dtech1@paulbunyan.net

Dedicated Technology
1552 Carr Lake Road S.E.
Suite C
Bemidji, MN 56601

[Mike]

Baba: What kind of accuracy are you able to achieve with your 1:10 when you work up loads for that rifle? What bullet weight does it shoot best?

Thanks for the input!

[BabaOriley]

The 39sbk, just as for most everyone else in here, has shown great promise. I suspect the 40gr V-Max is going to be really good too, but have not really done proper load development for either of them. I have 600+ 39's but no V-Max left right now.

In preparation for prairie dogs in South Dakota this summer, I've tried to work up a load for the 34gr dogtown bullet using Ramshot TAC powder, because both components are very reasonably priced when considering loading 1000+ at a time. I've found 27.8gr TAC loaded at 2.244 COAL to be the best so far, although they're still only right at MOA at 100yds consistently.

I have 600+ 45gr Hornady soft points I plan on working up a load for this fall. I think these are going to be the go-to coyote bullet for this rifle. Hopefully they may be accurate to 300+yds.

I'll be playing with the 50gr Bergers some more this summer, but not really sure it's going to be a good coyote bullet. It may be best for long range fun on paper targets. With the few loads I've put together for these, you can almost feel the accuracy potential in them.

Sorry I don't have more information for you. I thought I'd have way more data collected for this rifle by now too. I've had it 9 months, but we had a long winter. I once had 7+ powders and like 8 bullets I wanted to use to do a comprehensive write-up on, and help find THE best load for my rifle, but someone (maybe in here) pointed out that by the time I shot all those combinations the barrel would be shot out anyway, and the replacement may not shoot the same combos the same anyway. I was told to pick from the best loads others have experienced, and start there. The problem is, nobody else with a 10 twist shares any information.

[Mike]

Thanks again for the information. Now, let me ask another question of you. If you were building an upper specifically for prairie dogs and 40 grain bullets, would you go with the 1:10 or 1:12?

[BabaOriley]

Thanks again for the information. Now, let me ask another question of you. If you were building an upper specifically for prairie dogs and 40 grain bullets, would you go with the 1:10 or 1:12?

I really don't know right now. Is there a 3rd option? 1:11.5? : ) I have yet to shoot prairie dogs with mine. It does seem I should be seeing more velocity out of a 23" barrel. I don't think I've asked the experts whether a tighter twist will rob velocity. I'm pretty sure the AR's gas operation will eat up some velocity, but not sure how much. Like I said, I do have a slightly stiffer spring on the way. Maybe that will improve something. Who knows.

I guess if I could be guaranteed the 1:12 would shoot all 40gr and under bullets, I may lean that way. I've said it before in here, that I think the advantage of the .204 over other cartridges may be lost when trying to shoot bullets heavier than 40gr. I'd probably order an 11.5 if I could on the next one.

[MT204]

Greetings. I've been a lurker for quite some time but have some opinions/questions about barrels.
I,m also building an AR-15 204.
I also struggled with twist/barrel length for quite some time.
About a month ago I ordered a Shilen 1:10 twist 24" and hope that I made the right choice.
I would have preferred a 1:11.
Both of my sons have Remington 700 SPS Varmits that are tack drivers.
The Remingtons have 1:12 Twist (measured) and 26" barrels and are shooting 40 grainers without any problems.
What I'm wondering is if that with the 26" barrels you can shoot 40 grainers but with 24" maybe, maybe not? Maybe I should have gotten a 26" with a 1:12 twist? When I talked to Shilen they said no to 26" barrel.
I'm hoping that the 1:10 will make up for the 26" barrel.
By the way Ill never be shooting anything bigger than 40 grain.

[Glen]

Welcome to the Forums MT!! Glad to have you here.

[Mike]

I guess if I could be guaranteed the 1:12 would shoot all 40gr and under bullets, I may lean that way. I've said it before in here, that I think the advantage of the .204 over other cartridges may be lost when trying to shoot bullets heavier than 40gr. I'd probably order an 11.5 if I could on the next one.

I would agree with you completely about the heavier bullets detracting from the .204's appeal. That's exactly why I want to shoot the 40 grain bullets well and don't care about the 45's and 50's.

I'm afraid that Shilen only has three twist options. I've ruled out the 1:9, so it's between the 10 and 12.

[MT204]

I called Shilen this morning just to double check if they could do a 1:12 twist 26" barrel, which I'm 99% sure would shot 40 grainers, but no luck.
So I guess we will wait for the 1:10 twist 24" and hope it will work.

[BabaOriley]

If Shilen won't produce a 1:11 I'm pretty sure someone will. I could swear I read somewhere that if it's a truly custom barrel, you can order whatever twist you want. It's just a setting on the machine. I understand this could raise the price, but I'm thinking Mike at Dtech doesn;t use drop-in AR barrels. I thought he machines the profile and threads himself from a 1" blank. Might want to check. If he does, that means you could order a (in no particular order) PacNor, Lilja, WOA, Krieger, Douglas, Satern, whatever manufacturer you want. I would bet one of them would build you an 11.5 twist if you want. It's probably just a matter of money. I know WOA has an 11 twist standard.

[Mike]

One more perplexing question about Shilen. If you look at Midway's web site, the Shilen barrel/bolt combos are significantly cheaper than if you buy direct from Shilen. Of course, Midway is out of stock (due to bolt backorder at Shilen). I'm sending my bolt to Shilen so that I can get the barrel ordered, but I still don't understand why it's more expensive to buy direct?

There are benefits to orderind direct from Shilen that might make up for the difference. I can specify the twist rate (with limited options) and Shilen will cut the throat to match my dummy rounds. I'm not complaining, but am curious about the price difference. Any thoughts?

[glenn asher]

Mike, I'd guess that Shilen doesn't want to undercut it's wholesale customers, and that's the reason for the price differences. Midway buys a LOT of barrels, while you and I, the retail customers, do not buy as many. In an effort NOT to irritate the big buyer(s) they have a different price structure.
The countertop company I work for, does the same thing, we charge more for countertops straight from our shop, than Home Depot or Lowes, who buy them from us. Partly, it's due to contractual obligations, of course. We couldn't sell nearly as many tops directly, so we need the monster stores to help move the product, we cut them a deal. It helps keep people working in tough times, or I'd be out of work I don't like it, but that's what it takes.
I have no way of knowing for sure, but that's pretty standard practice in business.

[Mike]

Good insights, Glenn. I would agree that you are most likely correct in your assessment.

[nad1967]

Guys I'm in the same boat... I shoot 32 - 40gr (Mostly 32gr VMAX and 39gr SBLTZK) and I am in a toss up between the Shilen 1-9" or the sabre defense 1-12"

your thoughts/experiences?