Official (DTA) SRS, HTI, Covert, Hunter Thread

Re: Idea! Official DTA SRS, HTI, Covert, Hunter Th

My first thought was also that the mags could be better. But you know, the more I run them, the better I'm liking them. I've now run several hundred rounds through each and they do what they're supposed to do. Absolutely no mag-related failures of any kind as yet. For me, they loosened up and became quite easy to load after a few tens of rounds, even when the temp has been in the teens and while wearing gloves. So my take now is that the only thing about these mags that I'll probably never completely get used to is that they don't hold 30 rounds like my 5.56s (LOL). Can't have everything.
 
Re: Some load development

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killer Penguin</div><div class="ubbcode-body">Worked up a ladder today since the weather finally broke.

Date: 1/2/2011
Time: 3pm
Location: Home
Rifle: Thor 338LM, 26" 1:10 DTA factory barrel
Elev: 0
Humidity: 91%
Temp: 21f
Pressure: 28.37
Light: bright/snow
Wind: 10mph 4 O'clock

Bullet: 300gr Scenar
Case: 1x fired lapua FL sized
Primer: CCI 250
Powder: Retumbo

10rnds loaded at 91gr. I fired 3 to get zeroed at 100yds, then 2 more to confirm zero. I then let the rifle cool, and fired a 5rnd group at 300yds. My first shot, I neglected to put elevation in the gun and it dropped a mil low. Oops.
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The next four dropped in a little low and left.

<span style="font-weight: bold">Charge - Velocity</span>
<span style="color: #008000">91gr - 2678
92gr - 2680
93gr - 2739
94gr - 2767</span>
<span style="color: #0000FF">95gr - 2773 slight ejector wipe</span>
<span style="color: #FF8000">96gr - 2805 ejector wipe, slight primer flow into firing pin hole</span>
<span style="color: #FF0000">97gr - 2837 ejector wipe, primer flow into firing pin hole
98gr - 2865 pronounced ejector wipe, pronounced primer flow into firing pin hole</span>

I'm going to load up a few rounds at 94gr's and see how they behave.

With my current numbers at 94gr of retumbo and 100yd zero, I have enough elevation in my turret to get to 2060yds. That will increase to about 2100yds when the temp gets up to 70f+. So says Ballistic FTE anyway.
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With the premier 5-25 and 40MOA DTA base, I've got 27 mils of available elevation in my turret. From dead bottom of the mechanical adjustment, I had to come up 5 mils to get zeroed at 100yds.

I can't wait to stretch it's legs a little bit... and I REALLY can't wait for my suppressor. This thing is LOUD. The YHM QD brake/suppressor adapter is actually a pretty effective brake. They offer two QD mounts. One is just the standard bird cage looking thing. The other is an actual brake. I opted for the brake, and I'm glad I did. It attenuates recoil quite well. I fired 18rnds total today off a bench and it was very manageable.
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Great info here. This is the stuff that I like to see on this thread.

Thanks to all that have contributed information in regards ot the DTA line of rifles and keep it up!
 
Re: Some load development

I just dropped down from a S&B 5-25x56 to a S&B 4-16x50 and need to change out mounts from DTA's 40MOA to a 30MOA. Are there any choices out there from LaRue or others that will maintain proper height of scope to DTA's built in cheek "rest" ?
 
Re: Some load development

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ColdBore007</div><div class="ubbcode-body">Killer Penguin, Looks like you have a hell of a nice space to shoot not far from home! I'm loving the setup! </div></div>

Thanks.
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My woman took those pictures right out the front window. That very same window that I shoot my suppressed stuff out of in the winter. I figured the lapua with no suppressor would break my window though! So I had to go outside. Once the suppressor shows up, I won't be out there. lol

Yesterday we drug some steel out to 725yds. Here is why I usually shoot in the house. We had to dig a trench through the snow to clear a shooting lane.

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Re: Some load development

Oh boy. I took the barrel out tonight while cleaning, and noticed a ton of rust on the barrel extension. Any of you guys seeing anything like that? I just had it out a couple days ago and there was no problem.

It was just on the barrel extension, not on the barrel itself. I noticed on both my 338 and 308 barrels that the barrel extension is not colored the same as the rest of the barrel. The barrel is dark black, while the extension is kind of maroonish color or something. Definitely different than the barrel, and apparently VERY prone to rusting.

Now I'm sitting here trying to figure out how to clean down inside where the barrel gets clamped. This makes me very nervous about leaving a barrel in this thing for any period of time.
 
Re: Some load development

Penquin, the barrel extension is steel the receiver is all machined aluminum. Just great a few Bounty and some good gun oil and just lub and rub until the reddish stuff quits coming on to the Bounty and then put a little gun grease like Riggs or what ever you have on the extentiona and rub it in good. Thats all I do to mine and it pretty much makes the surface rust a none issue. Howeer, I did that first night I got my first DTA and never had the issue.

My guess is in shipping...the gun was in and out of a lot of hot and cold places and it had condensation form.
 
Re: Some load development

Penguin,

I just checked mine...no rust whatsoever, and I've had it in and out of 20 degree weather many times in the last month. FWIW, I went ahead and did what Guns suggested prior to replacing the barrel. Probably can't hurt. I would add that if you've already got some rust on yours, you might want to try a little penetrating oil (Kroil or similar), just as a preventative. Also, the color of both of my barrel extensions is a darkish gray, definitely lighter than the flat black of the barrel, but not anything like "maroonish".
 
Re: Some load development

Penguin, I am wondering what kind of accuracy you are getting? I couldn't get Retumbo, or H-1000 to shoot real well through mine. I finally went to R25 and with 89 grains (above max, work up) I get awesome accuracy with the 300 Scenars. Shoots .5" at 100 easy, and when I can put my shooting habits aside does sub .25". Velocity is like 2680 though.
 
Re: Some load development

I cleaned up the barrel/extension good with #9, then lubed it up good with break free. I'm pretty confident that it will be just fine. The look of horror when I found the rust was award winning no doubt, but I've since gotten over it. However, I'd recommend everyone clean theirs up and put a light coat of something on there. I talked to Ethan today and he was prepared to do whatever it took to make me happy. I just suggested that he add something to the manual saying to lube up the barrel extension good. I hope no one took my comments as a shot at DTA. If I was that concerned about it I'd have them replace the barrel. It was just surface rust, and I was just shocked to see it so fast is all. In any event, Those reading this thread now know to oil that up a bit!

As for accuracy, I honestly couldn't tell you yet fireguy. I'm still working with load development and getting the rifle setup how I want it. I felt like I was stretching when shooting it so I grabbed a tape measure and measured my AICS. LOP measured from the trigger to the end of the butt was 13 1/2" on the AICS. On the DTA, I had all 3 shims installed, and it was like 16 or something crazy like that. I took all the shims out and it is MUCH more comfortable now. I forget what it measured with the shims removed. Something like 14" I think. The big dudes will really like the DTA.
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I'm not getting too crazy with load development until my suppressor shows up. That, and frankly its hard to do any solid testing here in the winter time. It's windy as hell every day, and shooting when its 2 degree's out just isn't that fun no matter what you are wearing.
 
Re: Some load development

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The big dudes will really like the DTA.
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I'm a pretty small dude
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- and I love DTA's ergonomics and size!

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I'm not getting too crazy with load development until my suppressor shows up.</div></div>
And my suppressor won't show up until my state changes its, er, political orientation.
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Re. winter load: my plan is to develop a good summer/mid-season load, and then "bite the bullet" (no pun intended) and just accept the fact that in winter it will not reach as far (accept some measured performance degradation).
 
Re: Some load development

Penguin,
Best all around anti-rust I have found is Kroil from Kano Labs. Works great for cleaning out the barrels as well (creeps into spaces as small as One Millionth of an inch!! Great pics btw!
 
Re: Some load development

Just pulled my .308 barrel out for the first time in a while and found the same rust issue. Accuracy wasn't effected, but I scrubbed it pretty good with some Hoppes #9. I'll oil it up real good tonight. I'll be looking for that Krones though. Sounds like good stuff!
 
Re: Some load development

Well I would imagine their coating options are limited in order to ensure proper headspace and all that. I've no problem putting a little extra lube on it, but knowing to do that out of the box would have been better than seeing it rust and getting blindsided. As fast as it got that way (2 days) I knew I wouldn't be the only one having the issue. It didn't come from DTA oiled up, so I figured the coating would take care of itself.

DTA isn't the only company I've dealt with where they were juggling coating's around and using paying customers for R&D. It's sad, but a situation that happens when some companies are in their infancy.

Anyone know if kroil will eat the plastic skins on the DTA?
 
Re: Some load development

Depends on the type of plastic. Your best bet with Kroil is simply to wet a rag with some and carefully wipe down the outside of the barrel extension where the corrosion is located. Let it sit a few minutes, then wipe it off as carefully/thoroughly as you can. The Kroil will do most of the work for you, it's incredibly "penetrating" as penetrating oils go. I'm not sure of what plastic skins you're referring to (maybe they're not on my Covert chassis?), anyhow, unless you're sure that it's resistant, I'd keep the Kroil away from the plastic.
 
Re: Some load development

Nick, what would you recommend for us as a prevention for those who would rather avoid the rust in the first place? BreakFree CLP? Kano Kroil? Which of the protector oils would be safe on the plastic parts? Should we oil the extension inside as well? Chamber - for the time the rifle is not being actually used?
 
Re: Some load development

Any standard oil lube/protectant will work, I use KG or CLP. Current barrel extensions and bolts are parkerized which has great corrosion resistance, but lube is still recommended for smooth bolt operation.
 
Re: Some load development

I'll follow up Penguin's post by adding my own load development

Date: 1/10/2011
Time: 2pm
Location: Northern California
Rifle: DTA SRS w/ DTA 338 Lapua barrel
Elev: 146 ft
Humidity: 58%
Temp: 48 F
Light: Overcast
Wind: 5-10mph at 45 degrees

Bullet: 250 gr Lapua HPBT Scenar
Case: 4 x fired lapua. Primer pocket mic'd and cases cut to 2.714.
Primer: Federal Match - GM215M
Powder: Hodgdon 4831SC

Fired 5 round groups at 100 yards except for the highest charge. Cold Bore (clean barrel) on my DTA is always high first round. All follow on shots are on target.

Charge - Velocity
Cold Bore (84 gr) - 2684 fps
84gr - 2716 Average, ES 9 fps, SD not available (4 shots - 5 needed)
86gr - 2781 Average, ES 22, SD 9
88gr - 2838 Average, ES 44, SD 15.5
90gr - 2895 Average, ES 11, SD 3
92gr - 2961 Average, ES 9, SD not available (2 shots - 5 needed)

All show slight primer flow into firing pin hole.

Also LOVE my new tactical bag...has barrel rest. The whole rife fits in the bag either up or down.

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Re: Some load development

I was having surface rust issues on my barrel too; decided it was a good idea to cerakote the rifle since it will be packed away for the next year or two. Did all of the laborious degrease work Saturday afternoon, then coated the barrel, brake, receiver and mags all separately, then cooked them on and let them sit overnight. Looks and feels amazing!

Lesson learned: don't Cerakote where the barrel attaches to the receiver.

Result: Cerakote is too thick and the barrel will no longer seat into the receiver.

 
Re: Some load development

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sr90</div><div class="ubbcode-body">but lube is still recommended for smooth bolt operation. </div></div>

So we're clear here, the OUTSIDE of the barrel extension is what rusted up on me, not the inside. This wouldn't effect bolt operation in any way that I can think of.

I run a red grease on my lugs and tend to clean the action of my rifles quite well, so I wouldn't guess rust would be a problem in there.
 
Re: Some load development

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BBB</div><div class="ubbcode-body">All show slight primer flow into firing pin hole.</div></div>

This is my first 338LM, so can someone tell me if this is just a DTA thing, or if most 338's abuse the primers like this?

Another question. When I push the 5th round into my magazine, its quite tight. Tight enough so that it is very difficult to get it into the chassis with the bolt closed. Everyone else's like this as well?
 
Re: Some load development

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killer Penguin</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BBB</div><div class="ubbcode-body">All show slight primer flow into firing pin hole.</div></div>

This is my first 338LM, so can someone tell me if this is just a DTA thing, or if most 338's abuse the primers like this?

Another question. When I push the 5th round into my magazine, its quite tight. Tight enough so that it is very difficult to get it into the chassis with the bolt closed. Everyone else's like this as well? </div></div>

I suppose it depends on the load and what primers you're using. I can tell you that out of a few hundred rounds fired last june in both my DTA SRS and a friends Sako TRG42 we couldn't tell the difference in the brass as far as case stretching, primer flattening or anything else. I'd say check your load.

Frank
 
Re: Some load development

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: biffj</div><div class="ubbcode-body">I'd say check your load.

Frank </div></div>

I'm still doing load development, but was just curious if this happens on most 338's or just DTA's. I get flow pretty quick. I mean 94gr of retumbo behind 300gr scenar's isn't that "hot" from what I've read.
 
Re: Some load development

some of this will depend on what primers and brass you are using. I started out working with retumbo, federal large magnum rifle primers and brass from hornady, privi and lapua. What I found was that 93gr of retumbo would push a 250gr sierra match king bullet at about 2750fps in the lapua brass, 2850 or so in the hornady brass and 2950 in the privi brass. I had some primer flow in all of them. The privi brass seems to have the thickest case head and therefore the lowest powder capacity and it builds more pressure. I tried using Remington large magnum rifle primers and have no where near as much primer flow. I think the federals are softer.
I quit using the retumbo. I couldn't seem to get near the claimed velocity out of the powder. I started using IMR 5010 and got up to 97gr with no pressure signs using the same brass, bullet and primer. Velocity is very similar to the retumbo. The problem with this powder is capacity. 97gr in the privi case is about max. You can hear the bullet crunching when you seat unless you shake the case down well....even then there isn't room for any more. I'm still getting more velocity out of the privi cases but not nearly as much as before. I'm looking at some other powders to try like WC868 which has been used with great success in many other cals like 30-378Wby, 7mm Mag, some of the 6 and 6.5mm rounds, .50 BMG etc. Its a ball powder instead of the extruded 5010 so it will fill the case more efficiently as well as being a slower burn. There are many things to take into account when reloading and what works in my rifle may be a slug in yours or maybe show high pressure evidence. My buddies Sako is running 95gr of Retumbo with the 250gr SMK's in Lapua brass and getting 2950fps quite regularly. Running that load in my DT SRS give hard bolt lift, flat primers and about 2850fps. Might have something to do with the extra inch on the Sako (27" vs 26"bbl) or who knows what. I'm just working on my rifle so thats the scoop.
On the 300gr side I've not done a lot of loading other than to find that 92gr of retumbo is about max in my rifle. Thats about 2450fps and pretty disappointing. I've loaded some with 5010 and I'm working on a load with WC868 and WC890 to see if I can fling the heavies out there a bit faster. In my opinion 94gr of retumbo is a hot load with a 300gr bullet.
Frank
 
Re: Some load development

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: biffj</div><div class="ubbcode-body">On the 300gr side I've not done a lot of loading other than to find that 92gr of retumbo is about max in my rifle. Thats about 2450fps and pretty disappointing. </div></div>

Wow. That would be disappointing. I just went back and looked and 92gr retumbo gave me 2680fps. Strange to see that much variation amongst these rifles.
 
Re: Some load development

The variation is in the powder or the chrono's. The barrels are from the same manufacturer. We don't see this type of variation between barrels with the same loads from the same lots of powder.

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Re: Some load development

I have noticed flow on everything I have shot including factory Lapua 338 ammunition (i.e. non-reloads). If I remember correctly if I looked at the bolt face the firing pin hole seems to be larger in diameter than the firing pin by an amount similar to the flow diameter. I have not seen any adverse effects to date. Have also not seen any primer compression. Only flow.

I did however have an ejection problem. Almost every round would not eject properly. I tracked it down to the extractor. I took the extractor out of the bolt and polished the edges using a polishing stone and compound. My brass now flies out. I attribute it to the edges of the extractor. Before the fix the brass would get caught on the edge of the extractor. The brass would show two marks were the edge of the extractor gouged the brass.
 
Re: Some load development

Anytime. Now just saving funds for a second barrel and bolt. The bullpup is perfect for completely fitting in my Eberlestock G4 tactical bag. The tactical bag looks like it will also hold the barrels nicely on the long side pockets. One side for barrel and the other for the bipod.
 
Re: Some load development

The excessive flow is coming from the firing pin clearance. Maybe Fredo can chime in and explain why they are running so much clearance on the pins. I suspect is because of the floating pin design and to insure that you don't get any slam fires from a sticky pin. The pin in my bolt measures about .065 thousands and the hole in the bolt measures .081 thousands. That is .016 total clearance. I actually bushed my bolt and turned pin to .060 thousands. I have approximately 150 rounds down mine since bushing it with no problems at all.
 
Re: Idea! Official DTA SRS, HTI, Covert, Hunter Thread

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> Maybe Fredo can chime in and explain why they are running so much clearance on the pins.</div></div>

I will ask the developer tomarrow.
 
Re: Idea! Official DTA SRS, HTI, Covert, Hunter Th

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fredo</div><div class="ubbcode-body">HTI with .50BMG Conversion with new DTA Brake. Got a couple photo's while shooting yesterday. More to come.
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Looks like the muzzle break is designed to take a suppressor? Can you tell us more? Or do we need to visit the booth at SHOT Show?
 
Re: Idea! Official DTA SRS, HTI, Covert, Hunter Thread

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This is a recent one in Coyote for a DTA owner that runs 1 Spacer and needed allot of forward weld. Plus he wanted me to add space to hold a piece of 1/4 up to 1/2 Sorbo I made the weld 1/4 to 3/4 inch adjustable. I was going To add rubber to the top but that 1 1/2 inch webbing actually felt very nice and solid weld. Plus it's dam near bullet proof.