300 grain Berger velocity results!

Tyler Kemp

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Shot through my 338 Lapua Improved, velocities were consistent with about 10 fps spread. Shot with a 32" barrel, and 104 grains Retumbo. I shot groups under MOA at 425, but mirage was horrible, couldn't shoot precisely.

MobilePhotoMay30201092943PM.jpg


MobilePhotoMay30201092824PM.jpg


MobilePhotoMay30201092905PM.jpg
 

patches

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Re: 300 grain Berger velocity results!

104 grains of Retumbo!!!! Holy crap. That is smokin'. Any signs of pressure?

Glad to see you had good results. I am looking forward to see what kind of results others have had with these bullets. I should have some loaded for a regular 338 Lapua Magnum and will start at 96 grains of Retumbo.

BTW what is the case capacity differences between a regular 338 lapua magnum and 338 improved?
 

Tyler Kemp

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Re: 300 grain Berger velocity results!

My fired cases hold over 120 grains of water.

104 grains showed the slightest hint of an ejector mark, but the primer still
looked perfect. I can get some pics of fired cases soon.
 

strictlyRUM

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Re: 300 grain Berger velocity results!

If Lapua brass is showing ejector mark you are WAY hot. Not the best indicator for pressure. Looks like a burr scar twords the top of the case too. Thats what is looks like if your reamer grabs a burr and makes a gouge around the chamber. Have you had a casting done on the chamber? Does that show on all your brass?
 

Tyler Kemp

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Re: 300 grain Berger velocity results!

I have not done a chamber cast however...don't see any need to.
 

rman1

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Re: 300 grain Berger velocity results!

Tyler, are you using a Redding die set?

Thanks.

R.
 

Lt. Arclight

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Re: 300 grain Berger velocity results!

My Lapua brass fired in a GAP chambered Bartlein (25" 1/9.5" twist) holds 116. Quickload uses 108 as a default case capacity-obviously very conservative. I shot them with 90.0 retumbo and got very good results at 300 yards- 5 shots in 1.3inches- I am NO way over 2650fps-at least compared to come-up based on my 300SMK loads. Hot hazy day. 86degrees @1600feet.

96 of Retumbo gives me pressure signs with 250 Lock bases stiff bolt lift-FWIW. YMMV according to your chamber. I am limited to 3.610 or so with AI mags. And its a VERY tight chamber with 3.600" being .020" from the rifling.

3066 is REALLY stout.What twist are you using. That is impressive velocity.The coal looks alot longer than 3.681"-is it?
 

Tyler Kemp

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Re: 300 grain Berger velocity results!

1-9.5" twist. As stated, it's an improved case, tons more capacity. I forget the exact amount, but well over 120, and possibly 130.
 

strictlyRUM

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Re: 300 grain Berger velocity results!

I am talking about the ring just under the shoulder to body junction. This is a typical place for a reamer to wrap a chip during one of the cleanouts. It is also a common place for cases to come apart if you are running too much preasure or headspace is set too heavy. I am not trying to attack you just worries me running that much powder. I have a 338 improved and wont run that load. I have also seen that mark before. Just something to check out. Rather be safe than sorry.
 

Tyler Kemp

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Re: 300 grain Berger velocity results!

That ring under the shoulder is where they rub in their slots in my ammo case. So all of them have it, but just because of that.
 

psinclair

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Re: 300 grain Berger velocity results!

Tyler....very impressive!!

Are you shooting single shot or will those feed through a mag?

Really like the looks of that AI'ed!! I may have to try that one my next re-barrel..
 

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Re: 300 grain Berger velocity results!

strictlyRUM-

I have had really good results with 300 grain scenars in the past and 96 grains of Retumbo and no signs what so ever. Gets somewhere in the area of 2800 fps. I have been debating going up since my DTA SRS can handle quite a long round in the magazine. I think I have heard about guys going out to 3.7-3.71" with the DTA. What is the hottest load you have run in a 338 using Retumbo?


Tyler-

Why is the neck of your brass black?
I would like to see the fired case as well.
Was 3066 an average for the day?

Thanks for the info!
 

Lt. Arclight

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Re: 300 grain Berger velocity results!

Quickload data is not to be discussed as per forum rules and that said,the program is only a tool. I will say that Hodgdon's data for the 300SMK loaded to 3.600" coal states 94 is the max load and even if you consider there data conservative(I personally don't)94grains is a compressed load.

Granted longer seating lengths will give up a little more case capacity but I wouldn't even remotely consider 96gr. as your STARTING load. On the other hand, you have had good results with 96gr.-I'd be careful if you get a new lot though. That is a HOT load.
 

strictlyRUM

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Re: 300 grain Berger velocity results!

I try and stay away from sharing load info. Everyones chambers, brass, powdermeasurers, etc are different. I was just concerned when someone says extractor marks on lapua? I have had them about 5 degrees before I was popping and burning thru primers. Bolt still opened fine. That is not the best way to test preasures. You dont get velocity with out something? Its not majic its science.
 

patches

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Re: 300 grain Berger velocity results!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: nolo263</div><div class="ubbcode-body">What is the BC on the berger? </div></div>
.891
 

Lt. Arclight

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Re: 300 grain Berger velocity results!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: strictlyRUM</div><div class="ubbcode-body">I try and stay away from sharing load info. Everyones chambers, brass, powdermeasurers, etc are different. I was just concerned when someone says extractor marks on lapua? I have had them about 5 degrees before I was popping and burning thru primers. Bolt still opened fine. That is not the best way to test preasures. You dont get velocity with out something? Its not majic its science. </div></div>

I agree 100%. Lapua brass is so strong,I think it gives a false sense of security. Most loads flatten primers,but depending on your action and chamber dimensions some overpressure loads won't even give you a stiff bolt lift. But when you have brass trying to flow into the ejector-things are about to happen. Its a bad day when it happens with 68K Pmax.

I've recently had some very high pressure excursions with a new supply of RL25-hence my switch to Retumbo.
 

Jerry R

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Re: 300 grain Berger velocity results!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: strictlyRUM</div><div class="ubbcode-body">Looks like a burr scar twords the top of the case too. Thats what is looks like if your reamer grabs a burr and makes a gouge around the chamber. Does that show on all your brass? </div></div>

All my formed 338 Imp. cases have the same mark on them. The ring is where the original shoulder was before it was blown out to 40 degrees. Nothing to worry about.

Every one of my improved cases from all calibers have a very similar mark.
 

762frmafr

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Re: 300 grain Berger velocity results!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jerry R</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: strictlyRUM</div><div class="ubbcode-body">Looks like a burr scar twords the top of the case too. Thats what is looks like if your reamer grabs a burr and makes a gouge around the chamber. Does that show on all your brass? </div></div>

All my formed 338 Imp. cases have the same mark on them. The ring is where the original shoulder was before it was blown out to 40 degrees. Nothing to worry about.

Every one of my improved cases from all calibers have a very similar mark. </div></div>
+1...not only that, i was present at load development with TYLER...we were very careful, and between the 2 of us we have forgotten more about interior and exterior ballistics than most men. that load is safe....AND FAST!!!
 

Jerry R

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Re: 300 grain Berger velocity results!

I've been using US869 in my 338 Lapua Imp. with an average of 3004 fps with spreads between 14-22 and have been entertaining the idea of trying some Retumbo. Now you have aroused my curiosity just enough to load some and try it next weekend.

Thanks a lot!!!!!
crazy.gif
 

Tyler Kemp

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Re: 300 grain Berger velocity results!

Nathan Dagley of straightshotgunsmithing.com did all the work.
 

strictlyRUM

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Re: 300 grain Berger velocity results!

+1...not only that, i was present at load development with TYLER...we were very careful, and between the 2 of us we have forgotten more about interior and exterior ballistics than most men. that load is safe....AND FAST!!!

Ok again I think people are fealing a bit attacked. No need to prove how much you know about ballistics. "most men" on here know far most than "most men" on other sights so you may not want to go throwing that around. I am not talking ballistics anyways. I am talking metalurgy. That mark is not where the shoulder was. Period. I have done a few ackleys and none of them have that mark. When brass is formed at say 50,000 cup it takes the form of the chamber. That is why you can even see marks left in the chamber from scotch bright if you dont do it correctly. That mark means one of two things. The first is a burr ring. VERY common on ackleys if you are not carefull in chambering, because of the sharp shoulder and very low taper of the case. The second can be case head separation. Either too generous on the head spacing or bolt setback from overpreasure loads.

Now on to the preasure issue. I am sure if you are guaranteeing that is "safe" you hooked up a strand guage to it and you can tell us what preasure you were running. I can tell you that ackleys are much harder to get the brass to "flow" into the ejector. The ackley is built around the idea of little to no brass flow or bolt thrust. If you are getting brass to flow on lapua 338 in paticular you are around 68,000-72,000. Now I am not sure on the improved because my experience with the preasure guages was before I improved one. But with the other ackleys it will jump you flow preasure up quite a bit. Around 70-75,000. I am not trying to get into a knowledge based pissing match. Just informing you that what you have is some extremely high preasures. What is safe to you at your current temperature may blow the next guy up. Or at least ruin his barrel.(most common in extreme over preasure cases) Just not a good idea to go telling others its "safe". They shoot your load at an outside temp 20+ degrees higher or even with a different primer and things could go very wrong. With retumbo it is so temperature sensitive I will have loads broken down to 10 degree spreads if I am running full tilt loads. I have spent alot of time in a ballistics room with the propper equiptment and even more time building the machines that make bullets for some of you. I have even spent time trying to purposefully blow up an action to test it before it was made available to the public. I am not saying I havent run my 338 lapua imp up to 3050. I am saying I would never tell anyone its safe. It also didnt take that much powder.

This is what a formed case should look like

beb40911.jpg


Oh yeah when we were testing said action..... The cases got a mark similar to yours quite a while before the barrel blew off of it. For the record we were using a hammer to open the bolt around 20grns of blue dot and if I remember corectly the barrel didnt blow off until around 23.5? Did I mention we were testing a 300WSM?



 

strictlyRUM

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Re: 300 grain Berger velocity results!

I forgot. There is another way to get that mark. Over working brass during reloading. If you size it back too much it has the same effect as too much headspace and can cause case head separations. But you had mentioned the neck sizer and the mark was only half way down the neck. So I kinda ruled that one out. But that is another way.

Jason
 

Lt. Arclight

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Re: 300 grain Berger velocity results!

"+1...not only that, i was present at load development with TYLER...we were very careful, and between the 2 of us we have forgotten more about interior and exterior ballistics than most men. that load is safe....AND FAST!!! "


+1 stricklyRUM- agree 100%

762frmafr that's a pretty bold statement.
sleep.gif
 

Tyler Kemp

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Re: 300 grain Berger velocity results!

Look, I never said anything. The mark around the case is
from the ammo box it sits in. It's an MTM case. Every box of ammo
I have gives these marks.

As far as I know case head seperation happens at the case head, never have saw it occur that high up.

Anyways, I can assure you that this isn't happening. I wasn't trying to get into any knowledge contest either, was just reporting some speeds. I guess this is the reason I rarely post on here.
 

strictlyRUM

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Re: 300 grain Berger velocity results!

No sweat brother. Unbind the panties. How the heck does and ammo box do that? Not being an ass just asking? Case head separation is yes near the case head. It is used as a broad term. But yes when an ackley fails its usually in that area.
 

shootaround

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Re: 300 grain Berger velocity results!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: strictlyRUM</div><div class="ubbcode-body">I try and stay away from sharing load info. Everyones chambers, brass, powdermeasurers, etc are different. I was just concerned when someone says extractor marks on lapua? I have had them about 5 degrees before I was popping and burning thru primers. Bolt still opened fine. That is not the best way to test preasures. You dont get velocity with out something? Its not majic its science. </div></div>

Sharing info including loads is what this site is about right?
I wish I know half about guns and reloading as you do.
 

Tyler Kemp

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Re: 300 grain Berger velocity results!

I'll try to make this simple.

When my brass ride in their cases, they get rubbed by the plastic, leaving a brighter than the rest of the case ring. For my 338 this is just below the shoulder, for my 6mm it is right on it.

Allow me to demonstrate:

MobilePhotoJun2201090429AM.jpg


MobilePhotoJun2201090548AM.jpg


MobilePhotoJun2201090626AM.jpg


MobilePhotoJun2201090656AM.jpg


MobilePhotoJun2201090508AM.jpg


MobilePhotoJun2201090747AM.jpg


MobilePhotoJun2201090723AM.jpg


Make more sense now?
 

Bugholes

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Re: 300 grain Berger velocity results!

Every parent case I have ever improved had this ring in exactly the same location as where the original shoulder was. Jerry R is right
 

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Re: 300 grain Berger velocity results!

TylerKemp,

Pics aren't good enough, we need video of said cases rattling around in the ammo box...j/k
wink.gif


I had trouble with the MTM's rattling my loads around also, so I put a piece of foam rubber in the top of the case and problem solved. Just be careful not to use to thick of a piece or over time it can seat your bullets a little deeper.

Those are some impressive numbers! I wonder how Viht N570 would do in your rifle?
 

PreArms

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Re: 300 grain Berger velocity results!

I noticed your MTM box holds the rounds bullet up. I keep ordering MTM boxes, supposed to be bullet up but they only hold .338 rounds bullet down. What is the part # of your boxes?
Thanks, John
 

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Re: 300 grain Berger velocity results!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: strictlyRUM</div><div class="ubbcode-body">With retumbo it is so temperature sensitive I will have loads broken down to 10 degree spreads if I am running full tilt loads.
</div></div>

I thought Retumbo was one of Hodgdon's extreme powders that was supposed to be pretty temperature stabile? I have seen my Varget loads stay nearly the same in both 15 degree and 70 degree weather. Please let me know what's up, as I'm trying to select a powder for my 338LM and am looking for as much information as possible.

Thanks,

Mark
 

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Re: 300 grain Berger velocity results!

I have a 338 Allen Express (338 Lapua Improved) with a Seekins DM installed, so I can seat them long (3.895"). My go to load is 100.0 grains of Retumbo which is nowhere near a top load. I get 2950 fps with this load using 300 SMK. From what I have heard, the 300 gr. Bergers run about 50 fps faster than SMKs. I don't see any reason why someone couldn't run the Bergers at 3066 fps within safe pressures.

Not to mention, the improved Lapua case has minimal body taper which serves as a fairly sensitive pressure indicator if you are getting into the dangerous range. If you run into any sticking during extraction, you know you need to back off.

It's great to get some feedback on the Bergers in a 338 Lapua Improved. Good work, Tyler! Keep it up as I will be working on some loads for my 338 AX with the Bergers here shortly.

I'm sure anyone expressing concern with your load is just trying to ensure you stay safe which I have no doubt you are. Don't take it personally.

I have also found Retumbo to be fairly heat stable. Especially when compared with US 869 or WC 872!
 

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Re: 300 grain Berger velocity results!

I also just noticed that Tyler is using a 32" barrel. I have a 26" barrel on mine. Should be able to get up to 3066 fps no problem with that long barrel. I would expect a little more velocity with 104.0 grains of Retumbo. Could be a slower lot of powder.

Did you work up to 104.0 grains? If so, what kind of velocities were you getting with lighter loads? I'm probably going to start at 100.0 grains and work up, but I'd be curious to hear your results first.