Hornady 338 300 grain A-Tip

[BoltActionBrotherhood]

I was finally able to test them at distance a couple days ago. I came up with a G7 of 0.448 for the whole trip to 2300 yards. The bullet was almost down to 1100 fps. G7s for higher velocities/closer distances will likely be higher.

The BC isn't really the point, it's an added benefit. They held vertical better than anything I've seen except the 30 caliber 230 grain ATip, and they certainly weren't any worse than that.

I didn't have any problems with seating using the Tubb 33xc dies. With the 30s and RCBS or Redding dies, I bore the seater stem with a 3/16 end mill until the tip of the bullet doesn't bottom, polish the edge of the hole, and then lap it in with a bullet.

I agree the do awesome. Here is a group at 2000 yards 7/10 impacts with the atips

 

[BoltActionBrotherhood]

The .338 A-Tip seating stems are just beginning to show up. I've had the projectiles over two months. I'll be at the loading bench this weekend. I've already figured out I've got concentricity issues with the 285 ELD-M and have narrowed it down to the seating step of the process. I'll post how it goes.

Best price I've seen for the stems is Bruno's. Checkout said S&H was $13.99. They put it in a USPS First Class 2 oz. padded envelope and only charged $3.05.

But you are talking about the seating stem for the hornady dies right?

 

[Howland]

But you are talking about the seating stem for the hornady dies right?

Yes, the Match Grade die set.

Observed max TIR is half of the 0.0015" max variation in neck thickness I measured so I think case and neck prep and sizing isn't the issue but I'm seeing max 0.00425" halfway between the ogive and tip. In my mind that pretty much points the finger of blame at the seating step. We'll see if I can straighten that out.

Nice shooting! I've got a few groups in the low 5s with the 285 ELD-M but at 200, not 2,000.

And to comment on @SIDS01 and his BC calculation, Hornady calculates BC for it's match grade projectiles at 800 yards and 200 for other types. Thanks! I'll plug a profile with each into the rangefinder and see which is closest.

 

[M289]

I was finally able to test them at distance a couple days ago. I came up with a G7 of 0.448 for the whole trip to 2300 yards. The bullet was almost down to 1100 fps. G7s for higher velocities/closer distances will likely be higher.

The BC isn't really the point, it's an added benefit. They held vertical better than anything I've seen except the 30 caliber 230 grain ATip, and they certainly weren't any worse than that.

I didn't have any problems with seating using the Tubb 33xc dies. With the 30s and RCBS or Redding dies, I bore the seater stem with a 3/16 end mill until the tip of the bullet doesn't bottom, polish the edge of the hole, and then lap it in with a bullet.

Thanks for sharing @SIDS01
May I ask what cartridge, speed and barrel you shot the 300gr A-Tips with?

 

[SIDS01]

33xc using the solids reamer with the shorter freebore. The ATips are loaded 5 thou into the lands at 4.215. 30" Bartlein 1:9.3 MTU profile. 115 grains of 24N41, 215M primer, Tubb brass on its 6th firing. The brass will take another 75 fps, but this one bugholes and gives the best velocity spreads.

I shot it a few weeks ago to just past 1700 yards. It was impressive, but I was uncertain of my zero. It turned out that I had zeroed it, but didn't slip the turrets. I also wanted to see how they did deep into the transonic before I posted anything.

 

[M289]

@SIDS01 A shorter freebore? Isn't that a disadvantage with the A-Tips?

Impressive speeds with the 33XC, but that's to be expected from the case capacity
I wonder what performance I will get in the 338 Norma Magnum and standard CIP freebore of about .241"

By the way, might you have measured the length and diameters of the boat tail?
Earlier you posted an OAL of 1.872" and BTO of 0.997". I was hoping you also have the boat tail dimensions so I can add it all to the bullet database of Gordon's Reloading Tool and use it for load development.
I heard the latest update for QuickLOAD should have the 300gr A-Tip included in the Hornady bullet file but I don't have that version available.

 

[Howland]

@SIDS01 A shorter freebore? Isn't that a disadvantage with the A-Tips?

Impressive speeds with the 33XC, but that's to be expected from the case capacity
I wonder what performance I will get in the 338 Norma Magnum and standard CIP freebore of about .241"

By the way, might you have measured the length and diameters of the boat tail?
Earlier you posted an OAL of 1.872" and BTO of 0.997". I was hoping you also have the boat tail dimensions so I can add it all to the bullet database of Gordon's Reloading Tool and use it for load development.
I heard the latest update for QuickLOAD should have the 300gr A-Tip included in the Hornady bullet file but I don't have that version available.

I measured the boattail beginning at 0.256" from the base and 0.275" diameter at the point where the radius begins.

I measured 1.869" length but only 0.948" BTO using the Giraud comparator with all the limitations that entails but it appears to be pretty darn close to the .334" that one would expect. The shoulder end is .476" as close as I can measure. Again, just where one would expect. Weight and dimensional uniformity of the A-Tips appears to be better by 1/3 compared to the 285 gr. ELD-M.

A shorter freebore could be an advantage if you want a short jump but still want it to feed from a magazine and not have to single feed. I've just finished case prep and will be loading some of these up today. To feed from the RPR magazine I'll be jumping at least 0.146" just to start with.

I still don't see the 300 gr. A-Tips in the ABS or Hornady 4DoF yet. I've had the A-Tips since early March but the seating stems are only just showing up at the distributors.

I'd be interested in the Gordon's prediction for this. I'm using H1000. Please share your output.

 

[SIDS01]

The back story on the solid bullet freebore in the jacketed bullet rifle is I started the 33xc project with the intent of testing solid bullets in it. I chamber my own barrels so bought the 1:9.3 barrel that's on it off the shelf to get the ball rolling with load development while I waited for Bartlein to deliver a 1:7 barrel. I'd tested the 285 ELDm and 300 Hybrids at long range with fairly disappointing results when the 300 Atips were announced. The barrel still has some life in it, so I decided to wait for the ATips. After testing the ATips last week, I ordered more of them, 16# of 24N41, and two 1:9.3 barrels from Bartlein. I'll test the 1:7 in the time between the death of the current barrel and the arrival of the new ones. I'm not going to bother with another reamer to get the freebore right with the internet, this is working. I have a pretty good idea about how the solid bullet testing will go from a buddy's 375 Snipetac tests on my range. They probably won't beat the ATips by enough to justify the additional cost for the solids, if they outscore them at all. I wasn't expecting the project to go this way when it started, but that's why I test.

 

[SIDS01]

And to comment on @SIDS01 and his BC calculation, Hornady calculates BC for it's match grade projectiles at 800 yards and 200 for other types. Thanks! I'll plug a profile with each into the rangefinder and see which is closest.

I wouldn't expect a BC estimated from one point deep in the transonic to be the one to use if you're shooting relatively short distances unless the bullet's drag curve closely matches the G7 curve.

The reason I mentioned it is if you're shooting them long distances, starting with the BC on the box and getting no calls, they're probably going over the top. This is a good problem to have.

 

[MEPienta]

I agree the do awesome. Here is a group at 2000 yards 7/10 impacts with the atips

Enquiring minds want to know what 2000 yard range are you using in Chico.

 

[BoltActionBrotherhood]

Enquiring minds want to know what 2000 yard range are you using in Chico.

not a “range” but this spot is about 45-60 minutes outside of Chico in the Plumas forrest. However just this last week we started on our new range on private land which is really close to black butte lake and we will have targets set all the way out to two miles. Do you live in the area?

 

[MEPienta]

not a “range” but this spot is about 45-60 minutes outside of Chico in the Plumas forrest. However just this last week we started on our new range on private land which is really close to black butte lake and we will have targets set all the way out to two miles. Do you live in the area?

Thx for the reply. I live in Yuba City. I have some land in Nevada that I can potentially shoot 3000+ meters but it is many hours away. I have “stations” at 1000 meters and a mile and will eventually extend out to 3000 meters once I get “dialed in” with a longer rifle barrel.

Please let me know when you open your private range. I would be willing to host a group on my land in Nevada, later this summer, if there is interest.

Regards, Michael

 

[BoltActionBrotherhood]

Thx for the reply. I live in Yuba City. I have some land in Nevada that I can potentially shoot 3000+ meters but it is many hours away. I have “stations” at 1000 meters and a mile and will eventually extend out to 3000 meters once I get “dialed in” with a longer rifle barrel.

Please let me know when you open your private range. I would be willing to host a group on my land in Nevada, later this summer, if there is interest.

Regards, Michael

Yeah man totally, it won't be a "Private Range" where we will be taking on members or anything, But we would love to have you out there. Do you shoot any of the Sacramento matches?

 

[MEPienta]

Yeah man totally, it won't be a "Private Range" where we will be taking on members or anything, But we would love to have you out there. Do you shoot any of the Sacramento matches?

I’m an “enthusiast “ with a demanding job so I can only shoot on very specific weekends and don’t currently possess the skill set to compete.

I’m just trying to “push the envelope “ on my own terms. Hoping to connect at 2000 meters next weekend and maybe 3000 by the end of the year.

 

[BoltActionBrotherhood]

I’m an “enthusiast “ with a demanding job so I can only shoot on very specific weekends and don’t currently possess the skill set to compete.

I’m just trying to “push the envelope “ on my own terms. Hoping to connect at 2000 meters next weekend and maybe 3000 by the end of the year.

2000 with the 338 is easy, you will get it within 10 shots! The more you true up your dope, and master your ammo, you will find it to be a lot easier. =)

 

[M289]

I measured the boattail beginning at 0.256" from the base and 0.275" diameter at the point where the radius begins.

I measured 1.869" length but only 0.948" BTO using the Giraud comparator with all the limitations that entails but it appears to be pretty darn close to the .334" that one would expect. The shoulder end is .476" as close as I can measure. Again, just where one would expect. Weight and dimensional uniformity of the A-Tips appears to be better by 1/3 compared to the 285 gr. ELD-M.

A shorter freebore could be an advantage if you want a short jump but still want it to feed from a magazine and not have to single feed. I've just finished case prep and will be loading some of these up today. To feed from the RPR magazine I'll be jumping at least 0.146" just to start with.

I still don't see the 300 gr. A-Tips in the ABS or Hornady 4DoF yet. I've had the A-Tips since early March but the seating stems are only just showing up at the distributors.

I'd be interested in the Gordon's prediction for this. I'm using H1000. Please share your output.

Would it be possible for you to mark your measurements on this image?
Just a marking/letter on specific location in the image and tell me what your measurement is.

I think I understand 90% of what you wrote, but I'd like to be sure. Thanks!
Hopefully I soon get a couple of 300gr A-Tips myself.

 

[Howland]

Would it be possible for you to mark your measurements on this image?
Just a marking/letter on specific location in the image and tell me what your measurement is.

I think I understand 90% of what you wrote, but I'd like to be sure. Thanks!
Hopefully I soon get a couple of 300gr A-Tips myself.

Artwork courtesy of Cro-Magnon Cave Scribblings. Not to scale.

 

[M289]

Artwork courtesy of Cro-Magnon Cave Scribblings. Not to scale.

View attachment 7337909

Haha, awesome! Thanks a lot.
Let me get to it and I’ll share the results here.
If people are interested I could share the QuickLOAD and Gordon’s Reloading Tool bullet files I create here.

 

[M289]

As promised here are the bullet files for Gordon's Reloading Tool and QuickLOAD.
Because of forum limitations I had to zip the files but for transparency reasons I'll post them here in plain text as well.

Gordon's Reloading Tool file: Hornady A-Tip Match 300gr 33389.projectile

<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<GordonsReloadingTool>
  <projectilefile>
    <var name="mname" value="Hornady" />
    <var name="pname" value="A-Tip%20Match%2033389" />
    <var name="lotid" value="2020" />
    <var name="caliber" value=".338" />
    <var name="gdia" value="8.59" />
    <var name="glen" value="47.55" />
    <var name="gmass" value="300.0" />
    <var name="gmaterial" value="0" />
    <var name="gpressure" value="250" />
    <var name="gtailDiaA" value="8.59" />
    <var name="gtailDiaB" value="6.99" />
    <var name="gtailh" value="6.50" />
    <var name="gtailType" value="2" />
    <var name="g1bc" value="0.863" />
    <var name="g7bc" value="0.435" />
    <var name="gUBCS" value="" />
    <var name="cdate" value="2020-05-29" />
    <var name="cby" value="Marty" />
    <var name="mdate" value="2020-05-29" />
    <var name="mby" value="Marty" />
    <var name="type" value="" />
    <var name="mode" value="userfile" />
    <var name="status" value="" />
    <var name="origin" value="" />
    <var name="descr" value="Created%20by%20M289%20with%20help%20from%20Howland%20and%20SIDS01%20from%20Sniper%27s%20Hide%20Forums." />
    <var name="imageUuid" value="" />
  </projectilefile>
</GordonsReloadingTool>

QuickLOAD file: Hornady-ATip-300gr-33389.bul

; M289 QuickLOAD Bullet File for 338cal Hornady A-Tip Match 300gr #33389 - 2020-05-29
; Created with help from Howland and SIDS01 from Sniper's Hide Forums
" 1 [bullet]"
".338, 300, Hornady A-Tip 33389          ","300","1.872","6.99","8.59","6.50","G1","2",".338",".863",".863","","","","","","","","","","25"

As always, use with caution when developing loads in theoretical models.
Also, these files have been created by me based on the data shared by @Howland and @SIDS01. The official Hornady Bullet file as it will be distributed by QuickLOAD might have different values.

That said, I'm confident that I didn't mess up the bullet definitions and I will verify and update this topic when I receive my own Hornady A-Tip 300gr bullets

 

[M289]

What do you guys use to seat the A-Tips?

Do you use a regular or VLD seating stem, or for those using the special Hornady A-Tip seating stem: is that a VLD type seating stem?

Thanks!

 

[Quicksilver338]

I’ve used my redding vld stem for the 230 and 153 a tips just fine.

 

[M289]

I’ve used my redding vld stem for the 230 and 153 a tips just fine.

It's not leaving a small ring or marking and it is not gripping the bullet?

I have some trouble with my Sinclair/L.E. Wilson micro-adjust seater with the VLD drift/stem. I need a small flat head screwdriver to pry the cartridge out by the rim after seating.
It's not the case, all new brass that has been ran through the expander mandrel, chamfered and deburred, as the seating part of the die is stuck.

 

[SIDS01]

It's not leaving a small ring or marking and it is not gripping the bullet?

I have some trouble with my Sinclair/L.E. Wilson micro-adjust seater with the VLD drift/stem. I need a small flat head screwdriver to pry the cartridge out by the rim after seating.
It's not the case, all new brass that has been ran through the expander mandrel, chamfered and deburred, as the seating part of the die is stuck.

Use a bullet in a drill as a lap for the seating stem. 400 grit or finer for the lapping compound.

You can also go the other way and bed the stem with epoxy.

Sometimes it's the edge of the hole for the bullet tip. That can be knocked down with a small cratex bit in a dremel.

The thing that should be avoided is the tip of the bullet bottoming in the seating stem, but it's not likely a problem if the bullet is sticking in the stem.

 

[BoltActionBrotherhood]

What do you guys use to seat the A-Tips?

Do you use a regular or VLD seating stem, or for those using the special Hornady A-Tip seating stem: is that a VLD type seating stem?

Thanks!

Im using the RCBS match master dies, I did polish the stem a bit but it seats great without issues and gives me great concentricity. (338 300 atips)
WAAAAAY better than my 153 atips that I use the Hornady dies with the hornady steam, they atip stem seems to grip the bullet way to much and the concentricity it shit.

 

[BoltActionBrotherhood]

PS to everyone out there, the 300Gr 338 atip is FINALLY loaded into the 4dof app!

 

[SIDS01]

PS to everyone out there, the 300Gr 338 atip is FINALLY loaded into the 4dof app!

Thanks

For 2308 yards, Shooter with a 0.448 G7 gave 24.3 mils and 0.7L. The Hornady 4dof gives 24.3 and 0.6. This is the only confirmed data I have.

For 1760, Shooter - 14.7, 0.4L, 4dof - 14.5, 0.4L

For 1000, Shooter - 6.0, 0.2L, 4dof - 6.0, 0.2L

It looks like the bullet beats a 0.448 G7 curve by a bit at higher speeds. The half empty crowd will say the BC falls off with speed. Even at 2300 yards, it's better than the 0.435 they put on the box.

 

[M289]

Thanks

For 2308 yards, Shooter with a 0.448 G7 gave 24.3 mils and 0.7L. The Hornady 4dof gives 24.3 and 0.6. This is the only confirmed data I have.

For 1760, Shooter - 14.7, 0.4L, 4dof - 14.5, 0.4L

For 1000, Shooter - 6.0, 0.2L, 4dof - 6.0, 0.2L

It looks like the bullet beats a 0.448 G7 curve by a bit at higher speeds. The half empty crowd will say the BC falls off with speed. Even at 2300 yards, it's better than the 0.435 they put on the box.

Thank you for sharing, that is good data to have

 

[Howland]

Y'all make sure to go post in this thread an official request for Applied Ballistics to do Doppler testing and add it to their library. The order in the queue is based on demand and requests.

AB Library Update 951 (Barnes, Berger, Black Jack, & Nosler Additions)

We pushed Library Update 951 this weekend which includes the new Berger Long Range Hybrid Target, Black Jack 0.257 ACE, Barnes Match Burners, Nosler RDFs and some PDMs. You can see a complete list in the image below. All of the testing was performed using our RADAR system into subsonic ranges...

www.snipershide.com

 

[BoltActionBrotherhood]

As promised here are the bullet files for Gordon's Reloading Tool and QuickLOAD.
Because of forum limitations I had to zip the files but for transparency reasons I'll post them here in plain text as well.

Gordon's Reloading Tool file: Hornady A-Tip Match 300gr 33389.projectile

<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<GordonsReloadingTool>
  <projectilefile>
    <var name="mname" value="Hornady" />
    <var name="pname" value="A-Tip%20Match%2033389" />
    <var name="lotid" value="2020" />
    <var name="caliber" value=".338" />
    <var name="gdia" value="8.59" />
    <var name="glen" value="47.55" />
    <var name="gmass" value="300.0" />
    <var name="gmaterial" value="0" />
    <var name="gpressure" value="250" />
    <var name="gtailDiaA" value="8.59" />
    <var name="gtailDiaB" value="6.99" />
    <var name="gtailh" value="6.50" />
    <var name="gtailType" value="2" />
    <var name="g1bc" value="0.863" />
    <var name="g7bc" value="0.435" />
    <var name="gUBCS" value="" />
    <var name="cdate" value="2020-05-29" />
    <var name="cby" value="Marty" />
    <var name="mdate" value="2020-05-29" />
    <var name="mby" value="Marty" />
    <var name="type" value="" />
    <var name="mode" value="userfile" />
    <var name="status" value="" />
    <var name="origin" value="" />
    <var name="descr" value="Created%20by%20M289%20with%20help%20from%20Howland%20and%20SIDS01%20from%20Sniper%27s%20Hide%20Forums." />
    <var name="imageUuid" value="" />
  </projectilefile>
</GordonsReloadingTool>

QuickLOAD file: Hornady-ATip-300gr-33389.bul

; M289 QuickLOAD Bullet File for 338cal Hornady A-Tip Match 300gr #33389 - 2020-05-29
; Created with help from Howland and SIDS01 from Sniper's Hide Forums
" 1 [bullet]"
".338, 300, Hornady A-Tip 33389          ","300","1.872","6.99","8.59","6.50","G1","2",".338",".863",".863","","","","","","","","","","25"

As always, use with caution when developing loads in theoretical models.
Also, these files have been created by me based on the data shared by @Howland and @SIDS01. The official Hornady Bullet file as it will be distributed by QuickLOAD might have different values.

That said, I'm confident that I didn't mess up the bullet definitions and I will verify and update this topic when I receive my own Hornady A-Tip 300gr bullets

Thank you for this, do you happen to have a modified h1000 powder file... The one loaded is just super off!

 

[SIDS01]

I've had pretty good luck with the QL H1000 data. This is for the 300 ATip from a 338 Lapua RPR.

 

[BoltActionBrotherhood]

I've had pretty good luck with the QL H1000 data. This is for the 300 ATip from a 338 Lapua RPR.
View attachment 7359202

View attachment 7359199

See one thing that throws me for a loop is its showing you are almost overpressure. Like for me, my load is is 94.0 gr and I am getting 2962 fps (30 inch barrel) which according to quick load is showing WAY over pressure. But I am not really getting any pressure signs. And I am a very experienced reloader and can read pressure very well. That being said if I go over 94.0 I start seeing mild signs. Quickload says I was at like 78k psi Or something lol

 

[SIDS01]

The only thing that produces velocity is pressure and peak pressure does it much better than mean pressure. Have you ever calibrated pressure signs to an actual pressure measurement? I haven't. I use a blade micrometer in the extractor groove during pressure ladders with new brass to get an idea of how many firings the brass will give at each velocity, but that's still not pressure. It's how well the brass is dealing with whatever pressure there is. Lapua brass will take much higher pressure than SAAMI. Try to get that velocity with Hornady brass and see what shows up for pressure signs.

I'm running 2980 fps with a 30" 33XC because the velocities are very consistent and it bugholes there. I can run it up to 3050 fps without the primers looking much flatter and still no ejector mark, but the brass starts becoming more difficult to size. That QL model has 3050 fps at 73.4 ksi. Bolt lift doesn't go up at all in a Savage action that's had the primary extraction adjusted. I have access to a 2300 yard range and do a lot of testing. I haven't had much luck with the 338s against my baseline rifles before the 300 ATip. I'm starting to suspect that jacketed bullet ELR performance starts getting sketchy beyond ~70ksi. The larger case allows the same velocity at a lower pressure, but it's a huge trade off.

Boatwright schooled me on using the start pressure to calibrate QL models in one of the 33XC threads and I've taken it to heart. With the 33XC model, it takes a 12 ksi start pressure with the same bullet to line up the observed velocity. Match chamber in a match barrel compared with a factory barrel.

 

[amymorgan20]

I can't wait to try out these 338 ATips

 

[Howland]

I've had pretty good luck with the QL H1000 data. This is for the 300 ATip from a 338 Lapua RPR.
View attachment 7359202

View attachment 7359199

That is encouraging. Thanks.

I've got the first test loads ready and plan to hit the range Sunday. I'm also using H1000 in an RPR with Lapua brass and 215M but I didn't dare to venture beyond the 92 grains max load per Hodgdon. Nosler is even more conservative at 90 grains maximum.

 

[BoltActionBrotherhood]

I've had pretty good luck with the QL H1000 data. This is for the 300 ATip from a 338 Lapua RPR.
View attachment 7359202

View attachment 7359199

Also can you discuss you changes to Weighing factor (.45 instead of the deafult .55) and shot start initiatedquickload
pressure of 5900 opposed to the standard?

The only thing that produces velocity is pressure and peak pressure does it much better than mean pressure. Have you ever calibrated pressure signs to an actual pressure measurement? I haven't. I use a blade micrometer in the extractor groove during pressure ladders with new brass to get an idea of how many firings the brass will give at each velocity, but that's still not pressure. It's how well the brass is dealing with whatever pressure there is. Lapua brass will take much higher pressure than SAAMI. Try to get that velocity with Hornady brass and see what shows up for pressure signs.

I'm running 2980 fps with a 30" 33XC because the velocities are very consistent and it bugholes there. I can run it up to 3050 fps without the primers looking much flatter and still no ejector mark, but the brass starts becoming more difficult to size. That QL model has 3050 fps at 73.4 ksi. Bolt lift doesn't go up at all in a Savage action that's had the primary extraction adjusted. I have access to a 2300 yard range and do a lot of testing. I haven't had much luck with the 338s against my baseline rifles before the 300 ATip. I'm starting to suspect that jacketed bullet ELR performance starts getting sketchy beyond ~70ksi. The larger case allows the same velocity at a lower pressure, but it's a huge trade off.

Boatwright schooled me on using the start pressure to calibrate QL models in one of the 33XC threads and I've taken it to heart. With the 33XC model, it takes a 12 ksi start pressure with the same bullet to line up the observed velocity. Match chamber in a match barrel compared with a factory barrel.

I will tell you the Atips have done well for me at ELR ranges, Last weekend I took my 338 lapua with the atips (Savage elite precision rifile with stock 30 inch barrel) out to two miles, and ended up getting two back to back hits, and that was my first time shooting at this target.
Luckly our new range we build has targets set up from 100 yards all the way out to two miles.
I do need to adjust my load because h1000 was not as temp sensitive as I hoped, my load normally gives me 2962fps (70-80 degress) but it was 100 out and the speeds got all the way up to 3002 fps.

 

[SIDS01]

My first ladder started at 87.0 grains. It was based on the start pressures I'd seen for that bullet with the 33xc.

This ladder started at 91.0 grains which gave 2722 fps, with an ES of 10 and SD of 5.2.

92 grains gave 2756 fps with an ES of 16 and SD of 6.0 for 5 shots. It also gave the best accuracy. I was using the 215M primers and loaded to 3.865" which was .010 into the lands. The brass was neck turned to 0.0145".

The sample sizes are too small to take small differences in the SD or group sizes too seriously. The SDs are low enough for the whole pressure ladder to conclude the primer and powder pairing is solid.

2750 fps with a 300 grain bullet from a 26" 338 Lapua isn't a bad place to stop. The big RPR action and the brass will take more, but more won't necessarily get any more hits. At some point, the pressure starts working against you with jacketed bullets.

 

[SIDS01]

Also can you discuss you changes to Weighing factor (.45 instead of the deafult .55) and shot start initiatedquickload
pressure of 5900 opposed to the standard?

I will tell you the Atips have done well for me at ELR ranges, Last weekend I took my 338 lapua with the atips (Savage elite precision rifile with stock 30 inch barrel) out to two miles, and ended up getting two back to back hits, and that was my first time shooting at this target.
Luckly our new range we build has targets set up from 100 yards all the way out to two miles.
I do need to adjust my load because h1000 was not as temp sensitive as I hoped, my load normally gives me 2962fps (70-80 degress) but it was 100 out and the speeds got all the way up to 3002 fps.

2 miles is a pretty fair poke.....

The Weighting Factor adjusts the relationship between velocity and peak pressure. If you leave it constant and model larger and larger case volumes, you'll find that it exaggerates the overbore effect. Pressures go up, but velocities don't. A couple years ago, I started testing the effect of overbore on performance and barrel life. I used the Lapua 338 Lapua case as the basis for a series of increasingly overbore cartridges. The overbore was adjusted by necking the case down to 7 or 30 caliber and improving it. A 7/338 Lapua Improved is very similar in overbore to a 338 Snipetac, but was a lot cheaper to build with parts on hand. I started with a straight 7/338 Lapua, which is similar in overbore to the 375 Lethal Mag. Yes, I've turned a few bullets inside out. I've also done a 30/338 Lapua Improved which is just past a 28 Nosler. My latest 338 Lapua RPR recently became a straight 300 Lapua. By using the same case for all of them and using the blade mic on the extractor groove to gauge pressure, it became apparent that something in the QL models needed to change to get the pressures and velocities to line up. What I came up with was 0.45 works pretty well for overbore ratios along the lines of 300wm and 338 Lapua. 0.40 is pretty close for a 300 Norma or 338 Lapua Improved, I'm using 0.35 for the 33xc. Another way to go about it is 0.45 for cases with enough capacity to use H1000, 0.40 for Retumbo, and 0.35 for H50bmg. It's not a characteristic of the powder, it's a characteristic of cases with enough capacity to use those powders well.

A guy I shoot with did something similar with the 375CT case. He went through four 338 Snipetac barrels with very similar results to the 7/338 Lapua Improved.

Track down the 33XC thread where Boatwright schools me on Shot Start Pressure. Basically, Shot Start Pressure is a catch all for several things. It's not just the engraving pressure. It's also where you model the effects of things like jump/jam, neck tension, bore size, leakage in the freebore before obturation,.....

https://www.snipershide.com/shootin...tridges-designed-by-david-tubb.6899366/page-5

He starts at post 221. At post 220, I'm at where you're at now.

You may find that load is less temperature sensitive at lower pressures. I test a lot of stuff back to back. Maybe load a box of 50 half with what you're doing and half 3 grains lower. Check your 100 yard zeros and add the offset and new velocity to your solver as a different bullet. Shoot 5 of one, then 5 of the other. On the next iteration, switch the shooting order. By the end of the box, you'll have a pretty good idea of what the differences are. The primary thing I grade on is vertical spread. I always shoot with Labradar to keep tabs on how the velocity spread is contributing to that.

I like that Bagrider setup. I have them on both my big RPRs. Adapting them to my XLR chasis is on the projects list.

 

[BoltActionBrotherhood]

2 miles is a pretty fair poke.....

The Weighting Factor adjusts the relationship between velocity and peak pressure. If you leave it constant and model larger and larger case volumes, you'll find that it exaggerates the overbore effect. Pressures go up, but velocities don't. A couple years ago, I started testing the effect of overbore on performance and barrel life. I used the Lapua 338 Lapua case as the basis for a series of increasingly overbore cartridges. The overbore was adjusted by necking the case down to 7 or 30 caliber and improving it. A 7/338 Lapua Improved is very similar in overbore to a 338 Snipetac, but was a lot cheaper to build with parts on hand. I started with a straight 7/338 Lapua, which is similar in overbore to the 375 Lethal Mag. Yes, I've turned a few bullets inside out. I've also done a 30/338 Lapua Improved which is just past a 28 Nosler. My latest 338 Lapua RPR recently became a straight 300 Lapua. By using the same case for all of them and using the blade mic on the extractor groove to gauge pressure, it became apparent that something in the QL models needed to change to get the pressures and velocities to line up. What I came up with was 0.45 works pretty well for overbore ratios along the lines of 300wm and 338 Lapua. 0.40 is pretty close for a 300 Norma or 338 Lapua Improved, I'm using 0.35 for the 33xc. Another way to go about it is 0.45 for cases with enough capacity to use H1000, 0.40 for Retumbo, and 0.35 for H50bmg. It's not a characteristic of the powder, it's a characteristic of cases with enough capacity to use those powders well.

A guy I shoot with did something similar with the 375CT case. He went through four 338 Snipetac barrels with very similar results to the 7/338 Lapua Improved.

Track down the 33XC thread where Boatwright schools me on Shot Start Pressure. Basically, Shot Start Pressure is a catch all for several things. It's not just the engraving pressure. It's also where you model the effects of things like jump/jam, neck tension, bore size, leakage in the freebore before obturation,.....

https://www.snipershide.com/shootin...tridges-designed-by-david-tubb.6899366/page-5

He starts at post 221. At post 220, I'm at where you're at now.

You may find that load is less temperature sensitive at lower pressures. I test a lot of stuff back to back. Maybe load a box of 50 half with what you're doing and half 3 grains lower. Check your 100 yard zeros and add the offset and new velocity to your solver as a different bullet. Shoot 5 of one, then 5 of the other. On the next iteration, switch the shooting order. By the end of the box, you'll have a pretty good idea of what the differences are. The primary thing I grade on is vertical spread. I always shoot with Labradar to keep tabs on how the velocity spread is contributing to that.

I like that Bagrider setup. I have them on both my big RPRs. Adapting them to my XLR chasis is on the projects list.

Thanks for the info.
You are running adjustable bag riders as well? They are friken awesome huh? I helped the owned prototype this one for the accs chassis. I don't think I will ever have an elr rifle without one lol.

 

[BCX]

Also can you discuss you changes to Weighing factor (.45 instead of the deafult .55) and shot start initiatedquickload
pressure of 5900 opposed to the standard?

I will tell you the Atips have done well for me at ELR ranges, Last weekend I took my 338 lapua with the atips (Savage elite precision rifile with stock 30 inch barrel) out to two miles, and ended up getting two back to back hits, and that was my first time shooting at this target.
Luckly our new range we build has targets set up from 100 yards all the way out to two miles.
I do need to adjust my load because h1000 was not as temp sensitive as I hoped, my load normally gives me 2962fps (70-80 degress) but it was 100 out and the speeds got all the way up to 3002 fps.

Am i reading this correct? Your getting 3k FPS w a 338 Lapua and 300 A-Tips mag loaded? If thats correct your near 338 AI velocity.

 

[BoltActionBrotherhood]

Am i reading this correct? Your getting 3k FPS w a 338 Lapua and 300 A-Tips mag loaded? If thats correct your near 338 AI velocity.

Yes, but not mag length, but not too far from
Mag length. I’m at 3.802 coal.
this is a string from today when it was a bit cooler, and I took it down .1gr to get back in a node.
Ps here is an atip I recovered at two miles,you can see the aluminum tips in there with the lead, I assume this was an impacts.

 

[SIDS01]

What is your setup to get the required elevation? Looks like stacked bases in the picture?

 

[BoltActionBrotherhood]

What is your setup to get the required elevation? Looks like stacked bases in the picture?

Nope, I just had to run a 1.5’high scope mount to be able to line up to a Charlie tarac they has 50 mils.

 

[SIDS01]

Nope, I just had to run a 1.5’high scope mount to be able to line up to a Charlie tarac they has 50 mils.

What's your process for sighting in the CT?

I have a 30 mil version. It's currently mounted on my 6XC to allow testing at closer ranges.

 

[BoltActionBrotherhood]

What's your process for sighting in the CT?

I have a 30 mil version. It's currently mounted on my 6XC to allow testing at closer ranges.

I don’t sight it in, I just throw it on there and boom 50 mils

 

[SIDS01]

I don’t sight it in, I just throw it on there and boom 50 mils

Hard to fault a pragmatist.....

I'm an old engineer and compulsively suck the fun out of everything.

 

[BoltActionBrotherhood]

Hard to fault a pragmatist.....

I'm an old engineer and compulsively suck the fun out of everything.

Yeah honestly, I will shoot out to 2000 yards and then put the 50 mil on when shooting two miles, or the 20 mil on when shooting 3000 yards, and my dope doesnt change any, I thought I would have to true things up for with and without the Charlies but they seems to be just about spot on.

 

[BCX]

This will be the next bullet i try in the 338 AI, everyone is out of stock.

 

[Quicksilver338]

Right when I was going to buy they went out of stock too...oh well I’ll catch the next round.

 

[Quicksilver338]

Any word when these will be available again?

 

[Black71]

Any word when these will be available again?

Just got an email today that midway has them in stock