338 Lapua load to hot?

[fireguyty]

Guys. I am running 89 grains of R25 pushing a 300 grain Lapua Scenar. I developed the load when it was 95 out. Lately it has been much colder than that, but I went shooting and had a heavy bolt lift on every shot. It appears that I need to rework my load, which sucks because I'm getting .3" at 100 yards. I do have around 50 left. Will it damage my action to run the rest, or should I just pull em all?

I am on my 3rd reload with the Hornaday brass. Maybe that is my prob?

Specifics:
Rifle: DTA SRS 26" 1-10" twist
Bullet: 300 grain Scenar
Case: 3rd fired Hornaday
Primer: Rem 9 1/2 M
Powder: R25
COL: .02 out of lands
Only 2660 FPS

Had higher speeds, but shit accuracy with Retumbo, and H1000.

 

[ChadTRG42]

Re: 338 Lapua load to hot?

Yes, 89 grains with your components is a warm/hot load.

 

[QRE23]

Re: 338 Lapua load to hot?

FWIW, Per Quickload you are 15,000PSI OVER max. Now this will vary depending on throat length and how far out you are seating the bullet but even if you have a VERY long throat and you are seating out past 4.000 O.A.L. you still would be over max rec. PSI

 

[Bugholes]

Re: 338 Lapua load to hot?

I had done a "test" on several mag powders to determine temp sensitivity, including RL25, H4831SC, IMR7828ssc, Norma MRP, and others ive forgotten about. Rounds were fired from an ambient (92deg F) temp rifle and ambient temp ammo, then repeated with ammo directly from a cooler with ice. RL25 did show a decrease of 120 (+/-) fps from a chilled round, and MRP had excessive pressure (blew out primers) from a chilled round as well. What I'm getting at is there was definately a pressure spike in the colder ammo (at least with MRP) which I couldnt and still dont understand. If your RL25 load is a summertime load then shoot 'em up in the summertime. Either way, you should probably re-work the load

 

[fireguyty]

Re: 338 Lapua load to hot?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bugholes</div><div class="ubbcode-body">I had done a "test" on several mag powders to determine temp sensitivity, including RL25, H4831SC, IMR7828ssc, Norma MRP, and others ive forgotten about. Rounds were fired from an ambient (92deg F) temp rifle and ambient temp ammo, then repeated with ammo directly from a cooler with ice. RL25 did show a decrease of 120 (+/-) fps from a chilled round, and MRP had excessive pressure (blew out primers) from a chilled round as well. What I'm getting at is there was definately a pressure spike in the colder ammo (at least with MRP) which I couldnt and still dont understand. If your RL25 load is a summertime load then shoot 'em up in the summertime. Either way, you should probably re-work the load</div></div>

Wow, that is interesting. I have never heard that colder could cause pressure spikes, but this has got to be my problem. In 95 degrees I went like 2 grains higher before seeing any pressure signs, and dropped down to 89 to what I felt was "safe".

I guess that is the problem with using powder in a cartridge with no published data.

 

[jonaddis84]

Re: 338 Lapua load to hot?

Are you on your 3rd firing without full length sizing? If you have been just neck sizing then its possible your cases have just now grown to your chamber and now are seeing higher pressure due to no more expansion in brass.

 

[fireguyty]

Re: 338 Lapua load to hot?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jonaddis84</div><div class="ubbcode-body">Are you on your 3rd firing without full length sizing? If you have been just neck sizing then its possible your cases have just now grown to your chamber and now are seeing higher pressure due to no more expansion in brass.</div></div>

No my DTA's chamber is pretty tight. I FL size every time.

 

[penumbra]

Re: 338 Lapua load to hot?

do you trim the brass to spec?

 

[Guest]

Re: 338 Lapua load to hot?

Your load is pretty warm/hot as Chad has said. When running this close to max, lot-to-lot variations in powder can cause you to see the issues you are experiencing.

As per Quickload showing dangerously high pressure, the case capacity for 338 Lapua is several grains too low. If I recall, it lists 108 grains of water as the max case capacity, when most brands run 113-114 grains.

 

[fireguyty]

Re: 338 Lapua load to hot?

Penumbra, yes every time.

Mike, the lot to lot explanation could be the deal too. I'm just saying....it was fine when it was warm, I did go through several 1 pound containers before buying a 5 pound, which I have yet to break the seal....shit.

Anyway I look at it, I need to pull the rest and try another powder that is more temp stable and actually HAS published loads. Having said that, Retumbo and H1000 didn't really work out with my rifle. Can anyone comment on the temperature sensitivity of Winchester S780 and IMR 7828?

 

[Bugholes]

Re: 338 Lapua load to hot?

IMR 7828 is a really nice mag powder, I did not find it to be temp sensitive. In my opinion, it is a good substitute for H4831SC- almost always offering more velocity with same or less pressure. Lower charge densities as well

Unfortunalely, its on the fast side for 300 grain bullets in the 338LM, but the 250 is another story

I did not test VVN170 but it could be an option for you with the 300 grainers

 

[fireguyty]

Re: 338 Lapua load to hot?

Ok, so after a little over a month I got my RL 25 loads pulled and went back to work on load development. I took out 5 different powders: 4831sc, H1000, Retumbo, Magnum, and Magpro. I loaded all powders at minimum, and loaded each one up to two grains above max in one grain increments in order to determine velocity and to see when my rifle starts to get pressure signs. It was 75 degrees out.

Every powder had the same heavy/sticky bolt lift on the first shot or minimum powder charge except Magnum which made it to the second shot.

Then I shot 4 factory loads from Black Hills with a buttery smooth bolt lift.

My conclusion is that after the 3rd load my Hornaday brass is tapped out, and that has been the problem all along.

If there is another culprit I can't put my finger on it. Please offer up any thoughts or suggestions.

Thanks again.

 

[71firebird400]

Re: 338 Lapua load to hot?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: fireguyty</div><div class="ubbcode-body">Ok, so after a little over a month I got my RL 25 loads pulled and went back to work on load development. I took out 5 different powders: 4831sc, H1000, Retumbo, Magnum, and Magpro. I loaded all powders at minimum, and loaded each one up to two grains above max in one grain increments in order to determine velocity and to see when my rifle starts to get pressure signs. It was 75 degrees out.

Every powder had the same heavy/sticky bolt lift on the first shot or minimum powder charge except Magnum which made it to the second shot.

Then I shot 4 factory loads from Black Hills with a buttery smooth bolt lift.

My conclusion is that after the 3rd load my Hornaday brass is tapped out, and that has been the problem all along.

If there is another culprit I can't put my finger on it. Please offer up any thoughts or suggestions.

Thanks again. </div></div>

Do you have a way to measure case head expansion? I'd guess that you're expanding beyond .0005" each firing and that's causing your premature brass failure.

 

[fireguyty]

Re: 338 Lapua load to hot?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 71firebird400</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: fireguyty</div><div class="ubbcode-body">Ok, so after a little over a month I got my RL 25 loads pulled and went back to work on load development. I took out 5 different powders: 4831sc, H1000, Retumbo, Magnum, and Magpro. I loaded all powders at minimum, and loaded each one up to two grains above max in one grain increments in order to determine velocity and to see when my rifle starts to get pressure signs. It was 75 degrees out.

Every powder had the same heavy/sticky bolt lift on the first shot or minimum powder charge except Magnum which made it to the second shot.

Then I shot 4 factory loads from Black Hills with a buttery smooth bolt lift.

My conclusion is that after the 3rd load my Hornaday brass is tapped out, and that has been the problem all along.

If there is another culprit I can't put my finger on it. Please offer up any thoughts or suggestions.

Thanks again. </div></div>

Do you have a way to measure case head expansion? I'd guess that you're expanding beyond .0005" each firing and that's causing your premature brass failure. </div></div>

No, I don't. If this was the issue, do you think that running the hot load is the cause of the excessive case head expansion?

Sounds like I need to get some new brass, and run a powder with a published load.

 

[psinclair]

Re: 338 Lapua load to hot?

Get some Lapua brass and try again. Some of mine have 12 firings on it and still GTG...

 

[71firebird400]

Re: 338 Lapua load to hot?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: fireguyty</div><div class="ubbcode-body">
No, I don't. If this was the issue, do you think that running the hot load is the cause of the excessive case head expansion?

Sounds like I need to get some new brass, and run a powder with a published load. </div></div>


Yes, excessive case head expansion is one of the most definite ways to determine if you're running too hot. In my experience, the 338LM doesn't show a lot of the conventional pressure signs (flattened primers, difficult extraction, etc) until it's really too hot or after you've put several hot reloads through it. I can't really explain why this is, but I'd guess it could just be a really strong case that can tolerate a lot of abuse.

Like PGS suggested, I'd recommend going with Lapua brass; run just a couple cases (5-10) for several firings and see if it shows up again. I'd hate to see you prematurely wear out 100 Lapua cases with the same problem.

Good luck!

 

[fireguyty]

Re: 338 Lapua load to hot?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 71firebird400</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: fireguyty</div><div class="ubbcode-body">
No, I don't. If this was the issue, do you think that running the hot load is the cause of the excessive case head expansion?

Sounds like I need to get some new brass, and run a powder with a published load. </div></div>


Yes, excessive case head expansion is one of the most definite ways to determine if you're running too hot. In my experience, the 338LM doesn't show a lot of the conventional pressure signs (flattened primers, difficult extraction, etc) until it's really too hot or after you've put several hot reloads through it. I can't really explain why this is, but I'd guess it could just be a really strong case that can tolerate a lot of abuse.

Like PGS suggested, I'd recommend going with Lapua brass; run just a couple cases (5-10) for several firings and see if it shows up again. I'd hate to see you prematurely wear out 100 Lapua cases with the same problem.

Good luck!</div></div>

This is good advice, and I just put an order in with Powder Valley.

Another thing that i think may be the culprit after doing some web searching. I have Forester dies, and an RCBS shell holder. Apparently Forester dies are made for their own Co-Ax press that has no shell holder. Because of this, some people that are not using a Forester press and are not getting a good sizing even though they set the die up per instructions.

I got a different sizer die on the way, and I'll do your experiment.

Thanks again.

 

[jonaddis84]

Re: 338 Lapua load to hot?

+1 for Lapua, not the same rifle, but almost everything Ive read about the Savage 338 is that it will not tolerate Hornady brass at all, heavy bolt lift every time.

A shame you pulled all that ammo