[BB401]

Hello Gents...
I am currently working up loads for my 338mxlr that I have had for several years. My experience with factory 200gr FTX rounds was, well shall we say, inadequate. I put close to 300 factory rounds through the rifle, open sighted, and two scopes later still have the same results. Over 2" groups @ 100 yds and a very dirty barrel. So, after much research and testing, I've settled on this load for the Hornaday 200gr FTX...
All cases are Hornady Brass fired and inspected and trimmed to 1.890"... Full length resized each time.. CCI250 primers .. 2.585" COAL ... Very light crimping is needed ... 43.8gr IMR 4895 Powder ... Yielding 2390 fps ... and a three shot group of practically one hole at 100 yds..
Is any one else using a load like this? This load is right at the point of pressure signs and also charts that way on "Quick Loads Program".

The other load I am working on is for 600 yard target using Nosler's 180gr Unibond BalisticTip. So far I'm at 2610fps on 45.3 gr IMR 4895 and the COAL @ 2.660"... Yes, That's 0.075" long.. Still these show no signs of over pressure, but my grouping is not as good as I need.. 1.1" @ 100yds.
My next steps are to play with the seat depth in 0.010" increments and powder charge in 1/10gr like I did with the Hornaday FTX.

Any thoughts?



Marlin 338MXLR
Ruger M77 300 Win Mag
and more....

 

[Darkker]

You never specified the needed info, to be able to safely say anything about pressures; here is what you really need to know to stay safe.

QL is based upon bomb-testing, which is how you get info for burning rate charts. While that is helpful verses nothing, it isn't much more than that. Hartmut gets anything he wants from Groupe SNPE, and seems to do well with powder from Thales. He gets ZERO from General Dynamics, or Hodgdon(who won't tell anyone nominal info). So based upon pressure testing, seems to really struggle with GD powders.
There is a very good reason that there is a "Drop 10%" warning on what Hodgdon sells. Don't expect that QL knows what your actual pressures are.

Long ago it was discovered by SAAMI that much over @ 45,000psi, Very carefully calibrated copper crushers, can report variances on the order of tens-of thousands of PSI with the same reference loads.
All that is to say that a reloader using cases of an unknown alloy, unknown alloy in the primers, staring at the primer isn't going to be more accurate at it.

Short of pressure measurement, the only reasonable way for the reloader to closely approximate pressures are based upon velocity. If you follow book data, regardless of the charge weight/volume; see where you are RELATIVE to the velocity measurements. That will get you a good idea of how your burning rate approximates to what was tested. When you match book velocities, due to not having SAAMI minimum spec rifles, you are somewhat over-pressure.

Stay safe, and have fun!!

 

[BB401]

Thank you Darkker for the thorough reply. I did discover during testing that "matching" the published velocities off the factory ammo was unobtainable in my powder choice. Cases began to swell and stick in the chamber, primers were being flattened, groups sizes were begining to spread, etc....However, once I brought the powder charge to 43.5 & 44.0 things began to look right. Group size was decent (1.0-1.2") for the two charges, as well as velocity. (Right at 2400fps). When retesting three shot groups with 1/10 gr variances between 43.5 to 44.0,...the 43.8 gr charge is the clear winner. The barrel is clear of powder residue, unlike the LeverRevolution powder.
Now, I do not claim to be "within" SAAMI standards. Just regular signs off over pressure issues on shell casings. Although the load was from published data and is well below maximum. However, the load for the 180gr Nosler is not published and to my knowledge untested. I do know how bullet seating depth can have an effect on pressure/case volume. This is the load that I am currently working up. Has anyone worked up a lighter pointed bullet load for the 338mx MXLR than the 200gr FTX? (I do drop in the Nosler rounds one at a time.)

 

[Darkker]

I do know how bullet seating depth can have an effect on pressure/case volume.

That gets covered in about any reputable reloading manual. You owe it to yourself to pause and re-read the info in your manuals. More jump means less pressure, to a point.

....I just looked at Hodgdon data, you are well over loaded. "Regular Pressure signs" don't tell you much as I said before. In a modern bolt action, those "signs" typically manifest themselves above 75,000 psi. Other than being caught by the Pressure Trace, these shots below seemed perfectly normal.

 

[BB401]

Are we comparing Apples to Apples or is the chart just for representation? The load I am using is well under published maximum load for a 180 gr bullet with case volume of 53.5 gr water. That max being 49.0 of IMR 4895. I'm at 45.3.

 

[Darkker]

The chart is a middle of the range load for that bullet weight, but ignored construction warnings. I posted it to point out that if you are having "classic" signs, you are probably much higher than you think.
The load for the 200gr you listed, is well over. I missed the one about the 180.

 

[BB401]

Okay, I am starting to catch up. Now explain why at the bottom off the chart, this is for a 308 with a case length of 2.015" and not for a 338mx & 2.585" . If you are trying to show that I am loading unsafely, then the parameters need to be correctly entered. I do appreciate the concern though. If I am reading it wrong, then I apologize.

 

[Darkker]

I'll try this differently.

1) the 200gr load you listed is WAY over Pressure, FYI.
2) I don't have anything handy where I am to double check your 180gr load. Given your comment about "Normal Pressure signs", which don't exist at the pressures you think they do; I posted one of my Traces.
3) The point of my Trace above, which is a 308; is to tie my cautions to a tangible bit of evidence for you.

Today's bolt action rifles don't show " classic " signs of Pressure until you are far over Pressure. The Trace I showed above, is around a 60% of max charge for that weight class. Not that specific bullet, just the weight. The second peak you can see is called a secondary ignition, very dangerous. Charlie Sisk of Sisk rifles, ran into this some years ago and had a string of rifles that he was blowing the last 15" or so clean off his rifles. There are no "signs" that anything was wrong, in the Trace showing the secondary ignitions. Other than the velocities were off of where they should have been.

So my point is to try and help you understand that staring at your primers, or seeing if the brass is difficult to eject; is not what is going to keep you safe.

Load how ever makes you happy, just keep in mind those around you.

 

[BB401]

Alright as long as I have been reloading and researching about reloading (over 30 years) I have been told and read about working up your load from the “starting” powder charge. Then work your way up to the maximum charge looking for signs of pressure. IE.. flattened primers. Primers that have been pushed from their pockets. Extractor marks and flattened or flattening of the markings of the headstamp. Swelled cases that will not release from the chamber. Ect..ect..ect… You can read this just about anywhere on this forum alone.

I did my due diligence on this load before I put a reloaded cartridge in the chamber.
Here’s the research that I based the load on…

Hornady’s reconfigured powders make such efficiency possible, and that at pressures less than 47,000 psi.
“We load to 46,500 psi,” Dave explains. “The 336 action will handle a bit more, but extraction can get sticky. We insist on smooth function.”
Read more: All Aboard the .338 Marlin Express

I broke my rifle in by firing 240 rounds of factory ammo. As stated before, The grouping of the factory ammo was disappointing. Didn’t matter whether it was open sights, or scoped. Averaged 1 ½” @ 100 yds and left the barrel filthy.

These are the loads that were considered at one time or another. To simplify things I’ll show Powder…Max charge…Velocity…Pressure…
These loads came from multiple sources…Hodgdon…Speer…Real Guns…Chuck Hawks…Quick Loads…

POWDER CHG VLCY PRSS POWDER CHG VLCY PRSS
IMR 4064 42.0 2294 43400 .IMR 4895 41.3 2263 43000
WIN 748 45.9 2392 44300 .IMR 4895 45.0 2465 N/A
IMR 4007SSC 47.5C 2334 44900 .IMR 4895 43.4 2359 40250
H380 47.0 2339 41600 .H4895 41.8 2332 40250
H414 49.3 2364 44200 .H4895 38.0 2309 45400
WIN 760 49.3 2364 44200 .RE 17 48.0 2457 N/A
LVR 47.5 2493 46000 .BL-C2 47.0 2465 N/A
VARGET 42.5 2326 44600 .IMR 3031 41.0 2386 40250
BL-C2 46.7 2393 45400 .BL-C2 45.5 2366 40250
RS BIG GAME 48.5 2484 N/A .IMR 3031 38.5 2259 43000
H4895 38.0 2309 45400 .BENCHMK 38.2 2281 44800

Everyone of these loads is below the 336 action’s capabilities and yet I could not get close to duplicating the LVR load(the highest pressure load)without pressure signs, which you say cannot show up until 75000. Even if I was using the largest published IMR 4895 load, its not close to 75000.

So, as you can see I am not WAY over pressure.

 

[Darkker]

Do what you will, I was offering you some science to keep caution at the tip of your mind. I like shooters, want to keep them around and informed.
If you are using current powder lots, your 180gr load is over charge weight, but as I have said all along, need to know velocities.

 

[BB401]

Mr Darkker it seems that you are all over the Marlin Forum Promoting the RSI Shooting Lab Software. Do you have a vested interest in it?

Anyway, since you are so into it, here is some info provided by it.....

showing exactly as I have been saying all along.

45.3gr IMR 4895

three shots...100 YARDS... NOT OVERLOADED....


Marlin 336 338 Marlin Express MXLR
Ruger M77R 300 Winchester Magnum

 

[35remington]

Let me gently point out that the 338's average pressure ceiling is indeed at what is considered the limit for the 336 action.....and that's where they run it. No higher. It cannot and should not get anywhere near the 60Kpsi plus of many bolt action cartridges.

Many of the classic pressure signs you are looking for don't show up at this level. What you should be looking for is any increase in extraction effort, and when that is noticed that's usually your only tangible sign of problems wherein the load needs to be backed down. Or when you hit the maximum suggested charge, whichever comes first. I can't see any reason to exceed loading manual maximums for the cartridge, and I'm sure you don't either.

 

[BB401]

I do understand and agree with the pressure limits of the cartridge/336 action. As I did state in my first reply..

"I did discover during testing that "matching" the published velocities off the factory ammo was unobtainable in my powder choice. Cases began to swell and stick in the chamber, primers were being flattened, groups sizes were begining to spread, etc...."

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I got on this forum looking for help in developing a load for my 338 MX using a 180 grain bullet. So far all I have seen and done is defend my reloading techniques that are no different than anyone else's that I know of. And yet with all the data that I have provided showing that the load(s) that I am working with are under maximum charges of 46000psi, I am still being chastised for "Pressure signs @ 60k-75k". I do not know where that is coming from... All my data that I AM WORKING WITH HAS PRESSURES BETWEEN 40250 AND 46000.. The Factory Tested Velocity on my chronograph of the 200gr FTX is 2623fps.. I know of no, I repeat, NO published data that lists this velocity for reloading of 200 grain FTX ammo with ANY powder including LeverRevolution. But I digress...

...So, long story made short...I already have my 200gr bullet reload figured out. it's a secret...
Anyone interested in knowing what I have already done so far toward developing a 180grain 600 yard target load for the 338 Marlin Express?