Broken extractor Ruger RPR 338 Lapua

[ACK]

Howdy:

Load: 285 ELD. 93.5 Gr Retumbo, brass Norma.
Second attempt at neck sizing 338 (cause?)

Last month I started neck sizing using the listed load. No issues until the 10th round, failed to extract. Extractions appear to require higher force when compared to full length sizing. When I got home I noticed the extractor (small MIM small part) was chipped. Called Ruger and they sent me a new extractor.

Yesterday using 93 Gr after ~20 rounds, I broke the replacement.

1. Is neck sizing causing this issue? I neck size 6.5 and 308 with no issues.
2. Anyone makes a more robust extractor?

I will call Ruger in the morning and offer to buy a couple of extractors.

first and second

 

[Bradu]

Any pics of the fired brass so we can see if you had pressure indicators?

 

[Totoro]

Following as my brother has one in 338LM.

 

[NineHotel]

You want a stronger extractor?

Field rifles should have the brass full length sized with a minimum of .002" shoulder bump MEASURED using your chamber, not from looking at SAAMI specs.

Neck sizing only is for benchrest shooters.

You also need to be careful breaking up the shoulder bump, body sizing, and neck sizing into separate steps. You think you are affecting only one dimension with these isolated movement dies, but you open yourself up for corrupting one of the earlier movements/dimensions in the process.

A good full length sizer, correctly set to bump the shoulder back .002"-.003", should be your go-to regiment for reloading.

I can't comment on 93 Grs of powder; load development and pressure is a whole different issue.

 

[GrumpyOleFart]

The energy has to go somewhere, and if the case isn't up to spec, with sizing etc, shit will go wrong very quickly.
Losing two extractors has got to be setting off warning bells.
I don't know much about Rugers, but by reputation they are pretty solid.

 

[308pirate]

You want a stronger extractor?

Field rifles should have the brass full length sized with a minimum of .002" shoulder bump MEASURED using your chamber, not from looking at SAAMI specs.

Neck sizing only is for benchrest shooters.

You also need to be careful breaking up the shoulder bump, body sizing, and neck sizing into separate steps. You think you are affecting only one dimension with these isolated movement dies, but you open yourself up for corrupting one of the earlier movements/dimensions in the process.

A good full length sizer, correctly set to bump the shoulder back .002"-.003", should be your go-to regiment for reloading.

I can't comment on 93 Grs of powder; load development and pressure is a whole different issue.

/thread

Neck sizing is stupid

 

[shoot4fun]

/thread

Neck sizing is stupid

Yes it is and no, not even the BR guys do neck only these days.

Howdy:

Load: 285 ELD. 93.5 Gr Retumbo, brass Norma.
Second attempt at neck sizing 338 (cause?)

Hodgdon says 89.0 with a 275 grain bullet in Norma brass. I would think your bolt would be stiff after neck sizing only with a stout load like yours. That and , possibly, the extra amount of pressure is causing the extractor failure.
Have you ever seen pics of a catastrophic failure with a 338LM? It really does make a mess of (in the last case I saw) bench, shed roof, shooter's face, and undies.

 

[GrumpyOleFart]

Love my .338 Lapua Magnum.
It thumps the shit out of stuff at long range.
I am also very careful of it during reloading.
Was shown a video of a 338 tested to destruction.
Fuck Me, you are pulling the trigger on a hand grenade.
As with all reloading, you need to take each step seriously, if in doubt,chuck it out.

 

[j-huskey]

On my 338 lapuas with Lapua, Norma, and Frontier brass, by the 3rd firing, I have to body size the brass so it doesnt get sticky, hard bolt lift, with the exact same loads. (92.5 Retumbo with a 225 Speer Hotcore hunting bullet). (And Jerry s4f, that's not a hot load...)
And that's with minimum full length sizing. The case body at the head expands with each firing, and does not spring back, but, the body taper die puts it back for another two easy firings.

Best to you on this.

 

[Steel head]

/thread

Neck sizing is stupid

For a magnum case running some pressure you’re absolutely right.
And I’m guessing that’s some up there pressure and tight cases help things get spooky REAL fast.

 

[shoot4fun]

On my 338 lapuas with Lapua, Norma, and Frontier brass, by the 3rd firing, I have to body size the brass so it doesnt get sticky, hard bolt lift, with the exact same loads. (92.5 Retumbo with a 225 Speer Hotcore hunting bullet). (And Jerry s4f, that's not a hot load...)
And that's with minimum full length sizing. The case body at the head expands with each firing, and does not spring back, but, the body taper die puts it back for another two easy firings.

Best to you on this.

I would shoot anything you load @j-huskey but the OP is shooting 93.5 with a 285 grain bullet. I am sure I have the numbers somewhere but can't remember what my charge of Retumbo was with the 300 Sierra back when I had a 338LM. Have the parts and about to be back in that game BTW.

 

[ACK]

I would shoot anything you load @j-huskey but the OP is shooting 93.5 with a 285 grain bullet. I am sure I have the numbers somewhere but can't remember what my charge of Retumbo was with the 300 Sierra back when I had a 338LM. Have the parts and about to be back in that game BTW.

On my 338 lapuas with Lapua, Norma, and Frontier brass, by the 3rd firing, I have to body size the brass so it doesnt get sticky, hard bolt lift, with the exact same loads. (92.5 Retumbo with a 225 Speer Hotcore hunting bullet). (And Jerry s4f, that's not a hot load...)
And that's with minimum full length sizing. The case body at the head expands with each firing, and does not spring back, but, the body taper die puts it back for another two easy firings.

Best to you on this.

 

[ACK]

Thank you for the feedback.

Being reloading for several decades, for the 338 about two years. First time neck sizing for the 338.

Sorry no pictures from the fired brass, already resized and polished, they exhibited no signs of stress, no flattened primers, loose primers, or signs of case separation. Brass has been loaded three times.

I will contact Ruger and request a new extractor and will stop necksizing for the 338,. I am still not convinced that MIM for a highly stressed component is a good idea. The extractor on the 338 RPR is small with sharp corners (stress risers)

Labradar. Data (8) rounds; 1800 ft elevation, ~75 degrees. Shoots well to 1500 yards and the occasional mile shot.

Stats - Average	2846.88​	fps
Stats - Highest	2861.52​	fps
Stats - Lowest	2826.62​	fps
Stats - Ext. Spread	34.9​	fps
Stats - Std. Dev	10.97​	fps

 

[308pirate]

I am still not convinced that MIM for a highly stressed component is a good idea

Based on what professional experience or analysis?

 

[Bradu]

For a magnum case running some pressure you’re absolutely right.
And I’m guessing that’s some up there pressure and tight cases help things get spooky REAL fast.

That’s why I was wanting pics of the cases, I was wanting to see how bad they looked. I don’t understand why anyone wants to neck size but I don't think that is the only/main cause in this case.

 

[Steel head]

That’s why I was wanting pics of the cases, I was wanting to see how bad they looked. I don’t understand why anyone wants to neck size but I don't think that is the only/main cause in this case.

Neck sizing has its place but it’s definitely not for people running high pressure or magnum cases.

 

[j-huskey]

I would shoot anything you load @j-huskey but the OP is shooting 93.5 with a 285 grain bullet. I am sure I have the numbers somewhere but can't remember what my charge of Retumbo was with the 300 Sierra back when I had a 338LM. Have the parts and about to be back in that game BTW.

The 300 Sierra runs the lowest pressures, with the least bearing surface.
The 300 Scenar runs higher pressures bc its bearing surface is longer. I managed 2880 with vv570.... was going for 2900. 2825 w Retumbo.
The 300 Berger runs even higher pressures with the longest bearing surface. I was struggling to get 2825 in a 27" AI barrel with either powder.
Ed B gets 2900 with a factory Sako TRG, Peter and Jake... 2900....peters built gun with a 30" and Jake's factory Savage....
Why I couldnt get it w a factory AI.... who knows, every barrel is different. So, I've rebarrelled but on hold rt now.

Jake's savage has the same kind of extractor as the Ruger. No problems yet, and you know he pushes the envelope... Jake's extractor looks like a better metal than the Ruger, which looks like cheap cast.... looks like...


If I were OP, I would 00steel wool polish the chamber, then.....
@ACK

a. Measure a new case at the head, just above the head, shoulder, and neck. Record & Set case aside....
b. Measure 2nd/3rd-5... new cases same way and record. Load and fire 5 of them. Re-measure. Record. Add one of the fired cases aside with the new case. Marked #2.
c. Resize the 4 remaining cases. Measure them, record.. set one aside.. marked #3.
d. Load and fire the 3 remaining cases. Measure and record.
Pick one, mark it case 4. Compare growth with case 2.

If you are getting more/less spring back resizing, you should find it here. This will tell you when/if you need the body die.
Tedious, but, it will give you the answers.

If you run the same experiment on neck sized cases, you will find the growth sooner. By the 3rd neck sizing, you should be getting harder chambering. Which will increase the pressures bc the chamber itself isn't expanding like a new case.
All that adds to pressure, and sticky cases, which will break crappy cast metal extractors.

Best to you Sir Ack.

 

[phlegethon]

I ran the numbers provided by the OP in Gordon's Reloading Tool and calibrated with the velocity. It is predicting over 66,000 psi which is pretty high especially for a case that large, and remember the RPR also has an unusually small tenon and may give way a bit earlier than other 585 actions.

 

[GrumpyOleFart]

Too much pepper in the pot.
That graph is a nice format.