300 rum load development

[FURMAN]

Nk v FL I'm not ready to quit neck sizing. My 300UM Surgeon is a honest 1/4" gun on an average every day. I neck size. I only FL size when case grows too much or with annealing. (Every 4-6 firings) I never have a tight bolt or jammed case. Not once if pressure is right.

I have a perfect case in point. I recently bought a 24" 224 Valkyrie barrel from arguably one of the best makers around. I spent $790 five months ago. 240 rounds thru it, 5 powders, 6 bullets and my 30/30 is a better shooter. I use new Starline brass. After my first range trip I measured the cases. Every one grew .008" in lenght and .006" to 009 in diameter in different places. The lenght can be dealt with using a FL die but the diameter is another beast. So I FL resized several once fired cases. And they shot like ——/. The resized OD on the cases was exactly the same as the new Starline brass, and its not a small base die, which would be worse. So I neck sized. If bumping a shoulder for .002" clearance is required for accuracy how can sizing a case OD back .005-.009" only to have it expand back .005"-.009" for every firing help accuracy? It doesn't. I spend a lot of money on chambers. If one does not know the relationship between their chamber and OEM dies they are leaving accuracy on the table.

I fit, build or buy a die to be .002"/.002" (lenght and OD) to my chambers. This is very simple to do with any tapered case using the chamber reamer and a blank die body from PTG. You could sort of do it with a FL die but you wouldn't go in far enough to move the shoulder.

Using a SAMMI FL die, which means min spec FL OD die, in a custom chamber can work harden your brass if you move it .008" each time.

IF you have a chamber reamer that cut .002/.002 over min SAMMI then by all means FL every time.

There are no absolutes in what we do. So with some qualifications yes, full lenght size. However to say it as the be all end all to Precision loading is just wrong.

Has anyone noticed on the Valkyrie threads there is a pretty common load note from a lot of people? That is that neck sized fired brass is strangely 50% more accurate than new or FL sized brass? That has been my experience too.

As far as the competition crowd goes, many of the people I know use dies made by their smith or they send out fired brass to have custom dies made. Why?
When you have $10k in a gun and glass, $300 in match dies makes a lot of sense. And you can measure the difference in inches @ 1000.

Just my opinion.

The last part is the only valuable information. You said it. No one winning at the elite levels of competition are neck sizing. It becomes even more important with a hunting rifle because you never know when your lack of proper sizing is going to cause a round to stick in the chamber when you need a follow up shot. I think Erik might know what he is talking about. If the argument turns from off the shelf FL dies to custom dies then maybe we would actually have a discussion. I can assure you over the life of a rifle with loads properly developed with FL sizing the FL sized will have a smaller average group size. NK sizing in an ar makes even less sense than in a bolt gun. That is just begging for a stuck case in a chamber.

 

[Gcan]

The last part is the only valuable information. You said it. No one winning at the elite levels of competition are neck sizing. It becomes even more important with a hunting rifle because you never know when your lack of proper sizing is going to cause a round to stick in the chamber when you need a follow up shot. I think Erik might know what he is talking about. If the argument turns from off the shelf FL dies to custom dies then maybe we would actually have a discussion. I can assure you over the life of a rifle with loads properly developed with FL sizing the FL sized will have a smaller average group size. NK sizing in an ar makes even less sense than in a bolt gun. That is just begging for a stuck case in a chamber.

I thought I was clear. I bump my 224 cases to .002" off shoulder. Coincidentally I have about 1/2 the gas leakage around the cases versus New brass. No stuck cases.

When I hunted I absolutely FL sized everything but I disagree that FL will as a rule deliver better groups on average. Using OEM SAMMI DIES that is simply not the case. That doesn't mean there are not cases where FL sizing doesn't pruduce good results, where all the stars align and a particular chamber matches up with a particular die, powder, bullet, case and variables. And above lies the answer, variables. To say sizing is not among the variables cannot be true. I know a lot of bench folk and unless they are using custom dies they shoot fire formed, bumped and neck sized brass to minimize expansion.
But opinions vary. I can see how in F class or precision rifle where dirt and dust are part of the game and a jammed case is death, FL sizing is a must due to the sport. But to simply state that as a factual matter, because a bunch of folk who shoot in dirt, who must full length size, are aslo loading the most accurate ammo doesn't stand the logic test for the same reasons neck sizing only in an AR is a recipe for disaster. The math alone, the stacking of tolerances, the likelihood that a case OD that is .005" or more under the chamber wall OD, in a throat that might be .005" over the case neck OD, and under the angular pressure of the ejector will better align concentrically to the bore axis every time than one that is only .002" L and .002" OD to Chamber just doesn't compute.

What I said is there are no absolutes in this game, but clearly your experience says otherwise.

Evidence not opinion:
Also, because of the problems I had with the Valkyrie I bought 2 more barrels. Each was built on a Megalithic matched upper and lower. A jewel trigger, a Gold and Timney triggers. NSX and Leopold Glass.
I shot the Starline new brass and also Federal 90smk match ammo thru all.
I hope we can agree those loads were full lenght sized.

Strangely the barrel with the smallest chamber relationship to the nominal new brass size shot the same ammo better in every single instance. And that is true in order of chamber size. The larger the fired brass was from its nominal state, the worse it shot. The chamber that allowed the brass to grow the most (the $800 barrel) universally finished last each time. That is empirical data suggesting that FL sizing is NOT the most accurate in every circumstance.

 

[30calyooper]

This is the only Rum I own so the brass does stay with the rifle. The bolt is tight but not too tight. I think my head space is too tight.

I was hoping to stay with 230 to maximize long range potential. The only other bullet I'd like to shoot is the 245 when available.

I hope to make this a 1000 yard gun, use my 300 win mag for closer, then 308 for under 400.

Hmmm, could well be that your rifle does have excessively tight headspacing. OR - Maybe try a casting of your chamber to see if it's excessively tight around the case neck? Not sure if turning case necks can actually do enough to help if that's the case, but I have heard of instances where even a good polishing of the chamber can help.

Have you run the test to see how long (cartridge overall length) you can load that bullet for your rifle?

 

[stevers75]

I am going through the exact same thing you are. I started with 86.5 grains of RL 26 for 230's had 3050fps with bad ejector marks. I dropped down 2 grains and and still had ejector marks. Dropped to 83 grains and actually broke the ejector! So I'm waiting for my bolt to be sent back by my smith so I can start at a much milder load and work my way up. I have a 1:10 twist, wondering g if I should switch to 215 hybrids...

So im new to breaking in and going through a thorough cleaning process with a rifle. I realized that when i would clean after every few shots, that i was leaving boretech eliminator in my chamber. Now that ive figured that out, im loading 86.5 grains of RL 26 and getting 3050fps with 230gr bergers and no pressure signs. Bonehead move on my part but glad it was something simple that i was able to solve.

 

[30calyooper]

I've had fantastic results with RL-25 and both 190 gr Long-Range Accubonds & 200 gr Accubonds. Both hold about 1/2 MOA or less out to 400 yds, (tested in 4 different rifles) with the 190 leaving a 26" tube right around 3287 and the 200 right at 3220. No pressure signs in any of the launchers tested. Bang-flop on bull elk out to 500, no sweat.

Have to check exact charge weight in my notes at home...I plan to test RL-26 (soon as I can find some!) with both of these and probably the 210 LR Accubond. If anyone reading this has done so, I sure would appreciate hearing about it!

As mentioned by others, Retumbo also gave some pretty good results.

If you want a cheap ball powder for practice, try military surplus WC-872. It's pretty sensitive to temperature changes so I cannot recommend it for a hunting load, but for range practice at temps under 75 degrees it saves me a lot of $$. Anything that affordable that gives me 3 shots inside an inch at 300 with a 180 gr is worth having around...just watch your barrel temperature and swab the bore after every 10 shots or so. Like most mil surp powders it burns hot & dirty.

BTW, Fed 215 Match primers are the way to go with everything I've tested in this cartridge.

 

[Gcan]

I've had fantastic results with RL-25 and both 190 gr Long-Range Accubonds & 200 gr Accubonds. Both hold about 1/2 MOA or less out to 400 yds, (tested in 4 different rifles) with the 190 leaving a 26" tube right around 3287 and the 200 right at 3220. No pressure signs in any of the launchers tested. Bang-flop on bull elk out to 500, no sweat.

Have to check exact charge weight in my notes at home...I plan to test RL-26 (soon as I can find some!) with both of these and probably the 210 LR Accubond. If anyone reading this has done so, I sure would appreciate hearing about it!

As mentioned by others, Retumbo also gave some pretty good results.

If you want a cheap ball powder for practice, try military surplus WC-872. It's pretty sensitive to temperature changes so I cannot recommend it for a hunting load, but for range practice at temps under 75 degrees it saves me a lot of $$. Anything that affordable that gives me 3 shots inside an inch at 300 with a 180 gr is worth having around...just watch your barrel temperature and swab the bore after every 10 shots or so. Like most mil surp powders it burns hot & dirty.

BTW, Fed 215 Match
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primers are the way to go with everything I've tested in this cartridge.

I tried the Nosler LR in my Surgeon that shoots 1/2" at 300 like its free. They shot so poorly (1.5" @ 100) I use them in my 300 blk out for subs now. ) Was so bad I thought something was wrong with my rifle or SB glass. I have had great results with R25 on 180-190 class hunting bullets.
I use 90 grains of H1000 with 210 SMKs and 215 Berger Hy. As I recall I was loading 94-95 grains R25 when I was hunting. Shoulder/Neck Shot a very nice bull moose at a pretty far piece in Nuffee with a 180 partition 20-years ago. Never saw an animal disappear from a scope image like that. Round was strangely silly accurate with R25. Didn't have same results with 210-250 grain bullets. Went to H1000 for heavies.

 

[30calyooper]

I tried the Nosler LR in my Surgeon that shoots 1/2" at 300 like its free. They shot so poorly (1.5" @ 100) I use them in my 300 blk out for subs now. ) Was so bad I thought something was wrong with my rifle or SB glass. I have had great results with R25 on 180-190 class hunting bullets.
I use 90 grains of H1000 with 210 SMKs and 215 Berger Hy. As I recall I was loading 94-95 grains R25 when I was hunting. Shoulder/Neck Shot a very nice bull moose at a pretty far piece in Nuffee with a 180 partition 20-years ago. Never saw an animal disappear from a scope image like that. Round was strangely silly accurate with R25. Didn't have same results with 210-250 grain bullets. Went to H1000 for heavies.

Wow, I have not seen many rifles that do poorly with the accubonds or the long range accubonds, unless they were just plain lousy rigs and did not shoot anything very well! Not like you're shooting an old beater Rem 7400 here! So I'm curious - I assume you're trimming, loading and crimping carefully, etc...which brass/powder/primer combo gave you the poor results, what is your Surgeon's barrel contour and twist rate, and what velocities were you getting? Asking because like any brand, those long-for-caliber bullets can get persnickety if a combo of slower twist and/or lower velocity don't get the RPM's where they need to be for proper stabilization...I've seen the same sort of thing happen with Barnes TSX's.
And oh yes, if you launcher likes 180's and RL-25, no point fixing something that ain't broken! In the course of my life I've taken plenty of game with 180's and sure can't complain about Partitions on elk!