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Old May 3, 2013, 10:17 PM   #1
JimDandy
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.300 RUM Overall length

Maximum SAAMI length is listed at 3.600" I picked up an OAL gauge, modified case and so forth.. and I think I'm at 3.800" Is this normal? Way off like I did it wrong?
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Old May 4, 2013, 06:51 AM   #2
Bart B.
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If in fact the over all length from case head to bullet tip is 3.800 inches, then that's how the bullet seater was set up.

If you want a shorter over all length, then adjust the bullet seater stem down 2/10ths of an inch. Reseat all the bullets and that should do what you want.
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Old May 4, 2013, 06:52 AM   #3
steve4102
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Yup, normal.
The SAAMI max case length is there for Ammo Manufacturers not the handloader.

From Accurate and Ramshot powders.

SPECIAL NOTE ON CARTRIDGE OVERALL LENGTH “COL”
It is important to note that the SAAMI “COL” values are for the firearms and ammunition manufacturers industry and must be seen as a
guideline only.
The individual reloader is free to adjust this dimension to suit their particular firearm-component-weapon combination.
This parameter is determined by various dimensions such as 1) magazine length (space), 2) freebore-lead dimensions of the barrel, 3)
ogive or profile of the projectile and 4) position of cannelure or crimp groove.
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Old May 4, 2013, 07:18 AM   #4
Mike / Tx
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Whenever I set up a new load using new bullets I will usually just go by the max magazine length I can get to start with. Then I will set up a couple or three dummy rounds at that length to make sure I get a good feed when cycling the bolt or action.

There are some of the plastic tipped bullets that simply will not feed as good as their lead tipped counterparts. The plastic tips will sometimes grab the front lip of the magazine and hang up so they have to be seated just a bit more to alloy them to start up before hitting anything.

I will also throw this out as well. A lot of folks will go with the max lenght they can get expecting better accuracy. This is all well and good. However with calibers like the RUM where your possibly loading long for caliber bullets on top of copious charges of powder, you can get pressure issues a LOT quicker than with some other calibers. Keep that in mind as well. One other thing my friend and I found while working on his 300 RUM was that after trying a number of powders at around .035" or so off the lands, he finally just used one OAL that was listed in a manual and it dropped his group sizes by more than a half. He is using the Berger 185gr and ended up like .125" off the lands but is getting benched and bagged groups of less than an inch at 300yds.

Also if your just getting started with this round I highly suggest trying some Hodgdon H-1000. While Retumbo and RL-25 both excelled in velocity, they also had issues with pressure spikes in the temperature changes we experience here in Texas. It came as quite a shock, to have worked up perfectly functioning loads in 75'ish degree temps only to have a stuck bolt when it got 10-15 degree warmer. Not to mention the gigantic increase in muzzle blast and ruined primer pockets. Unfortunately for me, I was the one behind the trigger at the time, and I have NEVER experienced a concussion like that, and hope I never do again. I literally thought the action blew, and after I knew I could still seem, I seriously though I was going to have my nose and or ears bleed from it. The ear plugs felt like they were driven into my head. Not a fun experience at all. Just something to think about IF you go with RL-25 and any charge weights over around 82grs, it gets quirky quick in the higher temps.

Luckily for us we had only loaded up about 10-15 rounds in order to try them out on some hogs, so it wasn't a big deal to pull the other remaining bullets. We have not seen any issues what so ever with the H-1000 loads in temps running from the lower 30's up to the lower 100's. It is a very good powder for this round for sure. He has been using it for close to 8 years now with much satisfaction.

Hope this helps.
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Old May 4, 2013, 10:20 AM   #5
JimDandy
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Quote:
If in fact the over all length from case head to bullet tip is 3.800 inches, then that's how the bullet seater was set up.
I didn't seat a bullet. I used an overall length gauge like this one here.
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Old May 4, 2013, 01:18 PM   #6
reynolds357
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Coal is measured from tip of bullet to base of brass with a caliper or mic (if you have one big enough).
All these new gadgets to me are more aggravating than they are worth. If I want to know where a particular bullet touches the rifling I smoke a bullet and put it in the rifle in a case where I have sized about the first 1/32ned of an inch of the neck. Much simpler and quicker than using all these new gadgets designed to complicate something simple.
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Old May 4, 2013, 01:22 PM   #7
JimDandy
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It doesn't get seated. there's no powder, no primer, no dies, no press, not even a usable case yet.

You take a special case that screws onto a shaft at the primer pocket... wire inside the case to manipulate the bullet. Insert whole mess into chamber.. push wire until you feel the rifling... stop, remove mess, probably shake/tap/etc out the bullet.. reinsert onto now locked down wire and measure... Like in the video I linked up there? That explains and demonstrates the whole process? This isn't a loaded round, it's a process to really customize the round to your rifle and chamber- I was just asking if the results I came up with are within the realm of normal/possible for a Remington 700 BDL, or if it was more likely I did it wrong since it was my first time trying to do this.
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Old May 4, 2013, 01:23 PM   #8
reynolds357
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I know how to use one. I have used one that my friend has. To me, it just complicates something that should be extremely simple.
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Old May 4, 2013, 01:38 PM   #9
JimDandy
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Sorry Reynolds, was replying to a post I don't see anymore, not yours.
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Old May 4, 2013, 01:53 PM   #10
reynolds357
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Not a problem. The tool you are using is useful, but to me its just a complicated way of obtaining the information. Many people like them, but to me a candle is much simpler.
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Old May 5, 2013, 02:35 PM   #11
JimDandy
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No one can tell me if the number is within reason, or scary long and probably I couldn't figure out how to use the thing right?
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Old May 5, 2013, 02:47 PM   #12
Brian Pfleuger
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Jim,

The tool is very easy to use and you're a plenty smart guy. If that's the number you're getting, I'm sure it's right.

The only other change to make is to measure the headspace of your own cases and adjust you're OAL versus the comparator.

Realize that the two fixed points are the case shoulder and the bullet ogive. Everything else is variable. You want an OAL that puts the ogive the same distance from the shoulder as it was in the comparator.
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Old May 5, 2013, 02:59 PM   #13
JimDandy
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I wasn't sure if I pushed too hard on the wire.

Now I'm not a visual imagination guy, so I'm going to have to "talk" this out. The fixed spots are the shoulder, and the ogive of the bullet. So my cases may not have the same distance from primer end to neck edge. Meaning the shoulder may be in a different spot, even after FL resizing. So when I stick the bullet comparator on the calipers, even tho the Ogive may be the same distance, the shoulder may be in a different place, and that's something to watch for?

Edit to add: Because getting the same lenght that way, may involve seating the bullet deeper and may cause a pressure spike.
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Old May 5, 2013, 03:04 PM   #14
Brian Pfleuger
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Yes, measure your sized cases at the shoulder datum. Measure the comparator case at the datum. If the comparator is shorter, which it probably will be, you'll add the difference (to the OAL) so that the bullet is the same distance from the shoulder.

Making the ogive the same distance from the shoulder isn't putting it closer to the rifling, its putting it the same distance from the rifling.
The difference in OAL is from the head to the shoulder, not from shoulder to ogive.

Last edited by Brian Pfleuger; May 5, 2013 at 03:50 PM.
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