More 300 RUM/260 SXR Results

Jon A

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Dec 28, 2001
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Mukilteo, WA
Rich got me a bunch of these and there's no doubt they're going to work.

I used 98 grains of US869 and they clocked 2840 fps from my 27" 1:8 Benchmark. There was no sign of pressure or even any indication I was getting close to a pressure sign--I could have added more powder. I'm going to leave it there for now though since the temps were only in the high 50's, I want to leave some room for summer temps.

They're going to be there accuracy wise as well. I'll still play with seating depths a bit more, etc, but they're doing pretty well already with little load development. Here are the groups at 100 yds:

PICT0317.JPG


It should be noted those were shot with only a 10X scope which was removed and reinstalled for each group (testing the return to zero of new rings).
 

Jon A

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Dec 28, 2001
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Mukilteo, WA
I'm sorry, here's a pic:

PICT0320.JPG


From left: 208 A-Max, 210 SMK, 240 SMK, 260 SXR.

For this batch he also put serrations on the nose of the jackets so they should really expand at long range (I'm going to hunt with these next season).

Sometime in the next couple months I'll try and get an accurate BC measurement. I expect they'll be somewhere in the .420 G7 range, but we'll see what the Oehlers say. If they come anywhere close to that, they're in a whole different league than any 30 cals I've ever shot. Turns the 300 RUM (or other big 30) into a serious contender.
 

Oliveralan

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Sep 15, 2009
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993
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SW MT or noVA
What is the probability/ timeframe for these to go into production? That would really sway me towards building a 1-8 twist rum, I'm on the fence between one of those or a 338 edge once my 6.5mm Voodoo goes south. Which I don't expect to be too long!
 

elkaholic

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Dec 4, 2008
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10,021
Location
hauser, id.
I'm just testing the waters with these right now and using Jon as the "Voluntary Guinea Pig":D. If they work out well, and I think they will, I may well produce them if there is enough interest? They are not cheap to make, but well worth it if you want to hunt long range with a 300. I've been using a "lighter" version for some time in my 300 Sherman with great success. I could also make a bonded version, but really don't see the need when you have a S.D. similar to a javelin. (higher S.D. and B.C. than a 300 grain .338) and with the velocities Jon is getting, you can launch them as fast as most of the big .338's. I am expecting adequate expansion down to at least 1400'.......Rich
 
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elkaholic

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Joined
Dec 4, 2008
Messages
10,021
Location
hauser, id.
Rich got me a bunch of these and there's no doubt they're going to work.

I used 98 grains of US869 and they clocked 2840 fps from my 27" 1:8 Benchmark. There was no sign of pressure or even any indication I was getting close to a pressure sign--I could have added more powder. I'm going to leave it there for now though since the temps were only in the high 50's, I want to leave some room for summer temps.

They're going to be there accuracy wise as well. I'll still play with seating depths a bit more, etc, but they're doing pretty well already with little load development. Here are the groups at 100 yds:

PICT0317.JPG


It should be noted those were shot with only a 10X scope which was removed and reinstalled for each group (testing the return to zero of new rings).

Nice job Jon and REALLY good news! I'll be anxious to hear about b.c. and expansion.....Rich
 

trebark

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Jan 16, 2008
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3,555
Location
Falls Church, VA
Can you tell us a bit more about the construction process? are you making the bullets from the 'ground up'? or altering an existing bullet? (similar to the way royinidaho modified a 150g .277 Nosler BT by replacing the plastic tip with an aluminum tip making it a 160g projectile with a great BC)

While there would be a great deal of interest, few people have 1:8 twist 300's. I'm quite interested by my RUM is 1:10.

Also, the thread title is "More"...do you have another thread with more data?
 

elkaholic

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Dec 4, 2008
Messages
10,021
Location
hauser, id.
Can you tell us a bit more about the construction process? are you making the bullets from the 'ground up'? or altering an existing bullet? (similar to the way royinidaho modified a 150g .277 Nosler BT by replacing the plastic tip with an aluminum tip making it a 160g projectile with a great BC)

While there would be a great deal of interest, few people have 1:8 twist 300's. I'm quite interested by my RUM is 1:10.

Also, the thread title is "More"...do you have another thread with more data?

These bullets are built from the ground up a component at a time. They are designed "specifically" for long range hunting. I have been building lighter bullets for my own use for about 6 years now and have killed several animals in excess of 1000 yards. Jon was interested in the 260's so I've been working with him to perfect them. They can be "tweaked" to control expansion at different ranges if necessary. I started this because, like many of you, I have discovered that there are "Long range bullets" and "Hunting bullets", but no real reliable "Long range hunting bullets"!......Rich
 

Camshaft

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Jun 14, 2010
Messages
554
Location
Bakersfield, Ca
I intend to order one of Kirby's raptors in 300raptor in about 90days so I'm hoping by this time next year I can be running. These 260s at about 3100. But I don't want to order it with an 8 twist unless I'm sure I can either a. Stockpile them now. Or b. Know that they will be available a year from now.
 

elkaholic

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Dec 4, 2008
Messages
10,021
Location
hauser, id.
I intend to order one of Kirby's raptors in 300raptor in about 90days so I'm hoping by this time next year I can be running. These 260s at about 3100. But I don't want to order it with an 8 twist unless I'm sure I can either a. Stockpile them now. Or b. Know that they will be available a year from now.

Well, I told Jon in the beginning to "build one and they will come" so he challenged me to put up! So far it's working out pretty well:D I can make these in just about any weight from 100-260 grains.......Rich
 
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