The Accurate Reloading Forums
220gr Match King's in 300 Ultra

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https://forums.accuratereloading.com/eve/forums/a/tpc/f/2511043/m/71710535

24 July 2001, 04:54
<Boyd Heaton>
220gr Match King's in 300 Ultra
Saeed or any other reloading guru.I have found that RL22 shoot's best in my gun with that bullet.87.5gr with a Fed 215 primer.COL at 3.70.Ten shot ave of 3102fps with a ten shot group of 0.65.I'm not showing any sign's of pressure.Would someone run quick load for me to let me know if it would be safe to go any higher.The higher powder charges got better groups as I went up.

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My wife told me if I buy another gun she would leave me.I hope the door does not hit her on the way out!!!!!

24 July 2001, 13:39
<Boyd Heaton>
ANYBODY.

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My wife told me if I buy another gun she would leave me.I hope the door does not hit her on the way out!!!!!

24 July 2001, 16:19
<Bill Tompkins>
Boyd,
My quick load says that you are very near the top. I personally wouldn't go any higher especially considering that you are shooting a hunting rifle and not a bench gun. The very best that we have done is 0.625 for 5 shots at 200 meters. It was windy and ugly and only took 11 different loads. The chamber was cut with a special PPG reamer with a short throat to shoot 190 grain and 200 grain bullets.

Consider yourself highly accomplished, you have done extremely good job.

Bill

24 July 2001, 16:22
<Don G>
Hey, keep your shirt on, I've been out of town on business!


QuickLoad says that theoretically you are already over 76,000 PSI, so NO, I would not go any higher! I used a 26 inch barrel in the model. I assumed you were loaded on the lands so boosted the start pressure to 10000 PSI. QL then predicted a velocity of 3088 fps.

Don

25 July 2001, 02:48
<Bill Tompkins>
Boyd and Don,

We need to know if this is a factory or custom rifle. Sorry I jumped in so fast, I should have asked first.

If this is a factory rifle Boyd will not be close to the lands. The reason that we went to the effort of getting a custom reamer is due to the fact that you couldn't reach the lands with the 180's or 200's. The leade and throat are LONG. He might be getting close but not touching with the 220's. If Boyd was that far into the lands with his current load he would be seeing signs of pressure. The Remington brass does give good pressure indications.

Don is right to throw up the red flag. My error.

Bill

25 July 2001, 04:35
Ultraman
Bill T. Your losing me on the part where you indicate the factory throat is too long to seat into the lands with 220's or other. I have been cramming 220 BTHP MK's and 178A-Max's into the lands and also down .015" without problems. When you say the Rem cases do not show pressure signs what do you mean? I darn sure got them when using 91gr of RL-25 but not after dropping a grain. Maybe I am missing something.
25 July 2001, 06:08
<Bill Tompkins>
Ultraman,
I think if I re-read my post correctly I said it DOES show pressure signs, it is good brass.
The original factory rifles that we worked with had extremely long leade and throats. That's why we went to the custom reamer for our clients. Now that being said, I have not checked any new factory rifles and they may have improved the chambering.
Bill
25 July 2001, 09:51
<Pumba>
Boyd,

I just completed a series of runs using QuickLoad on the 300 RUM cartridge (3.70" LOA, 26 inch barrel):

- 87.5 grains of ReLoder 22 with a 220 grain Sierra MatchKing bullet = 3,028 fps @ 66,583 psi.

- 88.1 grains of IMR-7828 with a 220 grain Sierra MatchKing bullet = 3,054 fps @ 66,502 psi.

- 102.5 grains of H-870 with a 220 grain Sierra MatchKing bullet = 3,114 fps @ 66,552 psi.

THESE ARE EXTREMELY HIGH PRESSURES. THEY ARE ABOVE THE 65,000 psi DESIGN LIMIT OF THE CARTRIDGE.

PLEASE PROCEED WITH CAUTION.

How much case expansion are you getting with a new case, after firing, when measured by a 0.0001" accuracy blade micrometer just ahead of the extractor groove?


Good Hunting !

25 July 2001, 09:56
<Boyd Heaton>
Hey guy's.The gun is a Factory Sendero.With a muzzle brake and trigger job.Max oal is 3.739.I have the col at 3.70.At 3.70 they chambered in my gun easily.I am very happy with the above load.The temp that day was in the low 80's.And there was no wind.I think I might just stick with that load.As the gun shot another 10 shot group this morning of 0.669.Thank's for the help guy's.

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My wife told me if I buy another gun she would leave me.I hope the door does not hit her on the way out!!!!!

25 July 2001, 10:40
Ultraman
Bill T.: My mistake....glasses are on the way. I had just read a posting on the long distance website where someone was indicating that the 1000 yard guys are giving up on the RUM because of brass and I read yours too quickly. I take it that you have re-chambered some factory (?) barrels with your reamer? I have been interested in this on mine (26" fluted Send.). If that is the case how much length must be sacrificed?
25 July 2001, 14:10
<Don G>
Bill,

No worries, our posts were written at the same time. If we all agreed all the time this would be a boring place.

Pumba,

I match you to the nth decimal. I pushed the start pressure up to try to match the observed 3100 fps. Check the pressure when you do that. (Broemel's recommendation for starting on the lands is to add 7000 PSI to the start pressure.) I was guessing - probably wrongly. I never saw a Rem land I could touch with a practical bullet.

Boyd,

It is shooting well, and apparently safely, so just shoot it!

I just realized I missed the smiley face after my first squeal. I intended that as a humorous remark.

Don

[This message has been edited by Don G (edited 07-25-2001).]