300wm Loads Differences

Katana

Katana

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I was loading my 300 with 168gr Barnes TSX and RL22 so I open up my Lymans 49th reloading book and start to load up as per the manual. I started at 72.5 and up to 79.5c. Everything is great until the next day and I looking at Barnes site to see what there load data said. There's start at 66.2 to 73.5 :confused: Now if there were only 1 or 2 gr difference I wouldn't be to alarmed but Barnes max it were Lymans start. I'm assuming that Lymans data is GTG but I'm wondering why the big differences is loads??
 
I would wonder when the Lyman book was last updated too.

My experience with loading that bullet and powder in the 300 winny was I used several loading manuals and worked up.
 
RL-300mag said:
I believe the answer is copper my friend. It will produce higher pressure's with lower charge's.
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Actually some of my Barnes data is using more powder than some of my other data. I wouldn't use some of their max loads with any bullet. But in general, my experiences with the TSX/TTSX shows similar results as cup and core bullets. I an not seeing any of the pressure issues that I saw with the original Barnes X.
 
Well that will be an issue as mine are all primed with magnum's

Edited:
Yup, sure glad I started this thread. PS, your correct as Lyman's data is with LR primers, not Magnum. So it looks like I need to go with Barnes data.
 
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FWIW, I never had pressure issues with TSX bullets, for me they acted like traditional cup and core.

The two bullets I did experience pressure issues with were Nosler Etips and Swift Scirrocos.
 
I've had mixed results with Barnes bullets and data. Sometimes; maybe even most of the time loads worked out pretty close to those of cup and cores. In other cases I couldn't get within a mile of Barnes charge weights with their own bullets. Now that doesn't necessarily mean the speed isn't there. The 168 TSX load for one of my .300 Wins is a full 5.5 grains less than what they are calling maximum, but the chronographed velocity exceeds that of the book. The charge weight of IMR 4831 they called for would have been a pipe wrench intensive event.

There's a reason why we work up loads. Trying to out guess a rifle, or a Barnes bullet will eventually catch up. Get or borrow a chronograph.
 
You guys who are talking about magnum primers giving more pressure than standard primes, how many of you have proven to yourselves that this really happens?
Pressure equals velocity, so how many of you have loaded identical loads, except LR primers in some and LRM primers in the others and tested them in the same rifle on a chronograph? I would be extremely surprised if any difference in velocity, beyond the standard tolerance of the chronograph, could be determined.
 
H4831 said:
You guys who are talking about magnum primers giving more pressure than standard primes, how many of you have proven to yourselves that this really happens?
Pressure equals velocity, so how many of you have loaded identical loads, except LR primers in some and LRM primers in the others and tested them in the same rifle on a chronograph? I would be extremely surprised if any difference in velocity, beyond the standard tolerance of the chronograph, could be determined.
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I haven't. You are probably quite right. I was just pointing out that the Lyman's book used LR primers for the 300 wm. That would be a good experiment though.
 
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