300 weatherby reloading issues

[pockets380]

I just chronographed my reloads for my 300 weatherby mag. I'm shooting a 210 grain berger with 76 grains of RL-25, with cci magnum primers out of a 24in barrel. It only showed up as 2562 fps! Does that not seem right to anyone else? I had the chrono at 15 feet. The factor Hsm with a 210 Berger says 3036 fps! I know factory is inflated a bit but 500 fps! It seems like I shoul be up closer to there maybe in the 2900 range?

 

[CogburnR]

I'd put a new battery in the chronograph.

If the light is poor the chrony will read low also.

 

[pockets380]

I just put a new one in before I went so that should be good. It was overcast today but I was out at 1 pm so it was still pretty bright out. The chrony hadn't been used in years. Maybe it was dusty?

 

[CogburnR]

Well the max load for a 200g bullet is around 85g of RL25.

It could be that slow since it is a very mild load.

 

[pockets380]

According to Berger 74.5g is the min load at 2776 fps and 78.3g is max at 2905 fps. I would think I should be right in between!

 

[CogburnR]

Interesting, I have not looked at the Berger data.

I don't have a 300 weatherby mag but the charge seems a little low. Alliant shows the 85g max for the 200g speer sp and RL25. The RL22 load is in the upper 70's. I would not think that the Berger bullet would make that much of a change but you never know.


Alliant Powder - Reloader's Guide



You should be seeing more velocity than you are though. I would try a different chronograph if available.I was out the other day and it was overcast and a little late and my chrony was reading quite low. Replaced the battery, better light earlier in the day and day later picked up 200fps with the same rifle and load.

 

[pockets380]

Thanks for the info! Yeah I might see if can get my hands on another one

 

[backwoods83]

Do yourself a favor while your getting your hands on stuff, get your hands on some Imr4350, H4831sc, Hybrid100v, or H1000 and toss the RE25 to the side, I'm working on putting my third 300wby together and I will say RE25+300wby=garbage. That powder is good for one thing imo and that's ridiculous speed from a 257wby with 100 grain pills if you can get it to group.

 

[pockets380]

Ok thanks! I think you may have told me that before in a different post Its good to here from someone that has experience with the weatherby. What loads are you using for yours? And what is their speed and grouping like?

 

[backwoods83]

Load depends on oal but H1000 slightly compressed gives the highest velocity and accuracy combo. In my bench rifles I use 75.5grns Imr4350, norma 340wby cases necked down and neck turned, fed210m or CCI BR2 primers, 210berger, 3.812" or .015" in the lands, runs 2970 from a 28" tube. If I jump them .010" with 82grns of H4831sc and br2s I get 3060fps, 77.5grns Hybrid with a fed210m and a 208 amax .010" in the lands gives me 3110, all of these will group .2-.3". With a 28" barrel I can hit 3155 with 86.5grns H1000 but accuracy is .5-.7". Keep in mind all of mine are match chambers falling between only .060-.065" freebore. DO NOT start anywhere close to these loads, especially if your loading at standard length, reduce by 15%. Fyi the 210 berger, fed210m, Imr4350 load has a es of 2 and regularly shoots in the .2s

 

[pockets380]

Thanks! Yeah I won't start with those loads. Mine is a hunting rifle, so I seat the bullets to fit in the mag. Those are some really good numbers. The accuracy and velocity combo is great! I was wondering if you would know if my rifle as a big freebore since its not a weatherby rifle. It's a Remington 700 chambered for 300 weatherby.

 

[backwoods83]

Remington has to use saami spec reamers so you can use factory which is a minimum of .275", most of the remingtons I've saw had around .325" which is a little less than a weatherby, they are around .360".

 

[4xforfun]

I shoot the 210 exclusivly with the 300wby. Hunting and 1K comp......My comp loads have been as low as 74 gr RL25 to as high as 82 gr. I have shot from 72 gr all the way up to 85 Gr RL25 in my comp guns...never did get to the "max max", but I was close. My Hunting 300 (rem action, 30" Spencer1-10 twist) was 83 with moly, but it was just to hard on brass....down to 81 gr with good brass life. Remember..this is with Moly in the hunting gun...I had to reduce 5 grains to get the same velocity with naked bullets!!! And no, I can not explain the massive charge difference between moly and non moly...I just know that I almost blew my face off trying to shoot 80 gr of RL 25 with naked bullets!!! I put a big red skull and cross bones in my journal just to remind me!!

None of my 300's have the wby free bore......although I am mag limited with my hunting gun by about .12". Luckaly it shoots just as good with the bullet jump. My comp guns are loaded so I can load out to 3.95" and just touch the lands.......very, very long OAL.


Now, what kind of PSI signs are you showing? I usually work up every gun to the top....just so I know where the "end" is. Also, there is a danger to life and limb with to light of loads.....secondary explosion.....very, very bad!!

Also, try and barrow another chrono......set them up so you are shooting through them both together. That will tell you about your chrono.

Good luck...the 300 WBY/ 210 VLD is an AWSOME lr combo!!!

 

[Bart B]

I know factory is inflated a bit but 500 fps!

Factorys don't inflate muzzle velocity. They use barrels that may differ in chamber, bore and groove dimensions as well as different lots of powder and/or bullet release force than what you have. Plus, if they use pressure/velocity test barrels set up to SAAMI specs, they're in fixed mounts that don't move in recoil and therefore will shoot the same load faster than a human shooting a shoulder fired rifle with the same barrel specs.

It's not uncommon for barrels with oversize bore and groove dimensions to shoot a given load 100 to 200 fps slower than other barrels, but 500 fps is a bit too much. I'd check your chrony out or use another to verify data.