6.5-300 Weatherby

[stokesrj]

I'm moving from my beloved 6.5 Shooting Times Western to the 6.5-300 Weatherby. I think that the performance is nearly identical but I became fed up with trying to find 6.5 STW brass or 7mm STW or 8mm Remington Magnum brass from which to form cases. I have also run into problems in international settings when my rifle said 6.5 STW on the barrel and my cartridges case heads said 7mm STW. Additionally, although my 6.5 STW barrel still shoots great, the throat is heavily fire cracked and I don't want to find myself in a situation with an important hunt coming up and finding my barrel is giving up, so I decided to preempt that possibility.

I took two courses of action.

I ordered a new barrel for my Prairie Gun Works M18ti, which is a Remington 700 Clone made from Titanium, with dual ejectors, coned bolt face, Sako Extractor, Sako bolt release, Timney trigger, and McMillan Edge Ultralight Hunter stock. I ordered a number 5 contour Pac-Nor Stainless Ultra Match barrel, 24" long threaded with 5/8-24 TPI, smooth thread protector muzzle cap, timed Pac-nor solid bottom brake, and cerakoted graphite black.

Additionally Pete (Arrowgun) sent me a 28" Carbon wrapped Satern Barrel for my Blaser R8. It is scheduled to arrive tomorrow. I already have Weatherby Factory Ammunition, Redding Dies, IMR 7977 Enduron Powder, US 869, Retumbo, H1000 and other suitable powders and an assortment of bullets from Hornady, Sierra, Berger, Barnes, Nosler, Swift, Peregrine, and so on. I think I will find out what the 6.5-300 Weatherby is made of. And it will be fun.

[dchamp]

Congrats and good luck I look forward to your results and impressions with the 6.5-300Wby. I ordered a Weatherby MK-V 6.5-300Wby from their custom shop in Oct 2015 an received it Oct 2016. It has a 26" Kieger barrel. When I ordered the rifle I also ordered some ammo from them, 10 boxes of 127 LRX, 1box of 130 Scirocco and 1 box with A-Frames. I received the ammo a couple of months back. In the interim I purchased a box of the 127 LRX's online. I have not hand loaded for it yet but have some US 869, H-1000, VVN 570 and Norma 217.

Initial results I've had at 100 yds are 140gr A-Frame 3295fps 1-1/8" group, 130gr Scirocco 3414fps 1-1/2" group, 127gr LRX 3493 fps 1-1/4" group. Two shots fired at 300 yd gong touching center 127gr LRX. The new lot of 127gr LRX ammo is running about 3400 fps.

I pulled apart one round from the two lots of 127gr LRX. Their load is 94.0gr's of powder that is a blend I don't recognize.

[ebrownw2]

Very cool, Bob. Looking forward to reading about your trials. The 6.5-300 looks like an awesome LR hunting round.

Great info, dchamp. Thanks for sharing.

[stokesrj]

There isn't much information out there yet on loading for this caliber. I'll be using 26 Nosler data as a starting point or reference. Pete has done some load development with IMR7977 and Western Hunter powder. It will be interesting to see what I find out and with the two barrel lengths, 24" and 28" it will be interesting to see how much this caliber depends upon length. Perhaps when Dchamp gets to handloading we can put together some useful information.

[dchamp]

There is an article in the Dec 2016 HandLoader Magazine written by Brian Pearce on pet loads for the 6.5-300Wby. US 869 seems to be the best overall powder in his testing. Quote from the article " Other notable accuracy powders included Norma 217, Vihtavuori N165, Ramshot Magnum and Alliant Reloader 25 with each producing a best single group with a specific bullet."

[Ringo]

How is the load workup coming? My 6.5-300 barrel is enroute and I'm eager to start working with it.

[stokesrj]

I’ve had to change from Redding to RCBS dies but all is well now. A test matrix with H1000, Retumbo, and 50BMG and the 140 Nosler LRAB has shown me that 50 BMG is to slow, but H100 and Retumbo look very promising. I can easily hit 3150 with no high pressure signs with my 24” Barrel.
I haven’t had time to narrow it down further yet. It may be a while before I do as most of my gear is in storage preparing to move to Arizona.

[Ringo]

Moving sucks.

Based on reading only, US869 appears in every set of data as a top performer, particularly with the 127 LRX and heavier bullets. I will likely start with that one.

[stokesrj]

I did some testing with US869 but ran into high pressure signs before reaching max. It did produce high velocities and good accuracy but ES and SD were greater than what I like. Anyway, be careful as you approach max.

[Ringo]

I have used a pound of US869 and haven't had the same experiences. I've run to the max in Pearce's article with no visible pressure signs with two different bullets.

I have a great load with 140 AB's right at 93.5 grains and 3.600". I've not found anything that makes the 127 LRX run, yet, but I'm still working on it. The Pearce data says to seat the LRX to an overall length of 3.500", which seems awfully short to me, and, Quickload estimates that round at around 75,000 psi. I shot it, working up, didn't see pressure signs, but it was less than spectacular. I need to go back with the LRX and start over as I think the 127 LRX is the perfect match for the caliber.

[stokesrj]

Yes, in my terminal testing the 127 LRX was the best performing bullet from a deep penetration and straight tracking standpoint. It also developed a wide temporary cavity in the ballistic gelatin that started almost immediately upon entry. It took three 16" 10% gelatin blocks to stop it. My accuracy testing was interrupted and won't resume until I get settled in Arizona but please continue to share your results on this thread. I may need to return to testing US869.

[SPEEDY]

I've always considered 26" long fir hunting, 28" must be long but it can't be denied that its going to be one effective LR rig.
If its anything like other Weatherby rounds tgen it should do amazing things with Reloader 25, you can stuff a lot in, compress it quite heavily and get great velocity and accurcy from the lighter projectiles in particular.

[Ringo]

My barrel is a wonderful Elmer barrel at 26". I won't try to stuff anything any longer into a scabbard!

[Ringo]

Here's a 140 AB group using 93.5 grains of US869. The length is 3.60, the maximum for caliber. The lengths of 3.59" and 3.58" got groups that were over 1 MOA.

6.5x300 140 AB.png

I'm going to try to find a node below 3.56. Pearce recommends 3.555"

[Ringo]

I think I have a load that will work. I ran the Pearce data (3.50") and the Barnes data (3.58"). I wasn't able to get any speeds. I used US869, CCI 250 primers, 1X Weatherby brass and the 127 LRX. I didn't see any pressure signs even with the Pearce data. I really think those are over max.

6-5x300 127 LRX-1 (Analysis).jpg

6-5x300 127 LRX-2 (Analysis).jpg

I think I'll stick with the 90.0 grain load at 3.58", but, pagosawingnut may want me to tighten the group a little.