New 6.5 Idea

[7mmRHB]

Montana Rifleman, I think you will be able to get to 3050 fps with the 180s on the 7 Dakota improved. The 300 Dakota improved, necked to 7mm will get you to 3200+ but the case life will be a bit short. The guys that I did that version for, backed their loads of to about 3180 and the primer pockets have held up since then. The 7mm RHB does 3240 with the 180s but shoots best at 3150. Best accuracy is with 86 to 87 grs. H 50 BMG and the 180 Berger jammed .010. The 200 Wildcats ran at 3020 but my gun didn't like them? I have 250 left if anybody wants them?

The 7mmRHB bbl is 28" long and the gun weighs 9lbs total. The base dimensions stay the same with .010 taper removed at the shoulder and tight neck . ( .0025" total clearance.)

Good luck with your projects ---- 7mmRHB

 

[elkaholic]

Keep on keepin' on guys! You have a sweet looking case there and having fun is all part of the program. Whether it makes the velocity you are looking for or not, it will be a great cartridge I'm sure......Rich

 

[trigger puller]

looks very interesting good luck keep us posted.

 

[MontanaRifleman]

Montana Rifleman, I think you will be able to get to 3050 fps with the 180s on the 7 Dakota improved. The 300 Dakota improved, necked to 7mm will get you to 3200+ but the case life will be a bit short. The guys that I did that version for, backed their loads of to about 3180 and the primer pockets have held up since then. The 7mm RHB does 3240 with the 180s but shoots best at 3150. Best accuracy is with 86 to 87 grs. H 50 BMG and the 180 Berger jammed .010. The 200 Wildcats ran at 3020 but my gun didn't like them? I have 250 left if anybody wants them?

The 7mmRHB bbl is 28" long and the gun weighs 9lbs total. The base dimensions stay the same with .010 taper removed at the shoulder and tight neck . ( .0025" total clearance.)

Good luck with your projects ---- 7mmRHB

Thanks for the info, much appreciated.

 

[sj-pratt]

Finally took a picture of the sectioned out brass to show a comparison of 6.5-284 when the bullet is seated to fit a standard Remington magazine box. Granted alot of 6.5-284 are in long actions or shot as single shots but this kind of shows where the thought started.
The picture is with my cell phone and is not very good quality but I think it shows the bullet base takes up alot of space in the 6.5-284, so a simple look would be by staighting the walls the short case it holds almost the same amount powder but will run at different burn rate and the case will be 90%+ full compaired to say 75%?? on the 284 case, making the short case more efficient. (we hope).
The stock is all painted and I think the only thing left is making the full lenth sizing dies and we are ready to move forward. I'm going to chamber a take off barrel for fire forming, those Proof Research barrels cost to much to fire form with.

Thanks again for following our project, it kind of spurs me along to get it done when I,m writing about the progress.

 

[7mmRHB]

Steve got the last of the little parts that needed to be coated last night so it's time to get this sucker put together.!! We'll get some pics to add to this thread and then fire form a bit of brass while doing the break-in this weekend. If Steve gets the sizing die done we'll run a velocity test with a couple of powders we think will be the correct burn rate and report back, good news or bad!

Thanks to all of you that have taken some interest in this little project. ( even the skeptics ) ----- 7mmRHB

 

[elkaholic]

Lookin' good guys! The 6.5 Rem mag had the same problem in factory rifles and never performed up to par for the capacity so your idea is sound. I am still quite skeptical of 3075' in a 26" barrel, but we'll see. Good luck and keep the data coming.......Rich

 

[Steyr Luxus]

Take a standard case shorten it, reduce taper, modify shoulder angle as required or not in this case. Is this not the same concept behind why the 22 and 6 PPC were developed (i.e. to increase case efficiency) and evolved into such a successful round?
I too am very interested to see what develops out of this idea!!!

 

[Daveinjax]

That looks sweet ! Can you describe the case forming and what it would take to make it ? I was looking to build a 6.5 saum but this looks interesting.

 

[7mmRHB]

Daveinjax, this is an overview of the process to form shortened cases.
The steps needed to make the 6.5 BPX from 6.5 x284 Lapua brass. Pushing the shoulder back .250 and lengthening the neck to .320.



1. Square case heads.
2. uniform primer pockets.
3. Deburr and chamfer flash hole.
4. Anneal shoulder and neck.
5. Lube inside of the neck, then expand necks to .290 with expander mandrel.
6. Lube the outside of the case and run it into Form Die #1.
7. Lube the new neck area again and run the case into Form Die #2.
8. Clean the cases inside and out.
9. Trim cases to 1.965 length.
10. Chamfer inside case mouth.
11. Aneal case necks.
12. Expand case necks with a .269 Expander mandrel.
13. Ream inside necks with a .280 reamer.
14. Expand w/ 7mm mandrel and outside neck turn to .014 neck thickness.
15. Chamfer outside of necks and polish inside with 0000 steel wool.
16. Lube cases inside and out, then run them into Form Die #3, 6.5 mm, with the expander ball attached.
17. Clean the lube off of the outside of the cases.
18. Expand neck to fir 6.5mm neck turn mandrel.
19. Turn necks to .0125 thickness. (.289 neck diameter with 140 Berger seated)
20. Chamfer necks inside and out.
21. Polish cases inside and out.
22. Fireform brass using 140 grain bullet with 40 gr. Varget.
23. Reprep brass to a trim length of 1.960

The 6.5 BPX is an improved cartridge design with minimum taper ( .0125 ) and 35* shoulder.

This was my original work list that has been changed a few times but gives an idea of the difficulty in shortening cases!! ---- 7mmRHB

 

[sj-pratt]

Ok lets see If I can remember the parts we put on this 6.5 BPX Test Rifle (noticed we picked a name)
Remington 700 Action
Trued and Refinshed, Jewelled bolt
Sako Extractor
Kiff Bolt Handle
Gre-Tan Firing Pin Assembly
Jewell Trigger
Proof Research Barrel 26" 1:8 Twist
Of course 1.00" Titanim Brake
MCS-T 90% Shell Manners Stock Custom Paint and webbing
6.5x20 VX-3 30mm Tube M1 Turret on Elevation

I'm sure I forgot something but you get the idea it's a pretty nice rifle weighs in at 8lbs.
Encluded picture of custom made Pillars and Stress Free Bedding.

 

[elkaholic]

Ok lets see If I can remember the parts we put on this 6.5 BPX Test Rifle (noticed we picked a name)
Remington 700 Action
Trued and Refinshed, Jewelled bolt
Sako Extractor
Kiff Bolt Handle
Gre-Tan Firing Pin Assembly
Jewell Trigger
Proof Research Barrel 26" 1:8 Twist
Of course 1.00" Titanim Brake
MCS-T 90% Shell Manners Stock Custom Paint and webbing
6.5x20 VX-3 30mm Tube M1 Turret on Elevation

I'm sure I forgot something but you get the idea it's a pretty nice rifle weighs in at 8lbs.
Encluded picture of custom made Pillars and Stress Free Bedding.

Very, very nice Steve! The stock looks a lot like my Greybull......Rich

 

[MontanaRifleman]

Sweet

 

[7mmRHB]

Thanks guys, I love the way it turned out. Steve does a mean custom paint job!! I just wanted something different and I think we accomplished that. After all the alterations I did on the stock to make it fit and look the way I wanted, it's good to see something besides Bondo!!

I think Steve does a great job!!Thanks Steve !!

Now it's time to see if it shoots? If Steve gets the resize dies done this weekend I'll break it in and see what we have next week? ------ 7mmRHB