Bench-Talk

This weekend in the IBS Michigan State Score Match, I used the 6.5mm BR.  I have been messing with this round for just over a year intermitantly.  This weekend I decided to take it to a 100, 200 agg.  Not knowwing fully what it takes to tune throughout the day, I had it tuned for the first three matches at 100.  after that it went out of tune and I struggled to get the load right.  when I fannaly cought up with the load, we were in the 3rd match of the 200 yard phase.  I had lost a lot of ground at that point, but gained some of it back once I had it working correctly.  Not exactly the situation I like to be in.  I will post a picture in the photo section of a 50-5x target that I fired in match 2 of the 100 yard phase.  the thing to notice is that the sighter shots are also dead ringer x's as well, and this was during a real windy day.  The bullets used were experimental TNT's 6.5mm 80 grain .905 jacket length for a finished bullet of .872'ish.  the laod range that worked best was about 34 grains of V V 133.  I used a barrel with a 1:15.3 twist

Paul

   Paul...what are your thoughts on the 6.5BR compared to the 30BR's? -Al

Al, and other that are interested:

Last year I was toying with the idea of a cartridge design that would fall between 6ppc, and .30 br to be used for score shooting that would be an advantage to either under a few conditions.  One of the conditions would be if a fellow wanted to shoot a 10.5 pound LVFS class rifle, and though recoil would be an issue, but still wanted more hole than a 6mm could provide.  Some shooters have complained that the .30 cal beats up the scope and the bags, yet the thirty has a diameter advantage for score, the 6.5mm has an advantage over the 6mm but doesn't have the recoil of the .30 caliber.  At 300 yards for score, some shooters may want a lighter faster bullet, but not as small diameter as the 6mm.

In building this round, I came up with a bullet design that would closely resemble the short flat based bullets that the 6PPC and .30BR are use.  In the 6.5mm caliber you know long vld bullets are the norm as are fast twist barrels.  I was able to get Rory DesJardin to build me bullets that were 6.5mm 80 grain flat base and only .872ish long.   This allows me to have cut rifled barrels made in the 15 to 16 twist range.  Rock Creek was able to do that for me.  My barrel is 1:15.3  I designed my reamer with a .284 nk diameter for turned necks, and the leade is .020, which fits Rory's bullets just right.

What surprised me was in going from .30 BR to 6.5mm BR I noticed a lot less recoil in my 12.5 pound rifle.  Recoil has never been a problem to me ever! But it was a nice surprise to feel less of it.  I use 30mm rings for the Big Leupold Scope and they are 4 screw rather than 2.  I never had a scope loosen before, but others that have the 2 screw rings have.  I believe the 6.5mm BR may protect against that problem.

Anything I forgot to mention?

Paul

Paul,

Those are good news, seeing you back working with the 6.5BR. This cartridge, in a good setup and good hands, can be competitive. For group it will give some to the 6PPC at 100Y (due to slight more recoil), but will regain that and maybe more at 200Y for a two-gun win (I think). Against the 30BR in score, it will give some -maybe too much- at 100Y due to the bullet hole difference. At 200Y will recover that, but not enough to come up with a two-gun win, will be close, but not the ticket. That's what I think after seeing the 30BR cleans 100Y targets over and over, no way to recover from that.

My experience is the same regarding recoil, I can hardly notice a difference compared to my 6PPC. As for the powder, my best luck so far has been with Benchmark/H322 at 50% mix (a no-no for the novice, don't do it!). Even N133 is not right on the money, giving me some vertical. H322 is just a tad too fast, and Benchmark is just a tad too slow. In theory N133 should have worked, but does not (in my case).

Bullets are of my own. Just started swaging them, using Blackmon's dies and J4 jackets trimmed down. Bullet weight is right at 83 gr, and overall bullet length of 0.875" (trimmed jacket are 0.860" long, so they are flowing/growing around 0.015" which I have heard is a good thing, don't know).

With the mix-powder I've had 5-shot groups in the 0.41" at 200Y. At 300Y stays within 1 inch depending on me.

In fewer words it has been lots of work, but lots of fun.

George