BR or IHMSA

[fwt1712]

I need some feedback on picking between 6.5 or 7BR and 6.5 or 7 IHMSA. My 'smith has the gear to run any of these cases plus there is a more more less readily available source of dies for these as well. At this stage the mind says the BRs are the 'neatest' solution (and enable the use of Lapua's excellent brass) but the alarm bells in the background wonder how many rams will be lost in the event of any headwind - in which case the IHMSA will have an edge (and probably not too much extra recoil).

[Arizona Jake]

I've been involved in silhouette shooting for a good number of years and have personal experience with marginal cartridges like the 7 mm BR. I have also observed the performance of many other cartridges. It all boils down to this: You want a cartridge that is flexible in use. That is, a cartridge that will allow you to develop accurate, mild loads for chickens, pigs and turkeys, and will also allow you to develop loads that push heavier bullets at high enough velocities to topple HARD-SET rams. All this, in addition to keeping recoil to a minimum level.

I have observed 4 cartridges of 6.5 mm diameter that will enable the development of optimum loads with 107-108 or 120 gr. bullets for distances up to turkeys and 139-142 gr. bullets for rams:

.260 Remington
6.5 MM IHMSA
6.5 mm TKS
6.5 mm Viking - almost the same as Dan's, but with even less body taper

Of the 7mm caliber cartridges I have used and observed, the optimum choices for bullets of 120 - 140 grains for distances up to turkeys and 150-168 gr, bullets for rams are as follows:

7mm-08
7mm IHMSA

The 7mm BR is a marginal cartridge when it comes to reliably knocking down rams. I got started in this game using a 7-08, then got on the "recoil lite" bandwagon and went to th 7mm BR for a few years. I tried multiple powder,load and bullet combinations for reliable ram loads and finally came to my senses and re-chambered the barrel to 7-08.

With the loads I developed, enough velocity is generated to reliably topple the rams. I still have to hit them, though.. :wink:

Hopping again on the "recoil lite" bandwagon, I obtained a 6.5 mm barrel with a 1 in 8" twist, and for simplicity's sake, I had it chambered in .260 Remington. Following Tony Tello's recommendations, I developed a load consisting of 36.0 grains of Varget in Lapua brass with Fed. 210M primers and either Sierra 107 or 120 gr. HPBTM moly-coated bullets. Precision runs at 3/4" groups at 200 meters. I also developed a load consisting of 39.3 grains of IMR4350 and Sierra 14 or 142 grain HPBTM moly coated bullets for rams.

I used the 107 gr. bullet load for chickens, pigs and turkeys and the 140 bullet load for rams at the Nationals at Ridgway, and anything I was able to hit went down, even the rams with low-belly hits.

It's nice to experiment, but if you want to save yourself some grief and frustration, avoid the pipsqueaks and go with either of the IHMSHA cartridges as a minimum. Best of luck,

[dave imas]

Hi Jake,

would you throw the 6.5x55 into the bunch or does it not work as well as the others?

dave

[Arizona Jake]

Ooops! :oops:

I apologize for the omission. As most of you know, the 6.5X55 Swede and the .260 Remington are essentially ballistic equivalents.

One of the guys I shot with in Phoenix uses a 7mm Cartridge on a 7-08 case shortened to 1-3/4 inches, which works very well. Others use a modified 6.5 mm IHMSA, with a 40 degree shoulder instead of the nominal 38 degrees.

[ajj]

I am a fan of the 7BR but I don't have Jake's level of experience with full-size rams. Our club course stops at 300 meters so our turkeys and rams are half-size, half-distance. I've been shooting this cartridge for three seasons. My 'big" ram experience is limited to three days at the Nationals in Raton and three trips to Zwolle. So when I say, truthfully, that I've never lost a ram, you have the disclaimer.
There is a neat ram bullet, which I've touted before, available for this cartridge from the Finns in Australia. It's a loooong 145 with a high BC and a hard core. I use a MAX load which gets it up to 2530. This approach just appeals to me more than heavier, slower bullets.
On the closer animals with lighter loads, it's just a dream. Those who like to play with brass can neck up the 6mm Lapua but as long as I'm getting .4 moa with the Remington stuff, I think I'll pass. The idea is to know what you're getting and why. Every cartridge is a compromise. Every cartridge is going to ring some rams. I suspect that if a headwind is involved it may not matter what you're shooting! Apologies to those who've seen these comments before. I've just really enjoyed this cartridge. We might consider the possibility that we're preoccupied with ram ringing. I know I am because it's so much fun to see them fall and so paiinful when they don't. But a cartridge that helps me HIT, which I think this one does, is entitled to a little weakness in ram knockdown (and it's fun to look for loads that minimize that weakness.) JMHO.