Re: Wichita 7mm int-r
Posted: Wed Sep 28, 2022 5:30 pm
This topic is right in my wheel house!
In the Wichita the 7R is a great choice. A big reason is the .45 Auto grip. And…..that .45 Auto grip is not a good one for really stout loads.
Back in the early to mid 90s I did a lot of sil shooting and nearly every match I shot the Wichita in standing. That .45 auto style grip perfectly fit my hand and inspired confidence. The trick I found was to use 139-140 bullets at 1750-1800 fps. This gave suitable knockdown for rams and reasonably flat trajectory. Recoil was there but not bad at all. Of course what I’m describing is a 7 TCU!
Find some Hornady load manuals from the 1990s. They all have good data for the 7R. eBay is a good source. Hornady did most, if not all, the early pressure testing for the 7R. The IHMSA book “Shooting Steel” also has a lot of data in it but some is way too hot and over pressure. Use the Hornady Manuals!
To get 1750-1800 fps I used 24.0 grains of AA5744 and a 139 Hornady SP. AA5744 is a faster burning rifle powder that has the ‘bulky’ quality that helps to fill the case.
Another good powder for the 7 R is H322. 26.0 grains and a 140 Sierra SP will get 1800 fps.
With those two loads, over five years, I had at least twenty scores of 30+ in Standing (that was in Sturgis, Alliance, Dickenson, and Sheridan when we all lived for the days where the wind blew at only 10-20 mph!).
Hope this helps!
In Liberty,
Gus
In the Wichita the 7R is a great choice. A big reason is the .45 Auto grip. And…..that .45 Auto grip is not a good one for really stout loads.
Back in the early to mid 90s I did a lot of sil shooting and nearly every match I shot the Wichita in standing. That .45 auto style grip perfectly fit my hand and inspired confidence. The trick I found was to use 139-140 bullets at 1750-1800 fps. This gave suitable knockdown for rams and reasonably flat trajectory. Recoil was there but not bad at all. Of course what I’m describing is a 7 TCU!
Find some Hornady load manuals from the 1990s. They all have good data for the 7R. eBay is a good source. Hornady did most, if not all, the early pressure testing for the 7R. The IHMSA book “Shooting Steel” also has a lot of data in it but some is way too hot and over pressure. Use the Hornady Manuals!
To get 1750-1800 fps I used 24.0 grains of AA5744 and a 139 Hornady SP. AA5744 is a faster burning rifle powder that has the ‘bulky’ quality that helps to fill the case.
Another good powder for the 7 R is H322. 26.0 grains and a 140 Sierra SP will get 1800 fps.
With those two loads, over five years, I had at least twenty scores of 30+ in Standing (that was in Sturgis, Alliance, Dickenson, and Sheridan when we all lived for the days where the wind blew at only 10-20 mph!).
Hope this helps!
In Liberty,
Gus