Bought someone elses wildcat....

[Harry O]

It is a 30-40 Krag case blown out, shoulder moved forward, and necked down to 7mm.  I have not found this one in Ackley's book or COTW.   If anyone has heard of this wildcat or has any information, let me know.

The case capacity is 67.0gr of water which places it in the area of the .284 Winchester and .280 Remington.  Naturally, it came with the dies (in fact, it had a sealed second set).  The gun is a Ruger No. 3 with a 26" Lilja barrel, an aftermarket trigger, and a laminated Ruger No. 1 stock.  Very nice workmanship.  I mounted a 3x9 Leupold.  It also came with 880 Sierra 168gr target bullets (I figure he probably fired 120 of these).  Got to shoot it the first time yesterday.  Looks like it has promise.

I worked up from 45.0gr of IMR4831 to 51.5gr (slightly compressed).  There were no signs of excessive pressure even at at 51.5gr.  I intend to work up the next set with IMR4350 powder.

[Reed1911]

I show it in my books as (ho-hum) 7mm Krag Improved. Figured it would have a fancy name. Although it may not be as by spec the capacity is 58.01g of water.

[Harry O]

Which book has it?  The shoulder on this one was moved forward to 1.857" from the base.  Standard Krag is 1.725", a difference of 0.132".  I wonder if that is the difference.

[Catfish]

Harry,
   The 7mm Krag imp. is listed in The Handloader`s Manual of Cartridge Conversions and does give the case volune as 58.1 gn. of H2O. The lenth stated from base to shoulder is 1.78 in with a shoulder angle of 20.39 and a total case lenth of 2.31 in. Dia at shoulder is .435. I have found some errors in this book and know nothing about this round, but it sound like one that would be fun to play with. The 6mm Rem has a case volume of 54.57 gn. of H2O so your looking at a velosity increasre over the 6mm Rem. of about 3.5%. I love finding Wildcats that someone else has built, you can usually pick them up cheap. 

[iiranger]

#1). I find the similarity of the .30/40 and the .303 Brit cases interesting. I know Mr. Ackley wrote of Mr. Epps, Canada, necking the .303 case up and down for use north of the border in SMLE's and P14s. I wonder if this might be of that "lineage???"

#2). Mr. Ackely remarked in his books that the .30/40 Ackley Improved could equal FACTORY .300 H&H Magnum preformance in strong actions... single shot and P14, NOT THE KRAG rifle... Good gun and you might rival the 7 Rem mag... luck

[Harry O]

I did some playing around with it the last couple of weekends.  The first weekend was with IMR4831 powder and the 168gr Sierra 7mm target bullet that came with the gun.  Bullets were set 0.015" to 0.020" off of the lands.  Worked up from 45.0gr to 51.5gr (slightly compressed).  No signs of pressure on the primer, not even as much as some factory 30-06 cases I have not gotten around to decapping yet.

Last weekend, I tried IMR4350 powder, working up from 47.0gr to 51.0gr (slightly compressed).  Towards the end, I did see some pressure signs, but no more than factory loads.  The primer was spreading (flattening) to narrow the groove between it and the case, but not very much.  Also, there was no ring around the firing pin intendation, the firing pin indentation was not flattening out, and there were no stretch marks inside on the wall near the base. 

I have not decided if I want to try a faster powder.  The next one up is IMR4320 and I don't have a pound of it.  I do have IMR4064 and it is probably too fast.  I have not checked the velocity yet, but I am guessing it is around 2,600fps (give or take) with the top loads.  Once I am comfortable with a load, I will check it for speed.  Accuracy is decent.   All but one group has been under one inch at 100 meters so far.  I hope that it will be less once everything is sorted out.

[Harry O]

Latest update.  I was able to get 55.0gr of IMR4831 into the case with a drop tube.  The 168gr Sierra did not compress it further.  Accuracy averaged 2" at 200 yards.  Nothing outstanding.  I did find that the long bullet did not stabilize at lower speeds (lower pressure) and was unsure at maximum. 

Next attempt was IMR4350 with the same bullet.  Eventually decided 52.0gr was maximum pressure for that combination.  Nothing special in the accuracy department.  I decided to get a lighter bullet/higher velocity to get better stability.  Visited several local places and the only thing they had that was lighter was 145gr Speer.  Unfortunately, was not able to seat it anywhere near the lands.  Was able to go up to 55.0gr (again with a drop tube) with that combination.  Bullet was fully stabilized.  The group size did not change as I worked up.  It was right at 1-3/4" to 2" at 200 yards. 

I needed a bullet about as long as the 168gr Sierra (so seat it next to the lands), but weighing no more than a 145gr Speer (to get enough velocity for stability).  In looking through the handloading catalogs, I ran across the 140gr Barnes Triple-Shock solid and ordered a box.  It works.  Worked up from 47.0gr to 55.0gr of IMR4350, but stopped at 53.5gr and dismantled the rest.  Best accuracy was 1-1/8" with 52.0gr and 1-3/16" with 53.0gr (both at 200 yards).  I just loaded up a bunch more at 52.0gr and will try them again next time the weather is nice.  Also intend to bring the chrono so I can get some accurate speeds.